Volume 12,Issue 4,2014 Table of Contents
2014, 12(4):1-5.
Abstract:
Based on the daily precipitation data at 11 meteorological stations in the Zhangwei River Basin during the period from 1957 to 2011, several SPI-based indices, including drought frequency, drought-affected area, drought severity and duration, and drought barycentric coordinates, have been selected to analyze the meteorological drought evolution before and after the precipitation mutation. The results showed that (1) precipitation mutation occurred in 1976, and the frequency and affected area of drought in the year scale have increased significantly from 20% and 23.2 % to 40% and 34.1% before and after precipitation mutation, respectively; (2) in the season scale, drought frequency and affected area decreased to some extent in the spring but increased greatly in both summer and autumn, and the drought frequency increased while affected area decreased in the winter; (3) the average drought duration and severity increased significantly in both the year and season scales, but decreased in the month scale; and (4) the drought barycentric coordinates showed insignificant change before and after the precipitation mutation.
Based on the daily precipitation data at 11 meteorological stations in the Zhangwei River Basin during the period from 1957 to 2011, several SPI-based indices, including drought frequency, drought-affected area, drought severity and duration, and drought barycentric coordinates, have been selected to analyze the meteorological drought evolution before and after the precipitation mutation. The results showed that (1) precipitation mutation occurred in 1976, and the frequency and affected area of drought in the year scale have increased significantly from 20% and 23.2 % to 40% and 34.1% before and after precipitation mutation, respectively; (2) in the season scale, drought frequency and affected area decreased to some extent in the spring but increased greatly in both summer and autumn, and the drought frequency increased while affected area decreased in the winter; (3) the average drought duration and severity increased significantly in both the year and season scales, but decreased in the month scale; and (4) the drought barycentric coordinates showed insignificant change before and after the precipitation mutation.
2014, 12(4):6-10.
Abstract:
The distributed hydrological model, Precipitation Runoff Modeling System (PRMS), takes into account of precipitation, climate, and land use, and can be used to simulate the important variables representing the water and mass cycle in a basin such as water and sediment. In this paper, the PRMS model was calibrated and validated with the observed runoff data, and then the validated model was used to simulate the impacts of urbanization and dams on runoff in the Shaying River basin. The results showed that the evaporation and infiltration decrease whereas runoff increases in the basin due to the expansion of impermeable land surface as a result of urbanization. The presence of dams can change the spatial and temporal distribution of water resources in the basin, dampen the variation of natural runoff, increase the water surface evaporation, decrease the peak runoff, and then delay the time of peak flow. The impacts of urbanization and dams on runoff were more obvious in the dry years.
The distributed hydrological model, Precipitation Runoff Modeling System (PRMS), takes into account of precipitation, climate, and land use, and can be used to simulate the important variables representing the water and mass cycle in a basin such as water and sediment. In this paper, the PRMS model was calibrated and validated with the observed runoff data, and then the validated model was used to simulate the impacts of urbanization and dams on runoff in the Shaying River basin. The results showed that the evaporation and infiltration decrease whereas runoff increases in the basin due to the expansion of impermeable land surface as a result of urbanization. The presence of dams can change the spatial and temporal distribution of water resources in the basin, dampen the variation of natural runoff, increase the water surface evaporation, decrease the peak runoff, and then delay the time of peak flow. The impacts of urbanization and dams on runoff were more obvious in the dry years.
2014, 12(4):11-15.
Abstract:
Compared with the traditional soil moisture monitoring methods, remote sensing technology has apparent advantages to obtain the large-scale land surface information rapidly and to improve the monitoring precision of regional soil moisture. In this paper, on the basis of Moderate Resolution Imaging Spectoradiometer (MODIS) and observed soil moisture data at the agro-meteorological monitoring stations, a remote sensing model of soil moisture based on temperature and vegetation index was developed and applied to estimate the soil moisture in the Jinghe Watershed and to analyze the spatio-temporal distribution of soil moisture between March and October from 2000 to 2010. The results showed that the method based on vegetation temperature condition index (VTCI) can reflect the distribution and variation of soil moisture in the Jinghe Watershed.
Compared with the traditional soil moisture monitoring methods, remote sensing technology has apparent advantages to obtain the large-scale land surface information rapidly and to improve the monitoring precision of regional soil moisture. In this paper, on the basis of Moderate Resolution Imaging Spectoradiometer (MODIS) and observed soil moisture data at the agro-meteorological monitoring stations, a remote sensing model of soil moisture based on temperature and vegetation index was developed and applied to estimate the soil moisture in the Jinghe Watershed and to analyze the spatio-temporal distribution of soil moisture between March and October from 2000 to 2010. The results showed that the method based on vegetation temperature condition index (VTCI) can reflect the distribution and variation of soil moisture in the Jinghe Watershed.
4 Spatial and Temporal Variation of Rainfall in the Hailar River Basin Based on Geostatistics Theory
2014, 12(4):16-20.
Abstract:
The geostatistics theory was introduced into the research field of hydrology and water resources and combined with random function theory to determine the experimental variation function of annual precipitation in the Hailar River Basin based on the measured annual precipitation data at a few stations. Then, the structural function of geometric anisotropy of hydrological variables was obtained by selecting, merging, and fitting the experimental variation functions in different directions. The theory of spatial estimation with anisotropy and universal kriging of multiple time periods was applied to achieve the analysis and calculation of average annual precipitation at an arbitrary point in space and in a basin with various scales. Finally, the advancement, convenience, and accuracy of the theory and method used in the paper were confirmed through the comparison of the results determined by the method of arithmetic average, inverse distance method, and Thiessen Polygon method.
The geostatistics theory was introduced into the research field of hydrology and water resources and combined with random function theory to determine the experimental variation function of annual precipitation in the Hailar River Basin based on the measured annual precipitation data at a few stations. Then, the structural function of geometric anisotropy of hydrological variables was obtained by selecting, merging, and fitting the experimental variation functions in different directions. The theory of spatial estimation with anisotropy and universal kriging of multiple time periods was applied to achieve the analysis and calculation of average annual precipitation at an arbitrary point in space and in a basin with various scales. Finally, the advancement, convenience, and accuracy of the theory and method used in the paper were confirmed through the comparison of the results determined by the method of arithmetic average, inverse distance method, and Thiessen Polygon method.
2014, 12(4):21-24.
Abstract:
In this paper, the characteristics of drift ice, freeze-up, and break-up dates were analyzed at the following four stations - Shizuishan, Bayangaole, Sanhuhekou, and Toudaoguai stations, in the Ningxia-Inner Mongolia reach of the Yellow River, and the ice peak and maximum channel-storage increment were also investigated. The results showed that the ice regime characteristics in the Ningxia-Inner Mongolia reach of the Yellow River have changed significantly in the recent 10 years due to the sustaining high temperature in the winter and reservoir control, which can be seen in the delayed freeze-up and break-up dates, decreasing in freeze-up duration, decreasing in ice peak flow, increasing in channel storage, and decreasing in the frequencies of ice dam and ice jam. The research can offer guidance on the mitigation of ice disasters in the Ningxia-Inner Mongolia reach of the Yellow River.
In this paper, the characteristics of drift ice, freeze-up, and break-up dates were analyzed at the following four stations - Shizuishan, Bayangaole, Sanhuhekou, and Toudaoguai stations, in the Ningxia-Inner Mongolia reach of the Yellow River, and the ice peak and maximum channel-storage increment were also investigated. The results showed that the ice regime characteristics in the Ningxia-Inner Mongolia reach of the Yellow River have changed significantly in the recent 10 years due to the sustaining high temperature in the winter and reservoir control, which can be seen in the delayed freeze-up and break-up dates, decreasing in freeze-up duration, decreasing in ice peak flow, increasing in channel storage, and decreasing in the frequencies of ice dam and ice jam. The research can offer guidance on the mitigation of ice disasters in the Ningxia-Inner Mongolia reach of the Yellow River.
2014, 12(4):25-29.
Abstract:
The Principal Component Analysis method was used to develop a comprehensive drought index and then to calculate the drought frequency. The AquaCrop model was used to assess the drought loss under a certain drought resistance capacity. On the basis, the relationships among drought frequency, drought resistance capacity, and drought loss were constructed and then applied to evaluate the agricultural drought risk quantitatively. The method was applied to the upstream of the West Bridge hydrological station in the Nanpanjiang River. The results showed that (1) Luliang County is the drought prone area under the current drought resistance level; (2) drought loss of Luliang County is relatively larger than that of Zhanyi County and Qilin District with the same drought degree, which is consistent with the actual situation; and (3) the crop loss rate of drought in the study area is between 15% and 20% when the study area experiences a severe drought of once in a hundred years under the current drought resistance level.
The Principal Component Analysis method was used to develop a comprehensive drought index and then to calculate the drought frequency. The AquaCrop model was used to assess the drought loss under a certain drought resistance capacity. On the basis, the relationships among drought frequency, drought resistance capacity, and drought loss were constructed and then applied to evaluate the agricultural drought risk quantitatively. The method was applied to the upstream of the West Bridge hydrological station in the Nanpanjiang River. The results showed that (1) Luliang County is the drought prone area under the current drought resistance level; (2) drought loss of Luliang County is relatively larger than that of Zhanyi County and Qilin District with the same drought degree, which is consistent with the actual situation; and (3) the crop loss rate of drought in the study area is between 15% and 20% when the study area experiences a severe drought of once in a hundred years under the current drought resistance level.
2014, 12(4):30-34.
Abstract:
The impacts of climate change and human activities on the runoff in the upper reaches of the Jinghe River Basin were investigated using the climate elasticity method based on the hydrological and meteorological data from 1973 to 2012. The results showed that the annual runoff decreased significantly with a rate of -13.1 mm/10a and an abrupt change occurred around year 1985. The climate change accounted for 36.8~43.8% to the decreasing in runoff, while human activities accounted for 56.2~63.2%. Both of the climate change and human activities can result in the decline of runoff in the upper reaches of the Jinghe River Basin, but human activities played a dominant role.
The impacts of climate change and human activities on the runoff in the upper reaches of the Jinghe River Basin were investigated using the climate elasticity method based on the hydrological and meteorological data from 1973 to 2012. The results showed that the annual runoff decreased significantly with a rate of -13.1 mm/10a and an abrupt change occurred around year 1985. The climate change accounted for 36.8~43.8% to the decreasing in runoff, while human activities accounted for 56.2~63.2%. Both of the climate change and human activities can result in the decline of runoff in the upper reaches of the Jinghe River Basin, but human activities played a dominant role.
2014, 12(4):35-37.
Abstract:
Time series analysis method has comprehensive importance and prospects in the precipitation forecast. Based on the precipitation data from 1971 to 2009 in Zhengzhou city, the trend component of precipitation was determined by the quadratic polynomial calibration, the periodic component of precipitation was extracted by the spectrum analysis, and the stochastic component was simulated using the auto-regression model. The precipitation prediction model in Zhengzhou City was established through the superposition of these components. In comparison with the simulated and measured data, the precipitation prediction model has a high accuracy. The model was applied to forecast the precipitation in Zhengzhou city from 2014 to 2016, which can provide reference for the water resources management in this area.
Time series analysis method has comprehensive importance and prospects in the precipitation forecast. Based on the precipitation data from 1971 to 2009 in Zhengzhou city, the trend component of precipitation was determined by the quadratic polynomial calibration, the periodic component of precipitation was extracted by the spectrum analysis, and the stochastic component was simulated using the auto-regression model. The precipitation prediction model in Zhengzhou City was established through the superposition of these components. In comparison with the simulated and measured data, the precipitation prediction model has a high accuracy. The model was applied to forecast the precipitation in Zhengzhou city from 2014 to 2016, which can provide reference for the water resources management in this area.
2014, 12(4):38-41.
Abstract:
Based on the Mann-Kendall nonparametric test and cumulative departure curve analysis on the annual temperature and precipitation of Hefeng County from 1954 to 2010, the mutation characteristics of annual temperature and precipitation were detected using the Mann-Kendall and Pettitt mutation tests. The results showed that the cumulative departure of temperature of 20 years is positive from 1988 to 2010, which indicated that the temperature has a significantly increasing trend from 1988 and it is verified by the Mann-Kendall nonparametric test. The mutation time of temperature was not detected. Annual precipitation had a gradually increasing trend with the lowest precipitation occurring in 1977 and the highest in 2007, but the trend was not significant and the occurrence of dry and wet years had an interlaced distribution. The mutation time of precipitation was detected as 2007.
Based on the Mann-Kendall nonparametric test and cumulative departure curve analysis on the annual temperature and precipitation of Hefeng County from 1954 to 2010, the mutation characteristics of annual temperature and precipitation were detected using the Mann-Kendall and Pettitt mutation tests. The results showed that the cumulative departure of temperature of 20 years is positive from 1988 to 2010, which indicated that the temperature has a significantly increasing trend from 1988 and it is verified by the Mann-Kendall nonparametric test. The mutation time of temperature was not detected. Annual precipitation had a gradually increasing trend with the lowest precipitation occurring in 1977 and the highest in 2007, but the trend was not significant and the occurrence of dry and wet years had an interlaced distribution. The mutation time of precipitation was detected as 2007.
YAN Zhi-jun
,
ZHANG Ming-yue
,
PANG Yong
,
ZHANG Shu-lin
,
WANG Yi-shu
,
CHEN Wei-hong
,
ZHANG Peng
,
WANG Hui-rong
,
2014, 12(4):42-46.
Abstract:
Jiangsu section is the source and main water diversion route for the Eastern Route of the South-to-North Water Diversion Project, and therefore water pollution treatment in the section is critical. In this paper, the improvement on water quality and reduction of pollutants in 102 pollution control projects in Jiangsu section were evaluated. Based on the analysis of structural characteristics of the main pollutants in the future key industries and key areas, it suggested that the key industries of pollution control are breeding industry, rural life, urban life, agricultural plant, and industrial manufacture, and the key areas of pollution control are Xuzhou, Huaian, and Yangzhou in Jiangsu section. The corresponding pollution control measures were proposed, which can provide a basis to ensure the security of water transfer and realize that water quality reaches standard in Jiangsu section before the project is officially working.
Jiangsu section is the source and main water diversion route for the Eastern Route of the South-to-North Water Diversion Project, and therefore water pollution treatment in the section is critical. In this paper, the improvement on water quality and reduction of pollutants in 102 pollution control projects in Jiangsu section were evaluated. Based on the analysis of structural characteristics of the main pollutants in the future key industries and key areas, it suggested that the key industries of pollution control are breeding industry, rural life, urban life, agricultural plant, and industrial manufacture, and the key areas of pollution control are Xuzhou, Huaian, and Yangzhou in Jiangsu section. The corresponding pollution control measures were proposed, which can provide a basis to ensure the security of water transfer and realize that water quality reaches standard in Jiangsu section before the project is officially working.
2014, 12(4):47-50.
Abstract:
The surface characteristics of sediments are important to understand the environmental impact of sediments. In order to investigate the effects of grain size and grading of different origins on surface properties of sediments, sediment samples were collected from the Poyang-Yangtze Waterway and Yangtze River in Nanjing, respectively. The sediments were divided into four particle-size fractions: 0-30μm, 30-62μm, 62-90 μm, and 90-125μm, and then the surface properties (specific surface area, pore volume, and pore diameter) were investigated. The results showed that (1) the sediments in the Poyang Lake and Yangtze River are mainly clay, silt, and fine sand, and the specific surface area is from 3.2 to 25.12 m2/g, indicating that the sediments are mesoporous materials; (2) the specific surface area is in a power exponent relationship with grain size, and it decreases with the increasing of grain size for silt and clay; (3) the relationship between the median grain size of mixing sediments and specific surface area is similar to that of grading sediments, with a slightly higher magnitude; and (4) the values of axial ratio and relative surface area increase along with the increasing of median diameter, and the increasing rates of axial ratio and relative surface area are much higher when the median grain size is in the range of 0~15 μm.
The surface characteristics of sediments are important to understand the environmental impact of sediments. In order to investigate the effects of grain size and grading of different origins on surface properties of sediments, sediment samples were collected from the Poyang-Yangtze Waterway and Yangtze River in Nanjing, respectively. The sediments were divided into four particle-size fractions: 0-30μm, 30-62μm, 62-90 μm, and 90-125μm, and then the surface properties (specific surface area, pore volume, and pore diameter) were investigated. The results showed that (1) the sediments in the Poyang Lake and Yangtze River are mainly clay, silt, and fine sand, and the specific surface area is from 3.2 to 25.12 m2/g, indicating that the sediments are mesoporous materials; (2) the specific surface area is in a power exponent relationship with grain size, and it decreases with the increasing of grain size for silt and clay; (3) the relationship between the median grain size of mixing sediments and specific surface area is similar to that of grading sediments, with a slightly higher magnitude; and (4) the values of axial ratio and relative surface area increase along with the increasing of median diameter, and the increasing rates of axial ratio and relative surface area are much higher when the median grain size is in the range of 0~15 μm.
2014, 12(4):51-56.
Abstract:
The mixture dilution experiment of Weihe River water and incoming water was performed to simulate the water environment evolution in the water receiving area after water transfer and to assess the pollution characteristics of heavy metals in the water environment and the potential ecological risk. The results showed that (1) the contents of Co, Cr, Mn, Mo, Pb, and V in the mixed water of Weihe River of the Weinan and Xianyang sections decrease with the increasing volume of incoming water due to the impacts of the interactions among pH, TDS, and heavy metals, and water quality of the mixed water improves; (2) the comprehensive pollution index of heavy metal (Nemoro P综合) of the mixed water reduces by about 60% in average due to mixture dilution, and the pollution degree of heavy metals decreases significantly; and (3) the potential ecological risk coefficient of single heavy metal and potential ecological risk index RI in the water environment of the water-receiving area after water transfer reduce apparently. The average decline rates of the potential ecological risk coefficients of Cr, Mn, and Pb are 50%, 70%, and 56% respectively, and the average decline rate of the potential ecological hazard index RI is 57%, which indicates that the mixture dilution can decrease the potential ecological risk of heavy metals significantly.
The mixture dilution experiment of Weihe River water and incoming water was performed to simulate the water environment evolution in the water receiving area after water transfer and to assess the pollution characteristics of heavy metals in the water environment and the potential ecological risk. The results showed that (1) the contents of Co, Cr, Mn, Mo, Pb, and V in the mixed water of Weihe River of the Weinan and Xianyang sections decrease with the increasing volume of incoming water due to the impacts of the interactions among pH, TDS, and heavy metals, and water quality of the mixed water improves; (2) the comprehensive pollution index of heavy metal (Nemoro P综合) of the mixed water reduces by about 60% in average due to mixture dilution, and the pollution degree of heavy metals decreases significantly; and (3) the potential ecological risk coefficient of single heavy metal and potential ecological risk index RI in the water environment of the water-receiving area after water transfer reduce apparently. The average decline rates of the potential ecological risk coefficients of Cr, Mn, and Pb are 50%, 70%, and 56% respectively, and the average decline rate of the potential ecological hazard index RI is 57%, which indicates that the mixture dilution can decrease the potential ecological risk of heavy metals significantly.
2014, 12(4):57-61.
Abstract:
Based on the monitoring data of the wetland ecosystem of the Dongping Lake from 2009 to 2011 and previous studies, the spatial and temporal variation of wetland water type and water nutrients and the purified function of wetland plants, soil, and hydrology were analyzed, and the reason of water quality variation and purified mechanism were discussed. The results showed that (1) the water type in the Dongping Lake has changed from carbonate-type in the 1980s to sulfate-type due to human activities; (2) the contents of total nitrogen (TN) and total phosphorus (TP) in the lake inlet are higher than those in the lake outlet as a result of pollution in the river flowing into the lake; (3) the contents of TN and TP in the 2000s decrease by 12% and 55% compared with those in the 1990safter pollution control; (4)the removal rates of potamogeton crispus on TN and TP in the wetland reach 85% and 54%, respectively; and (5) the contents of TN and TP are lower in both flood and dry periods than those in the normal period. Therefore, the purified function of wetland ecosystem in the Dongping Lake is related to the soil, plant, and hydrology and human activities.
Based on the monitoring data of the wetland ecosystem of the Dongping Lake from 2009 to 2011 and previous studies, the spatial and temporal variation of wetland water type and water nutrients and the purified function of wetland plants, soil, and hydrology were analyzed, and the reason of water quality variation and purified mechanism were discussed. The results showed that (1) the water type in the Dongping Lake has changed from carbonate-type in the 1980s to sulfate-type due to human activities; (2) the contents of total nitrogen (TN) and total phosphorus (TP) in the lake inlet are higher than those in the lake outlet as a result of pollution in the river flowing into the lake; (3) the contents of TN and TP in the 2000s decrease by 12% and 55% compared with those in the 1990safter pollution control; (4)the removal rates of potamogeton crispus on TN and TP in the wetland reach 85% and 54%, respectively; and (5) the contents of TN and TP are lower in both flood and dry periods than those in the normal period. Therefore, the purified function of wetland ecosystem in the Dongping Lake is related to the soil, plant, and hydrology and human activities.
2014, 12(4):62-67.
Abstract:
The contradiction between the river resource development and ecological protection is becoming increasingly conspicuous, and therefore research on the ecological water requirement is needed. In this paper, a method for determining the river ecological water requirement process based on fish biomass was proposed. Through the suitability analysis of fish habitat, the relationship between the single-target fish biomass during the specific life history and the river discharge was developed, which can be used to determine the water demand of the target fish for maintaining a certain biomass amount in the particular biological life history. Moreover, the weight relationship between the multi-target fish and the fish life history was established. By matching the needed river discharge for all target fishes in each life history with the corresponding weight coefficients in or among the fish fingerlings, the ecological water requirement process for the regional river was obtained. The method was applied in the water reduced reach of the Jinping Bay in the Yalong River to determine the ecological water requirement to maintain the stable fish biomass in the reach and the ecological water requirement process lines corresponding to different fish biomass conservation.
The contradiction between the river resource development and ecological protection is becoming increasingly conspicuous, and therefore research on the ecological water requirement is needed. In this paper, a method for determining the river ecological water requirement process based on fish biomass was proposed. Through the suitability analysis of fish habitat, the relationship between the single-target fish biomass during the specific life history and the river discharge was developed, which can be used to determine the water demand of the target fish for maintaining a certain biomass amount in the particular biological life history. Moreover, the weight relationship between the multi-target fish and the fish life history was established. By matching the needed river discharge for all target fishes in each life history with the corresponding weight coefficients in or among the fish fingerlings, the ecological water requirement process for the regional river was obtained. The method was applied in the water reduced reach of the Jinping Bay in the Yalong River to determine the ecological water requirement to maintain the stable fish biomass in the reach and the ecological water requirement process lines corresponding to different fish biomass conservation.
2014, 12(4):68-71.
Abstract:
In order to ensure the flood control safety in the Xicheng district of Luohe City and reduce the flood control pressure at the urban section of the Lihe River, a new river channel was planned to be excavated in the Dalouwei village where the Shahe River and Lihe River are the closest, and thus the flood in the Lihe River can be diverted into the Shahe River. In this paper, nine scenarios of flood discharge were selected to develop the three-dimensional numerical models and physical models. In order to provide the basis for project design, hydraulic characteristics in the Lihe River and Shahe River before and after the reconstruction project were investigated, and the effects of the reconstruction project on the river regime were analyzed. The results showed that the water level and flow velocity in the Shahe River have insignificant changes under different scenarios of flood discharge, and the flow velocity in the upstream of the Lihe River reconstruction section increases slightly and the water level in the upstream of the Lihe River reconstruction section can increase or decrease under different scenarios of flood discharge. Therefore, the implementation of the Lihe River reconstruction project has impacts on the river bend section of the Shahe River at the outlet of reconstruction section. The section needs to bear the two-way river flow in the upstream of Shahe River and Lihe River, which can have turbid flow field, and thus the slope protection engineering is needed.
In order to ensure the flood control safety in the Xicheng district of Luohe City and reduce the flood control pressure at the urban section of the Lihe River, a new river channel was planned to be excavated in the Dalouwei village where the Shahe River and Lihe River are the closest, and thus the flood in the Lihe River can be diverted into the Shahe River. In this paper, nine scenarios of flood discharge were selected to develop the three-dimensional numerical models and physical models. In order to provide the basis for project design, hydraulic characteristics in the Lihe River and Shahe River before and after the reconstruction project were investigated, and the effects of the reconstruction project on the river regime were analyzed. The results showed that the water level and flow velocity in the Shahe River have insignificant changes under different scenarios of flood discharge, and the flow velocity in the upstream of the Lihe River reconstruction section increases slightly and the water level in the upstream of the Lihe River reconstruction section can increase or decrease under different scenarios of flood discharge. Therefore, the implementation of the Lihe River reconstruction project has impacts on the river bend section of the Shahe River at the outlet of reconstruction section. The section needs to bear the two-way river flow in the upstream of Shahe River and Lihe River, which can have turbid flow field, and thus the slope protection engineering is needed.
2014, 12(4):72-76.
Abstract:
Based on a comprehensive evaluation of the present situation and problems of the ecological environment at the water source area in the Middle Route of South-to-North Water Diversion Project, an empirical analysis of the sustainable development in the area was conducted using the ecological footprint model. The results showed that the total ecological footprint of the water source area has an increasing trend with fluctuations, the ecological carrying capacity per capita is also increasing, and the ecological deficit increases first but then decreases without ecological surplus, which indicates that the water source area is unsustainable during the research period. The findings can provide reference for the ecological construction of the relevant departments of South-to-North Water Diversion Project.
Based on a comprehensive evaluation of the present situation and problems of the ecological environment at the water source area in the Middle Route of South-to-North Water Diversion Project, an empirical analysis of the sustainable development in the area was conducted using the ecological footprint model. The results showed that the total ecological footprint of the water source area has an increasing trend with fluctuations, the ecological carrying capacity per capita is also increasing, and the ecological deficit increases first but then decreases without ecological surplus, which indicates that the water source area is unsustainable during the research period. The findings can provide reference for the ecological construction of the relevant departments of South-to-North Water Diversion Project.
2014, 12(4):77-80.
Abstract:
In order to determine the current situation of shallow groundwater environment in Tangshan plain area, samples of shallow groundwater were collected and analyzed. The results showed that hydrochemical type of shallow groundwater in Tangshan plain area has apparent zonation characteristics and the total dissolved solid (TDS) and hardness increase gradually from north to south. The TDS, hardness and concentrations of manganese, nitrate-nitrogen, fluoride, nitrite, and ammonia nitrogen were above those defined in the “National Hygienic Standard of Living Water”, and more attention should be paid to the toxic and harmful heavy metals, especially arsenic and hexavalent chrome. It suggested that river pollution, industrial pollution, and agricultural production are the main reasons to cause the deterioration of groundwater quality.
In order to determine the current situation of shallow groundwater environment in Tangshan plain area, samples of shallow groundwater were collected and analyzed. The results showed that hydrochemical type of shallow groundwater in Tangshan plain area has apparent zonation characteristics and the total dissolved solid (TDS) and hardness increase gradually from north to south. The TDS, hardness and concentrations of manganese, nitrate-nitrogen, fluoride, nitrite, and ammonia nitrogen were above those defined in the “National Hygienic Standard of Living Water”, and more attention should be paid to the toxic and harmful heavy metals, especially arsenic and hexavalent chrome. It suggested that river pollution, industrial pollution, and agricultural production are the main reasons to cause the deterioration of groundwater quality.
2014, 12(4):81-85.
Abstract:
Interconnected River System Network (IRSN) is an important approach for regulating the matching relationship between water and land resources, enhancing river service function, enhancing water resources allocation capacity, improving ecosystem environment, and reducing flood risks. IRSN has rarely been investigated in the literature, thus there is an urgent need to summarize the practical experiences. In this paper, based on the historical evolution process of IRSN, the IRSN practices in China and abroad were analyzed from the perspectives of military and transportation, irrigation and water supply, river management, water resources allocation, and restoration of eco-hydrological environment. The development trend of IRSN was identified, which can provide good reference for the future studies on IRSN.
Interconnected River System Network (IRSN) is an important approach for regulating the matching relationship between water and land resources, enhancing river service function, enhancing water resources allocation capacity, improving ecosystem environment, and reducing flood risks. IRSN has rarely been investigated in the literature, thus there is an urgent need to summarize the practical experiences. In this paper, based on the historical evolution process of IRSN, the IRSN practices in China and abroad were analyzed from the perspectives of military and transportation, irrigation and water supply, river management, water resources allocation, and restoration of eco-hydrological environment. The development trend of IRSN was identified, which can provide good reference for the future studies on IRSN.
2014, 12(4):86-91.
Abstract:
In order to solve the water problems in China and promote the sustainable economic and social development, it is imperative to implement the Strictest Water Resources Management System, and constructing the performance evaluation system of the Strictest Water Resources Management is particularly important. In this paper, based on "The Implementation Scheme of the Strictest Water Resources Management Assessment " and the actual conditions in Zhengzhou, the overall idea of performance evaluation in municipal areas was proposed, and of the performance evaluation system of the Strictest Water Resources Management in Zhengzhou was developed. The system was applied to Xinmi City in order to provide reference for the performance evaluation of the regional Strictest Water Resources Management.
In order to solve the water problems in China and promote the sustainable economic and social development, it is imperative to implement the Strictest Water Resources Management System, and constructing the performance evaluation system of the Strictest Water Resources Management is particularly important. In this paper, based on "The Implementation Scheme of the Strictest Water Resources Management Assessment " and the actual conditions in Zhengzhou, the overall idea of performance evaluation in municipal areas was proposed, and of the performance evaluation system of the Strictest Water Resources Management in Zhengzhou was developed. The system was applied to Xinmi City in order to provide reference for the performance evaluation of the regional Strictest Water Resources Management.
2014, 12(4):92-97.
Abstract:
Total water consumption control is one of the “three lines” in the strictest water resources management system, and a reasonable evaluation of its implementation effects is important. In this paper, the connotation of regional total water consumption control was established first. Then, an evaluation index system of regional total water consumption control was developed from the perspectives of water resources, society, economy, and environment. The evaluation index system included 13 specific indexes, such as per capita possession of water resources, utilization efficiency of water resources, and regional water shortage rate. Finally, the evaluation criteria of each index were conducted and a fuzzy comprehensive evaluation model was developed based on AHP to evaluate the implementation effects of regional total water consumption control. The model was applied to the Gaochun district of Nanjing, , and the evaluation results were reasonable.
Total water consumption control is one of the “three lines” in the strictest water resources management system, and a reasonable evaluation of its implementation effects is important. In this paper, the connotation of regional total water consumption control was established first. Then, an evaluation index system of regional total water consumption control was developed from the perspectives of water resources, society, economy, and environment. The evaluation index system included 13 specific indexes, such as per capita possession of water resources, utilization efficiency of water resources, and regional water shortage rate. Finally, the evaluation criteria of each index were conducted and a fuzzy comprehensive evaluation model was developed based on AHP to evaluate the implementation effects of regional total water consumption control. The model was applied to the Gaochun district of Nanjing, , and the evaluation results were reasonable.
2014, 12(4):98-101.
Abstract:
The rubber was modified with several approaches, including washing, NaOH solution, KH570 solution, and homemade Na2SiO3 solution, and the experiments were conducted to investigate the impacts of different modification approaches on the strength of rubberized mortar. The test results showed that 10% NaOH solution has the best modification effects with 16.89% and 46.56% of increasing in the compressive strength and splitting tensile strength, respectively compared to the benchmark rubberized mortar. . The observation results using the electron microscope with a magnification of 1000 showed that after the modification with NaOH solution, the cleanliness and pores of the rubber surface increase, and the occlusion degree with cement reinforces, which explained the increasing strength mechanism of the cement mortar with modified rubber from the microscopic scale.
The rubber was modified with several approaches, including washing, NaOH solution, KH570 solution, and homemade Na2SiO3 solution, and the experiments were conducted to investigate the impacts of different modification approaches on the strength of rubberized mortar. The test results showed that 10% NaOH solution has the best modification effects with 16.89% and 46.56% of increasing in the compressive strength and splitting tensile strength, respectively compared to the benchmark rubberized mortar. . The observation results using the electron microscope with a magnification of 1000 showed that after the modification with NaOH solution, the cleanliness and pores of the rubber surface increase, and the occlusion degree with cement reinforces, which explained the increasing strength mechanism of the cement mortar with modified rubber from the microscopic scale.
2014, 12(4):102-106.
Abstract:
The permeability property of coarse grained soils is closely related to material composition, grain size distribution, particle shape, and particle density. Based on the laboratory permeability test, the effects of particle shape, grain size distribution, and particle density on the permeability property of coarse grained soils were studied. Nine orthogonal experiments and two particle shape experiments were performed. The results showed that grain size distribution has the largest impact on permeability based on the range analysis and variance analysis of the orthogonal tests, and permeability increases with the increasing of particle sphericity based on the comparative analysis of two particle shape tests. The estimation formula of critical hydraulic gradient was proposed using the permeability coefficient as a variable based on the analysis of permeability characteristics reflected by the above tests.
The permeability property of coarse grained soils is closely related to material composition, grain size distribution, particle shape, and particle density. Based on the laboratory permeability test, the effects of particle shape, grain size distribution, and particle density on the permeability property of coarse grained soils were studied. Nine orthogonal experiments and two particle shape experiments were performed. The results showed that grain size distribution has the largest impact on permeability based on the range analysis and variance analysis of the orthogonal tests, and permeability increases with the increasing of particle sphericity based on the comparative analysis of two particle shape tests. The estimation formula of critical hydraulic gradient was proposed using the permeability coefficient as a variable based on the analysis of permeability characteristics reflected by the above tests.
2014, 12(4):107-110.
Abstract:
Yaoguannan pumping station is one of the key projects in the Xingouhe extension and widening project, and its main task is to pump water from the Wujing Port area to the Bejing-Hangzhou Grand Canal and to storm drainage as well. The design pump head of the pumping station is extra-low, which is only 0.7 m.. Based on the test results of model pump system from the constructed pump station projects and the comparisons from the perspectives of hydraulic performance, engineering investment, construction, and operation management, the tubular pump model that has been successfully adopted in the Liyangxincun pumping station was selected for the Yaoguannan pumping station. Due to that the maximum pump head is about 3 times of the design head, the investment and operation costs for the Yaoguannan pumping station were analyzed between two design schemes of fixed and adjustable motor speeds. The investment for the pump set was much larger but the effect in lowering operation cost was not obvious for the scheme of adjustable motor speed, thus the fixed speed scheme was selected finally.
Yaoguannan pumping station is one of the key projects in the Xingouhe extension and widening project, and its main task is to pump water from the Wujing Port area to the Bejing-Hangzhou Grand Canal and to storm drainage as well. The design pump head of the pumping station is extra-low, which is only 0.7 m.. Based on the test results of model pump system from the constructed pump station projects and the comparisons from the perspectives of hydraulic performance, engineering investment, construction, and operation management, the tubular pump model that has been successfully adopted in the Liyangxincun pumping station was selected for the Yaoguannan pumping station. Due to that the maximum pump head is about 3 times of the design head, the investment and operation costs for the Yaoguannan pumping station were analyzed between two design schemes of fixed and adjustable motor speeds. The investment for the pump set was much larger but the effect in lowering operation cost was not obvious for the scheme of adjustable motor speed, thus the fixed speed scheme was selected finally.
2014, 12(4):111-115.
Abstract:
Based on the results of laboratory triaxial consolidated-drained tests on coarse grained materials and three-dimensional discrete particle flow theory, a numerical model of triaxial test for coarse grained materials with uniform particle contact points and same isotropic stresses was developed using the tool of PFC3D_EV and improvement of program code. Clump particles were introduced to improve the complexity of internal particle shape of the sample. The differences of stress-strain curves and volumetric strain - axial strain curves of triaxial tests under different confining pressures were compared, and the impacts of particle shape and the development law of shear bands on the strength and deformation characteristics of coarse grained materials were discussed. The results showed that (1) particle shape is the main factor on the mechanical behavior of coarse grained materials. The stress-strain curve obtained from the numerical simulation matches well with the experimental results if the complexity of internal particle shape is improved; (2) the shear dilatancy of numerical simulation is a little larger because the particle deformation and breakage cannot be performed in numerical simulation; (3) the development of displacement field indicates that strain softening accelerates the formation of shear bands; and (4) the thickness of shear bands becomes thinner with the decreasing of confining pressure .
Based on the results of laboratory triaxial consolidated-drained tests on coarse grained materials and three-dimensional discrete particle flow theory, a numerical model of triaxial test for coarse grained materials with uniform particle contact points and same isotropic stresses was developed using the tool of PFC3D_EV and improvement of program code. Clump particles were introduced to improve the complexity of internal particle shape of the sample. The differences of stress-strain curves and volumetric strain - axial strain curves of triaxial tests under different confining pressures were compared, and the impacts of particle shape and the development law of shear bands on the strength and deformation characteristics of coarse grained materials were discussed. The results showed that (1) particle shape is the main factor on the mechanical behavior of coarse grained materials. The stress-strain curve obtained from the numerical simulation matches well with the experimental results if the complexity of internal particle shape is improved; (2) the shear dilatancy of numerical simulation is a little larger because the particle deformation and breakage cannot be performed in numerical simulation; (3) the development of displacement field indicates that strain softening accelerates the formation of shear bands; and (4) the thickness of shear bands becomes thinner with the decreasing of confining pressure .
2014, 12(4):116-119.
Abstract:
Hydraulic tunnel bears loads such as water pressure, rock pressure, and elastic resistance, so reinforcement is often needed. In this paper, a FEM analysis reinforcement method was proposed based on FEM and secondary development of ANSYS. A whole FEM model of concrete lining and its surrounding rock mass was developed to analyze the stress distribution of the lining. With the post-processing function of ANSYS, the stress distribution and tensile force of the controlling sections can be obtained and reinforcement calculation was then performed. The reinforcement quantity determinate by this method was similar to that obtained from the standard method The FEM analysis reinforcement method was applied to the reinforcement design for the headrace tunnel lining of the ITACHI hydropower station, which indicated that the method is reasonable and feasible.
Hydraulic tunnel bears loads such as water pressure, rock pressure, and elastic resistance, so reinforcement is often needed. In this paper, a FEM analysis reinforcement method was proposed based on FEM and secondary development of ANSYS. A whole FEM model of concrete lining and its surrounding rock mass was developed to analyze the stress distribution of the lining. With the post-processing function of ANSYS, the stress distribution and tensile force of the controlling sections can be obtained and reinforcement calculation was then performed. The reinforcement quantity determinate by this method was similar to that obtained from the standard method The FEM analysis reinforcement method was applied to the reinforcement design for the headrace tunnel lining of the ITACHI hydropower station, which indicated that the method is reasonable and feasible.
2014, 12(4):120-122.
Abstract:
Based on the micromechanics theory of composite materials and Power’s Volume model, a multi-phase micromechanics model was developed to simulate the elastic properties of cement pastes. The hydrated products, unhydrated cement, and water (capillary pores) in the hardened cement paste were regarded as matrix, inclusion, and equivalent medium respectively, and the evolution law of elastic properties in the hydration process was simulated with different water-cement ratios. The inputs of the proposed model were the intrinsic properties of the components of cement pastes and thus can be easily obtained. The model results showed that with the development of the cement hydration process, the elastic modulus of cement paste increases gradually, but the Poisson's ratio is gradually reduced. Also, under the conditions of same hydration degree, the elastic modulus increased with the increasing of water-cement ratio. Compared with the experimental results, the model can effectively predict the elastic properties of cement paste.
Based on the micromechanics theory of composite materials and Power’s Volume model, a multi-phase micromechanics model was developed to simulate the elastic properties of cement pastes. The hydrated products, unhydrated cement, and water (capillary pores) in the hardened cement paste were regarded as matrix, inclusion, and equivalent medium respectively, and the evolution law of elastic properties in the hydration process was simulated with different water-cement ratios. The inputs of the proposed model were the intrinsic properties of the components of cement pastes and thus can be easily obtained. The model results showed that with the development of the cement hydration process, the elastic modulus of cement paste increases gradually, but the Poisson's ratio is gradually reduced. Also, under the conditions of same hydration degree, the elastic modulus increased with the increasing of water-cement ratio. Compared with the experimental results, the model can effectively predict the elastic properties of cement paste.
2014, 12(4):123-127.
Abstract:
The design and average heads of Jingtou pumping station in Suqian city are both 1.7 m, and thus shaft tubular pump system is applied to adapt its characteristics of low heads. The optimum hydraulic design for the inlet and outlet conduits of the pump system were conducted using the numerical simulation method of three-dimensional turbulence flow, and the hydraulic performance of the pump system was verified using model test. The results indicated that the flow pattern in the inlet and outlet conduits is uniform and smooth, the velocity distribution uniformity and the average angle into the pump reach 98.7% and 88.7° at the impeller chamber inlet section, respectively, and the hydraulic losses of the optimized conduits are low. Moreover, the efficiency and critical net positive suction head of the pump system were 80.3% and 3.11 m under the design head conditions, respectively, which were similar to those obtained from model test (the efficiency and critical net positive suction head were 81.1% and 3.3m under the design head conditions). Therefore, the selection and design for the shaft tubular pump system in Jingtou pumping station are reasonable and optimal, which lays a foundation for the safe, stable, and efficient operation of the pumping station.
The design and average heads of Jingtou pumping station in Suqian city are both 1.7 m, and thus shaft tubular pump system is applied to adapt its characteristics of low heads. The optimum hydraulic design for the inlet and outlet conduits of the pump system were conducted using the numerical simulation method of three-dimensional turbulence flow, and the hydraulic performance of the pump system was verified using model test. The results indicated that the flow pattern in the inlet and outlet conduits is uniform and smooth, the velocity distribution uniformity and the average angle into the pump reach 98.7% and 88.7° at the impeller chamber inlet section, respectively, and the hydraulic losses of the optimized conduits are low. Moreover, the efficiency and critical net positive suction head of the pump system were 80.3% and 3.11 m under the design head conditions, respectively, which were similar to those obtained from model test (the efficiency and critical net positive suction head were 81.1% and 3.3m under the design head conditions). Therefore, the selection and design for the shaft tubular pump system in Jingtou pumping station are reasonable and optimal, which lays a foundation for the safe, stable, and efficient operation of the pumping station.
2014, 12(4):128-133.
Abstract:
Soft soil foundation treatment methods and field monitoring schemes in the reclamation and soft soil foundation improvement project were introduced, and the monitoring results of the surfacial settlement, layered settlement, and pore water pressure and reinforcement effects of soft silty soil foundation with preloading method were analyzed. The results showed that (1) the settlement during the loading construction period is accounted for 65% of the total settlement, and the settlement during the loading intermittent period increases linearly with time. The settlement during the full load pre-compression period is accounted for 35% of the total settlement, and it shows an approximately parabolic increasing with time; (2) the settlement in the surfacial silt from 0 to 6 m is accounted for 53.9% of the total settlement, where the settlement mainly occurs, while the settlement in the underlying layer of silt is accounted for 22.8% of the total settlement, and the estimated foundation settlement should consider the settlement in the underlying layer of silt; (3) the excess pore water pressures in the surfacial and bottom silt layers dissipate faster than that in the middle layer. The excess pore water pressure at different depths dissipates by 80%after six months of full load, and it dissipates by 85% to 90% after eight months of full load; and (4) the physical and mechanical properties and strength of silt improve significantly after reinforcement, indicating an obvious reinforcement effect.
Soft soil foundation treatment methods and field monitoring schemes in the reclamation and soft soil foundation improvement project were introduced, and the monitoring results of the surfacial settlement, layered settlement, and pore water pressure and reinforcement effects of soft silty soil foundation with preloading method were analyzed. The results showed that (1) the settlement during the loading construction period is accounted for 65% of the total settlement, and the settlement during the loading intermittent period increases linearly with time. The settlement during the full load pre-compression period is accounted for 35% of the total settlement, and it shows an approximately parabolic increasing with time; (2) the settlement in the surfacial silt from 0 to 6 m is accounted for 53.9% of the total settlement, where the settlement mainly occurs, while the settlement in the underlying layer of silt is accounted for 22.8% of the total settlement, and the estimated foundation settlement should consider the settlement in the underlying layer of silt; (3) the excess pore water pressures in the surfacial and bottom silt layers dissipate faster than that in the middle layer. The excess pore water pressure at different depths dissipates by 80%after six months of full load, and it dissipates by 85% to 90% after eight months of full load; and (4) the physical and mechanical properties and strength of silt improve significantly after reinforcement, indicating an obvious reinforcement effect.
2014, 12(4):134-137.
Abstract:
Based on the laboratory mix ratio of C30 concrete，the fly ash-cement concrete was mixed with 30% fly ash to make three experimental groups which were also mixed with the best dosages of NaOH, sodium silicate, and CaO, respectively. After vibration molding, the impacts of alkali on the mobility and setting time were determined. The microstructure of mortar was investigated using the scanning electron microscope, and then the samples were maintained to age. According to the 《Standard for test method of mechanical properties on ordinary concrete》, the compressive strength and splitting tensile strength of the concrete were measured. Through the comparison of strengths, the intensity increasing rate was determined, which can help understand the impacts of mixing alkali on the strength development in the early and late times. The results showed that (1) mixing with alkali can coagulate and decrease the mobility of mortar；(2) the fly ash mixed with alkali has a rapid strength development in the early time and a slow strength development in the late time, and the strength at 90 days can meet the design requirements; (3) In the scanning electron microscope experiment, due to the quick cement hydration speed, the activity of fly ash motivates, and so the strength in the early time improves; and (4) the economic and technical benefit is remarkable for the fly ash-cement concrete mixed with alkali excitant.
Based on the laboratory mix ratio of C30 concrete，the fly ash-cement concrete was mixed with 30% fly ash to make three experimental groups which were also mixed with the best dosages of NaOH, sodium silicate, and CaO, respectively. After vibration molding, the impacts of alkali on the mobility and setting time were determined. The microstructure of mortar was investigated using the scanning electron microscope, and then the samples were maintained to age. According to the 《Standard for test method of mechanical properties on ordinary concrete》, the compressive strength and splitting tensile strength of the concrete were measured. Through the comparison of strengths, the intensity increasing rate was determined, which can help understand the impacts of mixing alkali on the strength development in the early and late times. The results showed that (1) mixing with alkali can coagulate and decrease the mobility of mortar；(2) the fly ash mixed with alkali has a rapid strength development in the early time and a slow strength development in the late time, and the strength at 90 days can meet the design requirements; (3) In the scanning electron microscope experiment, due to the quick cement hydration speed, the activity of fly ash motivates, and so the strength in the early time improves; and (4) the economic and technical benefit is remarkable for the fly ash-cement concrete mixed with alkali excitant.
2014, 12(4):138-142.
Abstract:
Unstable modes of expansive and replacement soil slope under the impacts of rainfall seepage and overload in the Middle Route of South-to-North Water Diversion Project were investigated using the limit equilibrium theory. The most dangerous instability mode and state of unstable destruction were obtained. The results showed that (1) the most dangerous sliding surface is the single curved surface or compound curved surface which has rupture surface between blocks in the shallow layer of expansive soil slope; and (2) the overload of slope top has significantly adverse impacts on slope stability. The limit overload value of of slope top is about 0.44 times of the weight of the soil column with the slope height or 1.4 times of the weight of the uniformly distributed load produced by the car with a carrying capacity of 20 tons. The results can provide beneficial reference for the reasonable design and safe construction and operation of the project.
Unstable modes of expansive and replacement soil slope under the impacts of rainfall seepage and overload in the Middle Route of South-to-North Water Diversion Project were investigated using the limit equilibrium theory. The most dangerous instability mode and state of unstable destruction were obtained. The results showed that (1) the most dangerous sliding surface is the single curved surface or compound curved surface which has rupture surface between blocks in the shallow layer of expansive soil slope; and (2) the overload of slope top has significantly adverse impacts on slope stability. The limit overload value of of slope top is about 0.44 times of the weight of the soil column with the slope height or 1.4 times of the weight of the uniformly distributed load produced by the car with a carrying capacity of 20 tons. The results can provide beneficial reference for the reasonable design and safe construction and operation of the project.
2014, 12(4):143-146.
Abstract:
The compound stabilizer was made using the EPS (expanded polystyrene) particles treated by self-made modifier and then mixed with the dredged sludge from the Bohai Bay in different mixing ratios to obtain the lightweight soil mixed with dredged sludge. The effects of modifier on the surficial properties of EPS particles were analyzed using the contact angle measurement and scanning electron microscopy (SEM) test, and the impacts of EPS particles with different quantities of modifier on the density, compression strength, and compression yield strain of the lightweight soil were investigated. The results indicated that the introduction of modifier can enhance the combination ability of EPS with sludge particles and improve the workability and structural stability of lightweight soil. When the quantity of modifier was 0.33% of that of EPS particles, the compression strength of lightweight soil increased while the density of lightweight soil decreased, but the effect on compression yield strain was insignificant.
The compound stabilizer was made using the EPS (expanded polystyrene) particles treated by self-made modifier and then mixed with the dredged sludge from the Bohai Bay in different mixing ratios to obtain the lightweight soil mixed with dredged sludge. The effects of modifier on the surficial properties of EPS particles were analyzed using the contact angle measurement and scanning electron microscopy (SEM) test, and the impacts of EPS particles with different quantities of modifier on the density, compression strength, and compression yield strain of the lightweight soil were investigated. The results indicated that the introduction of modifier can enhance the combination ability of EPS with sludge particles and improve the workability and structural stability of lightweight soil. When the quantity of modifier was 0.33% of that of EPS particles, the compression strength of lightweight soil increased while the density of lightweight soil decreased, but the effect on compression yield strain was insignificant.
2014, 12(4):147-150.
Abstract:
The low-speed table automatic balance centrifugewas used to perform the laboratory centrifuge simulation on the natural saline soil of the roadbed filling of Kuitun-Kelamayi highway of Xinjiang and to investigate the impacts of sanity content, temperature, and centrifugal force on the melting deformation of sulfuric saline soil. The research result showed that (1) the melting coefficient of sulfuric saline soil increases with the increasing of centrifugal acceleration speed, and is unrelated to sanity content; (2) the melting coefficient is most sensitive when the centrifugal force is less than 300kPa; and (3) the melting deformation is biggest when SO42- content is 2%. The nonlinear regression orthogonal analysis method was used to analyze the test data under five working conditions and to obtain the f~δ fitting formula of different sanity contents and temperatures. It suggested that the variation of temperature has insignificant impacts on the melting coefficient of natural saline soil when the centrifugal force is 300kPa. The research results can provide reference for the design and construction of highway engineering in the similar saline soil area.
The low-speed table automatic balance centrifugewas used to perform the laboratory centrifuge simulation on the natural saline soil of the roadbed filling of Kuitun-Kelamayi highway of Xinjiang and to investigate the impacts of sanity content, temperature, and centrifugal force on the melting deformation of sulfuric saline soil. The research result showed that (1) the melting coefficient of sulfuric saline soil increases with the increasing of centrifugal acceleration speed, and is unrelated to sanity content; (2) the melting coefficient is most sensitive when the centrifugal force is less than 300kPa; and (3) the melting deformation is biggest when SO42- content is 2%. The nonlinear regression orthogonal analysis method was used to analyze the test data under five working conditions and to obtain the f~δ fitting formula of different sanity contents and temperatures. It suggested that the variation of temperature has insignificant impacts on the melting coefficient of natural saline soil when the centrifugal force is 300kPa. The research results can provide reference for the design and construction of highway engineering in the similar saline soil area.
33 Program Implementation of Fractal Dimension Algorithm of Orientation Pole Distribution for Joints
2014, 12(4):151-155.
Abstract:
The distribution characteristics of joints with dominant orientation are difficult to determine because of the randomness and nonuniformity of spatial distribution of joints, and fractal dimension D is an important approach to describe quantitatively the orientation distribution using the boundary combination based on the judgment of instable block with stereographic projection. According to the mesh generation method of equatorial circle in fractal dimension D, the corresponding program was designed in this paper. In the design process, dip direction and dip angle were converted to polar coordinates and to realize the numerical representation of orientation pole distribution for joints. The program was designed with Visual Basic for Applications (VBA) and the data were processed directly in Excel, which made the program easy to operate and was beneficial to promote the application in the fractal dimension algorithm of orientation pole distribution for joints. Finally, based on the data of six sets of dominant joints collecting from the left dam foundation in the Dagangshan Hydropower Station, the fractal dimension D of six sets of dominant joints of the foundation rock was calculated before and after the excavation, which was verified with the conclusions on the fractal dimension D of orientation pole distribution for joints in previous studies, indicating the correctness and feasibility of the program.
The distribution characteristics of joints with dominant orientation are difficult to determine because of the randomness and nonuniformity of spatial distribution of joints, and fractal dimension D is an important approach to describe quantitatively the orientation distribution using the boundary combination based on the judgment of instable block with stereographic projection. According to the mesh generation method of equatorial circle in fractal dimension D, the corresponding program was designed in this paper. In the design process, dip direction and dip angle were converted to polar coordinates and to realize the numerical representation of orientation pole distribution for joints. The program was designed with Visual Basic for Applications (VBA) and the data were processed directly in Excel, which made the program easy to operate and was beneficial to promote the application in the fractal dimension algorithm of orientation pole distribution for joints. Finally, based on the data of six sets of dominant joints collecting from the left dam foundation in the Dagangshan Hydropower Station, the fractal dimension D of six sets of dominant joints of the foundation rock was calculated before and after the excavation, which was verified with the conclusions on the fractal dimension D of orientation pole distribution for joints in previous studies, indicating the correctness and feasibility of the program.
2014, 12(4):156-160.
Abstract:
Slug test is an important method to determine the permeability of rock and soil masses. In this paper, the permeability of the concealed Ordovician karst-fractured limestone aquifer in Daxing of Beijing was estimated. The production wells were selected according to the in-situ conditions, and the slug test design included the pump-off water level recovery method recorded by auto-monitoring system, HSZK oscillation method, and injection method. The results showed that the permeability obtained from the slug test is less than that determined by the conventional pumping test. The discrepancy was mainly due to the difference of influence radius in different test methods, and slug test can reflect the permeability at the local scale more accurately. Additionally, it is necessary to reduce or avoid the well skin effect while performing the slug test in the fracture and karst medium. The realization of instantaneous water level change needs to be conducted when designing the slug test and the plug-sealing sectional test can be used in the main fractures.
Slug test is an important method to determine the permeability of rock and soil masses. In this paper, the permeability of the concealed Ordovician karst-fractured limestone aquifer in Daxing of Beijing was estimated. The production wells were selected according to the in-situ conditions, and the slug test design included the pump-off water level recovery method recorded by auto-monitoring system, HSZK oscillation method, and injection method. The results showed that the permeability obtained from the slug test is less than that determined by the conventional pumping test. The discrepancy was mainly due to the difference of influence radius in different test methods, and slug test can reflect the permeability at the local scale more accurately. Additionally, it is necessary to reduce or avoid the well skin effect while performing the slug test in the fracture and karst medium. The realization of instantaneous water level change needs to be conducted when designing the slug test and the plug-sealing sectional test can be used in the main fractures.
2014, 12(4):161-164.
Abstract:
Seepage analysis of earth dam is the important basis for the evaluation of seepage safety and scheme design of seepage control. According to the vibration filling construction characteristics of the earth dam of Dalong water-control project in the middle and lower reaches of Ningyuan River in Sanya city of Hainan Province, the seepage fields of earth dam under different working conditions were analyzed based on the three-dimensional saturated-unsaturated seepage theory. The seepage fields based on the anisotropic and isotropic material permeability were compared and the results showed that (1) as for the earth dam under vibration compaction without foundation pit, layered compaction can cause the anisotropic material permeability, which can have greater impacts on the anti-seepage earth material with lower permeability and result in the phenomenon of increasing seepage velocity in the anti-seepage material upstream of earth dam and decreasing seepage velocity in the anti-seepage material in the middle stream of earth dam; (2) anisotropic material permeability can lower the seepage discharge significantly across the entire section of earth dam; and (3) distribution of pore water pressure in the earth dam is closely related to the upstream water level, and the seepage velocity and seepage discharge in the earth dam is affected by the difference of upstream and downstream water levels.
Seepage analysis of earth dam is the important basis for the evaluation of seepage safety and scheme design of seepage control. According to the vibration filling construction characteristics of the earth dam of Dalong water-control project in the middle and lower reaches of Ningyuan River in Sanya city of Hainan Province, the seepage fields of earth dam under different working conditions were analyzed based on the three-dimensional saturated-unsaturated seepage theory. The seepage fields based on the anisotropic and isotropic material permeability were compared and the results showed that (1) as for the earth dam under vibration compaction without foundation pit, layered compaction can cause the anisotropic material permeability, which can have greater impacts on the anti-seepage earth material with lower permeability and result in the phenomenon of increasing seepage velocity in the anti-seepage material upstream of earth dam and decreasing seepage velocity in the anti-seepage material in the middle stream of earth dam; (2) anisotropic material permeability can lower the seepage discharge significantly across the entire section of earth dam; and (3) distribution of pore water pressure in the earth dam is closely related to the upstream water level, and the seepage velocity and seepage discharge in the earth dam is affected by the difference of upstream and downstream water levels.
2014, 12(4):165-168.
Abstract:
Lila gully is a low-frequency debris flow gully. On June 6, 2011, most of the northern area of Wangmo County in Guizhou Province had the biggest rainfall in a century, which led to a large scale group of debris flow. The occurrence of massive mudslides caused great loss of life and property. Local transportation, communications, and other infrastructure have been damaged seriously. Based on the in-situ investigations of the material sources of debris flow and topographic conditions and interpolation of rainfall in Lila Gully, the formation mechanism of debris flow was analyzed. It suggested that the 1# tributary has steep slopes on both sides and large longitudinal gradient, which is not suitable for the accumulation of residual deposits as the deposits in the gully can be washed away easily under light rain conditions. Therefore, 1# tributary did not have the landslide conditions. Meanwhile, it found that 2# and 3# tributaries have gentle slopes on both sides and thick layer of residual deposits, which can lead to the occurrence of shallow landslide-induced debris flow, especially when the slope of both sides is about 20 to 40°. Consequently, the criteria for the occurrence of shallow debris flow in each tributary of Lila Gully under the same geological, topographic, and rainfall conditions were obtained.
Lila gully is a low-frequency debris flow gully. On June 6, 2011, most of the northern area of Wangmo County in Guizhou Province had the biggest rainfall in a century, which led to a large scale group of debris flow. The occurrence of massive mudslides caused great loss of life and property. Local transportation, communications, and other infrastructure have been damaged seriously. Based on the in-situ investigations of the material sources of debris flow and topographic conditions and interpolation of rainfall in Lila Gully, the formation mechanism of debris flow was analyzed. It suggested that the 1# tributary has steep slopes on both sides and large longitudinal gradient, which is not suitable for the accumulation of residual deposits as the deposits in the gully can be washed away easily under light rain conditions. Therefore, 1# tributary did not have the landslide conditions. Meanwhile, it found that 2# and 3# tributaries have gentle slopes on both sides and thick layer of residual deposits, which can lead to the occurrence of shallow landslide-induced debris flow, especially when the slope of both sides is about 20 to 40°. Consequently, the criteria for the occurrence of shallow debris flow in each tributary of Lila Gully under the same geological, topographic, and rainfall conditions were obtained.
2014, 12(4):169-172.
Abstract:
The development of Karst seepage channel is a major safety hazard to the hydropower projects, and therefore the identification of the presence or absence of seepage channel in the water conservancy and hydropower project is an important work. Tracer method is a popular method in terms of detecting the existence of seepage channel , because this method can detect the connection between each test points and then determine the process of groundwater movement. In this paper, tracer test was applied in the left abutment of a hydropower station in Western China, which detected the presence of seepage channel between each test points.
The development of Karst seepage channel is a major safety hazard to the hydropower projects, and therefore the identification of the presence or absence of seepage channel in the water conservancy and hydropower project is an important work. Tracer method is a popular method in terms of detecting the existence of seepage channel , because this method can detect the connection between each test points and then determine the process of groundwater movement. In this paper, tracer test was applied in the left abutment of a hydropower station in Western China, which detected the presence of seepage channel between each test points.
38 Joint Operation Policy for Cascade Reservoirs using Genetic Algorithms Searching in Feasible Region
2014, 12(4):173-176.
Abstract:
In this study, an optimization model of hydropower generation was built for joint operation of cascade reservoirs with the objective function to maximize the annual average amount of hydropower generation and guarantee ratio of ten-day hydropower generation and with the operation chart of each reservoir as the decision variable. The model was solved using the generic algorithms searching in feasible region, which can avoid extra efforts on the infeasible solution search and improve the optimization effectively. The model was applied to the cascade reservoirs in the Hanjiang River Basin to verify the efficiency of the model and algorithm.
In this study, an optimization model of hydropower generation was built for joint operation of cascade reservoirs with the objective function to maximize the annual average amount of hydropower generation and guarantee ratio of ten-day hydropower generation and with the operation chart of each reservoir as the decision variable. The model was solved using the generic algorithms searching in feasible region, which can avoid extra efforts on the infeasible solution search and improve the optimization effectively. The model was applied to the cascade reservoirs in the Hanjiang River Basin to verify the efficiency of the model and algorithm.
2014, 12(4):177-180.
Abstract:
Water is an indispensable resource in industrial production, and the fluctuation of water resource fee has great impacts on the production process. At present, 31 provinces and autonomous regions have collected the water resources fee, but the criteria are quite different and haven’t been adjusted with the social and economic development. In this paper, the factors of social economy and natural environment which affect the water resource fee were analyzed and a fuzzy comprehensive evaluation method was developed to quantify the factors and applied in the calculation of industrial water resource fee in a city of Jiangsu Province. The results suggested that the water resource fee in different area is related to the local environment and economic development. Therefore, the local conditions should be considered in the enactment of the criteria of water resource fee.
Water is an indispensable resource in industrial production, and the fluctuation of water resource fee has great impacts on the production process. At present, 31 provinces and autonomous regions have collected the water resources fee, but the criteria are quite different and haven’t been adjusted with the social and economic development. In this paper, the factors of social economy and natural environment which affect the water resource fee were analyzed and a fuzzy comprehensive evaluation method was developed to quantify the factors and applied in the calculation of industrial water resource fee in a city of Jiangsu Province. The results suggested that the water resource fee in different area is related to the local environment and economic development. Therefore, the local conditions should be considered in the enactment of the criteria of water resource fee.
40 Development of Fitness Evaluation Model for Rural Safe Drinking Water Project Based on User Demand
2014, 12(4):181-184.
Abstract:
According to the rural safe drinking water projects in Xianyou district of Mianyang city in Sichuan Province, a fitness evaluation model for the safe drinking water projects in the rural areas based on the user demand was established using the methods of factor analysis and analytic hierarchy process (AHP). The weight coefficients of the second-grade indexes with regard to the first-grade indexes were determined by the contribution rate of the common factor extracted from factor analysis, and the. weight coefficients of the third-grade indexes with regard to the second-grade indexes were determined by the subjective weight from AHP and objective weight from factor analysis. The results showed that the reasonableness of water fee standard, the convenience of access to drinking water resource, and the reliability of quality of engineering construction management are the main factors affecting the fitness. The model results were similar to the actual survey results, which suggested that the fitness evaluation model based on the user demand is applicable to guide the evaluation of safe drinking water projects in the rural areas.
According to the rural safe drinking water projects in Xianyou district of Mianyang city in Sichuan Province, a fitness evaluation model for the safe drinking water projects in the rural areas based on the user demand was established using the methods of factor analysis and analytic hierarchy process (AHP). The weight coefficients of the second-grade indexes with regard to the first-grade indexes were determined by the contribution rate of the common factor extracted from factor analysis, and the. weight coefficients of the third-grade indexes with regard to the second-grade indexes were determined by the subjective weight from AHP and objective weight from factor analysis. The results showed that the reasonableness of water fee standard, the convenience of access to drinking water resource, and the reliability of quality of engineering construction management are the main factors affecting the fitness. The model results were similar to the actual survey results, which suggested that the fitness evaluation model based on the user demand is applicable to guide the evaluation of safe drinking water projects in the rural areas.
2014, 12(4):185-188.
Abstract:
Unbalanced bid is a recognized improper way in bids. With the increasing competition of construction market in our country, unbalanced bid often happens for the realization of the bid profitability, which has become an important means of bids for the enterprise. Unbalanced bid has a great influence on the owners. During the process of bidding, the bidder who takes advantage of the unbalanced bid once wins the bidding, which can cause the owners to suffer additional losses. In this paper, according to the unit bidding price and the appropriate evaluation basis, the recognition method of unbalanced bid based on entropy weight and fuzzy comprehensive evaluation was proposed and used to analyze the imbalance of bidding. Application of the method to the case studies suggested that the method is more objective and accurate to analyze the imbalance of biddings of each bidder, which can provide basis for the owners to make decisions.
Unbalanced bid is a recognized improper way in bids. With the increasing competition of construction market in our country, unbalanced bid often happens for the realization of the bid profitability, which has become an important means of bids for the enterprise. Unbalanced bid has a great influence on the owners. During the process of bidding, the bidder who takes advantage of the unbalanced bid once wins the bidding, which can cause the owners to suffer additional losses. In this paper, according to the unit bidding price and the appropriate evaluation basis, the recognition method of unbalanced bid based on entropy weight and fuzzy comprehensive evaluation was proposed and used to analyze the imbalance of bidding. Application of the method to the case studies suggested that the method is more objective and accurate to analyze the imbalance of biddings of each bidder, which can provide basis for the owners to make decisions.
2014, 12(4):189-193.
Abstract:
Low guarantee rate of water supply safety in small towns is caused by of the occurrence of too many water sources, water supply systems, water supply enterprises, and administrative departments. Based on the concept of Hazard Analysis Critical Control Point (HACCP), a real-time control mathematical model of key nodes of water supply was developed. The mathematical model adopted the water yield, water pressure, and water quality of key positions in the water supply system as input data, and compared them with the design values in the water supply system and those presented in the national standard and then assigned appropriate values to them. On one hand, when the sum of assigned values was “0”, it indicated that the critical position is normal. On the other hand, when the sum of assigned values was greater than “1” or equal to “1”, an alert can be reported for the corresponding position. Application of the model on the water supply safety in a small town was analyzed, which suggested that the mathematical model is of important significance to decrease the risks in the process of water production, process, and transfer in the water supply system, and therefore to improve the guarantee rate of water supply safety in small towns.
Low guarantee rate of water supply safety in small towns is caused by of the occurrence of too many water sources, water supply systems, water supply enterprises, and administrative departments. Based on the concept of Hazard Analysis Critical Control Point (HACCP), a real-time control mathematical model of key nodes of water supply was developed. The mathematical model adopted the water yield, water pressure, and water quality of key positions in the water supply system as input data, and compared them with the design values in the water supply system and those presented in the national standard and then assigned appropriate values to them. On one hand, when the sum of assigned values was “0”, it indicated that the critical position is normal. On the other hand, when the sum of assigned values was greater than “1” or equal to “1”, an alert can be reported for the corresponding position. Application of the model on the water supply safety in a small town was analyzed, which suggested that the mathematical model is of important significance to decrease the risks in the process of water production, process, and transfer in the water supply system, and therefore to improve the guarantee rate of water supply safety in small towns.
2014, 12(4):194-197.
Abstract:
The standard difference evolution algorithm is often used to analyze the optimal operation of cascade reservoirs, but with the increasing of melting length, the performance of algorithm solution decreases, the population diversity at late evolution decrease, and thus the algorithm may only determine the local optimal solution. In this study, the parameter of individual difference was defined to perform dynamic control on the scaling factor of difference evolution algorithm, and the parameter of evolution possibility was defined to perform dynamic control on the selection mechanism of the algorithm. Two standard testing functions and optimal operation of the cascade reservoirs were solved using the standard difference evolution algorithm, progressive optimization algorithm, and dynamic difference evolution algorithm. The simulation results indicated that the global searching ability of dynamic difference evolution algorithm increases significantly compared to that of standard difference evolution algorithm
The standard difference evolution algorithm is often used to analyze the optimal operation of cascade reservoirs, but with the increasing of melting length, the performance of algorithm solution decreases, the population diversity at late evolution decrease, and thus the algorithm may only determine the local optimal solution. In this study, the parameter of individual difference was defined to perform dynamic control on the scaling factor of difference evolution algorithm, and the parameter of evolution possibility was defined to perform dynamic control on the selection mechanism of the algorithm. Two standard testing functions and optimal operation of the cascade reservoirs were solved using the standard difference evolution algorithm, progressive optimization algorithm, and dynamic difference evolution algorithm. The simulation results indicated that the global searching ability of dynamic difference evolution algorithm increases significantly compared to that of standard difference evolution algorithm
44 Reduction of Cable Saddle Displacement in Anchorage of Suspension Bridge Using Post Filling Method
2014, 12(4):198-201.
Abstract:
Large displacement can occur in the cable saddle of the anchorage of suspension bridge built on the soft foundation under large pulling force, which can endanger the bridge structure. In order to prevent this, a post filling method with the anchorage of open caisson was proposed. The reverse torque caused by the weight of filling body can balance out the torque produced by the large pulling force, which can compensate and control the displacement in the anchorage. Based on the analysis of the impacts of displacement in the anchorage on horizontal displacement of main tower saddle, the determination method of filling quantity was proposed using the optimization principle. The variation of safety coefficient of anchorage foundation during the post filling process was investigated, which suggested that the construction using post filling method would not decrease the stability of anchorage. Finally, the construction technique of post filling was discussed and an example was introduced for an anchorage of bridge with the post filling method.
Large displacement can occur in the cable saddle of the anchorage of suspension bridge built on the soft foundation under large pulling force, which can endanger the bridge structure. In order to prevent this, a post filling method with the anchorage of open caisson was proposed. The reverse torque caused by the weight of filling body can balance out the torque produced by the large pulling force, which can compensate and control the displacement in the anchorage. Based on the analysis of the impacts of displacement in the anchorage on horizontal displacement of main tower saddle, the determination method of filling quantity was proposed using the optimization principle. The variation of safety coefficient of anchorage foundation during the post filling process was investigated, which suggested that the construction using post filling method would not decrease the stability of anchorage. Finally, the construction technique of post filling was discussed and an example was introduced for an anchorage of bridge with the post filling method.
2014, 12(4):202-204.
Abstract:
In this paper, the structural force status of a pile-anchor retained deep box culvert pit with a large external surface load was simulated using the finite element method. Four retaining schemes were studied, and the force and loading process of the supporting structure under each scheme were compared to investigate the impacts of different stress characteristics on the supporting structure. The results showed that the surface load can cause a large lateral stress on the upper pit, and therefore the first-level cable should be strengthened and set on the pile top, which can effectively limit the displacement and inner force of the pile. The double-row pile did not improve the inner force of the pile, thus it was suggested not to be applied. Moreover, the anchor pile was also not suggested due to that it is weakly constrained and translational displacement occurs with the horizontal pull from the cable force.
In this paper, the structural force status of a pile-anchor retained deep box culvert pit with a large external surface load was simulated using the finite element method. Four retaining schemes were studied, and the force and loading process of the supporting structure under each scheme were compared to investigate the impacts of different stress characteristics on the supporting structure. The results showed that the surface load can cause a large lateral stress on the upper pit, and therefore the first-level cable should be strengthened and set on the pile top, which can effectively limit the displacement and inner force of the pile. The double-row pile did not improve the inner force of the pile, thus it was suggested not to be applied. Moreover, the anchor pile was also not suggested due to that it is weakly constrained and translational displacement occurs with the horizontal pull from the cable force.
2014, 12(4):205-208.
Abstract:
Reasonable fertilization is an important measure to achieve the objectives of high and stable production, low cost, and environmental protection. In this paper, an experimental study was conducted to compare and analyze the application amounts of nitrogen, phosphate, and potash fertilizers in the demonstration area of water saving transformation of Shijin irrigation area in Hebei province, which was used to determine the relationship between the application amount of fertilizer and yield of winter wheat. The results suggested that in order to ensure the yield of winter wheat above 6750 kg/hm2, the reasonable application amount is 210 kg/hm2 for nitrogen fertilizer (net quantity), 45～75 kg/hm2 for phosphate fertilizer (P2O5),and 22.5～45kg/hm2 for potash fertilizer (K2O) when the other conditions are relatively stable.
Reasonable fertilization is an important measure to achieve the objectives of high and stable production, low cost, and environmental protection. In this paper, an experimental study was conducted to compare and analyze the application amounts of nitrogen, phosphate, and potash fertilizers in the demonstration area of water saving transformation of Shijin irrigation area in Hebei province, which was used to determine the relationship between the application amount of fertilizer and yield of winter wheat. The results suggested that in order to ensure the yield of winter wheat above 6750 kg/hm2, the reasonable application amount is 210 kg/hm2 for nitrogen fertilizer (net quantity), 45～75 kg/hm2 for phosphate fertilizer (P2O5),and 22.5～45kg/hm2 for potash fertilizer (K2O) when the other conditions are relatively stable.
2014, 12(4):209-212.
Abstract:
Reservoir sedimentation affects the reservoir benefits and threatens the reservoir life. Based on the basic equations of the hydrodynamic and sediment mathematical model and under certain assumptions, the one-dimensional model of non-uniform flow and non-equilibrium sediment transport model was simplified, and the model parameters were calibrated and verified using the observed data of the reservoir. In this paper, the model was applied to Yayangshan Reservoir and verified the parameter feasibility according to the measured data in the reservoir, which can provide reference for the sedimentation calculation of the Yayangshan Reservoir in future.
Reservoir sedimentation affects the reservoir benefits and threatens the reservoir life. Based on the basic equations of the hydrodynamic and sediment mathematical model and under certain assumptions, the one-dimensional model of non-uniform flow and non-equilibrium sediment transport model was simplified, and the model parameters were calibrated and verified using the observed data of the reservoir. In this paper, the model was applied to Yayangshan Reservoir and verified the parameter feasibility according to the measured data in the reservoir, which can provide reference for the sedimentation calculation of the Yayangshan Reservoir in future.
2014, 12(4):213-216.
Abstract:
Based on the synchronous observation results of the 20 m2 evaporation pool and E601 type evaporator at the Hengshui experiment station, the conversion coefficients of the two instruments were calculated. According to the observation data of E601 type evaporator in the Zhuzhuang reservoir, the amount of water surface evaporation in the reservoir was calculated. Based on the evaporation data and reservoir conditions from 2000 to 2010, the average annual evaporation in the Zhuzhang reservoir was calculated as 794.38×104 m3 and the evaporation per unit area was 85.60×104 m3/km2. The maximum monthly average evaporation, 106.30×104 m3, occurred in May, while the minimum monthly average evaporation, 12.96×104 m3, occurred in January. The extreme ratio of variation within a year was 8.20, and the extreme difference was 93.34×104 m3.
Based on the synchronous observation results of the 20 m2 evaporation pool and E601 type evaporator at the Hengshui experiment station, the conversion coefficients of the two instruments were calculated. According to the observation data of E601 type evaporator in the Zhuzhuang reservoir, the amount of water surface evaporation in the reservoir was calculated. Based on the evaporation data and reservoir conditions from 2000 to 2010, the average annual evaporation in the Zhuzhang reservoir was calculated as 794.38×104 m3 and the evaporation per unit area was 85.60×104 m3/km2. The maximum monthly average evaporation, 106.30×104 m3, occurred in May, while the minimum monthly average evaporation, 12.96×104 m3, occurred in January. The extreme ratio of variation within a year was 8.20, and the extreme difference was 93.34×104 m3.
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