Volume 14,Issue 4,2016 Table of Contents
2016, 14(4):1-7.
Abstract:
By collecting groundwater table data of shallow aquifer of each province in Haihe plain and applying ARCGIS technique, the groundwater table contours in the end of year 1959, 1984, 2005 to 2013 were plotted. The results were checked by independent data sources and proved reliable. Then the quantity of the excess pumping of groundwater was estimated according to the depression cone and specific yield of aquifer. The results showed that cumulative over-exploitation of shallow groundwater aquifer of the Haihe plain was 979.45×108 m3 in 1959~2013，the average water table lowered by 10.99 m. Temporally, the annual over-exploitation was 16.34×108 m3 and the cumulative average water table lowered by totally 3.93 m, the annual average water table lowered by 0.141 m in 1959~1984; and 21.21×108 m3 and 6.28 m, 0.299 m respectively in 1984~2005; 15.67×108 m3 and 1.05 m, 0.131 m in 2005~2013. It should be noted that over-exploitation of groundwater in Haihe plain mainly occurred in the period from 1984 to 2005, and the over-pumping has been controlled effectively in recent years. Spatially, the depression cone was located mainly in cities which are in sub mountain region and consume relatively more groundwater, especially in Shijiazhuang city and Xingtai city in the west of the Ziyahe plane.
By collecting groundwater table data of shallow aquifer of each province in Haihe plain and applying ARCGIS technique, the groundwater table contours in the end of year 1959, 1984, 2005 to 2013 were plotted. The results were checked by independent data sources and proved reliable. Then the quantity of the excess pumping of groundwater was estimated according to the depression cone and specific yield of aquifer. The results showed that cumulative over-exploitation of shallow groundwater aquifer of the Haihe plain was 979.45×108 m3 in 1959~2013，the average water table lowered by 10.99 m. Temporally, the annual over-exploitation was 16.34×108 m3 and the cumulative average water table lowered by totally 3.93 m, the annual average water table lowered by 0.141 m in 1959~1984; and 21.21×108 m3 and 6.28 m, 0.299 m respectively in 1984~2005; 15.67×108 m3 and 1.05 m, 0.131 m in 2005~2013. It should be noted that over-exploitation of groundwater in Haihe plain mainly occurred in the period from 1984 to 2005, and the over-pumping has been controlled effectively in recent years. Spatially, the depression cone was located mainly in cities which are in sub mountain region and consume relatively more groundwater, especially in Shijiazhuang city and Xingtai city in the west of the Ziyahe plane.
2016, 14(4):8-13.
Abstract:
Baseflow is an important part of the evaluation of groundwater resources, the baseflow calculation has been a fundamental problem of hydrology. Using the 1958-1988 and 2006-2014 years of daily runoff data of Qilinzui Hydrological Station on the downstream of Zengjiang River, according to the advantages and disadvantages of various methods of baseflow separation, and Zengjiang’s hydrogeological conditions and runoff variation characteristics, first Kalinin trial method was used to calculate the baseflow of this region, and the effects of subjective factors on the baseflow calculation result in the application of this method was studied in depth. The results showed that the parameter selection was very important for the Kalinin trial method on the baseflow segmentation. Assuming that the selection of recession coefficient was in line with uniform distribution, the corresponding coefficient scale factor B obtained by the recession coefficient would not be uniformly distributed. Baseflow was calculated based on the two parameters. Without considering the influence of subjective factors, the multi-year baseflow of Zengjiang River had an average of 7.8 billion cubic meters for many years. Under the influence of subjective factors, the 95% confidence interval was 6.68-8.72 billion cubic. The direct calculation result was within this confidence interval, and the corresponding assurance rate was 41%. Therefore, considering the subjective uncertainty in baseflow calculation could not only be used to check the calculation results, but also put forward the reliability of the calculation results at the same time, which will provide important basis for decision making of groundwater resources management.
Baseflow is an important part of the evaluation of groundwater resources, the baseflow calculation has been a fundamental problem of hydrology. Using the 1958-1988 and 2006-2014 years of daily runoff data of Qilinzui Hydrological Station on the downstream of Zengjiang River, according to the advantages and disadvantages of various methods of baseflow separation, and Zengjiang’s hydrogeological conditions and runoff variation characteristics, first Kalinin trial method was used to calculate the baseflow of this region, and the effects of subjective factors on the baseflow calculation result in the application of this method was studied in depth. The results showed that the parameter selection was very important for the Kalinin trial method on the baseflow segmentation. Assuming that the selection of recession coefficient was in line with uniform distribution, the corresponding coefficient scale factor B obtained by the recession coefficient would not be uniformly distributed. Baseflow was calculated based on the two parameters. Without considering the influence of subjective factors, the multi-year baseflow of Zengjiang River had an average of 7.8 billion cubic meters for many years. Under the influence of subjective factors, the 95% confidence interval was 6.68-8.72 billion cubic. The direct calculation result was within this confidence interval, and the corresponding assurance rate was 41%. Therefore, considering the subjective uncertainty in baseflow calculation could not only be used to check the calculation results, but also put forward the reliability of the calculation results at the same time, which will provide important basis for decision making of groundwater resources management.
2016, 14(4):14-20.
Abstract:
In order to simulate the flood wave propagation through the breaches，a two-dimensional hydrodynamic model was developed. Roe method of unstructured mesh was used to solve the 2D model. Based on the actual characteristics such as linear features in the flood protected zone，ways and irrigation ditches were generalized to broad crested weir for calculation and endowed real height，considering it as special border and coupled unstructured mesh. Using the Natural Neighbor Interpolation， separated interpolation was conducted between protected zone and aqueduct，and terrain of aqueduct in the area was recovered，and model with real terrain was obtained through the above methods. The model was applied to the case of Qingtongxia West Irrigation of Yellow River on Sipaikou，effectively simulated water blocking of special border such as ways and irrigation ditches and water flow of bridge culverts，and the effect of drain in the aqueduct and intrusion in the estuary，and truly simulated the flood wave propagation and inundation area of flood in calculation area，thus the paper has bright application value.
In order to simulate the flood wave propagation through the breaches，a two-dimensional hydrodynamic model was developed. Roe method of unstructured mesh was used to solve the 2D model. Based on the actual characteristics such as linear features in the flood protected zone，ways and irrigation ditches were generalized to broad crested weir for calculation and endowed real height，considering it as special border and coupled unstructured mesh. Using the Natural Neighbor Interpolation， separated interpolation was conducted between protected zone and aqueduct，and terrain of aqueduct in the area was recovered，and model with real terrain was obtained through the above methods. The model was applied to the case of Qingtongxia West Irrigation of Yellow River on Sipaikou，effectively simulated water blocking of special border such as ways and irrigation ditches and water flow of bridge culverts，and the effect of drain in the aqueduct and intrusion in the estuary，and truly simulated the flood wave propagation and inundation area of flood in calculation area，thus the paper has bright application value.
4 Spatial-temporal variation characteristics of China terrestrial water storage in the last ten years
2016, 14(4):21-28.
Abstract:
Water storage change trend, annual change characteristics, intra-year distribution characteristics and spatial-temporal variation characteristics of China and the ten main basins in the last ten years were analyzed using the GRACE (Gravity Recovery and Climate Experiment) data. The relationship between total water storage and precipitation was analyzed by combining the TRMM (Tropical Rainfall Measuring Mission) precipitation data. The results were as follows: In the last ten years, China water storage trend showed some different characteristics. Most of China southwest part, North China Plain and the middle and lower reaches of Yellow River, the Junggar Basin of northwest China all showed a decrease in water storage. Meanwhile, southeast of China, most part of Yangtze River Basin, the origin area of Yellow and Yangtze River and Tarim Basin showed an increase. The annual change range of China water storage was very narrow. The annual change ranges of Huaihe, Haihe, Pearl, Songhuajiang river basins were wide and that of Northwest river basin was the narrowest. The water storage annual change in most of river basins had a significant positive correlation with the precipitation change except Yellow River Basin, Haihe Basin and northwest river basins. The correlation coefficients of southeast river basins, Pearl Basin and Yangtze River Basin were more than 0.7. In intra-annual distribution, China water storage was lack in winter and spring, and adequate in summer and autumn. Southwest river basins and Yangtze River Basin showed a severe deficiency in March and April, and showed more surplus from July to September. North China Plain showed a deficiency from May to July and showed a surplus in other months. Yellow River Basin, Yangtze River Basin, southeast river basins, southwest river basins and Pearl Basin showed a good consistence in intra-annual water storage and precipitation. Northwest river basins showed a good consistence except in the period of February to April. The other basins showed a bad consistence.
Water storage change trend, annual change characteristics, intra-year distribution characteristics and spatial-temporal variation characteristics of China and the ten main basins in the last ten years were analyzed using the GRACE (Gravity Recovery and Climate Experiment) data. The relationship between total water storage and precipitation was analyzed by combining the TRMM (Tropical Rainfall Measuring Mission) precipitation data. The results were as follows: In the last ten years, China water storage trend showed some different characteristics. Most of China southwest part, North China Plain and the middle and lower reaches of Yellow River, the Junggar Basin of northwest China all showed a decrease in water storage. Meanwhile, southeast of China, most part of Yangtze River Basin, the origin area of Yellow and Yangtze River and Tarim Basin showed an increase. The annual change range of China water storage was very narrow. The annual change ranges of Huaihe, Haihe, Pearl, Songhuajiang river basins were wide and that of Northwest river basin was the narrowest. The water storage annual change in most of river basins had a significant positive correlation with the precipitation change except Yellow River Basin, Haihe Basin and northwest river basins. The correlation coefficients of southeast river basins, Pearl Basin and Yangtze River Basin were more than 0.7. In intra-annual distribution, China water storage was lack in winter and spring, and adequate in summer and autumn. Southwest river basins and Yangtze River Basin showed a severe deficiency in March and April, and showed more surplus from July to September. North China Plain showed a deficiency from May to July and showed a surplus in other months. Yellow River Basin, Yangtze River Basin, southeast river basins, southwest river basins and Pearl Basin showed a good consistence in intra-annual water storage and precipitation. Northwest river basins showed a good consistence except in the period of February to April. The other basins showed a bad consistence.
2016, 14(4):29-35.
Abstract:
The synergetic method of dry season operation of cascade reservoirs is an important part of the joint operation of cascade reservoirs. A research was carried out in the background of the cascade reservoirs including Xiluodu, Xiangjiaba, Three Gorges and Gezhouba. The runoff in dry season was separated into three groups including high hydrological years, normal hydrological years and low hydrological years. A stochastic optimal dispatching model for cascaded reservoirs in dry season was established taking the maximum mathematical expectation of generated energy in each group as the object. A calculation was carried out considering the different water levels at the beginning of dry season and the synergetic schemes of different hydrological years were obtained. The result showed that the synergetic method of dry season operation in Three Gorges cascade reservoirs coulf increase overall generated energy in some degree. The water supply benefit was great under the condition that the inflow was low and the beginning water level of Three Gorges was low. At last, the synergetic strategy of dry season operation of Xiluodu- Three Gorges cascade reservoirs was summed up to guide the practical operation of the downstream Jinsha River and Three Gorges cascade reservoirs.
The synergetic method of dry season operation of cascade reservoirs is an important part of the joint operation of cascade reservoirs. A research was carried out in the background of the cascade reservoirs including Xiluodu, Xiangjiaba, Three Gorges and Gezhouba. The runoff in dry season was separated into three groups including high hydrological years, normal hydrological years and low hydrological years. A stochastic optimal dispatching model for cascaded reservoirs in dry season was established taking the maximum mathematical expectation of generated energy in each group as the object. A calculation was carried out considering the different water levels at the beginning of dry season and the synergetic schemes of different hydrological years were obtained. The result showed that the synergetic method of dry season operation in Three Gorges cascade reservoirs coulf increase overall generated energy in some degree. The water supply benefit was great under the condition that the inflow was low and the beginning water level of Three Gorges was low. At last, the synergetic strategy of dry season operation of Xiluodu- Three Gorges cascade reservoirs was summed up to guide the practical operation of the downstream Jinsha River and Three Gorges cascade reservoirs.
2016, 14(4):36-41.
Abstract:
After the identification of the hydrogeological conditions and the environmental geological problems caused by groundwater exploitation，the water-balance and numerical simulation methods were used to evaluate the amount of groundwater in Linhe district of Bayan Nur City, Inner Mongolia. A model was utilized to simulate the change of groundwater flow field in the study area from 2013 to 2033 according to the local water resources exploration and utility scenario, and the results showed that the groundwater drawdown funnel will cease to expand and the groundwater level will rise. This provides a meaningful guidance for the water resources management in the study area.
After the identification of the hydrogeological conditions and the environmental geological problems caused by groundwater exploitation，the water-balance and numerical simulation methods were used to evaluate the amount of groundwater in Linhe district of Bayan Nur City, Inner Mongolia. A model was utilized to simulate the change of groundwater flow field in the study area from 2013 to 2033 according to the local water resources exploration and utility scenario, and the results showed that the groundwater drawdown funnel will cease to expand and the groundwater level will rise. This provides a meaningful guidance for the water resources management in the study area.
2016, 14(4):42-47.
Abstract:
Base on the daily temperature data of 34 meteorological stations in the Yangtze River Delta region during 1960~2012, by using trend analysis, wavelet analysis, Mann-Kendall test, and spline interpolation method, the temporal and spatial variation characteristics of extreme temperature in Yangtze River Delta were analyzed. The results showed that: in recent 53 years, cold index showed a significantly upward trend, and passed the 0.01 reliability test, with the climate tendency rate of -2.8d/10a, -4.1d/10a and 0.45℃/10a, respectively. The warm index had a rising trend but the trend was not significant, only warm day index and the extreme maximum temperature passed the 0.05 reliability test. From a spatial distribution perspective, the number of high temperature days and the extreme maximum temperature showed the distribution rules of north low and south high, east low and west high, and coastal low and inland high. Low temperature days and extreme minimum temperature were contrary. From a change trend perspective, extreme temperature index showed a rising trend, and the most obvious upward trend areas of the extreme low and extreme high temperature were Shanghai, Nanjing, Hangzhou and other large cities and surrounding areas.
Base on the daily temperature data of 34 meteorological stations in the Yangtze River Delta region during 1960~2012, by using trend analysis, wavelet analysis, Mann-Kendall test, and spline interpolation method, the temporal and spatial variation characteristics of extreme temperature in Yangtze River Delta were analyzed. The results showed that: in recent 53 years, cold index showed a significantly upward trend, and passed the 0.01 reliability test, with the climate tendency rate of -2.8d/10a, -4.1d/10a and 0.45℃/10a, respectively. The warm index had a rising trend but the trend was not significant, only warm day index and the extreme maximum temperature passed the 0.05 reliability test. From a spatial distribution perspective, the number of high temperature days and the extreme maximum temperature showed the distribution rules of north low and south high, east low and west high, and coastal low and inland high. Low temperature days and extreme minimum temperature were contrary. From a change trend perspective, extreme temperature index showed a rising trend, and the most obvious upward trend areas of the extreme low and extreme high temperature were Shanghai, Nanjing, Hangzhou and other large cities and surrounding areas.
2016, 14(4):48-53.
Abstract:
Decision makers usually face decision-making difficulties on Pareto feasible solutions generated by reservoir multi-objective operation model. To solve this problem, visualization tool together with marginal benefit analysis and fuzzy optimization method were proposed for gradual optimization of feasible solution set. The results showed that, by using different analysis tools and decision methods, feasible solutions received visual representation meanwhile some of the decision preference information was integrated to obtain the satisfactory solutions for different decision-making demands. By using different decision methods, the number of alternative solutions was reduced gradually to make the problem less complex. This paper can provide some references for multi-objective solution selection problem for decision makers.
Decision makers usually face decision-making difficulties on Pareto feasible solutions generated by reservoir multi-objective operation model. To solve this problem, visualization tool together with marginal benefit analysis and fuzzy optimization method were proposed for gradual optimization of feasible solution set. The results showed that, by using different analysis tools and decision methods, feasible solutions received visual representation meanwhile some of the decision preference information was integrated to obtain the satisfactory solutions for different decision-making demands. By using different decision methods, the number of alternative solutions was reduced gradually to make the problem less complex. This paper can provide some references for multi-objective solution selection problem for decision makers.
2016, 14(4):54-59.
Abstract:
By improving the hydrological parameterization schemes of the land surface model (CLM3.5) using the Distributed Time Variant Gain Model（DTVGM) which was developed independently, embedding a module which reflects the impact of groundwater exploitation on water cycle process, considering domestic water, industrial water and ecological water，a large-scale land water cycle model was developed which could describe the nature and human process of a basin. The Haihe River Basin where groundwater is extracted seriously was chosen as the study area, using high spatial and temporal resolution meteorological element data sets of China established by the Institute of Tibetan Plateau as atmospheric forcing drivers, this paper conducted simulation test for the water cycle process in 1980-2010 in the Haihe River Basin, and analyzed the impacts of groundwater exploitation activities on the water cycle process. The results showed that: groundwater exploitation caused the decrease in runoff and soil moisture in the overall basin; the evapotranspiration in the overall basin increased, and the spatial variation of water cycle elements was large.
By improving the hydrological parameterization schemes of the land surface model (CLM3.5) using the Distributed Time Variant Gain Model（DTVGM) which was developed independently, embedding a module which reflects the impact of groundwater exploitation on water cycle process, considering domestic water, industrial water and ecological water，a large-scale land water cycle model was developed which could describe the nature and human process of a basin. The Haihe River Basin where groundwater is extracted seriously was chosen as the study area, using high spatial and temporal resolution meteorological element data sets of China established by the Institute of Tibetan Plateau as atmospheric forcing drivers, this paper conducted simulation test for the water cycle process in 1980-2010 in the Haihe River Basin, and analyzed the impacts of groundwater exploitation activities on the water cycle process. The results showed that: groundwater exploitation caused the decrease in runoff and soil moisture in the overall basin; the evapotranspiration in the overall basin increased, and the spatial variation of water cycle elements was large.
2016, 14(4):60-64.
Abstract:
Based on the annual runoff and precipitation data of Jinghe Hydrological Station from 1964 to 2012 in Jinghe River，the paper studied the changing trend and multi-time scale correlation between the annual runoff and precipitation by using the methods of Mann-Kendall test, cross-wavelet test and double mass curve, and the effects of the precipitation change on runoff was also quantitatively analyzed. The results showed that runoff increased insignificantly and precipitation increased significantly, respectively. The multi time scale correlativity was significant between the annual runoff and precipitation in Jinghe River, which was dominated by positive correlation. The significantly correlated regions were the 2-4-year periods during 1986-1991, the 7-year periods during 1985-1990, and the 4-5-year periods during 2002-2011. The result of double mass analysis showed that the increases of runoff in JingheRiver was mainly attributed to precipitation change, and its contribution was 68.4%.
Based on the annual runoff and precipitation data of Jinghe Hydrological Station from 1964 to 2012 in Jinghe River，the paper studied the changing trend and multi-time scale correlation between the annual runoff and precipitation by using the methods of Mann-Kendall test, cross-wavelet test and double mass curve, and the effects of the precipitation change on runoff was also quantitatively analyzed. The results showed that runoff increased insignificantly and precipitation increased significantly, respectively. The multi time scale correlativity was significant between the annual runoff and precipitation in Jinghe River, which was dominated by positive correlation. The significantly correlated regions were the 2-4-year periods during 1986-1991, the 7-year periods during 1985-1990, and the 4-5-year periods during 2002-2011. The result of double mass analysis showed that the increases of runoff in JingheRiver was mainly attributed to precipitation change, and its contribution was 68.4%.
2016, 14(4):65-71.
Abstract:
Study on the characteristics of precipitation and its temporal and spatial evolution is of an important guiding significance for the development and utilization of water resources in the basin. Based on the precipitation data (1960-2014) from 80 meteorological stations in upper reaches of the Yangtze River, we studied the characteristics of precipitation. Besides, the temporal and spatial evolution was analyzed by drawing the spatial distribution map and using Mann-Kendall test, Pettitt test, Morlet wavelet analysis method. The results showed that, during 1960 to 2014, the mean annual precipitation depth of upper reaches of the Yangtze River was 900.8 mm and the mean annual precipitation volume was 8925.1 m3, the annual variation of precipitation was great, the ratio of extreme annual precipitation was 1.5 and reached 3.9 in winter, monthly and the seasonal mean precipitation was very uneven, and the precipitation in flood season accounted for more than 80%; spatially, precipitation was large in southeast and small in northwest; temporally, significant negative trend was detected in annual precipitation in upper reaches of the Yangtze River, and the abrupt change took place in 1985, the primary period of precipitation in upper reaches of the Yangtze River was 28a, 13a, 8a in the descending order of strength, and the period of precipitation in the partitions was mainly 28a.
Study on the characteristics of precipitation and its temporal and spatial evolution is of an important guiding significance for the development and utilization of water resources in the basin. Based on the precipitation data (1960-2014) from 80 meteorological stations in upper reaches of the Yangtze River, we studied the characteristics of precipitation. Besides, the temporal and spatial evolution was analyzed by drawing the spatial distribution map and using Mann-Kendall test, Pettitt test, Morlet wavelet analysis method. The results showed that, during 1960 to 2014, the mean annual precipitation depth of upper reaches of the Yangtze River was 900.8 mm and the mean annual precipitation volume was 8925.1 m3, the annual variation of precipitation was great, the ratio of extreme annual precipitation was 1.5 and reached 3.9 in winter, monthly and the seasonal mean precipitation was very uneven, and the precipitation in flood season accounted for more than 80%; spatially, precipitation was large in southeast and small in northwest; temporally, significant negative trend was detected in annual precipitation in upper reaches of the Yangtze River, and the abrupt change took place in 1985, the primary period of precipitation in upper reaches of the Yangtze River was 28a, 13a, 8a in the descending order of strength, and the period of precipitation in the partitions was mainly 28a.
2016, 14(4):72-76.
Abstract:
The middle and lower reaches of the Yangtze River are important production bases of grains, cotton and oil crops in China, where droughts and floods occur frequently, which often result in the reduction of crop output. In this paper, based on the monthly meteorological data of 72 meteorological stations in the Yangtze River region, the temporal and spatial variation in droughts and floods of the Yangtze River region in near 50 years was analyzed using standardized precipitation index (SPI), empirical orthogonal function (EOF), and geo-statistical analysis combined with GIS technology. The results showed that the spatial distribution pattern of droughts and floods SPI3 in the Yangtze River region was almost the same in the whole region, but there was a difference in the south-north direction. Due to the climate, droughts and floods in Yangtze River region appeared alternately in summer and autumn, and the flood disaster occurred mainly in the critical period of growth and development of crop.
The middle and lower reaches of the Yangtze River are important production bases of grains, cotton and oil crops in China, where droughts and floods occur frequently, which often result in the reduction of crop output. In this paper, based on the monthly meteorological data of 72 meteorological stations in the Yangtze River region, the temporal and spatial variation in droughts and floods of the Yangtze River region in near 50 years was analyzed using standardized precipitation index (SPI), empirical orthogonal function (EOF), and geo-statistical analysis combined with GIS technology. The results showed that the spatial distribution pattern of droughts and floods SPI3 in the Yangtze River region was almost the same in the whole region, but there was a difference in the south-north direction. Due to the climate, droughts and floods in Yangtze River region appeared alternately in summer and autumn, and the flood disaster occurred mainly in the critical period of growth and development of crop.
13 Evolution of interconnected river and lake networks in the Huai River Basin over the last millennium
2016, 14(4):77-83.
Abstract:
In this study, the natural evolution and human disturbance of interconnected river system networks in the nearly one the thousand years in Huai River Basin were analyzed, and the causes were discussed. Furthermore, some urgent resolved scientific questions were proposed. The results showed that: the current interconnected river system was the integrated flooding control, drainage, irrigation, and water supply system which was formed during the long-term struggling against the flooding and sediment of Yellow River. It obeyed the natural rules and considered the development of soc-economy. The main rivers and tributaries were regulated by human activites, the natural-artificial river networks were anastomatic, the water exchange between rivers and lakes was frequent, and the sea-entryway and Yangtze-entryway was straightway, the river systems were interconnected with Yellow River, Yangtze River and Hai River. The interconnected river system networks pattern resolved the problems that the flooding had no way to sea and the floods happened frequently. The river system networks promoted the economy development and the society unity in Huai River Basin, but also brought a certain negative impact on ecosystem and environment. The studies on the water resource variation, the eco-environmental and soc-economic pattern influences under the impact of interconnected river system were some urgent resolved scientific questions in current interconnected river system networks.
In this study, the natural evolution and human disturbance of interconnected river system networks in the nearly one the thousand years in Huai River Basin were analyzed, and the causes were discussed. Furthermore, some urgent resolved scientific questions were proposed. The results showed that: the current interconnected river system was the integrated flooding control, drainage, irrigation, and water supply system which was formed during the long-term struggling against the flooding and sediment of Yellow River. It obeyed the natural rules and considered the development of soc-economy. The main rivers and tributaries were regulated by human activites, the natural-artificial river networks were anastomatic, the water exchange between rivers and lakes was frequent, and the sea-entryway and Yangtze-entryway was straightway, the river systems were interconnected with Yellow River, Yangtze River and Hai River. The interconnected river system networks pattern resolved the problems that the flooding had no way to sea and the floods happened frequently. The river system networks promoted the economy development and the society unity in Huai River Basin, but also brought a certain negative impact on ecosystem and environment. The studies on the water resource variation, the eco-environmental and soc-economic pattern influences under the impact of interconnected river system were some urgent resolved scientific questions in current interconnected river system networks.
2016, 14(4):84-90.
Abstract:
The research on reservoir ecological operation is a hotspot problem in the current river ecological restoration research. The connotation of reservoir ecological operation is introduced firstly. Based on the concept of reservoir ecological operation, the domestic and foreign research advance of reservoir ecological operation is reviewed. Aiming at the main existent problems in this field, the future development trend of reservoir ecological operation research is put forward. It is suggested that the further study of reservoir ecological operation should be emphasized on aspects of the theoretical framework system, quantitative objectives of ecological operation, multi-objective optimization and simulation technology, effect evaluation of operation schemes and the management system of reservoir ecological operation. It provides the reference for carrying out multi-objective ecological operation of reservoirs in the future.
The research on reservoir ecological operation is a hotspot problem in the current river ecological restoration research. The connotation of reservoir ecological operation is introduced firstly. Based on the concept of reservoir ecological operation, the domestic and foreign research advance of reservoir ecological operation is reviewed. Aiming at the main existent problems in this field, the future development trend of reservoir ecological operation research is put forward. It is suggested that the further study of reservoir ecological operation should be emphasized on aspects of the theoretical framework system, quantitative objectives of ecological operation, multi-objective optimization and simulation technology, effect evaluation of operation schemes and the management system of reservoir ecological operation. It provides the reference for carrying out multi-objective ecological operation of reservoirs in the future.
2016, 14(4):91-98.
Abstract:
The municipal domestic sewage was treated by a membrane bioreactor-reverse osmosis (MBR-RO) combined process. The SDI of MBR effluent was between 2.5 and 3.5, which met the demand of RO influent, and the fouling of RO membrane could be controlled after adding 10 mg/L of the antisludging agent. The product water quality of MBR-RO was good, and NH4+-N, NO2--N, TP and TOC concentrations of the effluent were respectively 0.15 mg/L, 2.82 mg/L, 0.12 mg/L and 0.51 mg/L, and the concentrations of CODMn and NO2--N were below 0.05 mg/L and 0.7 mg/L respectively in MBR-RO. According to the 73 major indexes in the national drinking water sanitary standard, the effluent could meet the drinking water quality. The result showed that MBR-RO combined process for direct potable reuse water production is feasible.
The municipal domestic sewage was treated by a membrane bioreactor-reverse osmosis (MBR-RO) combined process. The SDI of MBR effluent was between 2.5 and 3.5, which met the demand of RO influent, and the fouling of RO membrane could be controlled after adding 10 mg/L of the antisludging agent. The product water quality of MBR-RO was good, and NH4+-N, NO2--N, TP and TOC concentrations of the effluent were respectively 0.15 mg/L, 2.82 mg/L, 0.12 mg/L and 0.51 mg/L, and the concentrations of CODMn and NO2--N were below 0.05 mg/L and 0.7 mg/L respectively in MBR-RO. According to the 73 major indexes in the national drinking water sanitary standard, the effluent could meet the drinking water quality. The result showed that MBR-RO combined process for direct potable reuse water production is feasible.
2016, 14(4):99-106.
Abstract:
Relatively detailed environmental units of shallow groundwater were divided in the Guanzhong Basin on the basis of the intensive study of groundwater flow field, recharge and discharge conditions and groundwater environment. Natural background levels of K++Na+,Ca2+,Mg2+,Cl-,SO42-,HCO3-,TDS of different units were calculated by using the iterative 2-σ technique, the calculated distribution function, and the spatial distribution regularity of background levels for major components as well as its controlling factors were discussed on the basis of 487 groundwater samples collected from the Guanzhong Basin. The results indicated that the spatial distribution of the major components was mainly controlled by groundwater recharge, runoff, discharge and hydrogeochemical process, in which the anion in the area was mainly HCO3-, the cation in the north shore of Weihe was mainly K++Na+ while in the south shore of Weihe was mainly Ca2+; moreover, the hydrogeochemical process in the northern area of Weihe was mainly mineralization and evaporation, and in the southern area of Weihe was mainly lixiviation. The results obtained provide scientific reference for the evaluation of groundwater contamination and the future development and protection of water resources.
Relatively detailed environmental units of shallow groundwater were divided in the Guanzhong Basin on the basis of the intensive study of groundwater flow field, recharge and discharge conditions and groundwater environment. Natural background levels of K++Na+,Ca2+,Mg2+,Cl-,SO42-,HCO3-,TDS of different units were calculated by using the iterative 2-σ technique, the calculated distribution function, and the spatial distribution regularity of background levels for major components as well as its controlling factors were discussed on the basis of 487 groundwater samples collected from the Guanzhong Basin. The results indicated that the spatial distribution of the major components was mainly controlled by groundwater recharge, runoff, discharge and hydrogeochemical process, in which the anion in the area was mainly HCO3-, the cation in the north shore of Weihe was mainly K++Na+ while in the south shore of Weihe was mainly Ca2+; moreover, the hydrogeochemical process in the northern area of Weihe was mainly mineralization and evaporation, and in the southern area of Weihe was mainly lixiviation. The results obtained provide scientific reference for the evaluation of groundwater contamination and the future development and protection of water resources.
2016, 14(4):107-111.
Abstract:
Using the Graphic method, Grubbs test, Shapiro-Wilk method etc, this paper analyzed the hydrochemical characteristics of groundwater and then calculated the environment background values. The results showed that the main cations of the plain area of Yili River were Ca2+ and Mg2+, and the main anion was HCO3-. HCO3-Ca, HCO3-Ca-Mg, and HCO3-SO4-Ca-Mg were the main hydrochemical types of groundwater. The chemical composition of the groundwater in this area was mainly related to leaching effect, cation exchange and adsorption, but also depended on human activities. The study is of great importance to the groundwater environmental impact analysis and prediction, judgment of environmental pollution and quality assessment, reasonable exploitation and utilization of groundwater resources.
Using the Graphic method, Grubbs test, Shapiro-Wilk method etc, this paper analyzed the hydrochemical characteristics of groundwater and then calculated the environment background values. The results showed that the main cations of the plain area of Yili River were Ca2+ and Mg2+, and the main anion was HCO3-. HCO3-Ca, HCO3-Ca-Mg, and HCO3-SO4-Ca-Mg were the main hydrochemical types of groundwater. The chemical composition of the groundwater in this area was mainly related to leaching effect, cation exchange and adsorption, but also depended on human activities. The study is of great importance to the groundwater environmental impact analysis and prediction, judgment of environmental pollution and quality assessment, reasonable exploitation and utilization of groundwater resources.
2016, 14(4):112-116.
Abstract:
To study the effects of root structure on the ability of oxygen release from the root systems of plants(expressed by root oxygen release rate and sensibility of root oxygen release rate to dynamic water level), four different wetland plants were used(Acorus calamus Linn, Thalia dealbata, Typha orientalis Presl , Phragmites australis).The root oxygen release rates in five different water levels were measured using titanium citrate buffer. Standard deviation was also used to illustrate the sensibility to dynamic water level of different wetland plants. In addition, root porosity was measured by pycnometer method and root structure was observed by microscope. The results showed that the root oxygen release rate of these wetland plants decreased in the following order as a whole: Typha> Phragmites> Thalia> Acorus. The sensibility of root oxygen release rate to dynamic water level decreased in the following order: Typha> Phragmites> Acorus > Thalia. Moreover, it was found that more developed Aerenchyma and less oxygen barrier may have positive relationship with the ability of root oxygen release. The more sensitive to the release rate of the plant root system, the more sensitive to the change of water level.
To study the effects of root structure on the ability of oxygen release from the root systems of plants(expressed by root oxygen release rate and sensibility of root oxygen release rate to dynamic water level), four different wetland plants were used(Acorus calamus Linn, Thalia dealbata, Typha orientalis Presl , Phragmites australis).The root oxygen release rates in five different water levels were measured using titanium citrate buffer. Standard deviation was also used to illustrate the sensibility to dynamic water level of different wetland plants. In addition, root porosity was measured by pycnometer method and root structure was observed by microscope. The results showed that the root oxygen release rate of these wetland plants decreased in the following order as a whole: Typha> Phragmites> Thalia> Acorus. The sensibility of root oxygen release rate to dynamic water level decreased in the following order: Typha> Phragmites> Acorus > Thalia. Moreover, it was found that more developed Aerenchyma and less oxygen barrier may have positive relationship with the ability of root oxygen release. The more sensitive to the release rate of the plant root system, the more sensitive to the change of water level.
2016, 14(4):117-122.
Abstract:
Stand density imposed the large effects on forest hydrological effects. Based on vegetation layer, litter layer and soil layer of different intensities Pinus tabulaeformis plantation in mountainous area of north Hebei province, forest hydrological effects was studied. Results showed that: 1) canopy interception reduced with the decreasing intensity, but the undergrowth vegetation interception raised with the decreasing intensity, 2) litter water retention reduced with the decreasing intensity, litter water retentions of the three plots with stand density of 1584 trees?hm-2, 864 trees?hm-2 and 684 trees?hm-2 had smaller disparities, but accounted for 155.66%, 149.58% and 142.25% of the sample stand with 388 trees?hm-2 ; 3) soil water-holding ability raised with the increasing stand density, plots with stand density of 1584 trees?hm-2, 864 trees?hm-2 and 684 trees?hm-2 accounted for 103.79%, 113.88%, 114.02% of the sample stand with 1584 trees?hm-2. Soil-water storage capacity of sample 864 trees?hm-2 and 684 trees?hm-2 plot were close to each other. Pinus tabulaeformis platation thinning reasonably could improve forest water conservation.
Stand density imposed the large effects on forest hydrological effects. Based on vegetation layer, litter layer and soil layer of different intensities Pinus tabulaeformis plantation in mountainous area of north Hebei province, forest hydrological effects was studied. Results showed that: 1) canopy interception reduced with the decreasing intensity, but the undergrowth vegetation interception raised with the decreasing intensity, 2) litter water retention reduced with the decreasing intensity, litter water retentions of the three plots with stand density of 1584 trees?hm-2, 864 trees?hm-2 and 684 trees?hm-2 had smaller disparities, but accounted for 155.66%, 149.58% and 142.25% of the sample stand with 388 trees?hm-2 ; 3) soil water-holding ability raised with the increasing stand density, plots with stand density of 1584 trees?hm-2, 864 trees?hm-2 and 684 trees?hm-2 accounted for 103.79%, 113.88%, 114.02% of the sample stand with 1584 trees?hm-2. Soil-water storage capacity of sample 864 trees?hm-2 and 684 trees?hm-2 plot were close to each other. Pinus tabulaeformis platation thinning reasonably could improve forest water conservation.
2016, 14(4):123-128.
Abstract:
In hydraulic engineering, the plunge pool is the key to the safety of protecting structure. It affects whether the dam can operate safely or not under impact of high-speed water flow. Based on a plunge pool hydraulic model test and its results, this paper discussed the characteristics of fluctuating pressure acting on the under-surface of the slab with different gap widths. The analysis results showed that in the stable hydraulic jump area, the fluctuating pressure intensity coefficient of slab with keyway increased with the increase of the gap width between slot plates. The probability density distribution was in accordance with the normal distribution. When the gap width increased, the maximum fluctuating uplift force decreased. At the same point, the greater the gap width was, the greater the average eddy scale and spatial integral scale were. With the decrease of the gap width, the pressure fluctuation energy of slab was concentrated more on low frequency section.
In hydraulic engineering, the plunge pool is the key to the safety of protecting structure. It affects whether the dam can operate safely or not under impact of high-speed water flow. Based on a plunge pool hydraulic model test and its results, this paper discussed the characteristics of fluctuating pressure acting on the under-surface of the slab with different gap widths. The analysis results showed that in the stable hydraulic jump area, the fluctuating pressure intensity coefficient of slab with keyway increased with the increase of the gap width between slot plates. The probability density distribution was in accordance with the normal distribution. When the gap width increased, the maximum fluctuating uplift force decreased. At the same point, the greater the gap width was, the greater the average eddy scale and spatial integral scale were. With the decrease of the gap width, the pressure fluctuation energy of slab was concentrated more on low frequency section.
2016, 14(4):129-134.
Abstract:
Theory and earthquake induced damage show that the hoist room frame on intake tower of hydroelectric power station are more vulnerable to earthquake damage due to the whiplash effect. In this paper, the intake tower and the hoist room frame were simplified into two distribution parameter beam models by analysis of the basic mechanical characteristics of intake tower, and then the frequency equation was derived using analytic methods. After statistics of hoist room frame and tower height range and according to the principle of equal bending stiffness, the hoist room frame column was equivalent to a single section of the tower fasting column, then the vibration amplitude ratio and frequency distribution of six kinds of models under conditions of different height ratios and different stiffness-mass ratios were analyzed to get the influence rules between each other. The analysis showed that the height of the upper structure had greater influence on the vibration amplitude ratio of first modal shape, and smaller influence on the stiffness ratio, but the stiffness ratio was more significance. Compared with numerical analysis, structural vibration type and frequency by analytic results was relatively consistent with numerical results, verifying the correctness of the above procedure, and indicating that the analytical method for solving such fundamental mode structure was simple and effective.
Theory and earthquake induced damage show that the hoist room frame on intake tower of hydroelectric power station are more vulnerable to earthquake damage due to the whiplash effect. In this paper, the intake tower and the hoist room frame were simplified into two distribution parameter beam models by analysis of the basic mechanical characteristics of intake tower, and then the frequency equation was derived using analytic methods. After statistics of hoist room frame and tower height range and according to the principle of equal bending stiffness, the hoist room frame column was equivalent to a single section of the tower fasting column, then the vibration amplitude ratio and frequency distribution of six kinds of models under conditions of different height ratios and different stiffness-mass ratios were analyzed to get the influence rules between each other. The analysis showed that the height of the upper structure had greater influence on the vibration amplitude ratio of first modal shape, and smaller influence on the stiffness ratio, but the stiffness ratio was more significance. Compared with numerical analysis, structural vibration type and frequency by analytic results was relatively consistent with numerical results, verifying the correctness of the above procedure, and indicating that the analytical method for solving such fundamental mode structure was simple and effective.
22 Water dynamics of the bridge pier of the four-line parallel skew bridge of Rongshan River in Haikou
2016, 14(4):135-141.
Abstract:
For the study of hydrodynamic characteristics of the bridge pier of the four-line parallel skew bridge of Rongshan River in Haikou City and the overall self vibration characteristics of the pier and bridge system under different water levels, FLUENT and ANSYS software were used, based on the DES method, the three-dimensional flow model was established for the four-line skew bridge river channel , the flow field distribution under different flow rate and different oblique angle as well as the self-vibration characteristics of the pier-bridge system under fluid solid coupling was simulated. The results showed that the maximum flow capacity of the four-line parallel skew bridge could reach 400 m3/s, and the bridge had a certain safe distance, with a maximum backwater height of 0.69 m. The natural frequency of the pier-bridge system under the condition of fluid solid coupling was 7.66 Hz, without the risk of resonance with the passing trains.
For the study of hydrodynamic characteristics of the bridge pier of the four-line parallel skew bridge of Rongshan River in Haikou City and the overall self vibration characteristics of the pier and bridge system under different water levels, FLUENT and ANSYS software were used, based on the DES method, the three-dimensional flow model was established for the four-line skew bridge river channel , the flow field distribution under different flow rate and different oblique angle as well as the self-vibration characteristics of the pier-bridge system under fluid solid coupling was simulated. The results showed that the maximum flow capacity of the four-line parallel skew bridge could reach 400 m3/s, and the bridge had a certain safe distance, with a maximum backwater height of 0.69 m. The natural frequency of the pier-bridge system under the condition of fluid solid coupling was 7.66 Hz, without the risk of resonance with the passing trains.
2016, 14(4):142-146.
Abstract:
In order to study the effect of temperature on the saturated - unsaturated hydraulic parameters, the measurement device for determining hydraulic parameters of saturated - unsaturated soils under variable temperature was developed based on Darcy's law, which contained test column, water supply and return system, and data acquisition system. The device could obtain the saturated permeability coefficient, water and soil water characteristic curve, and unsaturated permeability coefficient parameters, the water capacity and the diffusion rate at different temperatures. Then, the mathematical expressions of temperature and these parameters could be further obtained. In addition, it was shown that the high automatic degree device had popularization and application value for large samples to reduce the randomness of the small sample and determined the parameters of saturated - unsaturated soils.
In order to study the effect of temperature on the saturated - unsaturated hydraulic parameters, the measurement device for determining hydraulic parameters of saturated - unsaturated soils under variable temperature was developed based on Darcy's law, which contained test column, water supply and return system, and data acquisition system. The device could obtain the saturated permeability coefficient, water and soil water characteristic curve, and unsaturated permeability coefficient parameters, the water capacity and the diffusion rate at different temperatures. Then, the mathematical expressions of temperature and these parameters could be further obtained. In addition, it was shown that the high automatic degree device had popularization and application value for large samples to reduce the randomness of the small sample and determined the parameters of saturated - unsaturated soils.
24 Design of drainage and flood control in mountainous city during the process of urbanization planning
2016, 14(4):147-152.
Abstract:
Simulation of the drainage network operation in Yunxian as a typical mountainous city in northwestern Hubei was conducted using MIKE FLOOD and SWMM model, the distribution of flood points and waterlogging areas was analyzed，and the risk of waterlogging was assessed. And the result showed serious city waterlogging. The reasons for waterlogging were clarified based on the simulation results. Then based on the green storm water infrastructure，gray rainwater infrastructure was used to enhance the drainage and flood control capacity in the region，ensuring the security of Yunxian old town drainage and flood control in the process of urbanization. In conclusion, MIKE FLOOD model was used for verification of the engineering program，proving the feasibility of the engineering project.
Simulation of the drainage network operation in Yunxian as a typical mountainous city in northwestern Hubei was conducted using MIKE FLOOD and SWMM model, the distribution of flood points and waterlogging areas was analyzed，and the risk of waterlogging was assessed. And the result showed serious city waterlogging. The reasons for waterlogging were clarified based on the simulation results. Then based on the green storm water infrastructure，gray rainwater infrastructure was used to enhance the drainage and flood control capacity in the region，ensuring the security of Yunxian old town drainage and flood control in the process of urbanization. In conclusion, MIKE FLOOD model was used for verification of the engineering program，proving the feasibility of the engineering project.
2016, 14(4):153-157.
Abstract:
In order to explore the influence of fly ash on the long-term autogenetic volume deformation of concrete mixed with magnesium oxide (MgO), the long-term autogenetic volume deformation of up to 4-year-old MgO concrete specimens with different contents of fly ash was measured, and cores were taken from part of specimens for scanning election microscopy (SEM) and energy spectrum detection．The results showed that the longer the time was, the stronger the inhibitory effect of fly ash on autogenetic volume deformation of MgO concrete was, and it was strongest for one-grade MgO concrete, followed by the two-grade MgO concrete and three-grade MgO concrete. The microstructure of MgO concrete with fly ash in proper content was densified gradually with ages.
In order to explore the influence of fly ash on the long-term autogenetic volume deformation of concrete mixed with magnesium oxide (MgO), the long-term autogenetic volume deformation of up to 4-year-old MgO concrete specimens with different contents of fly ash was measured, and cores were taken from part of specimens for scanning election microscopy (SEM) and energy spectrum detection．The results showed that the longer the time was, the stronger the inhibitory effect of fly ash on autogenetic volume deformation of MgO concrete was, and it was strongest for one-grade MgO concrete, followed by the two-grade MgO concrete and three-grade MgO concrete. The microstructure of MgO concrete with fly ash in proper content was densified gradually with ages.
2016, 14(4):158-162.
Abstract:
In order to improve the uniformity of water distribution of efficient centrifugal spray nozzle, the Eulerian model, one of multiphase flow, and the RNG turbulence model were chosen in there-dimensional numerical simulation to investigate the hydraulic characteristics of efficient centrifugal spray nozzle. Comparison of numerical simulation results with experimental results verified the correctness of the model. The hydraulic characteristics of efficient centrifugal spray nozzle were comparatively analyzed under three head conditions and four speed conditions with this numerical simulation method. The results showed that it could achieve uniform water distribution in a wide head range and a wide speed range. The uniformity of water distribution of efficient centrifugal spray nozzle could be improved by raising the head and reducing the speed in a certain range. Accordingly, the recommended working speed range of the efficient centrifugal spray nozzle was 60 r/min~120 r/min.
In order to improve the uniformity of water distribution of efficient centrifugal spray nozzle, the Eulerian model, one of multiphase flow, and the RNG turbulence model were chosen in there-dimensional numerical simulation to investigate the hydraulic characteristics of efficient centrifugal spray nozzle. Comparison of numerical simulation results with experimental results verified the correctness of the model. The hydraulic characteristics of efficient centrifugal spray nozzle were comparatively analyzed under three head conditions and four speed conditions with this numerical simulation method. The results showed that it could achieve uniform water distribution in a wide head range and a wide speed range. The uniformity of water distribution of efficient centrifugal spray nozzle could be improved by raising the head and reducing the speed in a certain range. Accordingly, the recommended working speed range of the efficient centrifugal spray nozzle was 60 r/min~120 r/min.
2016, 14(4):163-167.
Abstract:
Based on flood routing result and construction investment estimation of Xueshan Reservoir, the facture surface size of the diversion tunnel and the front water of diversion dam were proposed. The diversion tunnel presented a kind of flow which was the first mixed free-surface pressurized flow at maximum flood lever of 2449.99m. The diversion tunnel inducer of different water inlet styles was modeled by the CFD numerical software FLUENT. By analyzing the dynamic pressure and flow velocity in the case of this water flow along the diversion tunnel, the results indicated that the bell-mouth inlet could better improve the flow condition and reduce the negative impact of mixed free-surface pressurized flow.
Based on flood routing result and construction investment estimation of Xueshan Reservoir, the facture surface size of the diversion tunnel and the front water of diversion dam were proposed. The diversion tunnel presented a kind of flow which was the first mixed free-surface pressurized flow at maximum flood lever of 2449.99m. The diversion tunnel inducer of different water inlet styles was modeled by the CFD numerical software FLUENT. By analyzing the dynamic pressure and flow velocity in the case of this water flow along the diversion tunnel, the results indicated that the bell-mouth inlet could better improve the flow condition and reduce the negative impact of mixed free-surface pressurized flow.
2016, 14(4):168-172.
Abstract:
Erosion of sluice is a common problem in water conservancy projects. Many researchers have conducted systematic studies on this problem. The results showed that application of scrap tires was an effective approach to increase the roughness of apron and thus reduce erosion. By comparison and analysis of the different turbulence models, numerical methods, grid scale and wall surface methods, finally the RNG k-ε turbulence model and PISO algorithm were used, the whole flow field was divided into 672700 grids, and standard wall functions were used to deal with the boundary condition to calculate the flow field of scrap tires in energy dissipation and erosion control under sluice. The calculation results were in good agreement with the model test results, indicating that the model could be used to the flow field with enhanced roughness.
Erosion of sluice is a common problem in water conservancy projects. Many researchers have conducted systematic studies on this problem. The results showed that application of scrap tires was an effective approach to increase the roughness of apron and thus reduce erosion. By comparison and analysis of the different turbulence models, numerical methods, grid scale and wall surface methods, finally the RNG k-ε turbulence model and PISO algorithm were used, the whole flow field was divided into 672700 grids, and standard wall functions were used to deal with the boundary condition to calculate the flow field of scrap tires in energy dissipation and erosion control under sluice. The calculation results were in good agreement with the model test results, indicating that the model could be used to the flow field with enhanced roughness.
2016, 14(4):173-178.
Abstract:
The only one ground fissures geological disaster along the middle route of the South-to-North Water Transfer Project (SNWTP) is the Baizhuang Ground fissure. In order to analyze the causes for the fissure development, the distribution and morphological characteristics of the ground fissure were investigated. And the influence of subsidence caused by the coal mining, the fracture structure of the JiuLi mountain, the effects of the stress relief, the conditions of the environmental geological and the effects of the ground water were studied. The results showed that the ground fissures were not caused by the subsidence of the mined out area, and the development of the ground fissures was mainly controlled by the fracture structure of the JiuLi mountain. Other environmental and geological conditions (i.e., the stress release caused by mining activities, the ground water decline, and the surface water infiltration) also had a synergic effect on the ground fissures. The cause analysis and preliminary monitoring showed that the activity of the ground fissure still existed but its strength was weak, and the ground fissure activity tended to be stable as a whole.
The only one ground fissures geological disaster along the middle route of the South-to-North Water Transfer Project (SNWTP) is the Baizhuang Ground fissure. In order to analyze the causes for the fissure development, the distribution and morphological characteristics of the ground fissure were investigated. And the influence of subsidence caused by the coal mining, the fracture structure of the JiuLi mountain, the effects of the stress relief, the conditions of the environmental geological and the effects of the ground water were studied. The results showed that the ground fissures were not caused by the subsidence of the mined out area, and the development of the ground fissures was mainly controlled by the fracture structure of the JiuLi mountain. Other environmental and geological conditions (i.e., the stress release caused by mining activities, the ground water decline, and the surface water infiltration) also had a synergic effect on the ground fissures. The cause analysis and preliminary monitoring showed that the activity of the ground fissure still existed but its strength was weak, and the ground fissure activity tended to be stable as a whole.
2016, 14(4):179-184.
Abstract:
The index system of the initial water rights allocation was constructed following the principle of effectiveness, equity and sustainability. Aiming at the problems of significant correlation of index system and inconsistency of weight preference of initial water rights allocation, Principle Component Analysis (PCA) was applied to the initial water rights allocation to eliminate the impact of correlation. In the method, firstly, Principle Component Analysis (PCA) was proposed to empower the index system, Thereafter, improved AHP and entropy method were adopted to determine weights for multi-lever index system, which eliminated the unilateral result. And game theory was used to carry out the comprehensive integration of index weight. Finally, a comprehensive evaluation method was used to allocate initial water rights. The method was applied to study the initial water rights allocation in Yingcheng, Hubei province. The verification of the model and the analysis of the experimental results showed that the proposed method worked well and was rational and practical. The model could provide a reference for initial water rights allocation in other areas and lay the foundation for the unity management of the water resources.
The index system of the initial water rights allocation was constructed following the principle of effectiveness, equity and sustainability. Aiming at the problems of significant correlation of index system and inconsistency of weight preference of initial water rights allocation, Principle Component Analysis (PCA) was applied to the initial water rights allocation to eliminate the impact of correlation. In the method, firstly, Principle Component Analysis (PCA) was proposed to empower the index system, Thereafter, improved AHP and entropy method were adopted to determine weights for multi-lever index system, which eliminated the unilateral result. And game theory was used to carry out the comprehensive integration of index weight. Finally, a comprehensive evaluation method was used to allocate initial water rights. The method was applied to study the initial water rights allocation in Yingcheng, Hubei province. The verification of the model and the analysis of the experimental results showed that the proposed method worked well and was rational and practical. The model could provide a reference for initial water rights allocation in other areas and lay the foundation for the unity management of the water resources.
2016, 14(4):185-191.
Abstract:
Underground pipelines inevitably go across rivers. For different crossed rivers, large differences may exist in their catchment areas, topography, rainfall, underlying conditions and so on, and then their flood threat will vary among corresponding infrastructure segments. Therefore, a simple but effective assessment method for flood threat is urgently needed. In this paper, the section of the Shaanxi-Beijing Gas Pipeline in Linxian County, Shanxi Province was chosen for case study. Firstly, flood factors were quantified for each crossed river, including the area, rainfall, elevation difference, planar shape, land use, vegetation index of each river catchment, and the longitudinal slope and cross-sectional elevation difference of each cross-over region. Secondly, three key factors were selected after the cross-correlations among the factors and the relationships between each factor and the number of historical flood damage events were examined. Thirdly, the multivariate linear regression and logistic regression methods were used to establish a flood threat assessment model. Finally, the flood threat zoning map of the Shaanxi-Beijing Gas Pipeline in Linxian County was obtained. The result would provide a basis for the formulation and implementation of protection measures in pipeline safety management, and the method in this paper could be a reference for similar flood threat assessments of linear infrastructures.
Underground pipelines inevitably go across rivers. For different crossed rivers, large differences may exist in their catchment areas, topography, rainfall, underlying conditions and so on, and then their flood threat will vary among corresponding infrastructure segments. Therefore, a simple but effective assessment method for flood threat is urgently needed. In this paper, the section of the Shaanxi-Beijing Gas Pipeline in Linxian County, Shanxi Province was chosen for case study. Firstly, flood factors were quantified for each crossed river, including the area, rainfall, elevation difference, planar shape, land use, vegetation index of each river catchment, and the longitudinal slope and cross-sectional elevation difference of each cross-over region. Secondly, three key factors were selected after the cross-correlations among the factors and the relationships between each factor and the number of historical flood damage events were examined. Thirdly, the multivariate linear regression and logistic regression methods were used to establish a flood threat assessment model. Finally, the flood threat zoning map of the Shaanxi-Beijing Gas Pipeline in Linxian County was obtained. The result would provide a basis for the formulation and implementation of protection measures in pipeline safety management, and the method in this paper could be a reference for similar flood threat assessments of linear infrastructures.
2016, 14(4):192-197.
Abstract:
BMM model and POT model which based on extreme value theory are one of the newly-developing methods to assess the safety conditions of slope in recent years. The ignorant of secondary maximum points and the relatively small size of sample in the case of short-time data may lead to a big error in BMM model. A modified POT model was proposed in the paper to get the threshold with improved Hill estimator method and obtain the Pareto parameters with the maximum likelihood estimation so that the whole distribution could be determined. With the analysis of a slope engineering, the early-warning index which used the generalized Pareto distribution with the data exceeding the threshold was less than that using the normal distribution with the block maximum values in the case of same confidence level. It could be drawn from the results that the early-warning index based on modified POT model was more effective in slope safety monitoring, which could be made use of reducing the risk when extreme conditions happened.
BMM model and POT model which based on extreme value theory are one of the newly-developing methods to assess the safety conditions of slope in recent years. The ignorant of secondary maximum points and the relatively small size of sample in the case of short-time data may lead to a big error in BMM model. A modified POT model was proposed in the paper to get the threshold with improved Hill estimator method and obtain the Pareto parameters with the maximum likelihood estimation so that the whole distribution could be determined. With the analysis of a slope engineering, the early-warning index which used the generalized Pareto distribution with the data exceeding the threshold was less than that using the normal distribution with the block maximum values in the case of same confidence level. It could be drawn from the results that the early-warning index based on modified POT model was more effective in slope safety monitoring, which could be made use of reducing the risk when extreme conditions happened.
2016, 14(4):198-203.
Abstract:
Based on the C-D production function and Data Envelopment Analysis (DEA) method, this study recruited 7 cities’ farmers in Hebei plain as the research objects, selected the wheat production inputs and outputs indexes in 2013, and finally analyzed the returns to scale, effectiveness and the relaxation problems of wheat production on a microscopic level. The results showed that the return to scale for wheat production was in a state of decreasing, and wheat production inputs had reached saturation or redundancy. For the relaxation problems of wheat production in Hebei pain, the maximum redundancy of irrigation was 625.05 m3?hm-2 in Shijiazhuang while the minimum number was 0 m3?hm-2 in Langfang; the maximum redundancy of nitrogen fertilizer was 74.625 kg?hm-2 in Hengshui; for Phosphate fertilizer, there were many redundancies in all of the 7 cities, and the maximum redundancy was 48.45 kg?hm-2 in Baoding; the maximum redundancy of machine was small in Hengshui; the maximum increase of output was 1542.15 kg?hm-2 in Cangzhou. The pure technical efficiency, comprehensive technical efficiency and scale efficiency were all inefficient. Therefore, the pure technical efficiency and scale efficiency were slightly inefficient because the values of them were all above 0.7 which was bigger than the value of comprehensive technical efficiency. Therefore, there is lager space for the improvement of wheat production efficiency in Hebei plain.
Based on the C-D production function and Data Envelopment Analysis (DEA) method, this study recruited 7 cities’ farmers in Hebei plain as the research objects, selected the wheat production inputs and outputs indexes in 2013, and finally analyzed the returns to scale, effectiveness and the relaxation problems of wheat production on a microscopic level. The results showed that the return to scale for wheat production was in a state of decreasing, and wheat production inputs had reached saturation or redundancy. For the relaxation problems of wheat production in Hebei pain, the maximum redundancy of irrigation was 625.05 m3?hm-2 in Shijiazhuang while the minimum number was 0 m3?hm-2 in Langfang; the maximum redundancy of nitrogen fertilizer was 74.625 kg?hm-2 in Hengshui; for Phosphate fertilizer, there were many redundancies in all of the 7 cities, and the maximum redundancy was 48.45 kg?hm-2 in Baoding; the maximum redundancy of machine was small in Hengshui; the maximum increase of output was 1542.15 kg?hm-2 in Cangzhou. The pure technical efficiency, comprehensive technical efficiency and scale efficiency were all inefficient. Therefore, the pure technical efficiency and scale efficiency were slightly inefficient because the values of them were all above 0.7 which was bigger than the value of comprehensive technical efficiency. Therefore, there is lager space for the improvement of wheat production efficiency in Hebei plain.
2016, 14(4):204.
Abstract:
The comprehensive control line for the operation water level, anti water discharge line, anti destroy line, the limited water level of flood control and dead water level were used as reservoir operation guide line, and constituted the reservoir operation chart. The simulation and optimization model of operation chart was established according to the comprehensive dispatching rules for the operation chart. Simulation and optimization technology was adopted to optimize the reservoir operation chart, and the optimize method was applied in the lower reach of Yalong River cascade reservoirs. The study showed that the optimization operation chart has good operability and practical value based on guiding the reservoir operation.
The comprehensive control line for the operation water level, anti water discharge line, anti destroy line, the limited water level of flood control and dead water level were used as reservoir operation guide line, and constituted the reservoir operation chart. The simulation and optimization model of operation chart was established according to the comprehensive dispatching rules for the operation chart. Simulation and optimization technology was adopted to optimize the reservoir operation chart, and the optimize method was applied in the lower reach of Yalong River cascade reservoirs. The study showed that the optimization operation chart has good operability and practical value based on guiding the reservoir operation.
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