Issue 1,2013 Table of Contents
2013(1):1-6.
Abstract:
The instantaneous peak flow (IPF) is the basic information for hydraulic design，construction and management. It also has an important influence on the investment and safety of hydraulic structures. However, the IPF records in Tibet are generally short in length, while mean daily flow (MDF) records are relatively longer. In this study, the IPF records are extended by analyzing the relationship between corresponding IPF and MDF records. The results show that the ratio between IPF and MDF is stable in most of hydrological stations. The relative error between estimated IPF and observed IPF is less than 10%. The results of flood frequency analysis using extended IPF series are more reasonable than that using the measured IPF series. For the stations with limited measured MDF, the HIMS model is used to extend the available MDF. The HIMS model is applied in three representative rivers of Tibet: the Nianchu river, Lhasa river and Niang river. The results show that the model has a good performance in both daily and peak flow simulation. The end year of IPF series in the three representative hydrological stations has been extended from 2000 to 2010 by the simulation results of HIMS and the relationship between IPF and MDF.
The instantaneous peak flow (IPF) is the basic information for hydraulic design，construction and management. It also has an important influence on the investment and safety of hydraulic structures. However, the IPF records in Tibet are generally short in length, while mean daily flow (MDF) records are relatively longer. In this study, the IPF records are extended by analyzing the relationship between corresponding IPF and MDF records. The results show that the ratio between IPF and MDF is stable in most of hydrological stations. The relative error between estimated IPF and observed IPF is less than 10%. The results of flood frequency analysis using extended IPF series are more reasonable than that using the measured IPF series. For the stations with limited measured MDF, the HIMS model is used to extend the available MDF. The HIMS model is applied in three representative rivers of Tibet: the Nianchu river, Lhasa river and Niang river. The results show that the model has a good performance in both daily and peak flow simulation. The end year of IPF series in the three representative hydrological stations has been extended from 2000 to 2010 by the simulation results of HIMS and the relationship between IPF and MDF.
2013(1):7-11.
Abstract:
Historical study is integral in the social and ecological civilization development, especially in the river basin governance. This paper demonstrates a perspective that studying the river basin governance under the historical view is necessary in the water resource researches in the Hexi Corridor in northwestern China. It is supportive for deeply understanding the evolution of water resources and environment in north western China, and is helpful to get insights on the contemporary water governance issues thus to improve the governance solutions by involving the traditional water management intelligence in modern system. Several case studies are provided to illustrate the perspective, including reviews on the historical evolution processes of water resource development, socio-economic development and river basin governance in the major river basins in Hexi Corridor since 18 century, emphasized on the evolution of duration-based water rights which was the dominant water allocation regime in Hexi Corridor and still used in Taolai River Basin, and analyses on the challenges to the duration-based water rights under the changing environment and its requirement to integrate the traditional water rights with contemporary governance system.
Historical study is integral in the social and ecological civilization development, especially in the river basin governance. This paper demonstrates a perspective that studying the river basin governance under the historical view is necessary in the water resource researches in the Hexi Corridor in northwestern China. It is supportive for deeply understanding the evolution of water resources and environment in north western China, and is helpful to get insights on the contemporary water governance issues thus to improve the governance solutions by involving the traditional water management intelligence in modern system. Several case studies are provided to illustrate the perspective, including reviews on the historical evolution processes of water resource development, socio-economic development and river basin governance in the major river basins in Hexi Corridor since 18 century, emphasized on the evolution of duration-based water rights which was the dominant water allocation regime in Hexi Corridor and still used in Taolai River Basin, and analyses on the challenges to the duration-based water rights under the changing environment and its requirement to integrate the traditional water rights with contemporary governance system.
2013(1):12-16.
Abstract:
The hydrological model approach is considered as an efficient way to assess the characteristics of spatiotemporal variation of blue and green water resources, after review on the concept of blue water and green water, and comprehensive analysis of assessment methods. In order to quantify the available water resources in the Wei River Basin (WRB), a hydrological model was developed by using SWAT (Soil and Water Assessment Tool), and calibrated and validated with SUFI-2 (Sequential Uncertainty Fitting program) based on river discharge in the WRB. Sensitivity and uncertainty analysis were also performed to improve the model performance. Different components of water resources for blue water flow, green water flow, and green water storage were estimated at the Hydrological Response Unit (HRU) scale, river catchments, and city/region scales during the past 50 years. This study will provide scientific basis for the planning and management of water resources, and optimal utilization of water resources in the water scare region in the Northwest of China.
The hydrological model approach is considered as an efficient way to assess the characteristics of spatiotemporal variation of blue and green water resources, after review on the concept of blue water and green water, and comprehensive analysis of assessment methods. In order to quantify the available water resources in the Wei River Basin (WRB), a hydrological model was developed by using SWAT (Soil and Water Assessment Tool), and calibrated and validated with SUFI-2 (Sequential Uncertainty Fitting program) based on river discharge in the WRB. Sensitivity and uncertainty analysis were also performed to improve the model performance. Different components of water resources for blue water flow, green water flow, and green water storage were estimated at the Hydrological Response Unit (HRU) scale, river catchments, and city/region scales during the past 50 years. This study will provide scientific basis for the planning and management of water resources, and optimal utilization of water resources in the water scare region in the Northwest of China.
2013(1):17-22.
Abstract:
Using the recording of runoff series of Shixiali, Xiangshuibao, Guanting reservoir gauge station in Yongding River basin among 1956-2003, Mann-kendall test, Pettitt test, Moving-T test and Wavelet analysis are applied to characterize the runoff trend, periodicity and mutation, the influencing factors are discussed as climate change and human activities. The results showed that 1) annual runoff of Yonding River Basin was declining significantly among 1956-2003, 2) it had a major period of 21-year, and 3) runoff varied abnormally in 1982-1983. The variations of runoff were mainly influenced by human activities like land use, dam construction and groundwater exploitation, climate change also has an impact on the runoff decline.
Using the recording of runoff series of Shixiali, Xiangshuibao, Guanting reservoir gauge station in Yongding River basin among 1956-2003, Mann-kendall test, Pettitt test, Moving-T test and Wavelet analysis are applied to characterize the runoff trend, periodicity and mutation, the influencing factors are discussed as climate change and human activities. The results showed that 1) annual runoff of Yonding River Basin was declining significantly among 1956-2003, 2) it had a major period of 21-year, and 3) runoff varied abnormally in 1982-1983. The variations of runoff were mainly influenced by human activities like land use, dam construction and groundwater exploitation, climate change also has an impact on the runoff decline.
2013(1):23-28.
Abstract:
The concept and its evaluation of drought resistance capacity were investigated based on summarizing the current worldwide related research advances. Comprehensively taking the natural and social properties into consideration, and the two essence of capacity were generalized, i.e. the capacity was linked with degree or magnitude of the disaster, and it emphasized the human resistant activity and the concept of maximum extent. On this basis, the definition of drought resistance capacity and its connotation were expounded by referring the definitions of other natural disaster resistant capacity and natural resources carrying capacity. Then the assessment methodology of the drought resistance capacity was constructed on the basis of the elements and the definition analysis respectively. The framework of drought resistance capacity was preliminarily presented.
The concept and its evaluation of drought resistance capacity were investigated based on summarizing the current worldwide related research advances. Comprehensively taking the natural and social properties into consideration, and the two essence of capacity were generalized, i.e. the capacity was linked with degree or magnitude of the disaster, and it emphasized the human resistant activity and the concept of maximum extent. On this basis, the definition of drought resistance capacity and its connotation were expounded by referring the definitions of other natural disaster resistant capacity and natural resources carrying capacity. Then the assessment methodology of the drought resistance capacity was constructed on the basis of the elements and the definition analysis respectively. The framework of drought resistance capacity was preliminarily presented.
2013(1):29-33.
Abstract:
The construction of the high standard farmland is very necessary to improve farmland quality, increase crop yields and raise agricultural productivity. Huanghua City of Hebei Province situated in Heilonggang River basin is seriously short of water, but it is flat and the farmland is widely distributed. The potential of land utilization is great so that it is a key area for the construction of high standard farmland. To carry out the analysis and assessment of high standard farmland construction based water resources supply and demand as well as the probe of the new land consolidation techniques and measures can make the water resources used rationally and land utilization efficiency improved remarkably. In this paper, the water resources supply and demand volume was calculated with hydrological response unit based water resources model method and the spatial analysis was made with the MAPGIS, then the analysis and assessment results were obtained high standard farmland construction based water resources supply and demand. The results showed that water and land resources are extremely abundant in the eastern part of the city near the coast, are balanced in southern and northwestern parts of city and are short or extremely short in the western and central parts of the city.
The construction of the high standard farmland is very necessary to improve farmland quality, increase crop yields and raise agricultural productivity. Huanghua City of Hebei Province situated in Heilonggang River basin is seriously short of water, but it is flat and the farmland is widely distributed. The potential of land utilization is great so that it is a key area for the construction of high standard farmland. To carry out the analysis and assessment of high standard farmland construction based water resources supply and demand as well as the probe of the new land consolidation techniques and measures can make the water resources used rationally and land utilization efficiency improved remarkably. In this paper, the water resources supply and demand volume was calculated with hydrological response unit based water resources model method and the spatial analysis was made with the MAPGIS, then the analysis and assessment results were obtained high standard farmland construction based water resources supply and demand. The results showed that water and land resources are extremely abundant in the eastern part of the city near the coast, are balanced in southern and northwestern parts of city and are short or extremely short in the western and central parts of the city.
2013(1):34-38.
Abstract:
At present, the population increasing with less water, the uneven temporal and spatial distribution of water resources as well as the incoordination between economic society development and water resources distribution constitute the fundamental water regime and the state situation, furthermore, water pollution situation is increasingly serious, making the reasonable and effective implement of water resources management an urgent. As the latest water control strategy, the strictest water resources management system controls strictly on water develop, use as well as drain, forming corresponding system related to those three above sides in addition to water management. This paper introduces the background of the strictest water resources management system, understands the basic philosophy, constructs the theoretical framework of the system, states the guiding ideology of the system, fundamental principles, technological support, main content, theoretical methods as well as Safeguards of the system, providing a reference for in-depth research to the strictest water resources management system in addition to practice.
At present, the population increasing with less water, the uneven temporal and spatial distribution of water resources as well as the incoordination between economic society development and water resources distribution constitute the fundamental water regime and the state situation, furthermore, water pollution situation is increasingly serious, making the reasonable and effective implement of water resources management an urgent. As the latest water control strategy, the strictest water resources management system controls strictly on water develop, use as well as drain, forming corresponding system related to those three above sides in addition to water management. This paper introduces the background of the strictest water resources management system, understands the basic philosophy, constructs the theoretical framework of the system, states the guiding ideology of the system, fundamental principles, technological support, main content, theoretical methods as well as Safeguards of the system, providing a reference for in-depth research to the strictest water resources management system in addition to practice.
2013(1):39-43.
Abstract:
Different from the mountainous and highland area, the application of SWAT model in the polder area is quite difficult and limited, because the polder areas in plain region have flat topography, complicated and uncertain hydrologic processes due to various pumping and irrigation stations, and usually no useful monitored hydrological data. In this paper, the JiangXiang polder of the down-stream Ganjiang River was selected for case study, and subbasin delineation, which is a key step for a successful SWAT application, was carried out under manually corrections of drainage area boundary demarcation, multi-outlet definition, and “Burn-in” technique. Then hydrologic processes of the polder area were simulated based on SWAT model, and the pumping discharge data in the year of 2006~2007 and 2008 was applied for model calibration and validation, respectively. The results showed that the coefficient of determination (R2) and Nash-Sutcliffe coefficient (NSE) in each drainage area were greater than 0.63 and 0.70 respectively in calibration period, and R2 and NSE were greater than 0.70 and 0.79 respectively in validation period. It shows that subbasin delineation results are quiet agreeable with the actual situation by using manually correction techniques, so that SWAT model is applicable for hydrological modeling in the polder area and can obtain reasonable simulation results.
Different from the mountainous and highland area, the application of SWAT model in the polder area is quite difficult and limited, because the polder areas in plain region have flat topography, complicated and uncertain hydrologic processes due to various pumping and irrigation stations, and usually no useful monitored hydrological data. In this paper, the JiangXiang polder of the down-stream Ganjiang River was selected for case study, and subbasin delineation, which is a key step for a successful SWAT application, was carried out under manually corrections of drainage area boundary demarcation, multi-outlet definition, and “Burn-in” technique. Then hydrologic processes of the polder area were simulated based on SWAT model, and the pumping discharge data in the year of 2006~2007 and 2008 was applied for model calibration and validation, respectively. The results showed that the coefficient of determination (R2) and Nash-Sutcliffe coefficient (NSE) in each drainage area were greater than 0.63 and 0.70 respectively in calibration period, and R2 and NSE were greater than 0.70 and 0.79 respectively in validation period. It shows that subbasin delineation results are quiet agreeable with the actual situation by using manually correction techniques, so that SWAT model is applicable for hydrological modeling in the polder area and can obtain reasonable simulation results.
2013(1):44-49.
Abstract:
The paper expounded the problems on the watershed water cycle research with the high development and utilization of water resources. And on the basis of these problems, the paper discussed the watershed water cycle research methods to cope with the development and utilization of water resources from four levels of .perceive, experiments, theory and method. And it constructed a of the multi-objective control model that taking the water resources allocation and water cycle model coupling as the core, taking the watershed water supply and demand analysis and ecological, environmental and economic comprehensive evaluation as the response. The paper put the method into practice in the Yellow River, calculated the water resources rational allocation in the Yellow River with different water resources development and utilization condition. The results show that under the condition of current situation, the Yellow River basin suffer a serious water shortage, and it would be more terrible in the future, but the water saving can deeply alleviate water shortages.
The paper expounded the problems on the watershed water cycle research with the high development and utilization of water resources. And on the basis of these problems, the paper discussed the watershed water cycle research methods to cope with the development and utilization of water resources from four levels of .perceive, experiments, theory and method. And it constructed a of the multi-objective control model that taking the water resources allocation and water cycle model coupling as the core, taking the watershed water supply and demand analysis and ecological, environmental and economic comprehensive evaluation as the response. The paper put the method into practice in the Yellow River, calculated the water resources rational allocation in the Yellow River with different water resources development and utilization condition. The results show that under the condition of current situation, the Yellow River basin suffer a serious water shortage, and it would be more terrible in the future, but the water saving can deeply alleviate water shortages.
2013(1):50-54.
Abstract:
The data from 1951 to 2008 from Xi’an station were used to analyze the variation characteristics of precipitation, evaporation and available precipitation in the area. The available precipitation forecasting model based on weighted Markov chain was established and the relationship between model forecasting errors and the observed value of available precipitation was also analyzed. The forecasting results were amended by the frequency curve. The results show that the variation of available rainfall is significant in a year, and it is most abundant in September while is least in December. The proportion of available precipitation in autumn and winter are 44.5% and 2.1%, respectively and the available rainfall coefficients are 0.36 and 011 respectively for the two seasons. During the past 58 years from 1951 to 2008, the average available rainfall reduces in a linear tendency at 0.99 mm per year. The forecasting of available precipitation in Xi’an was taken as an example. The forecasting errors and the real value of local available precipitation are inversely related. The relative errors verified by theoretic frequency curve decreases. It is concluded that the available precipitation forecasting model based on weighted Markov chain modified by theoretic frequency curve can be used to predict the available precipitation in Xi’an.
The data from 1951 to 2008 from Xi’an station were used to analyze the variation characteristics of precipitation, evaporation and available precipitation in the area. The available precipitation forecasting model based on weighted Markov chain was established and the relationship between model forecasting errors and the observed value of available precipitation was also analyzed. The forecasting results were amended by the frequency curve. The results show that the variation of available rainfall is significant in a year, and it is most abundant in September while is least in December. The proportion of available precipitation in autumn and winter are 44.5% and 2.1%, respectively and the available rainfall coefficients are 0.36 and 011 respectively for the two seasons. During the past 58 years from 1951 to 2008, the average available rainfall reduces in a linear tendency at 0.99 mm per year. The forecasting of available precipitation in Xi’an was taken as an example. The forecasting errors and the real value of local available precipitation are inversely related. The relative errors verified by theoretic frequency curve decreases. It is concluded that the available precipitation forecasting model based on weighted Markov chain modified by theoretic frequency curve can be used to predict the available precipitation in Xi’an.
2013(1):55-59.
Abstract:
The paper analyzes the variation characteristics of climate factors air temperature and precipitation in Helingeer, Inner Mongolia based on the monitoring data of air temperature and precipitation from 1959-2010, anomaly, trend, correlation, mutation and Hurst index analyses of which are conducted in the paper. Results show that the trend of temperature (0.36 ?C /（10 a）) keeps or rises with time, while that of precipitation (-8.4 mm/（10a）) is likely to change; winter temperature and summer precipitation are the most important influencing factors of the annual average atmospheric temperature and annual precipitation, respectively; correlations among air temperature and precipitation are not obvious; air temperature had mutations during 1986?1988, while precipitation didn’t. Analysis results of characteristics of climate factors have great effects on the sustainable utilization of water resources, the development of ecological environment and others.
The paper analyzes the variation characteristics of climate factors air temperature and precipitation in Helingeer, Inner Mongolia based on the monitoring data of air temperature and precipitation from 1959-2010, anomaly, trend, correlation, mutation and Hurst index analyses of which are conducted in the paper. Results show that the trend of temperature (0.36 ?C /（10 a）) keeps or rises with time, while that of precipitation (-8.4 mm/（10a）) is likely to change; winter temperature and summer precipitation are the most important influencing factors of the annual average atmospheric temperature and annual precipitation, respectively; correlations among air temperature and precipitation are not obvious; air temperature had mutations during 1986?1988, while precipitation didn’t. Analysis results of characteristics of climate factors have great effects on the sustainable utilization of water resources, the development of ecological environment and others.
2013(1):60-65.
Abstract:
Based on the prototype observation results of dynamic displacement response from plunge pool slabs of Guandi hydropower station, the characteristics of vibration strength distribution in slabs were analyzed under different spillway conditions. The dominant frequency of vibration was studied using the modern spectral analysis method. Then the influence of spillway condition and discharge on the characteristics of vibration distribution in plunge pool slabs was analyzed, together with the correlation of the vibrations. The results show that the strongest vibration response occurs in the front (0+149m before dam) and decreases along the way. The asymmetry of water flow causes highly unequal distribution of vibration strength in slabs of different areas. Under normal operation, the plunge pool slabs vibrate randomly forced by flow load, with good correlation and stable dominant frequency between 0.6 ~ 1.7Hz. Because of the large scale vortex, the vibration has good similarity and synchronicity. The vibration strength increases stably with the increase of discharge amount, while the dominant frequency decreases slowly. When the discharge is more than 1500m3/s, the dominant frequency tends to decrease at low speed and become stable eventually.
Based on the prototype observation results of dynamic displacement response from plunge pool slabs of Guandi hydropower station, the characteristics of vibration strength distribution in slabs were analyzed under different spillway conditions. The dominant frequency of vibration was studied using the modern spectral analysis method. Then the influence of spillway condition and discharge on the characteristics of vibration distribution in plunge pool slabs was analyzed, together with the correlation of the vibrations. The results show that the strongest vibration response occurs in the front (0+149m before dam) and decreases along the way. The asymmetry of water flow causes highly unequal distribution of vibration strength in slabs of different areas. Under normal operation, the plunge pool slabs vibrate randomly forced by flow load, with good correlation and stable dominant frequency between 0.6 ~ 1.7Hz. Because of the large scale vortex, the vibration has good similarity and synchronicity. The vibration strength increases stably with the increase of discharge amount, while the dominant frequency decreases slowly. When the discharge is more than 1500m3/s, the dominant frequency tends to decrease at low speed and become stable eventually.
2013(1):66-70.
Abstract:
In order to research the energy characteristics of new type, high efficiency, low head, large discharge, bidirectional shaft tubular turbine for a tidal power station, we make the mode test and numerical simulation, and measure parameters such as the head, discharge and torque under positive and negative, different turbine blade angle, different guide vane opening, and draw the turbine model synthetic characteristic curve, and the curve is compared with numerical simulation results. The test results indicate that, when the turbine under rated operating mode, positive efficiency can reach 89.68%, reverse efficiency can reach 84.08%, which can satisfy the operation requirements of tidal power station; the results we test can meet the numerical simulation results which validate the reliability of numerical simulation results, by means of the compassion between prototype and model efficiency and CFD numerical simulation results, we found that when deviated from designed point but keep the rated head, the affection which the discharge change caused by changing the guide vane opening is a bit greater than which the discharge change caused by changing the blade angle.
In order to research the energy characteristics of new type, high efficiency, low head, large discharge, bidirectional shaft tubular turbine for a tidal power station, we make the mode test and numerical simulation, and measure parameters such as the head, discharge and torque under positive and negative, different turbine blade angle, different guide vane opening, and draw the turbine model synthetic characteristic curve, and the curve is compared with numerical simulation results. The test results indicate that, when the turbine under rated operating mode, positive efficiency can reach 89.68%, reverse efficiency can reach 84.08%, which can satisfy the operation requirements of tidal power station; the results we test can meet the numerical simulation results which validate the reliability of numerical simulation results, by means of the compassion between prototype and model efficiency and CFD numerical simulation results, we found that when deviated from designed point but keep the rated head, the affection which the discharge change caused by changing the guide vane opening is a bit greater than which the discharge change caused by changing the blade angle.
2013(1):71-74.
Abstract:
At present there is no common and perfect method for anti-sliding stability analysis of gravity dam with complex multi-zigzag plane base surface. Based on 3-D rigid body limit equilibrium theory and slice method, a method named 3-D anti-sliding stability slice method, which takes the dam body as many sliding rigid bodies, is put forward and the calculation program is developed. Combined with the preprocess module of ANSYS for load calculation, this method is used to analyze the anti-sliding stability of NO.7 bank dam of a hydropower station. The results show that the anti-sliding safety factor of this dam section can reach the requirement of standard. This method has strict computational theory and is easy to use, which can also be used with the current standard with reliable results and can be used for a reference in similar projects.
At present there is no common and perfect method for anti-sliding stability analysis of gravity dam with complex multi-zigzag plane base surface. Based on 3-D rigid body limit equilibrium theory and slice method, a method named 3-D anti-sliding stability slice method, which takes the dam body as many sliding rigid bodies, is put forward and the calculation program is developed. Combined with the preprocess module of ANSYS for load calculation, this method is used to analyze the anti-sliding stability of NO.7 bank dam of a hydropower station. The results show that the anti-sliding safety factor of this dam section can reach the requirement of standard. This method has strict computational theory and is easy to use, which can also be used with the current standard with reliable results and can be used for a reference in similar projects.
2013(1):75-80.
Abstract:
Based on the remote sensing TM images in 1979 and 2004 and the SPOT image in 2009 ,as well as relevant information, the study use the visual inter- pretation to obtain the information of utilizing the land of Binhai New District and analyzes the integrated characteristic of the ecological land ,the changing characteristics between ecological land and non-ecological land, as well as the driving factors. The results showed that from 1979 to 2009,the area of total ecological land decreased, before and after 2004,56424.74hm2 and 8874.35hm2 ecological land were separately translated to farmland and construction land ,the ratio of forest and urban green land is low, the beach was largely translated to brine,part of sea area was translated to beach, the driving factors were responsible for the land use change include natual factor,urban sprawl and economic factors.
Based on the remote sensing TM images in 1979 and 2004 and the SPOT image in 2009 ,as well as relevant information, the study use the visual inter- pretation to obtain the information of utilizing the land of Binhai New District and analyzes the integrated characteristic of the ecological land ,the changing characteristics between ecological land and non-ecological land, as well as the driving factors. The results showed that from 1979 to 2009,the area of total ecological land decreased, before and after 2004,56424.74hm2 and 8874.35hm2 ecological land were separately translated to farmland and construction land ,the ratio of forest and urban green land is low, the beach was largely translated to brine,part of sea area was translated to beach, the driving factors were responsible for the land use change include natual factor,urban sprawl and economic factors.
2013(1):81-86.
Abstract:
As a result of global warming, the meteorological and hydrological elements (temperature, precipitation, evaporation and runoff) and the hydrological environment (glacier, permafrost, snow, wetlands, swamp and vegetation) have been severely impacted in high and cold source region of the Yangtze River. The severe environment problems as permafrost degeneration, vegetation degeneration, freeze-thaw erosion and land desertification have occurred at the region. Through analysis of impact of last 50 years’ climate changes on the meteorological and hydrological elements and the hydrological environment, we point out the current problems urgently to be addressed and suggest future research fields based on science and national demand. And we hope these work can provide some referential experience for improving the ecological barrier construction in source regions of the Yangtze River, the Yellow River, the Minjiang River, the Dadu River and Jialing River, especially for safe water use in the Three Gorges Reservoir area.
As a result of global warming, the meteorological and hydrological elements (temperature, precipitation, evaporation and runoff) and the hydrological environment (glacier, permafrost, snow, wetlands, swamp and vegetation) have been severely impacted in high and cold source region of the Yangtze River. The severe environment problems as permafrost degeneration, vegetation degeneration, freeze-thaw erosion and land desertification have occurred at the region. Through analysis of impact of last 50 years’ climate changes on the meteorological and hydrological elements and the hydrological environment, we point out the current problems urgently to be addressed and suggest future research fields based on science and national demand. And we hope these work can provide some referential experience for improving the ecological barrier construction in source regions of the Yangtze River, the Yellow River, the Minjiang River, the Dadu River and Jialing River, especially for safe water use in the Three Gorges Reservoir area.
2013(1):87-92.
Abstract:
Aims at the problem of water sanilization widespread existed in Tianjin coastal reservoirs,the field investigation and sampling analysis method were conducted to vertical distribution of salinization in various seasons for Beidagang reservoir. Water salinization mechanism of reservoir and its impact factors were analyzed. Results show that from to the each site's representative sanilization index, such as electric conductivity, chloride ion and total dissolved solid (TDS),relative to the water diverted from the Yellow River, the sanilization tendency was presented for each site of reservoir, and the water sanilization phenomenon of outer was obviously higher than that of entrance. In different sites of the reservoir, the average level of electric conductivity, chlorine ion and TDS of reservoir water was 867.5μs/cm,0.41 g/L and 1.46 g/L respectively. It was weak alkaline in different sites of reservoirs. Seasonal variation characteristics of salinization indicators, such as Electric conductivity, chloride ion and TDS of Beidagang reservoir were showed that in winter was slightly higher than in spring. Vertical variation characteristics of the reservoir water of chloride ion and TDS vertical changed not significantly, and presented that chloride ion and TDS decreases with the increase of depth, but presented the opposite rule for electric conductivity. The study found that the sanilization of reservoir water quality was influence by soil salinity, temperature and the mixing actions.The closer to the coastline, and the higher soil salt content was, and the more serious sanilization phenomenon of water quality was from to the sites' horizontal distribution of sanilization index. Temperature rising would affect the release of salt from the sediment, and the higher the temperature was, the easier release for the chlorine ion of sediment was. Vertical mixing action were happened, and leading to little vertical direction change of chloride ion and TDS.
Aims at the problem of water sanilization widespread existed in Tianjin coastal reservoirs,the field investigation and sampling analysis method were conducted to vertical distribution of salinization in various seasons for Beidagang reservoir. Water salinization mechanism of reservoir and its impact factors were analyzed. Results show that from to the each site's representative sanilization index, such as electric conductivity, chloride ion and total dissolved solid (TDS),relative to the water diverted from the Yellow River, the sanilization tendency was presented for each site of reservoir, and the water sanilization phenomenon of outer was obviously higher than that of entrance. In different sites of the reservoir, the average level of electric conductivity, chlorine ion and TDS of reservoir water was 867.5μs/cm,0.41 g/L and 1.46 g/L respectively. It was weak alkaline in different sites of reservoirs. Seasonal variation characteristics of salinization indicators, such as Electric conductivity, chloride ion and TDS of Beidagang reservoir were showed that in winter was slightly higher than in spring. Vertical variation characteristics of the reservoir water of chloride ion and TDS vertical changed not significantly, and presented that chloride ion and TDS decreases with the increase of depth, but presented the opposite rule for electric conductivity. The study found that the sanilization of reservoir water quality was influence by soil salinity, temperature and the mixing actions.The closer to the coastline, and the higher soil salt content was, and the more serious sanilization phenomenon of water quality was from to the sites' horizontal distribution of sanilization index. Temperature rising would affect the release of salt from the sediment, and the higher the temperature was, the easier release for the chlorine ion of sediment was. Vertical mixing action were happened, and leading to little vertical direction change of chloride ion and TDS.
2013(1):93-96.
Abstract:
Functional Gene Array (FGA) is a cutting-edge microarray technology for rapid, sensitive and high-throughput detection of environmental samples. Recently, FGA has been developed to such a degree that more and more researches about the ecology of soil microorganisms have made great use of FGAs. This technology has offered great information about microbial community structure and function in the soil under different circumstances and pollution stress. The development of FGA will be a huge benefit to the understanding of the details of micro-ecological process, functional ecological networks and the prediction of the response of microbial community to environmental stress.
Functional Gene Array (FGA) is a cutting-edge microarray technology for rapid, sensitive and high-throughput detection of environmental samples. Recently, FGA has been developed to such a degree that more and more researches about the ecology of soil microorganisms have made great use of FGAs. This technology has offered great information about microbial community structure and function in the soil under different circumstances and pollution stress. The development of FGA will be a huge benefit to the understanding of the details of micro-ecological process, functional ecological networks and the prediction of the response of microbial community to environmental stress.
2013(1):97-100.
Abstract:
Based on ecological characteristics of Biliuhe Basin, The calculation method of river ecological water requirement is introduced in this paper. This method is applied in profit regulation of Biliuhe Reservoir in order to determine the river ecological water demand. The results show that the basic and improved ecological water supply of Biliuhe reservoir is 27.65 million cubic meters and 42.5 million cubic meters, respectively. The river ecological environment will be significantly improved with the implementation of the strictest water management system and the development and utilization of non-conventional water resources, as well as the implementation of the water diversion project and river-reservoir connectivity project.
Based on ecological characteristics of Biliuhe Basin, The calculation method of river ecological water requirement is introduced in this paper. This method is applied in profit regulation of Biliuhe Reservoir in order to determine the river ecological water demand. The results show that the basic and improved ecological water supply of Biliuhe reservoir is 27.65 million cubic meters and 42.5 million cubic meters, respectively. The river ecological environment will be significantly improved with the implementation of the strictest water management system and the development and utilization of non-conventional water resources, as well as the implementation of the water diversion project and river-reservoir connectivity project.
20 Development and Application of a Shaft-type Tubular Pumping System with a Siphon Discharge Passage
2013(1):O1-O6.
Abstract:
Based on the characteristics of large flow rate, low head, short annual operation time, and high reliability of the city flood-control pumping stations, a new-type shaft tubular pumping system featuring a shaft suction box and a siphon-type discharge passage with a vacuum breaker as the cutoff device was developed, which possesses such advantages as simple structure, reliable cutoff, and high energy performance. Taking some pumping stations as the case studies, in the light of the specified operation conditions, the hydraulic optimal design of the shaft-type tubular pumping system was determined and the optimized shape of the system was recommended. The performance prediction based on the computational fluid dynamics methodology was determined and the model test verification was conducted. The results show that the predicted data agree with the experimental head and efficiency so that both methods can be used to determine the performance of a real pumping station. Finally, the in-situ measurements of a pumping station during the commissioning period further verified that the shaft-type tubular pumping station with a siphon discharge passage is of higher efficiency, more reliable and stable.
Based on the characteristics of large flow rate, low head, short annual operation time, and high reliability of the city flood-control pumping stations, a new-type shaft tubular pumping system featuring a shaft suction box and a siphon-type discharge passage with a vacuum breaker as the cutoff device was developed, which possesses such advantages as simple structure, reliable cutoff, and high energy performance. Taking some pumping stations as the case studies, in the light of the specified operation conditions, the hydraulic optimal design of the shaft-type tubular pumping system was determined and the optimized shape of the system was recommended. The performance prediction based on the computational fluid dynamics methodology was determined and the model test verification was conducted. The results show that the predicted data agree with the experimental head and efficiency so that both methods can be used to determine the performance of a real pumping station. Finally, the in-situ measurements of a pumping station during the commissioning period further verified that the shaft-type tubular pumping station with a siphon discharge passage is of higher efficiency, more reliable and stable.
2013(1):O7-O15.
Abstract:
The turbulent flows through the channels with abrupt cross-sectional changes are common and important physical process in nature. For a better prediction of the mean flow and turbulent characteristics for this problem, a two-dimensional depth-averaged numerical model is developed. The model is robust and accurate in reproducing the recirculation flow behind a groyne and turbulent flows in channels with abrupt cross-sectional changes, when compared to the available experimental data of mean velocities and turbulence kinetic energy. Our results reveal that the abrupt cross-sectional change of a channel can affect the flow pattern significantly and introduces the complex turbulence characteristics. In particular, when the channel has an abrupt expansion, the mean flow pattern is mainly in longitudinal direction with rather small transverse component. Meanwhile, a recirculating region forms behind the expansion position and the turbulence has very strong intensity within this region. For the flow in the channel with an abrupt contraction, the longitudinal component of the flow is decreased by the obstruction on one side and accelerated on the other side, whereas the transverse velocity is small. The turbulence is extraordinarily strong in the regions adjacent to the contraction wall in the narrow channel. In both cases of abrupt cross-sectional changes, the TKE is generated dominantly by the shear of the longitudinal velocities.
The turbulent flows through the channels with abrupt cross-sectional changes are common and important physical process in nature. For a better prediction of the mean flow and turbulent characteristics for this problem, a two-dimensional depth-averaged numerical model is developed. The model is robust and accurate in reproducing the recirculation flow behind a groyne and turbulent flows in channels with abrupt cross-sectional changes, when compared to the available experimental data of mean velocities and turbulence kinetic energy. Our results reveal that the abrupt cross-sectional change of a channel can affect the flow pattern significantly and introduces the complex turbulence characteristics. In particular, when the channel has an abrupt expansion, the mean flow pattern is mainly in longitudinal direction with rather small transverse component. Meanwhile, a recirculating region forms behind the expansion position and the turbulence has very strong intensity within this region. For the flow in the channel with an abrupt contraction, the longitudinal component of the flow is decreased by the obstruction on one side and accelerated on the other side, whereas the transverse velocity is small. The turbulence is extraordinarily strong in the regions adjacent to the contraction wall in the narrow channel. In both cases of abrupt cross-sectional changes, the TKE is generated dominantly by the shear of the longitudinal velocities.
2013(1):101-103.
Abstract:
he experiment adopts biological membranes and artificial wetland as the way of sewage purification, which including five sewage treatment units. The experiment analyzed the effect of sewage purification under different conditions,1d,3d,5d,7d,respectively.Given the different removal rates of contaminants, there comes a conclusion: when concerning about purifying effect, unit I is the best, followed by unit Ⅱand unit Ⅴthen the poorest ones are unit IV and unit III.
he experiment adopts biological membranes and artificial wetland as the way of sewage purification, which including five sewage treatment units. The experiment analyzed the effect of sewage purification under different conditions,1d,3d,5d,7d,respectively.Given the different removal rates of contaminants, there comes a conclusion: when concerning about purifying effect, unit I is the best, followed by unit Ⅱand unit Ⅴthen the poorest ones are unit IV and unit III.
2013(1):104-109.
Abstract:
For the issues of groundwater sustainable utilization in the hilly area of the Taihang mountains piedmont, it is expounded on characteristics of storing non-uniformity and of the vulnerability of the aquifers to dewatering in the area in the exploitation, based on the pumping test data for many times from two of 500 meters depth of bedrock fissure groundwater wells in the distance of 3.92km, through the multiple quantitative comparison method. The research results show that, not only the different between the well area of groundwater occurrence is non-uniform, and the respective two well in their hole, different depth as differences. In the time of less than 70 minutes pumping time, groundwater level decline in the ZKs-3 well is more than that in the ZKs-2 well. 70 minutes later pumping time, the decline of the ZKs-2 well is much more than that of the ZKs-3 well, and the difference between the two decline increases gradually with the pumping time increased. These results indicates that the abundance water is more much in the upper aquifers of the ZKs-2 well area and is more weak in the lower aquifers; the abundance water is more weak in the upper aquifers of the ZKs-3 well area and is more much in the lower aquifers. The exploitation vulnerability of groundwater to dewatering is different in aquifer system of different, with pumping test times increase, the maximum drawdown and groundwater level recovery time in the ZKs-2 well were increased, but the level can be fully restored to the initial level state in each time test; the groundwater level did not return to the initial level state in the ZKs-3 well, and to the initial level distance increases as the increase of the number of test, but each time of the level recovery to stable state did not significantly change. Therefore, in the hill area in groundwater resources development and utilization, reasonable design, prevent the aquifers to dewatering.
For the issues of groundwater sustainable utilization in the hilly area of the Taihang mountains piedmont, it is expounded on characteristics of storing non-uniformity and of the vulnerability of the aquifers to dewatering in the area in the exploitation, based on the pumping test data for many times from two of 500 meters depth of bedrock fissure groundwater wells in the distance of 3.92km, through the multiple quantitative comparison method. The research results show that, not only the different between the well area of groundwater occurrence is non-uniform, and the respective two well in their hole, different depth as differences. In the time of less than 70 minutes pumping time, groundwater level decline in the ZKs-3 well is more than that in the ZKs-2 well. 70 minutes later pumping time, the decline of the ZKs-2 well is much more than that of the ZKs-3 well, and the difference between the two decline increases gradually with the pumping time increased. These results indicates that the abundance water is more much in the upper aquifers of the ZKs-2 well area and is more weak in the lower aquifers; the abundance water is more weak in the upper aquifers of the ZKs-3 well area and is more much in the lower aquifers. The exploitation vulnerability of groundwater to dewatering is different in aquifer system of different, with pumping test times increase, the maximum drawdown and groundwater level recovery time in the ZKs-2 well were increased, but the level can be fully restored to the initial level state in each time test; the groundwater level did not return to the initial level state in the ZKs-3 well, and to the initial level distance increases as the increase of the number of test, but each time of the level recovery to stable state did not significantly change. Therefore, in the hill area in groundwater resources development and utilization, reasonable design, prevent the aquifers to dewatering.
2013(1):110-114.
Abstract:
The Mt. Emei is a faulty block mountain, it is famous for the great and beautiful, but how it was formed? There is no systematically studied. Based on the engineering mapping of 1:25000 scale, the paper systematically studies the geological structure feature and structural superimposed folds, some research results can be concluded: The uplift of Mt. Emei began in the end of the Eocene, i.e. , during the Himalayan movement of the first epoch, under the pressure of NWW-NEE regional geo-stress, the NNE strike folds and NE faults have been formed, it uplifted and became the erosion area. Since the Neocene, under the nearly EW regional pressure geo-stress field, the blunt cone Daeshan faulty block was wedging eastward, the early NNE strike strata of the block frontier bent anti-clockwise, the strike of the strata in the frontier area (Longmendong–Baoguosi ) became SN, the strata dip westward; the Jianjianshi anticline bending eastward in north boundary of the block, forming NW strike tectonic superposition, while the outer area far from the block frontier, the attitudes of the strata are normal; The Emeishan fault slips in east boundary, Since the Quaternary, The intensive intermittent uplift，10 uplifting events happened and the relief gradually formed. Since the Cenozoic, uplifting distance of the Emeishan fault is about 6000m, the strike slip distance is 4000m.
The Mt. Emei is a faulty block mountain, it is famous for the great and beautiful, but how it was formed? There is no systematically studied. Based on the engineering mapping of 1:25000 scale, the paper systematically studies the geological structure feature and structural superimposed folds, some research results can be concluded: The uplift of Mt. Emei began in the end of the Eocene, i.e. , during the Himalayan movement of the first epoch, under the pressure of NWW-NEE regional geo-stress, the NNE strike folds and NE faults have been formed, it uplifted and became the erosion area. Since the Neocene, under the nearly EW regional pressure geo-stress field, the blunt cone Daeshan faulty block was wedging eastward, the early NNE strike strata of the block frontier bent anti-clockwise, the strike of the strata in the frontier area (Longmendong–Baoguosi ) became SN, the strata dip westward; the Jianjianshi anticline bending eastward in north boundary of the block, forming NW strike tectonic superposition, while the outer area far from the block frontier, the attitudes of the strata are normal; The Emeishan fault slips in east boundary, Since the Quaternary, The intensive intermittent uplift，10 uplifting events happened and the relief gradually formed. Since the Cenozoic, uplifting distance of the Emeishan fault is about 6000m, the strike slip distance is 4000m.
2013(1):115-121.
Abstract:
The heterogeneity is one essential property of karstic medium, resulting in the complicated hydrologic cycle and shallow geologic evolution. Moreover, the heterogeneity of medium also leads to the high difficulty for the evaluation of groundwater flow system and solute transportation. The SWMM developed by EPA (U.S. Environmental Protection Agency) was used in this study to simulate the hydrologic process conducted at the laboratory. The hydrologic effects of the heterogeneity were discussed through the calibrated SWMM model. The results indicate that SWMM model is appropriate to model the karstic hydrologic process for the conduit-fissure medium. The conduit size, the medium void and the exchange coefficient of groundwater and surface interaction has slight effect on the water level and discharge of the outlet of drainage area. However, the conduit size controls the highest groundwater level, the magnitude of medium void can change the process of groundwater increasing and decreasing, and the exchange coefficient has significant effects on the change speed of groundwater level and the highest groundwater level.
The heterogeneity is one essential property of karstic medium, resulting in the complicated hydrologic cycle and shallow geologic evolution. Moreover, the heterogeneity of medium also leads to the high difficulty for the evaluation of groundwater flow system and solute transportation. The SWMM developed by EPA (U.S. Environmental Protection Agency) was used in this study to simulate the hydrologic process conducted at the laboratory. The hydrologic effects of the heterogeneity were discussed through the calibrated SWMM model. The results indicate that SWMM model is appropriate to model the karstic hydrologic process for the conduit-fissure medium. The conduit size, the medium void and the exchange coefficient of groundwater and surface interaction has slight effect on the water level and discharge of the outlet of drainage area. However, the conduit size controls the highest groundwater level, the magnitude of medium void can change the process of groundwater increasing and decreasing, and the exchange coefficient has significant effects on the change speed of groundwater level and the highest groundwater level.
2013(1):122-126.
Abstract:
Considering the past definitions and characteristics of water security, the definition of urban water security is proposed tentatively. Based on these, the urban water security system is divided into four subsystems, including urban scale subsystem, flood control security subsystem, water supply security subsystem and water environment security subsystem. The evaluation index system and criterion for south China are built, and the weight of each hierarchy is confirmed by the analytical hierarchy process (AHP). The values of indicators are normalized using exponential efficacy function based on the law of diminishing marginal utility. The concepts of coordination index (CI) and development index (DI) are proposed to illustrate the degree of coordination and stability of water security system. The states of urban water security in Wuhan City from 2003 to 2009 are evaluated by the new model. The result shows that the city from 2003 to 2009 is in safe status, and the situation is getting better. The application results verify the feasibility effectiveness of the model.
Considering the past definitions and characteristics of water security, the definition of urban water security is proposed tentatively. Based on these, the urban water security system is divided into four subsystems, including urban scale subsystem, flood control security subsystem, water supply security subsystem and water environment security subsystem. The evaluation index system and criterion for south China are built, and the weight of each hierarchy is confirmed by the analytical hierarchy process (AHP). The values of indicators are normalized using exponential efficacy function based on the law of diminishing marginal utility. The concepts of coordination index (CI) and development index (DI) are proposed to illustrate the degree of coordination and stability of water security system. The states of urban water security in Wuhan City from 2003 to 2009 are evaluated by the new model. The result shows that the city from 2003 to 2009 is in safe status, and the situation is getting better. The application results verify the feasibility effectiveness of the model.
2013(1):127-131.
Abstract:
Delineation of drinking groundwater sources protection areas at the cities where groundwater is main water supply sources will increase the degree to drinking water security. This paper summaried the delineation principles and methods of near-river drinking groundwater source proctection area, and established a numerical groundwater flow model using FEFLOW software. Three scenerios were simulated based on planned groundwater exploriation mode. Finnally three-level groundwater protection ranges were delineated using the method of inverse particle tracking. This study can provide scientific references for groundwater management and effective protection at Wuzhong city or other cities with silimar hydrogeological conditions.
Delineation of drinking groundwater sources protection areas at the cities where groundwater is main water supply sources will increase the degree to drinking water security. This paper summaried the delineation principles and methods of near-river drinking groundwater source proctection area, and established a numerical groundwater flow model using FEFLOW software. Three scenerios were simulated based on planned groundwater exploriation mode. Finnally three-level groundwater protection ranges were delineated using the method of inverse particle tracking. This study can provide scientific references for groundwater management and effective protection at Wuzhong city or other cities with silimar hydrogeological conditions.
2013(1):132-136.
Abstract:
In order to solve the problem of the “intelligence” deficiency in the traditional decision support system of river basin flood control, the intelligent operation system framework of real-time river basin flood control based on Multi-Agent System (MAS) is established in this paper. The multi-agent decomposition model of river basin flood control system is proposed, which is divided into several agents with relative independence and limited contact. The composition and design methods of functional agents and communication methods among agents of different levels are developed. The organization and operation mechanisms of the multi-agent system which is characterized by autonomy, reactivity and intelligence are also proposed. The studies of the proposed system framework have offered a new way for the “intellectualization” of river basin flood control operation.
In order to solve the problem of the “intelligence” deficiency in the traditional decision support system of river basin flood control, the intelligent operation system framework of real-time river basin flood control based on Multi-Agent System (MAS) is established in this paper. The multi-agent decomposition model of river basin flood control system is proposed, which is divided into several agents with relative independence and limited contact. The composition and design methods of functional agents and communication methods among agents of different levels are developed. The organization and operation mechanisms of the multi-agent system which is characterized by autonomy, reactivity and intelligence are also proposed. The studies of the proposed system framework have offered a new way for the “intellectualization” of river basin flood control operation.
2013(1):137-142.
Abstract:
The combination of component technology and computer technology can conquer the difficulty to make large-scale system simulation integration by the traditional modeling method and can promote effectively the development of the watershed simulation model integration. Therefore, the paper analyzed the important role of the modeling component in the portability, flexibility, expansibility and third party software integration. The present situation of watershed simulation model integrated technology at home and at broad are discussed. The existing problems at home in this research field are proposed. The paper looked forward to the development trend of watershed simulation model integrated technology in modeling platform, modeling integration-based the cloud computing and the modeling application component.
The combination of component technology and computer technology can conquer the difficulty to make large-scale system simulation integration by the traditional modeling method and can promote effectively the development of the watershed simulation model integration. Therefore, the paper analyzed the important role of the modeling component in the portability, flexibility, expansibility and third party software integration. The present situation of watershed simulation model integrated technology at home and at broad are discussed. The existing problems at home in this research field are proposed. The paper looked forward to the development trend of watershed simulation model integrated technology in modeling platform, modeling integration-based the cloud computing and the modeling application component.
2013(1):143-146.
Abstract:
The sandy and silt quality coastal of the China is showing evolution trend in decade years. Based on the improvement of the spectral, temporal and spatial resolution of the satellite remote sensing data, and provide increasingly high accuracy of remote sensing data sources to monitoring the coastal erosion and deposition. Base on previous study, the writer using remote sensing techniques and filed surveys for study the coastline change and the erosion and deposition of the abandoned Yellow River in the northern Jiangsu province. The result shows us that using multi-temporal remote sensing data in coastline changes, erosion and deposition monitoring and prediction has the unparalleled advantage of other technologies, and has become a practical technique in monitoring of coastal geological environment.
The sandy and silt quality coastal of the China is showing evolution trend in decade years. Based on the improvement of the spectral, temporal and spatial resolution of the satellite remote sensing data, and provide increasingly high accuracy of remote sensing data sources to monitoring the coastal erosion and deposition. Base on previous study, the writer using remote sensing techniques and filed surveys for study the coastline change and the erosion and deposition of the abandoned Yellow River in the northern Jiangsu province. The result shows us that using multi-temporal remote sensing data in coastline changes, erosion and deposition monitoring and prediction has the unparalleled advantage of other technologies, and has become a practical technique in monitoring of coastal geological environment.
2013(1):147-151.
Abstract:
With the development of China's economy, the agricultural water facing enormous challenges, to enhance farmland water use efficiency is essential to solve the problem of water shortage in the food production process. Comprehensive analysis on the research progress and development trend for the agronomic water-saving technology measures about tillage for soil moisture conservation, covering for soil moisture conservation, organic fertilizer and crop straw to soil, water and fertilizer coupling, adjust crop layout, selection of water-saving varieties and chemical control etc. In the light of the achievement and existing problems on agronomic water-saving technology measures, put forward some important theoretical problems and key technologies, with a view to agronomic water-saving technology promotes a new height.
With the development of China's economy, the agricultural water facing enormous challenges, to enhance farmland water use efficiency is essential to solve the problem of water shortage in the food production process. Comprehensive analysis on the research progress and development trend for the agronomic water-saving technology measures about tillage for soil moisture conservation, covering for soil moisture conservation, organic fertilizer and crop straw to soil, water and fertilizer coupling, adjust crop layout, selection of water-saving varieties and chemical control etc. In the light of the achievement and existing problems on agronomic water-saving technology measures, put forward some important theoretical problems and key technologies, with a view to agronomic water-saving technology promotes a new height.
2013(1):152-155.
Abstract:
For an in-depth study on the soil moisture transfer law of snow-covered boundary conditions, a moisture transfer model of seasonal frozen soil under the stable snow-covered condition was established ,which through the observed experiments of the winter soil moisture and using the soil hydrodynamics theory. The study result shows that: the average temperature of soil which covered with snow is 1℃ higher than the bare and the water content of unit volume (soil profile is 0cm to 100cm) is 2% higher. It reflects that the covered snow can not only prevent the loss of soil heat, but also maintain the soil moisture content. The model can accurately simulate the transfer dynamics of frozen soil under the snow cover. The relative average inaccuracy is just 3.51%.The research result has important theoretical and practical significance to rich and perfect the frozen soil moisture transfer theory and solved the spring drought and “cold drawing” of winter wheat and so on.
For an in-depth study on the soil moisture transfer law of snow-covered boundary conditions, a moisture transfer model of seasonal frozen soil under the stable snow-covered condition was established ,which through the observed experiments of the winter soil moisture and using the soil hydrodynamics theory. The study result shows that: the average temperature of soil which covered with snow is 1℃ higher than the bare and the water content of unit volume (soil profile is 0cm to 100cm) is 2% higher. It reflects that the covered snow can not only prevent the loss of soil heat, but also maintain the soil moisture content. The model can accurately simulate the transfer dynamics of frozen soil under the snow cover. The relative average inaccuracy is just 3.51%.The research result has important theoretical and practical significance to rich and perfect the frozen soil moisture transfer theory and solved the spring drought and “cold drawing” of winter wheat and so on.
2013(1):156-161.
Abstract:
This experiment depended on the deep soil water profile observation system in Luanchen experimental station, using neutron moisture viewer to observe the soil water content on 15.4 meter soil profile in situ for one continuous year. Combine with the deep soil ahd water sample collection test at regular interval, analysised the dynamic changes of soil water and quantitated the drainage volume in deep soil layer. The follow results showed that the distribution charactoristics of soil moisture were controled by soil texture and it fluctuated with the influence of precipitation and irrigation event. The variability of soil moisture decreasing along with the increasing soil depth. With the influence of precipitation (irrigation) and evapotranspiration, dramatic variations of soil moisture occurred in the root zone. However, response to the precipitation for the soil moisture below the root zone was delayed. The soil water contents were surplus in the whole soil profile (15.4 meter) during the observation period and the gained soil water storage were 216 mm. Nevertheless, the soil water contents lost in the wheat seasons and the soil water storage depleted 208 mm. Based on the chloride mass balance method, the deep drainage were estimated. It was almost 65 mm soil water that percolated through the soil layer which beneath the 560 cm depth.
This experiment depended on the deep soil water profile observation system in Luanchen experimental station, using neutron moisture viewer to observe the soil water content on 15.4 meter soil profile in situ for one continuous year. Combine with the deep soil ahd water sample collection test at regular interval, analysised the dynamic changes of soil water and quantitated the drainage volume in deep soil layer. The follow results showed that the distribution charactoristics of soil moisture were controled by soil texture and it fluctuated with the influence of precipitation and irrigation event. The variability of soil moisture decreasing along with the increasing soil depth. With the influence of precipitation (irrigation) and evapotranspiration, dramatic variations of soil moisture occurred in the root zone. However, response to the precipitation for the soil moisture below the root zone was delayed. The soil water contents were surplus in the whole soil profile (15.4 meter) during the observation period and the gained soil water storage were 216 mm. Nevertheless, the soil water contents lost in the wheat seasons and the soil water storage depleted 208 mm. Based on the chloride mass balance method, the deep drainage were estimated. It was almost 65 mm soil water that percolated through the soil layer which beneath the 560 cm depth.
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