In this paper, we proposed a new method that has been developed based on the surface soil moisture content(SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this m...In this paper, we proposed a new method that has been developed based on the surface soil moisture content(SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this method, the empirical formula to calculate evaporation was modified and the value of the formula varies from zero to one as a closed interval. In addition, the simulation code for calculating the groundwater evaporation based on the SSMC method was incorporated into the EOS9 module of Tough2, a variably saturated flow modeling code. Finally, two numerical tests and a case simulation were conducted to verify the feasibility and accuracy of the SSMC method. Simulation results indicate that the SSMC method is capable of appropriately simulating the characteristics of water flow in vadose zone and the amount of evaporation with the variable water table. And such results are in coincidence with the value calculated by the logistic function method, and fit well with the measured data globally rather than locally.展开更多
Based on the special hydrogeological conditions of the Dahei River Plain in the Inner Mongolia area, assessment of shallow groundwater vulnerability is conducted based on DRASTIC model. Each evaluation indicator weigh...Based on the special hydrogeological conditions of the Dahei River Plain in the Inner Mongolia area, assessment of shallow groundwater vulnerability is conducted based on DRASTIC model. Each evaluation indicator weight is determined by using analytic hierarchy process(AHP). The most important indicators are lithology in soil media and vadose zone. Assessment model of shallow groundwater vulnerability of the Dahei River plain is constructed. Distribution map of vulnerability index in this area is made with the spatial analysis function of ARCGIS. The results show that the particularly sensitive area is the piedmont of the Daqing Mountain, where the upstream place of the groundwater and the south-central place of the plain has the lowest vulnerability. The assessment results are more in accordance with the actual vulnerability conditions of this area by using analytic hierarchy process, and is helpful for groundwater protection.展开更多
The developmental characteristics of groundwater flow system are not only controlled by formation lithology and groundwater recharge conditions,but also influenced by the physical properties of fluids.Numerical simula...The developmental characteristics of groundwater flow system are not only controlled by formation lithology and groundwater recharge conditions,but also influenced by the physical properties of fluids.Numerical simulation is an effective way to study groundwater flow system.In this paper,the ideal model is generalized according to the fundamental characteristics of groundwater system in inland basins of Western China.The simulation method of variable density flow on the development of groundwater system in inland basins is established by using EOS9 module in TOUGHREACT numerical simulation software.In accordance with the groundwater streamline,the groundwater flow system is divided into three levels,which are regional groundwater flow system,intermediate groundwater flow system and local groundwater flow system.Based on the calculation of the renewal rate of groundwater,the analysis shows that the increase of fluid density in the central part of the basin will restrain the development of regional groundwater flow system,resulting in a decrease of the circulation rate from 32.28% to 17.62% and a certain enhancement to the local groundwater flow system,which increased from 37.29% to 51.94%.展开更多
The deformation and the drainage of the aquitard is the main concern in the North China Plain(NCP), and the water released from aquitard compaction may be a large portion of the exploited groundwater. The skeletal spe...The deformation and the drainage of the aquitard is the main concern in the North China Plain(NCP), and the water released from aquitard compaction may be a large portion of the exploited groundwater. The skeletal specific storage of aquitard is the element parameter to the drainage of aquitard, and the undisturbed core samples are the best choice for the measurement of the physical parameters. In this study, the consolidation test was employed to analyze the skeleton specific storage of the clay sample drilled from Hengshui City, and the contribution from the drainage of aquitard to the groundwater exploitation. The results suggest the consolidation test can be utilized to understand the skeletal specific storage of aquitard, which is about 3.92×10-4 m-1 in the Hengshui. The water-saturation content of the aquitard was less than 100%, and the amount of the drainage of the aquitard was about 69% of the volume of land subsidence. The water released from aquitard compaction was about 35% of the groundwater exploitation to the deep aquifers.展开更多
基金supported by the China Geology Survey Work Program (No.1212011121277)
文摘In this paper, we proposed a new method that has been developed based on the surface soil moisture content(SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this method, the empirical formula to calculate evaporation was modified and the value of the formula varies from zero to one as a closed interval. In addition, the simulation code for calculating the groundwater evaporation based on the SSMC method was incorporated into the EOS9 module of Tough2, a variably saturated flow modeling code. Finally, two numerical tests and a case simulation were conducted to verify the feasibility and accuracy of the SSMC method. Simulation results indicate that the SSMC method is capable of appropriately simulating the characteristics of water flow in vadose zone and the amount of evaporation with the variable water table. And such results are in coincidence with the value calculated by the logistic function method, and fit well with the measured data globally rather than locally.
基金Basic Scientific Research Operating Expense Project of the Chinese Academy of Geological Sciences“Leaky System Numerical Modeling and Progressive Parameter Inversion Study”(YYWF201626)Geological survey project“1/50 000 Hydrogeological Survey of the Hutuo River-Fuyang River Basin Plain”(DD20160238)
文摘Based on the special hydrogeological conditions of the Dahei River Plain in the Inner Mongolia area, assessment of shallow groundwater vulnerability is conducted based on DRASTIC model. Each evaluation indicator weight is determined by using analytic hierarchy process(AHP). The most important indicators are lithology in soil media and vadose zone. Assessment model of shallow groundwater vulnerability of the Dahei River plain is constructed. Distribution map of vulnerability index in this area is made with the spatial analysis function of ARCGIS. The results show that the particularly sensitive area is the piedmont of the Daqing Mountain, where the upstream place of the groundwater and the south-central place of the plain has the lowest vulnerability. The assessment results are more in accordance with the actual vulnerability conditions of this area by using analytic hierarchy process, and is helpful for groundwater protection.
基金jointly funded by the National Natural Science Foundation of China (41702282, 41602268)China Geological Survey Project (DD20160311, DD20160238)the Basic Research Service Fee of the Chinese Academy of Geological Sciences (YYWF201626)
文摘The developmental characteristics of groundwater flow system are not only controlled by formation lithology and groundwater recharge conditions,but also influenced by the physical properties of fluids.Numerical simulation is an effective way to study groundwater flow system.In this paper,the ideal model is generalized according to the fundamental characteristics of groundwater system in inland basins of Western China.The simulation method of variable density flow on the development of groundwater system in inland basins is established by using EOS9 module in TOUGHREACT numerical simulation software.In accordance with the groundwater streamline,the groundwater flow system is divided into three levels,which are regional groundwater flow system,intermediate groundwater flow system and local groundwater flow system.Based on the calculation of the renewal rate of groundwater,the analysis shows that the increase of fluid density in the central part of the basin will restrain the development of regional groundwater flow system,resulting in a decrease of the circulation rate from 32.28% to 17.62% and a certain enhancement to the local groundwater flow system,which increased from 37.29% to 51.94%.
基金financially supported by the National Natural Science Foundation of China(NSFC grant No.41602268 and No.41702283)China Geological Survey Project(DD20160238,DD20160311)
文摘The deformation and the drainage of the aquitard is the main concern in the North China Plain(NCP), and the water released from aquitard compaction may be a large portion of the exploited groundwater. The skeletal specific storage of aquitard is the element parameter to the drainage of aquitard, and the undisturbed core samples are the best choice for the measurement of the physical parameters. In this study, the consolidation test was employed to analyze the skeleton specific storage of the clay sample drilled from Hengshui City, and the contribution from the drainage of aquitard to the groundwater exploitation. The results suggest the consolidation test can be utilized to understand the skeletal specific storage of aquitard, which is about 3.92×10-4 m-1 in the Hengshui. The water-saturation content of the aquitard was less than 100%, and the amount of the drainage of the aquitard was about 69% of the volume of land subsidence. The water released from aquitard compaction was about 35% of the groundwater exploitation to the deep aquifers.
