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
The desire to increase spatial and temporal resolution in modeling groundwater system has led to the requirement for intensive computational ability and large memory space. In the course of satisfying such requirement...The desire to increase spatial and temporal resolution in modeling groundwater system has led to the requirement for intensive computational ability and large memory space. In the course of satisfying such requirement, parallel computing has played a core role over the past several decades. This paper reviews the parallel algebraic linear solution methods and the parallel implementation technologies for groundwater simulation. This work is carried out to provide guidance to enable modelers of groundwater systems to make sensible choices when developing solution methods based upon the current state of knowledge in parallel computing.展开更多
With the completion of South-North Water Transfer Project in China, plenty of high quality water will be transported to Beijing. To restore the groundwater level in Beijing, part of transferred water is planned to be ...With the completion of South-North Water Transfer Project in China, plenty of high quality water will be transported to Beijing. To restore the groundwater level in Beijing, part of transferred water is planned to be used for artificial recharge. Clogging is an unavoidable challenge in the artificial recharge process. Therefore, a test is designed to analyse clogging duration and scope of influence and to test the reinjection properties of different recharge media. The test employs the self-designed sand column system with variable spacing and section monitoring, composed of four parts: Sand column, water-supply system, pressure-test system and flow-test system, to simulate the clogging of artificial recharge of sand and gravel pits. The hydraulic conductivity levels of all sand column sections are obtained to analyse the clogging of the injection of different concentrations in media of different particle sizes. In this experiment, two kinds of media are used–round gravel from sand and gravel pit in Xihuang village and the sand from sand and gravel pit by the Yongding River. The concentrations of recharge fluid are respectively 0.5 g/L and 1 g/L. The results show that clogging usually lasts for 20 hrs., and the hydraulic conductivity drops to the original 10%. Clogging usually occurs at 0–12 cm section of the sand column. The scope of influence is 0–60 cm. In column 3 and 4, whose average particle sizes are larger, section 20–50 cm also suffers from clogging, apart from section 0–12 cm. The effective recharge times are respectively 33 hrs. in column 1, 14 hrs. in column 2, 12 hrs. in column 3 and 12 hrs. in column 4. The larger the average particle size is, the quicker the clogging occurs. In media of larger particles, the change in suspension concentration does not have significant influence on the development of clogging. In conclusion, it is suggested that during artificial recharge, the conditions of reinjection medium should be fully considered and effective method of recharge be employed in order to improve effective recharge time.展开更多
Based on such principles as sustainable development and ecological cycle, this paper evaluates the water resources carrying capacity(WCC) of Changchun-Jilin region using a population-economy-water resources correlatio...Based on such principles as sustainable development and ecological cycle, this paper evaluates the water resources carrying capacity(WCC) of Changchun-Jilin region using a population-economy-water resources correlation evaluation model built on the basis of WCC evaluation method as elaborated in the methodology of Functional Zoning of Population Development. Results show that the annual WCC of Changchun-Jilin region is able to support the population there, as a basic balance is struck between population and water resources. The incorporation of WCC into overall urban planning is one of the building blocks for sustainable city development with an advisable size.展开更多
As a typical alluvial-proluvial fan area in the Qaidam Basin, Nuomuhong is important to the research on paleoclimate reconstruction in proluvial fan areas and basin climate change and ecological protection. This paper...As a typical alluvial-proluvial fan area in the Qaidam Basin, Nuomuhong is important to the research on paleoclimate reconstruction in proluvial fan areas and basin climate change and ecological protection. This paper analyzes features of 2H, 3H, 18 O and 14 C isotopes in Nuomuhong and reconstructs paleoclimate in this area. According to the results: since 28 ka B.P., the ground average temperature decreases and then increases in the Qaidam watershed, reaching the lowest in 17.7 ka B.P. before increasing gradually. In the past 30 000 years, average temperature has changed ranged from 1 ℃ to 5 ℃ in this area; the lowest temperature was different from today’s temperature only by 3 ℃. This shows that climate conditions and natural environment in this area have been relatively stable in the past 30 000 years.展开更多
The geological environment is the basis of ecological planning. In this article, the factor analysis combined with Analytic Hierarchy Process(AHP) and GIS(geographic information technology) was used. The method sets g...The geological environment is the basis of ecological planning. In this article, the factor analysis combined with Analytic Hierarchy Process(AHP) and GIS(geographic information technology) was used. The method sets geological disasters, landform type,surface slope, soil type and erosion as ecological suitability of geology factor; distribution of surface water,precipitation distribution,hydraulic engineering and degree of groundwater development as ecology suitability of water resources. Huairou, located in Beijing, was set as an example through the method. The article evaluated the suitability of the geological environment to ecology and solved quantitative description about the key technologies of the degree of influence to ecology which is affected by the geological environment. In the end, a theoretical guidance and a kind of technical method of establishing a scientific ecological planning system and guiding ecological planning were provided.展开更多
In order to simulate the recovery of groundwater funnels under the condition of reducing groundwater abstraction, hydrogeological conditions of recoverability construction of Shijiazhuang groundwater funnel were analy...In order to simulate the recovery of groundwater funnels under the condition of reducing groundwater abstraction, hydrogeological conditions of recoverability construction of Shijiazhuang groundwater funnel were analyzed, and a numerical simulation method was used based on the change of various parameters. The results show that the groundwater flow model can accurately reflect groundwater hydrogeological characteristics, and can guarantee the reliability of groundwater restoration prediction. The research has set up four schemes for rural water-saving, planting structure adjustment, urban reducing abstraction and integrated method. The effect of four restoration schemes on the restoration of groundwater funnels was compared with water table variations of two observation well. Comparison results show that the level changes of plan Three and Four are different from the other two kinds of exploitation and the drop trend of water table in the funnel area is flat. So we can conclude that Plan Three and Four have significant effect on the groundwater funnel restoration of Shijiazhuang.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supported by the National Basic Research Program (973 Program) of China under Grant No.2010CB428804 and 2011CB 309702
文摘The desire to increase spatial and temporal resolution in modeling groundwater system has led to the requirement for intensive computational ability and large memory space. In the course of satisfying such requirement, parallel computing has played a core role over the past several decades. This paper reviews the parallel algebraic linear solution methods and the parallel implementation technologies for groundwater simulation. This work is carried out to provide guidance to enable modelers of groundwater systems to make sensible choices when developing solution methods based upon the current state of knowledge in parallel computing.
基金supported by public welfare geological investigation and scientific project of Beijing (2010): The key technology on clogging features analysis of groundwater artificial recharge
文摘With the completion of South-North Water Transfer Project in China, plenty of high quality water will be transported to Beijing. To restore the groundwater level in Beijing, part of transferred water is planned to be used for artificial recharge. Clogging is an unavoidable challenge in the artificial recharge process. Therefore, a test is designed to analyse clogging duration and scope of influence and to test the reinjection properties of different recharge media. The test employs the self-designed sand column system with variable spacing and section monitoring, composed of four parts: Sand column, water-supply system, pressure-test system and flow-test system, to simulate the clogging of artificial recharge of sand and gravel pits. The hydraulic conductivity levels of all sand column sections are obtained to analyse the clogging of the injection of different concentrations in media of different particle sizes. In this experiment, two kinds of media are used–round gravel from sand and gravel pit in Xihuang village and the sand from sand and gravel pit by the Yongding River. The concentrations of recharge fluid are respectively 0.5 g/L and 1 g/L. The results show that clogging usually lasts for 20 hrs., and the hydraulic conductivity drops to the original 10%. Clogging usually occurs at 0–12 cm section of the sand column. The scope of influence is 0–60 cm. In column 3 and 4, whose average particle sizes are larger, section 20–50 cm also suffers from clogging, apart from section 0–12 cm. The effective recharge times are respectively 33 hrs. in column 1, 14 hrs. in column 2, 12 hrs. in column 3 and 12 hrs. in column 4. The larger the average particle size is, the quicker the clogging occurs. In media of larger particles, the change in suspension concentration does not have significant influence on the development of clogging. In conclusion, it is suggested that during artificial recharge, the conditions of reinjection medium should be fully considered and effective method of recharge be employed in order to improve effective recharge time.
基金The research and demonstration of key technologies and methods of eco-planning in urban construction,the 11th Five-year Plan of National Science and Technology Infrastructure Program,MOST,2007-2011(No.2007BAC28B02)
文摘Based on such principles as sustainable development and ecological cycle, this paper evaluates the water resources carrying capacity(WCC) of Changchun-Jilin region using a population-economy-water resources correlation evaluation model built on the basis of WCC evaluation method as elaborated in the methodology of Functional Zoning of Population Development. Results show that the annual WCC of Changchun-Jilin region is able to support the population there, as a basic balance is struck between population and water resources. The incorporation of WCC into overall urban planning is one of the building blocks for sustainable city development with an advisable size.
基金supported by the Open Fund Project of Groundwater and Ecology Key Laboratory in Arid-semi arid Region of the China Geological SurveyWork Project “Geological Survey on Hydrogeological Environment in Circular Economy Pilot Areas in Qaidam Basin” of the China Geological Survey (1212011220974)
文摘As a typical alluvial-proluvial fan area in the Qaidam Basin, Nuomuhong is important to the research on paleoclimate reconstruction in proluvial fan areas and basin climate change and ecological protection. This paper analyzes features of 2H, 3H, 18 O and 14 C isotopes in Nuomuhong and reconstructs paleoclimate in this area. According to the results: since 28 ka B.P., the ground average temperature decreases and then increases in the Qaidam watershed, reaching the lowest in 17.7 ka B.P. before increasing gradually. In the past 30 000 years, average temperature has changed ranged from 1 ℃ to 5 ℃ in this area; the lowest temperature was different from today’s temperature only by 3 ℃. This shows that climate conditions and natural environment in this area have been relatively stable in the past 30 000 years.
文摘The geological environment is the basis of ecological planning. In this article, the factor analysis combined with Analytic Hierarchy Process(AHP) and GIS(geographic information technology) was used. The method sets geological disasters, landform type,surface slope, soil type and erosion as ecological suitability of geology factor; distribution of surface water,precipitation distribution,hydraulic engineering and degree of groundwater development as ecology suitability of water resources. Huairou, located in Beijing, was set as an example through the method. The article evaluated the suitability of the geological environment to ecology and solved quantitative description about the key technologies of the degree of influence to ecology which is affected by the geological environment. In the end, a theoretical guidance and a kind of technical method of establishing a scientific ecological planning system and guiding ecological planning were provided.
基金supported by Public Welfare Project of Ministry of Water Resources(201501008)Natural Science Foundation of Hebei Province(D2015504019)
文摘In order to simulate the recovery of groundwater funnels under the condition of reducing groundwater abstraction, hydrogeological conditions of recoverability construction of Shijiazhuang groundwater funnel were analyzed, and a numerical simulation method was used based on the change of various parameters. The results show that the groundwater flow model can accurately reflect groundwater hydrogeological characteristics, and can guarantee the reliability of groundwater restoration prediction. The research has set up four schemes for rural water-saving, planting structure adjustment, urban reducing abstraction and integrated method. The effect of four restoration schemes on the restoration of groundwater funnels was compared with water table variations of two observation well. Comparison results show that the level changes of plan Three and Four are different from the other two kinds of exploitation and the drop trend of water table in the funnel area is flat. So we can conclude that Plan Three and Four have significant effect on the groundwater funnel restoration of Shijiazhuang.