Examining the descriptions of piezometric heads at two points in both the salt water and fresh water zones reveals that when the groundwater flow system is in steady state and satisfies the Dupuit assumption, the loca...Examining the descriptions of piezometric heads at two points in both the salt water and fresh water zones reveals that when the groundwater flow system is in steady state and satisfies the Dupuit assumption, the location of the fresh water-salt water interface in a homogeneous, isotropic, and unconfined coastal aquifer can be estimated based on a piezometric head of fresh water at a point in the fresh water zone （from the water table to the interface） vertically lined up with a piezometric head of salt water at a point in the salt water zone （from the interface down）. Research shows that the new method is a general relation and that both the Hubbert relation describing the location of the interface and the Ghy- ben--Herzberg relation are special cases of this method. The method requires two piezometric wells to be close to each other and each tapping into a different zone. Measurements of piezometric heads at a well cluster consisting of piezometric wells tapping separately into fresh water and salt water zones near Beihai, China at 5-day intervals for 15 months are used to illustrate the estimation of interface location. The depth of the interface for well H5 ranges from 32 to 72 m below the sea level.展开更多
Further development in the field of geothermal energy require reliable reference data on the thermophysical properties of geothermal waters,namely,on the thermal conductivity and viscosity of aqueous salt solutions at...Further development in the field of geothermal energy require reliable reference data on the thermophysical properties of geothermal waters,namely,on the thermal conductivity and viscosity of aqueous salt solutions at temperatures of 293–473 K,pressures Ps=100 MPa,and concentrations of 0–25 wt.%.Given the lack of data and models,especially for the dynamic viscosity of aqueous salt solutions at a pressure of above 40 MPa,generalized formulas are presented here,by which these gaps can be filled.The article presents a generalized formula for obtaining reliable data on the thermal conductivity of water aqueous solutions of salts for Ps=100 MPa,temperatures of 293–473 K and concentrations of 0%–25%(wt.%),as well as generalized formulas for the dynamic viscosity of water up to pressures of 500 MPa and aqueous solutions of salts for Ps=100 MPa,temperatures 333–473 K,and concentration 0%–25%.The obtained values agree with the experimental data within 1.6%.展开更多
Appropriate application of water-salt-crop function model can optimize agricultural water management in regions with declining water supply,such as the Hetao district.Appropriate use of saline water is also based on t...Appropriate application of water-salt-crop function model can optimize agricultural water management in regions with declining water supply,such as the Hetao district.Appropriate use of saline water is also based on the effects of irrigation water demand and water quality on crop growth quantitatively.Therefore,oil sunflower growth testing under both water and salt stress was completed from 2013 to 2014.Water salinity levels at 1.7 ds/m,4 ds/m,6 ds/m and 8 ds/m were used in the experiments.Two water deficit levels were reported,60%and 80%of the irrigation quota,which were considered moderate and mild deficit levels,respectively.All treatments were applied in planting the oil sunflower in critical growing periods,namely,floral initiation,anthesis and maturity.Linear,Cobb-Douglas,quadratic and transcendental function models were used to simulate the relative yield,evapotranspiration(ET)and electrical conductivity(EC).The predictive ability and sensitivity of each model were then evaluated.Compared with salt stress,water stress exerted a more significant effect on the oil sunflower yield;the water parameters(a1 and a3)were most sensitive in the water-salt-crop function model.Oil sunflower was most sensitive to water and salt stress during anthesis.The transcendental function generally showed a relatively high sensitivity coefficient and a relatively small statistical error.Therefore,the transcendental function is the most appropriate model for simulating and predicting the yield of oil sunflower irrigated with saline water.Applying the water-salt-crop function model in planting of oil sunflower can help in the development and utilization of saline water in the Hetao district.展开更多
基金supported by the Fund for the Special Research of Doctorate Subjects of the Ministry of Education of China (No.20070491522)
文摘Examining the descriptions of piezometric heads at two points in both the salt water and fresh water zones reveals that when the groundwater flow system is in steady state and satisfies the Dupuit assumption, the location of the fresh water-salt water interface in a homogeneous, isotropic, and unconfined coastal aquifer can be estimated based on a piezometric head of fresh water at a point in the fresh water zone （from the water table to the interface） vertically lined up with a piezometric head of salt water at a point in the salt water zone （from the interface down）. Research shows that the new method is a general relation and that both the Hubbert relation describing the location of the interface and the Ghy- ben--Herzberg relation are special cases of this method. The method requires two piezometric wells to be close to each other and each tapping into a different zone. Measurements of piezometric heads at a well cluster consisting of piezometric wells tapping separately into fresh water and salt water zones near Beihai, China at 5-day intervals for 15 months are used to illustrate the estimation of interface location. The depth of the interface for well H5 ranges from 32 to 72 m below the sea level.
文摘Further development in the field of geothermal energy require reliable reference data on the thermophysical properties of geothermal waters,namely,on the thermal conductivity and viscosity of aqueous salt solutions at temperatures of 293–473 K,pressures Ps=100 MPa,and concentrations of 0–25 wt.%.Given the lack of data and models,especially for the dynamic viscosity of aqueous salt solutions at a pressure of above 40 MPa,generalized formulas are presented here,by which these gaps can be filled.The article presents a generalized formula for obtaining reliable data on the thermal conductivity of water aqueous solutions of salts for Ps=100 MPa,temperatures of 293–473 K and concentrations of 0%–25%(wt.%),as well as generalized formulas for the dynamic viscosity of water up to pressures of 500 MPa and aqueous solutions of salts for Ps=100 MPa,temperatures 333–473 K,and concentration 0%–25%.The obtained values agree with the experimental data within 1.6%.
文摘Appropriate application of water-salt-crop function model can optimize agricultural water management in regions with declining water supply,such as the Hetao district.Appropriate use of saline water is also based on the effects of irrigation water demand and water quality on crop growth quantitatively.Therefore,oil sunflower growth testing under both water and salt stress was completed from 2013 to 2014.Water salinity levels at 1.7 ds/m,4 ds/m,6 ds/m and 8 ds/m were used in the experiments.Two water deficit levels were reported,60%and 80%of the irrigation quota,which were considered moderate and mild deficit levels,respectively.All treatments were applied in planting the oil sunflower in critical growing periods,namely,floral initiation,anthesis and maturity.Linear,Cobb-Douglas,quadratic and transcendental function models were used to simulate the relative yield,evapotranspiration(ET)and electrical conductivity(EC).The predictive ability and sensitivity of each model were then evaluated.Compared with salt stress,water stress exerted a more significant effect on the oil sunflower yield;the water parameters(a1 and a3)were most sensitive in the water-salt-crop function model.Oil sunflower was most sensitive to water and salt stress during anthesis.The transcendental function generally showed a relatively high sensitivity coefficient and a relatively small statistical error.Therefore,the transcendental function is the most appropriate model for simulating and predicting the yield of oil sunflower irrigated with saline water.Applying the water-salt-crop function model in planting of oil sunflower can help in the development and utilization of saline water in the Hetao district.
