The Numerical Simulation And Resource Evaluation Of Groundwater On The Allivial And Proluvial Plain In Dulan

Dulan basin is located in the southeastern edge of the Qaidam Basin,has rich mineral and agricultural resources.To promote economic and social development in Dulan County,the demand for these resources is increasing,which lead to the demand for waterincreasing,however,the study area is located in the arid basin,has very poor precipitation and limited amount of water resources,moreover,with the impact of human activities,the way of groundwater recharge has changed from the river seepage as the main supply source of groundwater under natural conditions tothe river seepage,field irrigation andcanal seepage under diversion conditions,so as to reduce the amount of groundwater recharge,so it is necessary to identify the water resourcein order to reasonableuse in the study area.The Quaternary loose rock pore water in Dulan basin was studied.Based on the collecting and analysing of information about previous studies andgeneralization of hydrogeological conditions,groundwater flow conceptual and numerical simulation model of Dulan basin single-layer structurewere established;finally,based on numerical method to evaluate groundwater resources,also formulating mining plan to predict groundwater level changes bycombining with local groundwater pumping plan,so putting forwarda reasonable developing and using plan.The study area is about 1235km~2,the numerical simulation model was partitioned by 200×200 square meshes,the simulation time isfrom July 1,2014 to July 1,2015,a month is a stressperiod.Under current conditions,the total amount of groundwater recharge is 14956.18×10~4m~3/a,the total amount of excretion is 18102.38×10~4m~3/a,groundwater balance is negative,whichtheamount of rivers leakage is8097.61×10~4m~3/a,accounting for 54.1%of recharge;theamount of field irrigation and canal leakage is 2891.68×10~4m~3/a,accounting for 19.3 percent of recharge;theamount of surface water recharge(river,field and canal leakage)is 10989.29×10~4m~3/a,less than 6355.44×10~4m~3/acompare to natural conditions;major excretion is lateral runoff,theamount of outflow is 18084.13×10~4m~3/a,accounting for 99.9%of excretion.Through the level linefitting of observation wellin the study area,recognizingand verifing the model,better fitting results show the model truly reflects the real hydrogeological conditions in the study area.Which,due to thedevelopment of fault severalwater scarpsareexisting,this paper deals them with GMS software package HFB1,the results show it better characterizes the effects of faults on groundwater.The numerical simulation results:groundwater recharge resources in the study area is 18781.31×10~4m~3/a,where the river leakage is 12746.80×10~4m~3/a,accounting for 67.6%;Mineable resourcesis 6570×10~4m~3/a.