Groundwater dynamic numerical simulation in the Ejina Oasis in an ecological water conveyance period

In the paper,based on the hydrogeological conditions of the Ejina Basin,a groundwater flow model for the Ejina oasis is established with the GMS software package. Groundwater dynamic and groundwater recharge and discharge from 2000 to 2011 with the time interval of one year are analyzed using the simulation results. The research results show that( 1) the average of the groundwater discharge is 3. 54 × 108m3/a while the average of the groundwater recharge is 3. 67 × 108m3/a within the modeling period. River leakage accounts for 78% of the total recharge,and evaporation,63% of the total discharge.( 2) Groundwater in the unconfined aquifer recharges the confined aquifer in the study area,and the amount of recharge is 0. 23 × 108m3/a.( 3) The annual groundwater storage in the study area increases within the modeling period,except for the 2001,2004,2009 and 2010. The difference in average groundwater balance is 0. 13 × 108m3/a.( 4)After the ecological water conveyance,the groundwater levels in the area rise slowly. The average annual rise rate is 0. 02 m /a. Compared to other region,the rise in the groundwater levels near the river,which were affected by the river evolution,is greater than 0. 04 m /a. The maximum rise is in the East River 's lower course.