Numerical Simulation And Prediction Of Groundwater Level In Momoge Wetland

The Momoge Wetland is located in the eastern part of Zhenlai County,Jilin Province.In recent years,the Momoge wetland has become increasingly degraded,and groundwater as a major source of wetland has an important impact on wetland degradation.In this paper,a numerical model of groundwater flow is established for the protection of underground resources in Momoge wetland,which predicts the change trend of groundwater level in the study area,and puts forward reasonable suggestions for the restoration of wetland from groundwater.This paper combines hydrometeorological data to analyze the groundwater level change and its influencing factors in the study area.Using Mann-Kendall trend analysis method and R/S analysis method,the change trend of precipitation in the study area from 1961 to 2016 was firstly reduced and then increased.From 2006 to 2012,the groundwater level in the recharge area showed an overall downward trend.The groundwater level in the discharge area remained stable.The groundwater level change in the recharge area was greatly affected by groundwater exploitation.Based on the geological,hydrological and hydrogeological data of the study area,a groundwater steady flow model and an unsteady flow model were established.After the parameter identification and adjustment,the groundwater flow field morphology and the water level fitting of the monitoring point are verified,and the model is basically in accordance with the actual situation of the study area,and the prediction simulation can be performed.According to the local groundwater exploitation situation and the current situation of water diversion project,three water use scenarios were designed to predict the change of groundwater level in the study area in 2022.In the first plan,the amount of groundwater exploitation continued to increase.The prediction results showed that the groundwater level in the recharge area decreased by 1.6 m,and the groundwater level in the discharge area decreased by 0.47 m.In the second scenario,the groundwater extraction volume remained unchanged,and the increased water was taken from surface water.The prediction results showed the recharge area.The groundwater level decreased by 0.32 m;the groundwater level in the discharge area increased by 0.19 m;in the third scheme,the amount of groundwater exploitation remains unchanged,and the water supply from the project of introducing water into White city is replenished to the wetland.The prediction results showed that the groundwater flow field morphology did not significantly change compared with 2012.This paper proposes the following suggestions for groundwater restoration in the study area:reforming irrigation technology,reducing agricultural water use;building water diversion projects to reduce dependence on groundwater.