Study Of Groundwater Artificial Recharge Modes In Plain Area Of Daqing River Basin

Due to the huge agricultural water consumption and serious dependence on groundwater in the plain area of Daqinghe River Basin,several large groundwater level drop funnels have been formed,and there is a certain negative ecological environment effect.The artificial recharge of groundwater is of great significance to the sustainable development and utilization of groundwater resources and the healthy evolution of ecological environment.On the basis of summarizing the characteristics of hydrological and hydrogeological conditions in the study area,this paper constructs the selection and evaluation system of groundwater artificial recharge mode based on GISAHP method,determines the suitable distribution of four groundwater artificial recharge modes such as well irrigation,infiltration pool,stagnant infiltration and river embankment construction,and analyzes the sensitivity of different index weights and index values to the evaluation results by single factor rotation method(OAT),so as to provide scientific basis for the design of actual groundwater artificial recharge engineering construction scheme.The main results are as follows:(1)Based on the screening of the main hydrological and hydrogeological factors affecting the artificial recharge of groundwater,the existing conditions of artificial recharge of groundwater in the study area were analyzed from the aspects of artificial recharge water source,recharge infiltration conditions and other factors,and the suitability evaluation index system of artificial recharge of groundwater was constructed,including six indexes such as recharge water source,lithology of unsaturated zone and aquifer permeability.The weight of each index of artificial recharge was determined by analytic hierarchy process(AHP).(2)Based on GIS-AHP method,the suitable areas of different artificial recharge(single)modes of groundwater are determined.The overlapping areas of different recharge modes are optimized according to the principle of the highest recharge efficiency.The results show that the southern and western parts of the study area are suitable for well irrigation recharge(the suitable area accounts for 69.94 % of the study area).The area near the northern and central river banks is suitable for the infiltration pool recharge project(the area ratio of the suitable area to the study area is 13.13 %);The area far from the river channel in the northern part of the study area and the central part of the study area are suitable for carrying out the recharge project of stagnant infiltration(the area ratio of the suitable area to the study area is 12.52 %);The suitable area for river channel replenishment is mainly distributed in the southern and northwestern rivers(the suitable length of river reaches accounts for 50.96 % of the total length of river channels).(3)Through the OAT,time series and index degradation method,the sensitivity of evaluation index weight and influencing factors to the results of artificial recharge suitability of groundwater is analyzed.The results show that under the above two maximum sensitivity conditions,the area change rate of well irrigation suitability area is 6.8 % and 25.3 %,respectively.the change rates of the infiltration pool were 112.2 %and 91.0 %,respectively;The change rates of stagnant infiltration were 87.5 % and57.0 %,respectively;The change rates of the suitable river length for river embankment replenishment are 6.36 % and 15.82 %,respectively.(4)Based on the weight and sensitivity analysis of influencing factors,the areas where the results did not change under the conditions of the two changes were taken as the optimization results.The results show that the well irrigation supply mode is mainly suitable for the northern part of the study area,the southern part of the study area and the southern part of the study area.The recharge mode of permeable pool is mainly applicable to the coastal areas of Daqing River,Ping River,Tang River Xindao,Xiaoyi River and Zhulong River.The recharge method of stagnant infiltration is mainly applicable to the coastal areas of the Zhulong River and Xiaobai River in the south of Baiyangdian.The suitable river sections for dike construction include some sections of12 main rivers,such as Nanjuma River,Baigou River and Zhongyi River.