Comprehensive Evaluation Of Groundwater Recharge In Irrigated Area Diverting From Yellow River In Northwest Of Shandong Province

Based on the analysis of the present situation and existing problems of groundwater resources development and utilization in the area of Liaocheng in the northwest of Shandong Province,this paper makes a preliminary feasibility study on the construction of the recharge project by using the feasibility evaluation template of the Australian aquifer supply management guide Evaluation.Through the establishment of the evaluation index system of recharge,the evaluation of the inherent ability of recharge in different areas was carried out.The two types of main recharge methods were used to study the infiltration volume,recharge and plugging.The results are as follows:Apllied for reference model recharge recharge of groundwater in irrigation capacity evaluation index system,selection of six main parameter variables as the evaluation indexes for evaluation of difficulty: a.groundwater buried depth;b.water sand thickness;c.the permeability coefficient;d.water level;e.supply intensity;f.mining intensity.And the index classification score,the highest score of 5 points,the lowest 1 point.In order to solve the problem of the weight of the evaluation index,the analytic hierarchy process(AHP)is used to calculate the consistency and verify the consistency of the evaluation index.Using the powerful function of GIS software to analyze the evaluation indexes,calculate the scores,and the calculated results,the score is 1.04,the maximum is 3.00.According to the natural classification method,the scoring results are divided into five grades,and the zoning of the recharge capacity is divided.From the district can be seen suitable for the construction of the recharge project for the western Shenxian-Guanxian-Linqing area,the area of aquifer thickness of lithology and groundwater depth for the construction of recharge engineering to provide adequate storage space,groundwater Mining area is high,there is an urgent need for recharge;the eastern and central regions of the groundwater level is high,adequate supply of surface water,although the aquifer water storage performance is superior,but there is no suitable for carry out the recharge project.Ditch infiltration is one of the main methods of artificial recharge of groundwater in the Yellow River Irrigation District.The infiltration process can be divided into three stages:unsteady free seepage,stable free leakage,top plug leakage,generalized unsaturated zone structure,The establishment of mathematical models to study the calculation of the three stages of leakage and leakage process.Under the condition of water supply 7d and single sandy sand,the lower the groundwater level is,the higher the leakage amount is,and the leakage of the channel is affected by the depth of the groundwater and the permeability coefficient.When the K is 1.5 m / d,the seepage of the groundwater depth is about 14 m,and when the K is 2.5 m / d,the maximum leakage occurs In the groundwater depth of 20 m.In the infiltration experiment of the surface infiltration method,it can be seen that the infiltration fronts appeared in the shape of the infiltration,and the water content above the frontal surface changed with time.Due to the heterogeneity of the upper aquifer,Under the movement will suddenly appear suddenly large and small jagged shape,with the extension of time will gradually disappear,continue to move down.The second day after irrigation,the pure increase in moisture content of 82.2mm,lasting 8 days of evaporation and lateral seepage,moisture consumption of 36.4mm,accounting for 44.3% of pure incremental,which lasted 15 days of consumption of 41 mm,accounting for pure An increase of 49.9%.There is a large evaporation and a large side seepage in the local field,and there is still a large amount of irrigation quota and longer transport time for the recharge of groundwater,and the amount of water,Deep,gas zone and other factors.In addition to ammonia nitrogen and iron ions in the small amount of the month,the general can reach the groundwater class III standard,the use of Australian aquifer recharge management guidelines,the impact of human health,environmental safety,engineering implementation of the three indicators of 14 indicators of well perfusion method,Of which13 indicators for low risk.The average sediment concentration of the river through the sedimentation tank is 2.9kg/m3(2900mg/L),much higher than 10 mg / L,the risk of plugging is very high.So the Yellow River water precipitation,filtration and other anti-blocking treatment,and strict control of water quality indicators to prevent the impact of groundwater drinking value.