Study On The Hydraulic Characteristics Of The Karst Aquifer In Maocun River Basin Of Guilin

The Karst area is widely distributed in China,with a total area of 3.46 ×106km2,accounting for about one third of the land area of China,and mainly distributed in the southwest region.Due to the differences of aquifer media in the karst area,often form large and sparse crack pipe,the yield of water time change is bigger,so the research on the hydraulic characteristics of the karst aquifer has always been difficulty.Karst groundwater resource is an important source of the supply of water supply in southwest China,but karst groundwater vulnerability to pollution,because karst development is complete,quick response of hydrology and soil in karst region is thinner,and the southwest karst area of the main research work is focused on the exploration of karst conduit connectivity,so the hydraulic characteristics of the karst aquifer in maintaining the management of the southwest karst area of groundwater resources has important practical significance.For this reason,this article first through the early stage of the geophysical data selected the develop better karst area Guilin MAO village,which is in the middle and lower reaches of underground river basin in front of the big rock area as the study area.Drilling two different size fissure area respectively,and then through the constant flow pumping test hydraulic connection between the crack size and the direction of anisotropy,and the contact between the hydrogeology parameters;By pumping under the condition of tracer test again,depicting aqueous medium characteristics in the study area,and the pumping test to verify the results.Based on the above experimental research,the following conclusions:1.zk3-1 drilling for pumping well flow pumping test and water flow rate is 7.18m3/d,pumped a total of 19 h continuously.Observation Wells zk3-2,zk3-3 and zk3-4 fell by: 10.7m,2m and 10.8m.According to the pumping test data to calculate the main permeability tensor in the study area are: 7.128m2/d and 0.672m2/d,water level of 1.19e-04 advantage is in the east by south 18.47°,is pointing in the direction of zk3-22.Tracer test zk3-1 for the receiving hole,other hole as put in hole.According to the water under the condition of constant flow tracer test for BTC curve shows that on the hole zk3-2 and zk3-3 and receiving hole zk3-1 have a good edge connectivity between circulation way,but the migration path between zk3-2 and zk3-1 is given priority to advantages of circulation way,and the migration channel between zk3-3 and zk3-1 is given priority to aqueous medium dispersion effect;And the main migration channel between the put in hole zk3-4 and receiving hole zk3-1 is relatively homogeneous,karst development poor aquifer medium.3.Tracer recovery not only affected by the anisotropic,more affected by the dispersion matrix effect.Contrasting the recovery rate of tracer concentration curve shape,the permeability coefficient of the pumping test data and the anisotropic principal direction known that the results are identical.Combine the pumping test data of the proceeds of the conclusion and the tracer test conclusion shows that the hydrogeology parameters from the test are reliable,which can provide reference for karst aquifer groundwater flow numerical model,provide a theoretical basis for the karst region's development and utilization of groundwater resources and pollution prevention.