[Effects of soil cover on drips hydrochemical characteristics in Jiangjun Cave, Guizhou]

Four drip points was monitored for a year in Jiangjun cave, Anshun county of Guizhou province, China. The result shows that drip water responding to rainfall is very quick (0-9 days). Drip water chemical components are directly originated from soil and greatly affected by the soil thickness. The thinner soil is, the less substances water dissolves. Water passes more quickly, which decreases the possibility of dilution happening in drip water, simultaneously, increases the contribution of rock to drip compositions. In some cases, JJD-1 and JJD-4 are affected by dilution, however, different sources of water affect drip water dynamic process, which leads to piston flow for JJD-1, and increase drip ratio and water head pressure for JJD-2 as well while water is of much quantity. All of these processes affect drip compositions in second effect intensity. Element variations of 4 drip waters are mainly controlled by the process of rock dissolution and calcite precipitation while water transports in the route and acts with soil and rock. Consequently, as an important karst environmental factor, soil decides and controls drip compositions of cave drip waters, which means more attentions must be paid to soil in future study.