贵州将军洞上覆土层对滴水水化学特征的影响

Effects of Soil Cover on Drips Hydrochemical Characteristics in Jiangjun Cave,Guizhou

对贵州安顺将军洞4个滴水点进行为期1a的动态监测．将军洞滴水对大气降雨的响应极快（0～9d）．滴水的物质来源于土壤．由于滴水点上覆土壤厚度的差异，极大地影响到滴水水化学特点．水通过的土壤较薄时，溶解的物质量少，降低了滴水点发生稀释作用的可能，也使得岩石对滴水化学组成的贡献增大．样点JJD-1、JJD-4滴水在一定程度上受到稀释作用的影响，而JJD-1滴水运移过程中还受到不同源来水的影响产生了“活塞效应”，JJD-2滴水也受到不同源来水的影响而产生滴率的跳跃式变化，这些作用只在次一级作用强度上对滴水水化学产生影响．岩石的溶解作用以及方解石的沉淀作用控制了洞穴4个滴水点水运移过程中所发生的地球化学作用．因此，土壤作为一个重要的岩溶环境因素决定和控制了洞穴滴水的水化学特点，应该给予必要的重视．

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.