岩溶水化学时空变化影响因素研究

Study on the Main Factors of the Spatial-Temporal Variability of Karst Water Chemistry

在分析后寨岩溶流域岩溶水水化学动态时空分布特征的基础上,研究在溶蚀作用和土地利用方式两种影响因素作用下岩溶水化学的响应特征。根据Ca2+浓度对1992—1994年后寨岩溶地下河流域上、中、下游3个代表性站点碳酸盐岩的溶蚀速率进行估算,结果表明:溶蚀速率大小受降水量和地下水径流量控制,上游溶蚀速率最大,下游溶蚀速率最小;丰水年的溶蚀速率大于枯水年。后寨岩溶地下河流域上、中、下游不同土地利用方式下,相同和不同降水入渗系数条件下,土壤淋滤到岩溶水中的K+、Na+、Cl-浓度计算结果表明:中游的土地利用方式有利于增大岩溶水中K+、Na+、Cl-的浓度,说明人类活动对岩溶水化学动态变化的影响非常大。

Based on the spatial- temporal variability of the karst geochemistry in Houzhai karst basin of Guizhou Province,this paper systematically analyzed the response characteristics of the karst water chemistry influenced by corrosion effect and land use. According to the concentration of Ca2 ＋,the corrosion velocities of three representative stations in upstream,midstream and downstream from 1992 to 1994 were calculated respectively. It indicates that the corrosion velocities in Houzhai karst basin are controlled by precipitation and groundwater runoff.Corrosion velocities in upstream is the fastest,and corrosion velocities in downstream is the lowest. Corrosion velocities in wet years are faster than that in dry years. Under different land use ways of different area in Houzhai karst basin,the leachate concentrations of K＋,Na＋and Cl-were calculated. The results show that the land use way in the middle stream makes for the increase of the leachate concentration of K＋,Na＋and Cl-which indicates that the impact of human activities on the karst water chemical dynamic change is very great.