中国南方岩溶水化学的某些特征

我国南方碳酸盐岩地区,岩溶水的化学类型和矿化度,从广西经贵州到滇东,在区域上有明显的差异。重碳酸钙型水比例减少,重碳酸钙镁型水呈现递增的趋势。宏观上看,乌江和红水河上游地下水化学径流模数大于下游,各省区平均值,滇东大于贵州又大于广西,即从西向东表现出由大变小的趋势。碳酸盐岩的溶蚀速率也显示这一特点,从而推断:现代岩溶发育强度,总的来看,云贵高原胜过广西地区。

CHEMICAL CHARACTERISTICS OF KARST WATER IN SOUTH CHINA

Based on the data of 1:200000 hydrogeological maps and typical groundwater systems, thehydrochemical composition, mineralization & hardness, chemical runoff module of karst waters inSouth China are discussed and the intensity of the modern karst development is evaluated. The chemical types and mineralization degrees of karst water in carbonate rock area in SouthChina are clearly different from Guangxi through Guizhou to Yunnan, showing a gradual decrementof calcium bicarbonate type of water and a gradual increment of calcium-magnesium bicarbonatetype of water. In general, the groundwater chemical runoff module of the upstreams of theWujiang and Hongshuihe rivers is more than that in the downstreams. The mean value of karstwater's chemical runoff module in East Yunnan is greater than that in Guizhou, and is evengreater than that in Guangxi. i. e. from west to east, the runoff module is obviously decreasing.The rate of dissolution of karstifiable rocks shows the same trend. Therefore, the intensity ofmodern karst development in the Yunnan-Guizhou plateau is supposed to be much higher than thatin Guangxi karstic plain.