喀斯特区现代溶蚀强度与环境的研究——以红水河流域为例

RELATION OF SOLUTION TO ENVIRONMENT IN KARST AREA──A CASE STUDY OF HONGSHUI RIVER BASIN

本文以喀斯特溶蚀作用的重要环境因素,即气候、碳酸盐岩性和水动力条件因素的分析为基础,对红水河流域内124个点的溶蚀量值与环境因素进行相关的统计分析,建立了综合因子溶蚀量计算公式,编制了溶蚀量图。得出溶蚀强度变化规律。通过对红水河流域典型区的试验研究,证明采用建立相关因子溶蚀量方程的方法是可行的,用此方法可进行大流域的喀斯特区溶蚀速度的编图,研究喀斯特溶蚀速度区域特征和分布规律。

Various environment factors affect the solution rate. A comprehensive model which is a modified Corbel Model, for estimating solution rate has been established by relating solution rate to environment factors based on the data from 124 samples: A Number of data for sites covering the whole river basin, have been estimated from the mo-del and a isogram of solution rate has been pre pared by using these data. It is shown on the map that solution rate tends to increase from upstream towards downstream. Average solution rate is 43 mm/103a in the upper part of the basin (Yunnan棗Guizou plateau), where annual average temperature is about 15癈, Rainfall is 1086 mm and the percentage of limestone in car-bonate rocks is 40%. The middle part (transitional slope zone) has an average solution rate of 55 mm/10sa, with annual average temperatu re being 16癈, rainfall being 1360 mm and limes-tone percentage being more than 40%. In the lower part (Guangxi Basin) the average solution rate raises up to 62 mm where annual average temperature reaches 22癈 rainfall is 1530 mm and the percentage of limestone is 76%. Solution rate in the lower part 44% and 10% greater than in the upper part and the middle part res pectively. Climate, Chemical contents of carbo-nate rocks and hydraulic dynamics associated with geomorphological features are responsible for the spatial variation variation of solution rate mentioned above. It has been proved in the case study of Hongshui River Basin that the comprehensive model established for estimation of solution rate is valid. As long as enough amount of environment parameters is available sufficient amount of data of solution rate can be obtained from the mo-del by extrapolation, which can be used for mapping solution rates in a large river basin and .studying spatial variation of solution rates in the karst region.