LUO Jin¹, AN Yan-ling^2，*, WU Qix-in^{2 3}, YANG Rui-dong², JIANG Hao¹, PENG Wen-bo², YU Xia², LIU Jie-mei²

(1. College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China；
2. Key Laboratory of Karst Environment and Geohazard Prevention, Ministry of Education, Guizhou University, Guiyang 550003, China;
3 . State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China） 

Abstract: Water samples were collected from the mainstream and distributaries of the middle and lower reaches of the Chishui River Basin in the withered water period to analyze the hydrochemical components. The results showed that the main basic cation was Ca²⁺, which accounts for above 64% of the total basic cationic concentrations, and the main basic ions were HCO₃^- and SO₄^2- , which account for 75%~91% of the total ions. The mechanisms controlling the water chemistry of river water from the Chishui River were illustrated, and the results indicated that the river water was mainly influenced by rock weathering. Piper diagram and element ratios suggested that the chemical composition of river water is controlled mainly by carbonate weathering, and silicate weathering also plays some role at some distritutaries. Spatial-temporal analysis showed that human activities have affected the weathering rates and hydrochemical characteristics.

Key words：Chishui River; water chemistry; major ion; element ratio

EARTH AND ENVIRONMENT Vol. 42, No.3, Tot No.299, 2014, Page 297-305