关键词: 水质评价;污染指数法;综合水质标识指数法;地表河流;喀斯特地貌地区;

Abstract: Guanshan Lake is an ecological civilization demonstration area in Guizhou Province.Baihua Lake is the largest drinking water source of Guanshan Lake and an important ecological barrier in the upper reaches of the Yangtze River.Taking the main surface tributaries of Baihua Lake basin as research objects, including the Maotiao River, Maijia River, Maicheng River, Songjiachong River and the Lijiachong River, the eight water quality indicators from 2016 to January 2017 were analyzed by water quality pollution index method and comprehensive water quality identification index.The results show that:(1) the surface temperature of the five surface rivers is about 16 ℃,the water is generally weakly alkaline and the pH value ranges from 7.52 to 8.19.(2)CODCr,BOD5,NH3-N and TP are the main pollution sources, the comprehensive pollution index ranges from 0.31 to 1.19,the comprehensive water quality identification index ranges from 2.200 to 5.220,and the most polluted river is the Maijia River.(3)For the five rivers, the comprehensive pollution index method shows that 7% water samples are severely polluted in three water periods, which is consistent with the 7% samples belonging to classⅤwater standard that is given by the comprehensive water quality index method.(4)The water quality status ranks as: Maotiao River>Maicheng River>Lijiachong River>Songjiachong River>Maijia River, the most polluted rivers, Maijia River and the Songjiachong river are alien rivers.

Key words: water quality evaluation; pollution index method; comprehensive water quality identification index method; surface river; Karst geomorphic area;