滇东高原牛栏江流域岩溶区地下水化学特征及成因分析

Hydrochemical characteristics and genesis of groundwater in karst area of Niulanjiang River watershed of eastern Yunnan Plateau

以滇东高原牛栏江流域岩溶区为例,利用水化学数据,探讨区内地下水化学特征及其成因.对研究区24组水样的水化学特征进行分析,结果表明,研究区水化学类型主要是以HCO_(3)^(-)Ca·Mg型和HCO_(3)^(-)Mg·Ca为主,HCO_(3)^(-)和Ca^(2+)是区内主要阴阳离子,反映了水化学特征主要受碳酸盐岩溶解影响.δD与δ^(18)O的关系显示,研究区内地下水主要受大气降水补给.地下水化学演化过程受地层岩性影响显著,岩石风化使东、西两区的地下水水化学特征有较大差异.Mg^(2+)、Ca^(2+)、HCO_(3)^(-)、SO_(4)^(2-)和Cl^(-)主要受岩石风化、大气降雨等自然条件控制,受到人类活动影响较小,Na++K+则是主要受农业活动等人类活动的影响.本研究对牛栏江-滇池补水工程区的水化学特征、水质保护和滇池生态恢复具有重要意义.

Based on the data of hydrochemistry,this article mainly discussed the hydrochemical characteristics and genesis of groundwater in the karst area of Niulanjiang river watershed of eastern Yunnan Plateau.Hydrochemical characteristics of 24 samples were analyzed in the study area.The analysis shows that the hydrochemistry type in the study area belonged to HCO_(3)^(-)Ca·Mg type and HCO_(3)^(-)Mg·Ca type.HCO_(3)^(-) and Ca^(2+) were the main anions and cations,reflecting that hydrochemical characteristics were mainly affected by the dissolution of carbonate rock.The relationship betweenδD andδ18O shows that atmospheric precipitation is the main recharge resources of groundwater in the study area.As a result of rock weathering,there are great differences in hydrochemical characteristics between the east and west area.Mg^(2+),Ca^(2+),HCO_(3)^(-),SO_(4)^(2-),and Cl^(-)were mainly affected by natural conditions,such as rock weathering and atmospheric rainfall;the impact of human activity was little.Meanwhile,Na++K+was mainly affected by human activities as agricultural activity.This study had a significant value for hydrochemical characteristics and water quality protection of Niulanjiang river-Dianchi lake water supplement project,and for ecological restoration of Dianchi lake.