Study On Hydrochemical Characteristics And Water Environmental Health In Gannan Pastoral Area

This research selected Xiahe County at Gannan pastoral area as study area. Based on field investigation, laboratory test, multivariate statistical analysis and fuzzy comprehensive evaluation method, the hydro-chemical characteristics of surface water and groundwater were studied and the water quality condition was evaluated. The index system of water environmental health evaluation at Gannan pastoral areas was constructed too. The water environmental health status of Xiahe County was assessed, based on fuzzy comprehensive evaluation model.This research was the first time to study the water environmental health theory of Gannan pastoral area. Building the evaluation index system of water environmental health at Gannan pastoral area has significant theoretical meaning and practical application value in protecting water environment health, maintaining ecological balance, promoting the social economy sustainable development and realizing the sustainable utilization of water and grass resources at Gannan pastoral area.The main research results and conclusions of paper were as follows:(1) The analysis results of water chemical characteristics showed that:the hydro-chemistry types in the surface water and groundwater in Xiahe County were type HCO3--Mg2+-Ca2+ and type HCO3--Mg2+-Na+, respectively; the anion and cation in surface water were mainly from the weathering and dissolution of carbonate rock; the anion and cation in groundwater were mainly from the dissolution of carbonate and evaporator rocks.(2) The quality evaluation results of surface water and groundwater showed that both of the surface water and groundwater quality are class Ⅰ, and the integrated health degree of surface water and groundwater quality is 0.99 and 0.97, respectively.(3) This thesis describes the connotation and characteristic of environmental health at pastoral area. This study built an index system which was suitable for water environmental health assessment at Gannan pastoral area, considering the following five aspects:building principle of index system, the overall structure of the index system, screening principle of evaluation index, meaning expressed by the evaluation index and evaluation standard. Based on the evaluation index and evaluation standard of the water environmental health evaluation at pastoral area, this study set up a fuzzy comprehensive evaluation model which was suitable for water environmental health evaluation at Gannan pastoral area.(4) According to the evaluation indicators and evaluation standards of water environment health evaluation in Xiahe County, this study applied fuzzy comprehensive evaluation model to evaluate the status of water environmental health. The results showed that the membership degree of water environment status relative to the "healthy" level was 0.8003, presenting the "health" condition. The water environment comprehensive health degree is 0.7407.