Application and Analysis of Different Evaluation Methods in Water Quality Evaluation of Jinxiuchuan Reservoir

Abstract

At present, there are many water quality assessment methods. How to screen suitable methods for scientific evaluation of water quality is a basic and important work in environmental protection. In this study, based on the water quality monitoring data of Jinxiuchuan Reservoir in Jinan City, Shandong Province for the period from 2015 to 2017, according to the principle of selecting water quality indicators and environmental quality standards for surface water, the following six indicators were selected to reflect the water quality such as dissolved oxygen (DO), permanganate index (CODMn), Biochemical Oxygen Demand (BOD5), ammonia nitrogen (NH4+- N), total nitrogen (TN), total phosphorus(TP), and three evaluation methods, including single factor evaluation, gray relational evaluation method and fuzzy comprehensive evaluation method, were used to evaluate the water quality condition of Jinxiuchuan Reservoir. The rationality and defects of these three methods were also explored by comparing their results. The results showed that: (1) the results of water quality assessment were greatly affected by the evaluation methods; (2) the water quality obtained by the gray relational evaluation method was the best; (3) the results obtained by the single factor evaluation and the fuzzy comprehensive evaluation method were similar. In order to accurately assess the water quality of surface water, different assessment methods are recommended for comprehensive analysis.