Improved Principal Component-Fuzzy Comprehensive Assessment Coupling Model for Urban River Water Quality: A Case Study in Chongqing, China

Siyuan Zhao,Xiaoting Li,Yixin Wang,Jiao Jiang,Wei Yang,Zhenyu Tian,Wei Li,Qiu Jin,Yue Sha,Huazu Liu,Jing Chen

doi:10.3390/w12051375

Abstract

An improved principal component-fuzzy comprehensive assessment coupling model for urban river water quality is proposed, which fully considers the influence of water quality and quantity. This model can not only choose the key indexes, but also specify the spatial variation and class of water quality. This proposed model was used to assess the water quality of the Qingshui and Fenghuang streams in Chongqing, China. Data of twelve indexes used in the assessment were collected from 17 monitoring points. The assessment results show that the key indexes include TN, TP, NH3-N, CODcr, pH, DO and velocity. Water quality of 14 monitoring points is classified as class Bad V, and that of the remaining points is class V. Mainly affected by the deposition of garbage and discharge of domestic sewage, water quality of the midstream is the worst. The upstream is mainly influenced by farmland non-point source pollution and rural domestic sewage pollution. The downstream is close to the scenic area, and environmental control measures such as river dredging and artificial aeration are regularly carried out. The water quality of it is the best. The results provide valuable information that allow local environmental departments to discover the source of pollutant and formulate water resource management strategies.

Highlights

As an important part of an urban ecosystem, a river plays a key role in water supply, flood control, sewage discharge, landscape entertainment and so on
The water quality assessment method, which can be widely used in environmental management should be easy to calculate and master, besides being scientific and accurate [7].The traditional water quality assessment methods are the single factor assessment method and water quality index method, which are widely adopted by the Environmental Protection Department in China [8,9].The single factor assessment method [10] is to select the class of the worst index as the water quality class according to the classification criteria of each monitoring index
In the results of fuzzy comprehensive assessment (Figure 6), only the water quality of monitoring points Q1, Z4, and Z5 is classified as class V, and that of the remaining is class Bad V, indicating that the three points have better water quality

Summary

Introduction

As an important part of an urban ecosystem, a river plays a key role in water supply, flood control, sewage discharge, landscape entertainment and so on. With the continuous promotion of urbanization in China, the deterioration of water quality is strongly associated with increased point and diffuse pollution, caused from rapidly expanding urban, industrial sewage, domestic sewage and agricultural activities [2,3]. It is urgent for policymakers and watershed managers. Water 2020, 12, 1375 to comprehensively assess the water quality of urban rivers, and provide the main causes of pollution and remediation strategies [4]. Many new methods have been applied to the water quality assessment, such as the fuzzy comprehensive assessment method [13,14],water pollution index method [15,16] and grey assessment method [17]

Methods

Results

Conclusion