School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
Sci Total Environ. 2021 Aug 20;783:146868. doi: 10.1016/j.scitotenv.2021.146868. Epub 2021 Apr 9.
In a multiregional river system, environmental features such as natural conditions and anthropogenic activities vary among regions, resulting in spatiotemporal variations in water quality. Therefore, a robust water quality assessment method (e.g., water quality index [WQI]) that considers various environmental features is essential for water resources management. This study developed a min/max autocorrelation factor analysis (MAFA) based WQI framework (MAFAWQI). The statistical procedure reduces the bias of expert opinions. The MAFAWQI characterizes impaired water quality variables as indicators and assesses appropriate weighting values of indicators at each sampling site to reflect site-specific environmental features. The MAFAWQI was successful for assessing water quality in the middle and down streams of Han River in central China with site-specific pollution features such as nitrogen and phosphorus pollution related to multiple-source in tributaries, impacts of tributaries on the main stream, and phosphorus pollution related to nonpoint-source in agricultural regions. The MAFAWQI exhibited a balanced rating of water quality compared to the strict assessment method using a single indicator and the lenient assessment method using stationary weighting values of indicators. The MAFAWQI scores indicated that the water quality in tributaries and during the spring were significantly worse than those in and during the other regions and seasons in the middle and down streams of Han River, respectively. The framework and application of the MAFAWQI may provide a new perspective for developing WQIs.
在多区域河流系统中，环境特征（如自然条件和人为活动）在各区域之间存在差异，导致水质在时空上发生变化。因此，需要一种稳健的水质评估方法（例如，水质指数[WQI]）来考虑各种环境特征，这对于水资源管理至关重要。本研究开发了一种基于最小/最大自相关因子分析（MAFA）的 WQI 框架（MAFAWQI）。该统计过程减少了专家意见的偏差。MAFAWQI 将受损水质变量特征化为指标，并评估每个采样点指标的适当加权值，以反映特定于地点的环境特征。MAFAWQI 成功地评估了中国中部汉河中、下游的水质，该地区具有特定的污染特征，如与支流多源相关的氮和磷污染、支流对干流的影响以及与农业区非点源相关的磷污染。与使用单一指标的严格评估方法和使用指标固定加权值的宽松评估方法相比，MAFAWQI 表现出了更均衡的水质评级。MAFAWQI 得分表明，汉河中、下游的支流和春季的水质明显差于其他地区和季节的水质。MAFAWQI 的框架和应用为开发 WQI 提供了新的视角。
