Assessment of a Multifunctional River Using Fuzzy Comprehensive Evaluation Model in Xiaoqing River, Eastern China

Abstract

Rivers are beneficial to humans due to their multiple functions. However, human meddling substantially degrades the functions of rivers and constitutes a threat to river health. Therefore, it is vital to assess and maintain river function. This study used the Xiaoqing River in Shandong Province, China, as a case study and established a multilayered multifunctional river evaluation indicator system consisting of environmental function, ecological function, social function, and economic function. The weights of indicators were calculated using the analytic hierarchy process (AHP) and the entropy method. Furthermore, a fuzzy comprehensive evaluation model based on the Cauchy distribution function was developed to assess the operation status of each function in each river segment. The results of the indicator and criterion layers in different river sections varied. The multifunctionality of the river decreased from upstream to downstream. The Jinan section was the most multifunctional, followed by the Binzhou, Zibo, and Dongying sections, and finally the Weifang section. Through additional analysis, this study determined the constraint indicators and functions of each river section. Overall, the results reveal that the idea of a “multifunctional river” can advance the theoretical understanding of a river’s function, and the fuzzy comprehensive evaluation model is demonstrated to provide fresh perspectives for evaluating river function.

Comprehensive River Health Evaluation Indicator System and Its Application

“…(3) Aquatic organism criterion: The aquatic organism criterion includes indicators for the indicator of indigenous fish retention and benthic macroinvertebrate diversity. The indigenous fish retention indicator was obtained by comparing the existing species of fish with historically recorded native species using the specific calculation formula shown in equation ( 7): (7) In the formula, C' 6 represents the proportion of native fish retention in rivers, %; S fo represents the number of native fishes retained during the evaluation period, species; S fe represents the number of native fishes retained during the historical period, species.…”

“…Xu et al [6] constructed a new aquatic ecological health evaluation system composed of water quality, ecosystems, and ecological landscapes for the evaluation of small rivers in Shanghai, China. Fu et al [7] took the Xiaoqing River in Shandong Province as an example, established a multi-level multifunctional river evaluation indicator system composed of environmental functions, ecological functions, social functions, and economic functions, and carried out a health evaluation of the Xiaoqing River in Shandong Province. Wang et al [8] combined the improved gray occurrence rate model to construct a comprehensive evaluation model including physical habitats, chemical conditions, and biological structures.…”

Evaluation Model and Application of the Implementation Effectiveness of the River Chief System (RCS)—Taking Henan Province as an Example

“…This method comprehensively evaluates phenomena by synthesizing multiple indicators, enabling the rational integration of evaluation factors from diverse perspectives and fields, thus providing an objective and comprehensive reflection of their essence and characteristics [13]. In domains such as environmental protection and water resource management, this evaluation method is frequently employed to assess the functionality of rivers [14] and the effectiveness of policy implementation [15]. Similarly, applying research on the effectiveness of implementation to the RCS can offer vital foundations for scientific management and decision-making.…”