This study aims to assess the multidimensional impacts of reclaimed water replenishment on river water environments. Taking a specific case study of a riverine reclaimed water supply project from a wastewater treatment plant in Ningbo City, the research focuses on developing a scientific method for assessing the environmental effects of reclaimed water input on surrounding river ecosystems. Through comparative analysis of the strengths and limitations of traditional single-factor method and comprehensive pollution index method, this paper proposes an improved assessment method—Entropy-AHP-TOPSIS (IEATM) —which combines entropy weight method and analytic hierarchy process. The conventional assessment methods often employ simplistic linear processing, frequently neglecting the actual characteristics of negative indicators and interval-type indicators. The IEATM effectively distinguishes and optimizes the treatment of negative and interval-type indicators. The results demonstrate that this method offers significant advantages in assessing river ecological health, effectively avoiding evaluation deviations caused by short-term exceedances of individual indicators. Additionally, the IEATM clearly reveals the spatial attenuation patterns and seasonal fluctuation characteristics of the reclaimed water replenishment effects. This provides a crucial theoretical foundation for optimizing reclaimed water replenishment strategies and offers practical guidance for segmented water inflow regulation, ecological wetland construction, and the improvement of river ecological monitoring networks.
Qian et al. (Tue,) studied this question.