Work

SWAT-WASP coupled modeling of ammonia nitrogen in rare earth mining watersheds

Year: 2026

Type: article

Abstract: ABSTRACT High concentrations of ammonia nitrogen (NH4+–N) are a dominant water pollutant in ionic rare earth mining basins, threatening aquatic ecosystems and drinking-water safety. To quantify these dynamics, this study developed a coupled SWAT–WASP model for the upper Dongjiang River Basin (UDRB), integrating remote sensing and long-term monitoring data; the model was calibrated and validated with 2016–2018 monthly observations, and quantitative evaluation via Nash–Sutcliffe Efficiency (NSE) and Percent Bias (PBIAS) showed good performance (runoff: NSE = 0.77–0.80; NH4+–N: SWAT NSE = 0.56–0.61, SWAT–WASP NSE = 0.65–0.87), confirming its reliability. 2022 simulations revealed strong NH4+–N spatial heterogeneity, with concentrations >1.8 mg L−1 near mining zones versus <0.5 mg L−1 in upstream natural areas; geodetector analysis identified population density combined with industrial–agricultural activity as the top driver of spatial differentiation (q > 0.40), while interactions between precipitation, temperature, and land use further amplified variability. Overall, the SWAT–WASP framework provides a robust tool for evaluating NH4+–N dynamics and supports targeted pollution control and ecological restoration in rare earth mining watersheds.

Source: Water Science & Technology

DOI: 10.2166/wst.2025.190

Authors: Zidan Wu, Youcun Liu, Mingyong Zhu, Jinfeng Zeng, David Labat, Fei Meng

Institutions: Jiaying University, Shandong Jianzhu University, Géosciences Environnement Toulouse, Université de Toulouse

Language: English

Topic: Hydrology and Watershed Management Studies

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: diamond

Funders: National Natural Science Foundation of China, Natural Science Foundation of Guangdong Province