Nitrogen and phosphorus non-point source pollution in the upper Wujiang River Karst Basin: Critical source areas identification and influencing factors

Non-point source (NPS) pollution poses a severe threat to the safety of aquatic environments. The self-cleaning ability of karst systems can effectively reduce the level of NPS pollution. However, affected by high-intensity rainfall and agricultural NPS pollution, the water quality deteriorated duri...

Full description

Saved in:
Bibliographic Details
Main Authors: Chengcheng Hu, Qixin Wu, Guodong Liu, Haiyan Ran, Mingzhe Guo, Jianping Zhu, Jie Zeng
Format: Article
Language:English
Published: Elsevier 2025-01-01
Series:Ecological Indicators
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1470160X24014468
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Non-point source (NPS) pollution poses a severe threat to the safety of aquatic environments. The self-cleaning ability of karst systems can effectively reduce the level of NPS pollution. However, affected by high-intensity rainfall and agricultural NPS pollution, the water quality deteriorated during a special period. In this study, based on the field sampling and process of nitrogen and phosphorus nutrient loss simulated by the Soil and Water Assessment Tool (SWAT), to evaluate water quality and NPS pollution of typical karst basins in the upper Wujiang River. The results of the water quality assessment indicated that the Baifu River was relatively poor. According to the SWAT model, the critical source areas of NPS pollution were located in areas with a significant proportion of cultivated land in the midstream of the basin. The analysis of influencing factors reveals that in the southwest plateau region, sloping agricultural land significantly affects NPS pollution in karst rivers, especially cultivated land with slopes ranging from 11° to 25°. Sloping agricultural land increases soil erosion, leading to intensified nitrogen and phosphorus loss. This study contributes to the effective and targeted management of NPS pollution in basins with a high proportion of sloping agricultural land in karst regions.
ISSN:1470-160X