Using soil erosion to locate nonpoint source pollution risks in coastal zones: A case study in the Yellow River Delta, China

Youxiao Wang; Gaohuan Liu; Zhonghe Zhao; Chunsheng Wu; Bowei Yu

doi:10.1016/j.envpol.2021.117117

Using soil erosion to locate nonpoint source pollution risks in coastal zones: A case study in the Yellow River Delta, China

Environ Pollut. 2021 Aug 15:283:117117. doi: 10.1016/j.envpol.2021.117117. Epub 2021 Apr 10.

Authors

Youxiao Wang¹, Gaohuan Liu², Zhonghe Zhao³, Chunsheng Wu⁴, Bowei Yu⁵

Affiliations

¹ State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: wangyx.19b@igsnrr.ac.cn.
² State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, 210023, China. Electronic address: liugh@lreis.ac.cn.
³ State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: zhaozhh@lreis.ac.cn.
⁴ Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China. Electronic address: wucs@igsnrr.ac.cn.
⁵ School of Environment, Beijing Normal University, Beijing, 100875, China. Electronic address: yubw@lreis.ac.cn.

PMID: 33872937
DOI: 10.1016/j.envpol.2021.117117

Abstract

Soil erosion contributes greatly to nonpoint source pollution (NSP). We built a coastal NSP risk calculation method (CNSPRI) based on the Revised Universal Soil Loss Equation (RUSLE) and geospatial methods. In studies on the formation and transport of coastal NSP, we analysed the pollution impacts on the sea by dividing subbasins into the sea and monitoring the pollutant flux. In this paper, a case study in the Yellow River Delta showed that the CNSPRI could better predict the total nitrogen (TN) and total phosphorus (TP) NSP risks. The value of the soil erodibility factor (K) was 0.0377 t h·MJ^-1·mm^-1, indicating higher soil erodibility levels, and presented an increased trend from the west to the east coast. The NSP risk also showed an increased trend from west to east, and the worst status was found near the Guangli River of the south-eastern region. The contributions of the seven influencing factors to CNSPRI presented an order of vegetation cover > rainfall erosivity > soil content > soil erodibility > flow > flow path > slope. The different roles of source and sink landscapes influenced the pollutant outputs on a subbasin scale. Arable land and saline-alkali land were the two land-use types with the greatest NSP risks. Therefore, in coastal zones, to reduce NSP output risks, we should pay more attention to the spatial distribution of vegetation cover, increase its interception effect on soil loss, and prioritize the improvement of saline-alkali land to reduce the amount of bare land.

Keywords: Nonpoint source pollution risks; Pollutant flux into the sea; Soil erosion; Yellow River Delta.

MeSH terms

China
Environmental Monitoring
Non-Point Source Pollution*
Rivers*
Soil
Soil Erosion

Substances

Soil