Assessment of nitrogen and phosphorus pollution based on multi-source data and the InVEST model in the Henan section of Yellow River Basin, China

Abstract

In recent years, non-point source pollution (NPSP) has become prominent in the Yellow River Basin (YRB) of China and seriously affects human survival and sustainable development. The Henan section was selected as an example region of the YRB in China, and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model has been used to quantitatively evaluate nitrogen (N) and phosphorus (P). The results show that (1) the cultivated land (CL), grassland (GL), and unused land (UL) decreased, while forest land (FL), water areas (WAs), and built-up areas (BAs) increased in 2000–2020, and precipitation increased from the northeast to the southwest in 2000–2020; (2) the N export was much more than P export in 2000, 2010, and 2020, and the N and P exports increased in 2000–2020; the spatial distribution of N and P export changes was different in the whole basin in 2000–2010, 2010–2020, and 2000–2020; (3) the N and P exports decreased in 2000–2010, 2010–2020, and 2000–2020 with increasing precipitation; and (4) the N and P exports on CL and BAs were more than those on the other land-use types, and the overall change trends of N and P exports on all land-use types increased from 2000 to 2020.