Anthropogenic total phosphorus emissions to the Tuojiang River Basin, China

The increased input of anthropogenic phosphorus to watershed ecosystems has caused eutrophication in the Yangtze River. Identifying total phosphorus (TP) sources is important for the management of watersheds. As a primary tributary of the Yangtze River, the Tuojiang River Basin (TJRB) plays important roles in the economy and ecology of the region. A watershed-level anthropogenic TP emission inventory was established using emission factors and loss coefficients for 2017 in the TJRB. The annual TP emissions to the TJRB were estimated to be 9253.55 t, of which livestock contributed 52.52%. The agricultural TP emissions to water bodies was 5201.87 t, followed by domestic emissions (3621.19 t) and industrial emissions (430.49 t). The TP contributions of the nonpoint sources were 3.07 times greater than those of the point sources. According to the Monte Carlo method, the uncertainty of TP emissions was [-69.71%, +68.06%] for the 95% confidence interval. Industrial emissions were identified as the largest contributor to the uncertainty [-33.75%, +38.37%]. The establishment of effective livestock breeding management practices along with the comprehensive utilization of facilities could help reduce TP emissions into the TJRB. This study presents an approach to the calculation of an estimated annual emission inventory of TP for the TJRB. The results enhance the fundamental data regarding pollution sources for subsequent research investigations. (C) 2021 Published by Elsevier Ltd.