Spatial characteristics and driving forces of anthropogenic phosphorus emissions in the Yangtze River Economic Belt, China

Excessive phosphorus emissions by anthropogenic activities are closely related to eutrophication in the Yangtze River. Quantitative spatial distribution of total phosphorus (TP) emissions and identifying their driving forces are important for the management of phosphorus pollution in the Yangtze River Economic Belt (YREB). In this study, anthropogenic TP emissions were estimated using emission factors in the YREB for 2017. Global and local spatial autocorrelation and multiple regression analysis were adopted to reveal the spatial agglomeration effects and driving forces of the TP emissions in 130 cities of the YREB. The TP emissions were estimated to be 155,940 t, and the agricultural TP emissions were 106,181 t, followed by domestic (46,032 t) and industrial emissions (3727 t) in 2017 in the YREB. Livestock breeding was the most significant anthropogenic source of TP emissions. The TP emissions in the middle and lower reaches were larger than those in the upper reaches. A significant spatial agglomeration effect of TP emissions was found in the YREB, with High-high aggregation in the middle reaches and Low-low aggregation in the upper reaches. The paddy land area was the most significant factor affecting TP emissions, followed by the population size and vegetable orchard area. The results provide fundamental data regarding pollution sources for subsequent research investigations. The results enhance the understanding of the TP source contributions; thus, accurate control measures could focus on the important sources and regions of TP pollution in the YREB.