【中国风采】全球视角下城镇化后流域磷源转移的甄别：基于同位素及贝叶斯混合模型的分析 [Water Research,2024]http://www.jlakes.org/ch/reader/view_news.aspx?id=20240115100059001

Ziteng Wang , Fuhong Sun,* , Qingjun Guo , Daren C. Gooddy , Fengchang Wu,*. Global scale identification of catchments phosphorus source shifts with  urbanization: A phosphate oxygen isotope and Bayesian mixing  model approach. Water Research 250 (2024) 121026

Abstract: Different scenarios of urban expansion can influence the dynamic characteristics of catchments in terms of  phosphorus (P). It is important to 

identify the changes in P sources that occur during the process of urbanization  to develop targeted policies for managing P in catchments. However, there is a knowledge gap in quantifying the  variations of potential P sources associated with urbanization. By combining phosphate oxygen isotopes from  global catchments with a Bayesian model and the urbanization process, we demonstrate that the characteristics  of potential P sources (such as fertilizers, urban wastewater, faeces, and bedrock) change as urban areas expand.  Our results indicate that using phosphate oxygen isotopes in conjunction with a Bayesian model provides direct  evidence of the proportions of potential P sources. We classify catchment P loadings into three stages based on  shifts in potential P sources during urban expansion. During the initial stage of urbanization (urban areas < 1.5  %), urban domestic and industrial wastewater are the main contributors to P loadings in catchments. In the mid term acceleration stage (1.5 % ≤ urban areas < 3.5 %), efforts to improve wastewater treatment significantly  reduce wastewater P input, but the increase in fertilizer P input offsets this reduction in sewage-derived P. In the  high-level urbanization stage (urban areas ≥ 3.5 %), the proportions of the four potential P sources tend to  stabilize. Remote areas bear the burden of excessive P loadings to meet the growing food demand and improved  diets resulting from the increasing urban population. Our findings support the development of strategies for  water quality management that better consider the driving forces of urbanization on catchment P loadings.

Keywords:  Phosphate oxygen isotopes,  P source shifts,  Urbanization stage,  Driving force,  Catchment P management.