Phosphorus Budgets and the Environmental Effects of the Pearl River Delta

Based on the data collection and analysis of the related industries，agriculture，environmental protection，natural conditions and population statistics in the Pearl River Delta(PRD) in the years of 2000，2005 and 2010，respectively，the phosphorus budgets and its regional differences during the past decade are assessed. The results indicate that the phosphorus inputs and outputs varied inconsistently during the last ten years. The phosphorus in- puts decreased in 2005 and increased slightly in 2010 compared with that in 2000，respectively. The phosphorus outputs decreased notably from 2000 until 2010. The amount of phosphorus surpluses in the PRD shows a significant increasing trend during the past decade，and the phosphorus surplus per unit area increases as well. The phosphorus from the excreta of human and animals and the fertilizer phosphorus are two major kinds of phosphorus sources in the PRD，and the phosphorus outputs mainly took place through the crop harvest in the region. Great regional differences exist in the phosphorus budgets of the PRD，several cities such as Shenzhen，Dong- guan，Foshan，Guangzhou and Zhongshan face potential severe phosphorus pollution.