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ARS Home » Plains Area » El Reno, Oklahoma » Grazinglands Research Laboratory » Agroclimate and Natural Resources Research » Research » Publications at this Location » Publication #307402

Research Project: ADAPTING SOIL AND WATER CONSERVATION TO MEET THE CHALLENGES OF A CHANGING CLIMATE

Location: Agroclimate and Natural Resources Research

Title: Phosphorus loss and its estimation in a small watershed of the Yimeng mountainous area, China

Author
item Li, Zhen-wei - Northwest Agricultural & Forestry University
item Zhang, Guang-hui - Beijing Normal University
item Yu, Xing-xiu - Linyi University
item Liu, Qian-jin - Linyi University
item Zhang, Xunchang

Submitted to: Environmental Earth Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2014
Publication Date: 7/8/2014
Citation: Li, Z., Zhang, G., Yu, X., Liu, Q., Zhang, X.J. 2014. Phosphorus loss and its estimation in a small watershed of the Yimeng mountainous area, China. Environmental Earth Sciences. 73(3):1205-1216.

Interpretive Summary: Non-point source pollution is severe in the Yimeng Mountainous area of China. Few studies have been conducted to identify and predict phosphorus loss at a watershed scale in this region. The objectives of this study were to identify the characteristics of phosphorus loss and further to develop regression models to estimate phosphorus losses of different forms based on the dataset of measured rainfall, runoff, and sediment of 24 rainfall events during the period of 2010 to 2011 in a typical small watershed from Yimeng Mountainous Area. Results showed that the ratio of particulate phosphorus (PP) to total phosphorus (TP) was 64.8%, which indicated that most of phosphorus loss was transported by eroded sediment. Among the dissolved phosphorus loss, the dissolved inorganic phosphorus (DIP) was the dominant form, accounting for 72.0% of the total dissolved phosphorus (DP) loss in runoff. Similar to soil loss, rainfall properties influenced phosphorus loss greatly, and most of phosphorus loss was produced by only a few heavy storms. The concentrations of different phosphorus forms during a rainfall event varied with similar trends and reached the maxima prior to the peak runoff. Phosphorus losses of different forms were influenced by rainfall kinetic energy, runoff volume, and sediment loss significantly and could be predicted with these factors. The results would be useful to water quality specialists and environmental scientists who are interested in predicting phosphorus loss in surface runoff.

Technical Abstract: Non-point source pollution is severe in the Yimeng Mountainous area of China. Few studies have been conducted to identify and predict phosphorus loss at a watershed scale in this region. The objectives of this study were to identify the characteristics of phosphorus loss and further to develop regression models to estimate phosphorus losses of different forms based on the dataset of measured rainfall, runoff, and sediment of 24 rainfall events during the period of 2010 to 2011 in a typical small watershed from Yimeng Mountainous Area. The results revealed that phosphorus (P) loss differed considerably with phosphorus forms. The dissolved inorganic phosphorus (DIP) was the dominant form of the total dissolved phosphorus (DP) loss by runoff, accounting for 72.0%. The ratio of particulate phosphorus (PP) to total phosphorus (TP) was 64.8%, which indicated that most of phosphorus loss was transported by eroded sediment. Similar to soil loss, rainfall properties influenced phosphorus loss greatly and most of phosphorus loss was produced by only a few heavy storms. The concentrations of different phosphorus forms during a rainfall event varied with similar trends and reached the maxima prior to the peak runoff. Phosphorus losses of different forms were influenced by rainfall kinetic energy, runoff volume, and sediment loss significantly. DIP and DP could be predicted with rainfall kinetic energy and runoff volume satisfactorily (NSE=0.94). PP and TP were estimated with rainfall kinetic energy, runoff volume, and sediment loss of rainfall event well (NSE=0.90). Further studies are necessary to assess the performance of the developed models under different conditions.