Pedosphere 13(1): 67--74, 2003
ISSN 1002-0160/CN 32-1315/P
©2003 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Quantitative relationship between land use and phosphorus discharge in subtropical hilly regions of China |
| YANG Jin-Ling and ZHANG Gan-Lin |
| Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) |
| ABSTRACT |
| The increase of phosphorus concentration is a crucial factor causing the eutrophication of water body, while land use has an important impact on agricultural non-point sources (NPS) phosphorus discharge. Seven sites controlling the water in four sub-watersheds and the main exit of the Meicun Watershed of Xuancheng County, Anhui Province, were investigated by dynamic monitoring of stream water and nutrient discharge, integrating interpretation of aerial image and GIS analysis to find out how the land use affects phosphorus loss with stream water in typical agriculture-forest watershed in subtropical China. These monitored sites are different in structure of land use. Phosphorus concentration of the stream water was analyzed every week and at the next day of rainfall. The velocity of flow was measured by kinemometer to calculate the runoff flux and phosphorus discharge. The results showed that the runoff flux and the discharges of dissolved phosphorus (DP), particle-associated phosphorus (PAP) and total phosphorus (TP) had significant exponential relationships with the area percentages of forest, pond and paddy field. There existed a significant linear relationship between the TP and PAP concentrations in stream water and the area percentages of forest, pond and paddy field, and the discharge of PAP was also significantly linearly correlated with the discharge of suspended soil particles. There was a logarithmic linear relationship between DP and PAP discharges. The study indicated that the adjustment of land use patterns and construction of ecologically sound landscape would be an important measure to reduce the runoff discharge of phosphorus. The results would be very useful in building the best management practices (BMPs) of agricultural watershed in subtropics. |
| Key Words: land use, phosphorus, runoff, watershed |
| Citation: Yang, J. L. and Zhang, G. L. 2003. Quantitative relationship between land use and phosphorus discharge in subtropical hilly regions of China. Pedosphere. 13(1): 67-74. |
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