Pedosphere 13(1): 23--30, 2003
ISSN 1002-0160/CN 32-1315/P
©2003 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Nutrient discharges from a typical watershed in the hilly area of subtropical China |
| ZHANG Gan-Lin, YANG Jin-Ling and ZHAO Yu-Guo |
| Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) |
| ABSTRACT |
| Agriculture is still the biggest contributor of non-point source(NPS) pollution to water bodies andrunoff discharges of nutrients and other chemicals are one of the most important pathways. This studywas conducted during 1998-1999 in a typical watershed with complex agriculture and forestry systems aswell 3, 8 dotted farmer villages, in a transitional region between the mid- and northern subtropical zones of China. Continuous sanlpling of stream water was performed regularly at a weekly frequency, with additionalsampling after all major rainfall events. The discharges of N and P nutrients and suspended materials weremeasured and the total and area-averaged annual discharges of all components were calculated. The resultsshowed an uneven seasonal distribution of nutrient discharges with summer storms contributing most tothe total fluxes. This study demonstrated a high dependence of runoff volume on rainfall but the overallrunoff coefficients were dependent on land use type and watershed size. The area-averaged annual discharges varied greatly among the sub-watersheds with different sizes and land use structures. This is the first study estimating the area-averaged annual discharges of N and P in the hilly areas of subtropical China, which were 1.5 g m-2 a-1 and 0.1 g m-2 a-1, respectively, providing important reference values for the assessment of regional agricultural non-point source pollution. |
| Key Words: discharge, nutrients, runoff, subtropical China, watershed |
| Citation: Zhang, G. L., Yang, J. L. and Zhao, Y. G. 2003. Nutrient discharges from a typical watershed in the hilly area of subtropical China. Pedosphere. 13(1): 23-30. |
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