Changes in Water Resources Systems: Methodologies to Maintain Water Security and Ensure Integrated Management (Proceedings of Symposium HS3006 at IUGG2007, Perugia, July 2007). IAHS Publ. 315, 2007., 85-91

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Impacts of human activity on long-term water balance in the middle-reaches of the Yellow River basin

YOSHINOBU SATO¹, XIEYAO MA², MASAYUKI MATSUOKA³ & YOSHIHIRO FUKUSHIMA¹

1 Research Institute for Humanity and Nature (RIHN), 457-4 Kamigamo-motoyama, Kita-ku, Kyoto 603-8047, Japan

s_yoshi@chikyu.ac.jp

2 Frontier Research Center for Global Change (FRCGC), 3173-25 Showa-machi, Kanazawa-ku, Yokohama 236-0001, Japan

3 Department of Forest Science, Kochi University, 200 Monobe-Otsu, Nankoku, Kochi 783-8502, Japan

Abstract To clarify the influences of climate change and human activities on river discharge, the long-term (1960–2000) water balance in the middle reaches of the Yellow River basin was analysed using a hydrological model. To estimate evapotranspiration from various land-use types, a high resolution land surface classification map in 2000 was used. When we applied the same land-use parameter of 2000 during the past 40 years, the results estimated by the model underestimated the river discharge. Then we modified the parameter to decrease evapotranspiration by reducing the vegetation cover. After that, the observed discharge was reasonably captured by the model. Consequently it was found that the massive land-use change and rapid decrease of available water resources in the middle reaches of the Yellow River basin will affect the water shortage in the lower reaches of the Yellow River basin.

Key words climate change; human activity; hydrological model s; long-term land-use change; water balance; Yellow River

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