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| Forest Hydrology Benefit of Duanfangxi Small Watershed in Three Gorges Reservoir Area |
| Shi Yuhu1,2,Zhu Shibao3,Xiongfeng1,Cai Sheng2,Liu Xuequan2，Pan Lei2,Chen Shuangtian2 |
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Abstract It is significant that the forestry hydrology function of reservoir area of Three Gorges gives play to the safe operation and benefit of the water control project in Three Gorges of Yangtze River. It all can play active roles in development and improvement on ecological environment in Three Gorges Reservoir Area. Based on the observation of the natural rainfall, runoff, etc. in 19922000, the roles of crown canopy, the roles of forest litter in Duanfangxi small watershed, the correlation between the forest coverage rates and the soil unit weight, total hole degree and the runoff have been analyzed. The result shows that, the weight of branches and leaves has linear positively correlated to the diameter of its stem, the water capacity of branches and leaves has linear positively correlated with its weight, the crown canopy cuts the allowance and rainfall and presents exponential functional relation. The interception amount of crown canopy of different forest type is 0.38mms～8.78mms, the interception rate of crown canopy is 10.27%～49.48%, and the crown canopy interception is exponential functional relation to its rainfall in Duanfangxi small watershed. With the increase of the coverage rate of forest, the soil unit weight of the forest land reduces, total hole degree increases; In the main forest type, the water capacity of litter in the conifer-broadleaf mixed forest is the largest, and the water capacity of litter can reach 2.8%～6.3% of rainfall, the runoff and precipitation is linear positively correlation in the same period in Duanfangxi small watershed, following the forest coverage rates increased by 1%, the depth of runoff reduces 6.95mm in flood season in Duanfangxi small watershed.
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Received: 23 February 2004
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