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Effect of typical forest vegetation on rainfall redistribution in the Three Gorges Reservoir |
Zhou Jianing, Wang Bin, Wang Yunqi, Liu Chunxia, Lü Chao, Du Wenji, Ma Liang |
College of Soil and Water Conservation, Beijing Forestry University, 100083, Beijing, China |
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Abstract In order to explore the effect of different forest vegetation types on rainfall redistribution in Three Gorges Reservoir area, we choose evergreen broadleaf forests and conifer-broadleaf mixed forests in the reservoir area as research objects, which are located near Badong County in the upper section of the reservoir of Hubei Province, Simian Mountain and Jinyun Mountain in the lower section of the reservoir in Chongqing. Using the observation data of rainfall, throughfall and stemflow for the 52 measured rain events in Jinyun Mountain of Chongqing from June to September in 2012, the canopy interception model was built up. Then we analyzed the characteristics of rainfall redistribution and compared the precipitation redistribution characteristics in Badong County with that in Simian Mountain. The result shows that the throughfall has a significant linear relationship with rainfall in the evergreen broadleaf forests and conifer-broadleaf mixed areas of Jinyun Mountain, Simian Mountain and Badong County. What is more, the amount of canopy interception has a significant exponential relationship with rainfall. According to the equation, the required minimum rainfalls to create throughfall in these areas for broadleaf forests are 1.0mm, 1.8 mm and 2.6 mm separately; on the other hand, it requires 1.1 mm, 3.0 mm and 1.1 mm for conifer-broadleaf mixed forests in the same areas. The average interception rate of conifer-broadleaf mixed forests is greater than the average entrapment rate of evergreen broadleaf forests at these locations. Under the same rainfall condition, the canopy interception rate of conifer-broadleaf mixed forests descends in the order of Jinyun Mountain in Chongqing (46.00%), Simian Mountain (41.42%) and Badong County in Hubei Province (22.30%); such ranking for broadleaf forests is Simian Mountain (28.78%), Jinyun Mountain in Chongqing (23.09%) and Badong County in Hubei Province (21.69%).
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Received: 03 April 2013
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