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Analysis on the Sediment Reduction Effects and Its Change Process of the Soil and Water Conservation Measures on Slopes in Dali River Watershed

Author: KangWei
Tutor: LiZhanBin；LiPeng
School: Xi'an University of Technology
Course: Hydrology and Water Resources
Keywords: Slope and soil conservation measures Sediment Reduction modulus Sediment reduction benefit Sediment reduction
CLC: S157
Type: Master's thesis
Year: 2008
Downloads: 141
Quote: 1
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Abstract

Dali River Basin as the object of study, the use of soil and water conservation, sediment kinematics, hydrology, landscape ecology and mathematical statistical theories, the system to carry out the the sediment reduction mechanism of the the Dali River basin slope and soil conservation measures and less sand The changing role of process research. Made the following conclusions: (1) to determine the quantity and quality of the the Dali River basin slope of soil and water conservation measures. Data collection and typical survey, combined with remote sensing image and GIS technology, Dali River Basin slope and soil conservation measures the quantity and quality of the dynamic process of change. 1956 Dali River Basin the terraced 430hm to 2; a woodland 3521hm to 2; a grass 451hm to 2; the end of 2002, Dali River Basin Total a terraced 21793hm to 2; a woodland 78872hm to 2; a grass 5012hm to 2, soil and water conservation area significantly increase. (2) The application of simulation and positioning observations, in-depth analysis of the mechanism of shrub and grass vegetation sediment reduction measures. The results showed that the vegetation coverage vary due to changes in vegetation types and growing season, the sediment yield characteristics also change accordingly; shrub and grass vegetation spatial structure and configuration form has a profound impact on the overland sediment yield and vegetation cover The high degree of slope has a more powerful function of soil and water conservation. (3) further analysis of the the Dali River basin slope sediment reduction benefit of soil and water conservation measures, establishment of the slope sediment reduction benefit of soil and water conservation measures in the flood season rainfall conditions under formula. , The Dali River Valley flood season rainfall greater than 300mm, terraced sediment reduction decreases; woodland coverage is less than 20%, woodland sediment reduction effect was not significant, the woodland cover more than 70%, woodland Less the conservation benefit not change significantly; the grassland coverage of greater than 60%, grassland sediment reduction benefit is no longer change significantly. (4) to determine the different levels of Dali River Basin slope soil and water conservation measures to reduce sediment. Watershed observational data and cell observations, combined with the quality of the soil and water conservation measures analysis to determine the Dali River Basin, three types of terraces, sediment reduction modulus were 155t/hm ~ 2,121 t / hm ~ 2 and 112t / hm ~ 2, one, two, three types of woodland Less sediment were 138t/hm ~ 2,52.5 t / hm ~ 2 and 22.5t/hm to 2, one, two, three types of grass to reduce sediment The number of 132t/hm ~ 2,84 t / hm ~ 2 and 63t/hm ~~ 2. (5) analysis of sediment reduction Dali River Basin slope and soil conservation measures. Hung count sand results shows that Dali River Basin slope soil and water conservation measures in the 1970s and 1990s the average annual sediment reduction 2.546 million tons and 549.2 million t and 9,486,000 t. Basin from 1970 to 2002 the average annual slope and soil conservation measures 7.242 million tons of sediment reduction which, terraced annual average 1.974 million tons of sediment reduction woodland average annual 5.139 million tons of sediment reduction grass an average annual 129,000 tons of sediment reduction .

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