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基于ArcGIS9.2,构建了生态系统减轻水库泥沙淤积的评估模型,并结合泥沙输移比(SDR)和通用水土流失方程(USLE),模拟了二滩水库集水区的产沙量和保沙量及其空间分布特征以及水库使用年限内其生态系统服务价值.结果表明:2000年,二滩水库集水区土壤保持量12.1×108t.a-1,土壤保持量高值区主要分布于雅砻江干流和支流水网附近;泥沙输移比的高值主要分布在河道附近和水库周边,水库周边是最主要的产沙区和保沙区;研究区实际产沙量为629.3×104t.a-1,占实际土壤侵蚀量的12.7%;农田是研究区最主要的产沙源,其产沙量占集水区总产沙量的62.9%;林地平均单位面积的保沙价值最高.在二滩水库使用年限内(100a),集水区对于减轻二滩水库泥沙淤积的总价值为27.53亿元.
Based on ArcGIS 9.2, an assessment model of ecosystem sediment mitigation in reservoirs was built. Combined with the sediment transport ratio (SDR) and generalized soil erosion equation (USLE), the sediment yield of Ertan Reservoir catchment area and The amount of sediment and its spatial distribution and its ecosystem service value during the service life of the reservoir.The results showed that in 2000, the soil retention of Ertan Reservoir catchment was 12.1 × 108t.a-1, In the vicinity of the Yalong River and in the vicinity of the tributary water network, the high value of sediment transport and discharge ratio is mainly distributed in the vicinity of the river and in the vicinity of the reservoir. The most important sediment yielding and sand holding area around the reservoir is the actual sediment yield in the study area, 629.3 × 104t.a-1, accounting for 12.7% of the actual soil erosion; farmland is the most important source of sediment in the study area, accounting for 62.9% of the total sediment yield; The highest value of Ertan Reservoir in the service life (100a), Catchment to ease the Ertan Reservoir Sedimentation of the total value of 2.753 billion yuan.