基于^137Cs技术的侵蚀产沙对土地利用变化响应--以三峡库区斑竹林小流域为例

Study on response of soil erosion and sediment yield to land use change by using ^(137)Cs tracing method:case of a small agricultural catchment( Banzhulin Catchment) in Three Gorges Reservoir region

小流域是三峡库区入库泥沙的策源地,研究其侵蚀产沙状况对正确预测三峡水库来沙变化趋势非常重要。以三峡库区典型农业小流域——斑竹林小流域为研究对象,通过^(137)Cs示踪技术,研究了土地利用变化对流域侵蚀产沙空间分布的影响。结果表明:旱地退耕的其他林地和水田改的旱地的侵蚀堆积情况与土地利用变化前相差不大;在土地利用变化后的短期内,该流域侵蚀产沙变化较小,旱地是流域主要的侵蚀产沙源地,水田是淤积区。

The small watersheds are the primary source of incoming sediment for the Three Gorges Reservoir region, so the study on erosion and sediment yield of small watersheds is important to the accurate forecast of incoming sediment variation of Three Gorges Reservoir. A small and typical agricultural catchment （ Banzhulin Catchment） was selected, the influence of land use change on the spatial distribution of sediment yield was researched by using^ 137 Cs tracing method. The results indicated that the soil erosion situation of the forestland and dry land transformed from paddy field changed little. The variation of soil erosion and sediment yield is small in short period after the land use change. The dry land is the main source of sediment yield and the paddy field is the sedimentation area.