Modeling soil erosion between 1985 and 2014 in three watersheds on the carbonate-rock dominated Guizhou Plateau, SW China, using WaTEM/SEDEM
Modeling soil erosion between 1985 and 2014 in three watersheds on the carbonate-rock dominated Guizhou Plateau, SW China, using WaTEM/SEDEM
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DOI：
10.1177/0309133320961274
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
Yao Luo;Hongya Wang;J. Meersmans;S. Green;T. Quine;Siwen Feng
中科院分区：
文献类型：
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作者：
Yao Luo;Hongya Wang;J. Meersmans;S. Green;T. Quine;Siwen Feng
中国西南部的贵州高原大部分被碳酸盐岩覆盖。由于土壤很薄，尽管侵蚀率很低，但土壤流失仍然是一个严重的问题。进一步了解降雨、土地利用变化和地形差异对产沙和输沙的影响，可能有助于制定减少高原土壤侵蚀的适当政策。利用空间分布的土壤侵蚀与输沙模型(WAEM/SEDEM)，研究了贵州省黔西南高原大渡口(DDK)、草坪头(CPT)和高车(GC)3个小流域1985~2014年间土壤侵蚀的时空变化。WaTEM/Sedem模型利用在分水岭尺度上测量的泥沙产量数据进行了校准和验证。总产沙量(SY)和土壤侵蚀模数(SEM)在30年间呈先减小后增大的趋势，而输沙率(SDR)基本保持不变。主要泥沙来源为旱地。在最大的DDK分水岭中，SY最高。CPT流域由于地势陡峭，坡度较大，旱地面积比例较大，土壤水分状况最好。在坡度较低、坡度较大的旱地比例较低的GC流域，土壤水分状况最低。由于其地形特征，SDR在GC分水岭中最高。土壤水分状况对降水波动非常敏感，特别是在陡峭和强烈侵蚀的CPT流域，而旱地比例的变化对CPT和DDK流域的土壤水分状况影响不大，而对轻度和轻度侵蚀的GC流域影响不大。林木比例的变化只对GC流域的土壤水分状况有显著影响。由于不同流域的土壤侵蚀对主要影响因子的变化或差异的响应不同，土壤保持策略应该针对不同的流域。
The Guizhou Plateau, SW China is largely underlain by carbonate rocks. Because soils are thin, soil loss remains a serious problem despite low erosion rates. Further understanding the impacts of changes in rainfall, land use and differences in topography on sediment yield and delivery may assist in the development of suitable policies to reduce soil erosion on the plateau. A spatially distributed soil erosion and sediment delivery model (WaTEM/SEDEM) was applied to investigate temporal–spatial changes in soil erosion between 1985 and 2014 in three watersheds (Dadukou (DDK), Caopingtou (CPT) and Gaoche (GC)) located in the southwest Guizhou Plateau. The WaTEM/SEDEM model was calibrated and validated using data on sediment yields measured at the watershed scale. The total sediment yield (SY) and soil erosion modulus (SEM) firstly decreased followed by an increase, whereas the sediment delivery ratio (SDR) remained almost unchanged over the 30-year period. The major sediment source was dry farmlands. SY was the highest in the largest DDK watershed. The highest SEM occurred in the CPT watershed due to steep terrain and high ratio of dry farmland areas on steeper slopes. SEM was the lowest in the GC watershed where slope gradient and ratio of dry farmland on steeper slopes are low. SDR was the highest in the GC watershed because of its topographic characteristics. SEM was sensitive to precipitation fluctuations in the GC, DDK and particularly in the steep and intensively eroded CPT watershed, while changes in dry farmland ratio influenced the SEM in the CPT and DDK watersheds but not in the gentle and mildly eroded GC watershed. Changes in forest ratio had significant impacts on SEM only in the GC watershed. Since responses of soil erosion to variations or differences in the main impact factors differ in the different watersheds, soil conservation strategies should be watershed specific.