Agroecology-based soil erosion assessment for better conservation planning in Ethiopian river basins
Agroecology-based soil erosion assessment for better conservation planning in Ethiopian river basins
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DOI：
10.1016/j.envres.2021.110786
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发表时间：
2021-01-31
影响因子：
8.3
通讯作者：
Sultan, Dagnenet
中科院分区：
文献类型：
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作者：
Fenta, Ayele Almaw;Tsunekawa, Atsushi;Sultan, Dagnenet
水土流失是埃塞俄比亚的主要环境问题之一。一些研究已经在地块和流域尺度上对此进行了研究，但没有系统的研究土壤侵蚀的严重程度和管理解决方案在全国范围内。这项研究调查了土壤侵蚀和土地覆盖和农业生态特定的土地管理措施，在减少土壤流失的潜力，通过采用修订的通用土壤流失方程和现有的最佳数据集。据估计，埃塞俄比亚因水蚀造成的土壤流失平均速率为16.5吨/公顷/年，年土壤流失总量约为1.5吨/公顷/年。1.9 x10（9）t，其中净流失量估算为ca. 410 x 10（6）t（占土壤流失总量的22%）。不同土地覆盖类型、15个农业生态区和10个流域的土壤流失各不相同，在各自的分析中，主要贡献者是农田（约100公顷）。23%的埃塞俄比亚; 50%的土壤流失;平均土壤流失率为36.5吨公顷（-1）年（-1）），潮湿的Weyna Dega（约。10%; 20%; 33.3吨公顷（-1）年（-1）），和Abay盆地（约。15%; 30%; 32.8 t ha（-1）yr（-1））。我们的研究结果表明，CA。埃塞俄比亚25%的地区（28 x 10（6）ha）的土壤流失率超过10 t ha（-1）yr（-1），高于埃塞俄比亚估计的可容忍土壤流失限度。事先分析表明，在这些地区实施土地覆盖和农业生态方面的土地管理措施（水平堤坝、分级堤坝、沟渠以及与沟渠和/或堤坝相结合的围栏），可以将平均土壤流失率从16.5吨公顷/年减少到5.3吨公顷/年（平均值约为2.5吨/年）。68%;范围，65-70%）。在阿拜和Tekeze流域以及Dega和Weyna Dega农业生态中，适当的土地管理做法会造成特别严重的侵蚀。土壤流失量分别减少50%和70%。这项研究有助于提高决策者和土地管理人员对水土流失的程度和严重性的认识，以便更好地制定河流流域的保护规划，支持土地和水资源的可持续利用。
Soil erosion by water is one of the main environmental concerns in Ethiopia. Several studies have examined this at plot and watershed scales, but no systematic study of soil erosion severity and management solutions at national scale is available. This study investigated soil erosion and the potential of land-cover- and agroecology-specific land management practices in reducing soil loss through employing the Revised Universal Soil Loss Equation and the best available datasets. The mean rate of soil loss by water erosion in Ethiopia was estimated as 16.5 t ha(-1) yr(-1), with an annual gross soil loss of ca. 1.9 x 10(9) t, of which the net soil loss was estimated as ca. 410 x 10(6) t (22% of the gross soil loss). Soil loss varied across land cover types, 15 agroecological zones, and 10 river basins, with the main contributors in the respective analyses being cropland (ca. 23% of Ethiopia; 50% of the soil loss; mean soil loss rate of 36.5 t ha(-1) yr(-1)), Moist Weyna Dega (ca. 10%; 20%; 33.3 t ha(-1) yr(-1)), and the Abay basin (ca. 15%; 30%; 32.8 t ha(-1) yr(-1)). Our results show that ca. 25% of Ethiopia (28 x 10(6) ha) has soil loss rates above 10 t ha(-1) yr(-1), which is higher than the tolerable soil loss limits estimated for Ethiopia. Ex-ante analysis revealed that implementation of land-cover- and agroecology-specific land management practices (level bunds, graded bunds, trenches, and exclosures combined with trenches and/or bunds) in such areas could reduce the mean soil loss rate from 16.5 t ha(-1) yr(-1) to 5.3 t ha(-1) yr(-1) (mean, by ca. 68%; range, 65-70%). Suitable land management practices in the Abay and Tekeze basins and Dega and Weyna Dega agroecologies, which experience particularly severe erosion, would account for ca. 50 and 70% of the estimated soil loss reduction, respectively. This study can help raise awareness among policy makers and land managers of the extent and severity of soil loss by water erosion for better conservation planning in river basins to support sustainable use of land and water resources.