Analyzing the hydrologic effects of region-wide land and water development interventions: a case study of the Upper Blue Nile basin
Analyzing the hydrologic effects of region-wide land and water development interventions: a case study of the Upper Blue Nile basin
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分析全区域土地和水资源开发干预措施的水文影响：以青尼罗河上游流域为例
DOI：
10.1007/s10113-015-0813-2
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发表时间：
2016
影响因子：
4.2
通讯作者：
Schutt B
中科院分区：
文献类型：
--
作者：
Haregeweyn N;Tsunekawa A;Tsubo M;Meshesha D;Adgo E;Poesen J;Schutt B
在上青尼罗河流域的旱地，气候高度多变和土地退化猖獗。为加强该区域的适应能力，实施了各种水土保持干预措施。此外，埃塞俄比亚文艺复兴大坝等水资源开发计划应在2025年前实施。我们使用空间显式的径流系数方法，模拟了当前和未来(2025年)流域条件下，这些干预措施对流域地表径流的影响。在当前条件下，观测到了年平均径流的高度空间变异性。青尼罗一号流域东北部年平均径流量最高(391×109m~3)，西北部青尼罗河-2号子流域年平均径流量最低(178m m/m~2×109m~3)。流域年产流总量为47.7×109m~3，其中约54%来自耕地。土地利用和地形之间的强烈关联掩盖了降雨对径流的直接影响。到2025年，如果在全流域范围内实施适当的水土保持干预措施和埃塞俄比亚文艺复兴大大坝，年径流总量可能减少高达38%。然而，在没有定期维护的情况下，大多数物理结构的全部作用只能持续一到两年。本研究提供了对青尼罗河上游流域水文动态的进一步了解，这将有助于规划者设计适当的管理方案。发展该流域的数据库对于全面了解未来发展干预措施的影响仍然很重要。
In the drylands of the Upper Blue Nile basin, high climate variability and land degradation are rampant. To enhance adaptive capacity in the region, various soil and water conservation interventions have been implemented. Moreover, water resources development schemes such as the Grand Ethiopian Renaissance Dam should be implemented by 2025. We modeled the effects of these interventions on surface runoff in the basin for both current and future (2025) basin conditions, using the runoff coefficient method in a spatially explicit approach. Under current conditions, we observed high spatial variability of mean annual runoff. The northeastern Blue Nile-1 sub-basin produces the highest mean annual runoff (391 mm or 10 × 109m3), whereas the northwestern Blue Nile-2 sub-basin produces the lowest mean annual runoff (178 mm or 0.2 × 109m3). The basin generates a total annual runoff volume of 47.7 × 109m3, of which about 54 % comes from cultivated land. The strong association between land use and topography masked the direct effect of rainfall on runoff. By 2025, total annual runoff yield could decrease by up to 38 % if appropriate basin-wide soil and water conservation interventions and the Grand Ethiopian Renaissance Dam are implemented. However, the full effects of most physical structures will only last for 1 or 2 years without regular maintenance. The improved understanding of the dynamics of the Upper Blue Nile basin’s hydrology provided by the present study will help planners to design appropriate management scenarios. Developing the basin’s database remains important for a holistic understanding of the impacts of future development interventions.