Afar in Ethiopia is a drought prone area characterized by low rainfall, high temperature and suffering from flash flood emerging from adjacent mountains. We introduced a flood barrier, water spreading weirs (WSWs) in 2015 to convert floods to a productive use and assessed its effect in 2016 and 2017. WSWs resulted in deposition of sediments where sand deposition was higher in the upside of upstream weir whereas silt and clay deposition was prominent at the central location between the two weirs. There was a moisture gradient across farming fields with volumetric water content (VWC) at 20 cm depth varying between 10 and 22% depending on the relative position/distance of fields from the WSWs, consequently, effecting significant difference in yield between fields. There was a positive relationship between VWC made available by WSWs at planting and the yield (P< 0.001,r= 0.76) and biomass productivity (P< 0.005,r= 0.46). WSWs created differing farming zone following soil moisture regime, affecting grain and biomass yield. In good potential zones with high moisture content, the WSW-based farming enabled to produce up to 5 and 15 t ha−1yr−1of maize grain and biomass, respectively, while in low potential zones there was a complete crop grain failure. The system enabled pastoralists to produce huge amount of biomass and grain during Belg (short) and Meher (long) growing seasons that was stored and utilized during succeeding dry periods. Furthermore, the practice ensured a visible recovery of degraded rangelands. This was evident from the filling up of the riverbed as well as the two WSW wings with 1 m high and about 450 m length each with fertile sediment from Belg and Meher seasons of 2016 and 2017. Hence, future studies should analyze the sustainability and the potential of flood-based development at large scale.

中文翻译：

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水扩散堰改变了埃塞俄比亚阿法尔干旱低地上游-下游环境中的洪水、养分分布和作物生产力

埃塞俄比亚的阿法尔地区是干旱多发地区，其特点是降雨量少、气温高、邻近山区出现山洪。我们在 2015 年引入了防洪屏障、扩水堰 (WSW)，以将洪水转化为生产性用途，并在 2016 年和 2017 年评估了其效果。WSW 导致沉积物沉积，上游堰上部的沙子沉积量较高，而淤泥和粘土沉积在两个堰之间的中心位置突出。农田间存在水分梯度，20 cm 深度的体积含水量 (VWC) 在 10% 和 22% 之间变化，具体取决于农田与 WSW 的相对位置/距离，因此，影响农田间产量的显着差异。磷< 0.001,r= 0.76) 和生物量生产力 (磷< 0.005,r= 0.46)。WSWs 根据土壤水分状况创造了不同的耕作区，影响粮食和生物量产量。在具有高水分含量的良好潜力区域，以 WSW 为基础的农业能够生产高达 5 和 15 吨/公顷-1年-1玉米谷物和生物量，而在低潜力区，作物完全歉收。该系统使牧民能够在 Belg（短）和 Meher（长）生长季节生产大量的生物质和谷物，并在随后的干旱时期储存和利用。此外，这种做法确保了退化牧场的明显恢复。这从 2016 年和 2017 年 Belg 和 Meher 季节的河床以及两个高 1 m、长约 450 m 的 WSW 翼的填充中可以看出。因此，未来的研究应该分析可持续性和洪水为基础的大规模开发潜力。