Several water resources projects are under planning and implementation in the Baro-Akobo basin. Currently, the planning and management of these projects is relied on historical data. So far, hardly any study has addressed water resources management and adaptation measures in the face of changing water balances due to climate change in the basin. The main bottleneck to this has been lack of future climate change scenario base data over the basin. The current study is aimed at developing future climate change scenario for the basin. To this end, Regional Climate Model (RCM) downscaled data for A1B emission scenario was employed and bias corrected at basin level using observed data. Future climate change scenario was developed using the bias corrected RCM output data with the basic objective of producing baseline data for sustainable water resources development and management in the basin. The projected future climate shows an increasing trend for both maximum and minimum temperatures; however, for the case of precipitation it does not manifest a systematic increasing or decreasing trend in the next century. The projected mean annual temperature increases from the baseline period by an amount of 1 °C and 3.5 °C respectively, in 2040s and 2090s. Similarly, evapotranspiration has been found to increase to an extent of 25% over the basin. The precipitation is predicted to experience a mean annual decrease of 1.8% in 2040s and an increase of 1.8% in 2090s over the basin for the A1B emission scenario. The study resulted in a considerable future change in climatic variables (temperature, precipitation, and evapotranspiration) on the monthly and seasonal basis. These have an implication on hydrologic extremes-drought and flooding, and demands dynamic water resources management. Hence the study gives a valuable base information for water resources planning and managers, particularly for modeling reservoir inflow-climate change relations, to adapt reservoir operation rules to the real-time changing climate.

中文翻译：

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埃塞俄比亚西南部Baro-Akobo流域的气候变化情景分析

Baro-Akobo流域的几个水资源项目正在规划和实施中。当前，这些项目的计划和管理依赖于历史数据。迄今为止，面对流域气候变化导致的水平衡变化，几乎没有任何研究涉及水资源管理和适应措施。造成这一问题的主要瓶颈是缺乏该盆地未来气候变化情景的基础数据。当前的研究旨在开发该盆地未来的气候变化情景。为此，采用了针对A1B排放情景的区域气候模型（RCM）缩减数据，并使用观测到的数据在流域一级对偏差进行了校正。使用偏差校正后的RCM输出数据制定了未来的气候变化方案，其基本目标是为流域的可持续水资源开发和管理提供基准数据。预计的未来气候将显示最高和最低温度均呈上升趋势。但是，就降水而言，在下一世纪它不会表现出系统的上升或下降趋势。在2040年代和2090年代，预计年平均温度从基准期分别升高1°C和3.5°C。同样，已发现整个盆地的蒸散量增加了25％。对于A1B排放情景，预计流域的降水在2040年代年平均减少1.8％，在2090年代年平均增加1.8％。该研究导致未来每月和季节性的气候变量（温度，降水和蒸散量）发生相当大的变化。这些对极端干旱和洪水的水文问题有牵连，并需要动态的水资源管理。因此，该研究为水资源计划和管理者，特别是为水库入库-气候变化关系建模提供了有价值的基础信息，以使水库运行规则适应实时变化的气候。