Abstract Effective watershed planning requires an understanding of the hydrology. In the humid tropical monsoon climates and especially in volcanic highland regions such as the Ethiopian Highlands, the understanding of watershed processes is incomplete. The objective is to better understand the hydrology of the volcanic regions in the humid highlands by linking the hillslope processes with the discharge at the outlet. The Ene-Chilala watershed was selected for this study. The infiltration rate, piezometric water levels and discharge from two nested sub watersheds and at the watershed outlet were measured during a four-year period. Infiltration rates on the hillsides exceeded the rainfall intensity most of the time. The excess rain recharged a perched hillside aquifer. Water flowed through the perched aquifer as interflow to rivers and outlet. In addition, saturation excess overland flow was generated in the valley bottoms. Perched water tables heights were predicted by summing up the recharge over the travel time from the watershed divide. Travel times ranged from a few days for piezometers close to the divide to 40 days near the outlet. River discharge was simulated by adding the interflow from the upland to overland flow from the saturated valley bottom lands. Overland flow accounted only for one-fourth of the total flow. There was good agreement between predicted and observed discharge during the rain phase therefore the hillslope hydrologically processes were successfully linked with the discharge at the outlet.

中文翻译：

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连接埃塞俄比亚高地的山坡和径流生成过程：Ene-Chilala 流域

摘要 有效的流域规划需要了解水文。在潮湿的热带季风气候中，尤其是在埃塞俄比亚高地等火山高地地区，对流域过程的了解尚不完整。目的是通过将山坡过程与出口处的排放联系起来，更好地了解潮湿高地火山区的水文。本研究选择了 Ene-Chilala 流域。在四年的时间里测量了两个嵌套子流域和流域出口的渗透率、测压水位和排放。大多数时候，山坡上的入渗率超过了降雨强度。过量的雨水为栖息的山坡含水层补水。水流过栖息的含水层，汇入河流和出口。此外，在谷底产生了饱和过量地表流。栖息地下水位高度是通过总结流域分水岭旅行时间的补给来预测的。旅行时间从靠近分水岭的压力计的几天到靠近出口的 40 天不等。通过添加从高地到饱和谷底地的地表流的互流来模拟河流流量。地表流量仅占总流量的四分之一。在雨期预测和观察到的流量之间有很好的一致性，因此山坡水文过程成功地与出口处的流量相关联。栖息地下水位高度是通过总结流域分水岭旅行时间的补给来预测的。旅行时间从靠近分水岭的压力计的几天到靠近出口的 40 天不等。通过添加从高地到饱和谷底地的地表流的互流来模拟河流流量。地表流量仅占总流量的四分之一。在雨期预测和观察到的流量之间有很好的一致性，因此山坡水文过程成功地与出口处的流量相关联。栖息地下水位高度是通过总结流域分水岭旅行时间的补给来预测的。旅行时间从靠近分水岭的压力计的几天到靠近出口的 40 天不等。通过添加从高地到饱和谷底地的地表流的互流来模拟河流流量。地表流量仅占总流量的四分之一。在雨期预测和观察到的流量之间有很好的一致性，因此山坡水文过程成功地与出口处的流量相关联。地表流量仅占总流量的四分之一。在雨期预测和观察到的流量之间有很好的一致性，因此山坡水文过程成功地与出口处的流量相关联。地表流量仅占总流量的四分之一。在雨期预测和观察到的流量之间有很好的一致性，因此山坡水文过程成功地与出口处的流量相关联。