ABSTRACT

Assessment of the spatial and temporal distribution of surface water balance (SWB) components for a river basin having complex topography with limited observed data is challenging. This paper focused on estimating the spatial-temporal variability of long-term average monthly, seasonal, and annual SWB components using the modified Water Energy Transfer between Soil, Plants, and Atmosphere in Steady State (WetSpass-M) physically based hydrological model in Ethiopia’s data-scarce Omo River basin. Further, the model output was used for estimating the spatial variation of the average monthly crop water deficit. A sensitivity analysis was performed on the global and local parameters of the model for analysing the relative variation in the SWB components. It was found that actual evapotranspiration (AET) and interception are insensitive to average rainfall intensity while surface runoff is highly sensitive. The variation of SWB under different combinations of land-use/land cover (LU/LC) and soil type indicates that SWB types such as surface runoff, AET, and interception are influenced more by LU/LC than by soil type.

摘要

对于具有复杂地形且观测数据有限的流域，评估地表水平衡 (SWB) 成分的空间和时间分布具有挑战性。本文着重于使用修正的稳定状态下土壤、植物和大气之间的水能转移 (WetSpass-M) 基于物理的埃塞俄比亚水文模型估计长期平均月、季和年 SWB 分量的时空变异性。数据稀缺的奥莫河流域。此外，模型输出用于估计平均每月作物缺水的空间变化。对模型的全局和局部参数进行了敏感性分析，以分析 SWB 分量的相对变化。结果表明，实际蒸散量（AET）和截流对平均降雨强度不敏感，而地表径流高度敏感。不同土地利用/土地覆盖（LU/LC）和土壤类型组合下的SWB变化表明，地表径流、AET和截留等SWB类型受LU/LC的影响大于土壤类型。