ABSTRACT

Land-use/land-cover (LULC) changes in the Gidabo basin, Rift Valley, Ethiopia, have greatly affected the hydrology of the basin. This study integrates hydrological modelling with statistical analysis to evaluate the hydrological response of LULC changes during the period 1988–2018. Using the Soil and Water Assessment Tool (SWAT) and partial least squares regression (PLSR) models, the influences of individual LULC changes on different components of the hydrological cycle are assessed. The results of the Mann-Kendall test showed no significant trends in annual rainfall over the basin at the 95% significance level. Change in LULC resulted in an increase in annual mean surface runoff by 23.6 mm during the period 1988–2018. Meanwhile, the annual mean baseflow, lateral flow, percolation and evapotranspiration (ET) were reduced by 9.1, 4.2, 10.2 and 12.2 mm, respectively. PLSR analysis indicated that cultivated land affected the lateral flow and ET negatively in contrast to agroforestry and grassland, which had a positive influence.

摘要

埃塞俄比亚裂谷的吉达博盆地的土地利用/土地覆盖（LULC）变化极大地影响了该盆地的水文学。这项研究将水文模型与统计分析相结合，以评估1988-2018年期间LULC变化的水文响应。使用土壤和水评估工具（SWAT）和偏最小二乘回归（PLSR）模型，评估了各个LULC变化对水文循环不同组成部分的影响。Mann-Kendall检验的结果表明，在95％的显着性水平下，该盆地的年降雨量没有显着趋势。LULC的变化导致1988-2018年期间的年平均地表径流量增加了23.6 mm。同时，年平均基准流量，侧向流量，渗流和蒸散量（ET）分别减少了9.1、4.2、10.2和12。分别为2毫米。PLSR分析表明，与农林和草地相反，耕地对横向流量和ET产生负面影响。