TITLE:
Effects of Land Use and Land Cover Change on Catchment Water Balance in Lagha Bor Catchment, Wajir County Kenya
AUTHORS:
Moses Muriuki, Joy Obando, Mary Makokha, Chris Shisanya, Justin Sheffield, Ryan Bailey
KEYWORDS:
Land Use, Land Cover, Groundwater, SWATPlus, Gwflow, Recharge, Goggle Earth Engine
JOURNAL NAME:
Open Access Library Journal,
Vol.10 No.3,
March
31,
2023
ABSTRACT: Groundwater is one of the most important water sources relied upon especially in arid and semi-arid areas where surface water is limited. The sustainability of groundwater resources has been under threat due to land use and land cover changes. This study aims to determine the effects of land use and land cover changes on integrated surface and groundwater resources within the Lagha-Bor catchment for the period 1990 to 2020. Landsat images of 1990, 2000, 2010 and 2020 were used along with integrated SWAT + gwflow model to predict the effects of the land use and land cover changes. Land use and land cover change analysis deduced that increased development of human and livestock watering points and settlements led to increase in bare-ground land cover from 35% to 45.8% while sparse shrubs decreased from 60.8% to 49%. Analysis of the catchment water balance revealed that the decrease of sparse shrubs and increase in bare-ground between year 2010 and 2020, led to a 33% decrease in groundwater recharge from 2860 mm to 1950 mm following an 8.5% reduction in sparse shrubs and 8.9 increase in bare-ground cover. In the period 2010 to 2020, reduction of 0.53% in groundwater volume was observed following a reduction of 7.2% in sparse shrubs and 7.5% increase in bare ground cover. Surface flow was least at 1655 mm in 2010 when the catchment recorded the highest area under sparse shrubs and the lowest area under bare-ground cover. The highest levels of percolation (3110 mm), lateral flows (480 mm), and groundwater return flows (1280 mm) were realized during the same period. This clearly showed that changes in land use and land cover had an effect on the water balance components in the catchment.