Dynamics of land use and land cover and its effects on hydrologic responses: case study of the Gilgel Tekeze catchment in the highlands of Northern Ethiopia

Abstract

Unprecedented land use and land cover (LULC) changes in the Gilgel Tekeze catchment of the upper Nile River basin in Ethiopia may have far-reaching consequences for the long-term sustainability of the natural resources base. This study analyzed the dynamics and hydrologic effects of LULC changes between 1976 and 2003 as shown in satellite imagery. The effects of these LULC changes on the hydrologic response were investigated using the WetSpa model to estimate spatially distributed average annual evapotranspiration, surface runoff, and groundwater recharge. Digital image analysis revealed major increments of cultivated land and settlements of 15.4 and 9.9%, respectively, at the expense of shrubland and grazing lands. Population growth and the associated demand for land were found to be the major driving forces. The WetSpa simulation showed an increase in annual surface runoff of 101 mm and a decrease in groundwater recharge of 39 mm over the period 1976-2003. These results signify an increasing threat of moisture unavailability in the study area and suggest that appropriate land management measures under the framework of the integrated catchment management (ICM) approach are urgently needed.

Effect of Land Use and Land Cover Change on Soil Erosion in Erer Sub-Basin, Northeast Wabi Shebelle Basin, Ethiopia

“…On the contrary, the net change-to-persistence ratio was negative for a water body, forestland, and shrubland, suggesting their net loss rather than their persistence in the study landscape [85]. The findings of this study were consistent with numerous studies' findings in other parts in Ethiopia [111][112][113][114][115][116][117][118][119], and elsewhere in the world [5,16,17]. These studies have revealed a heterogeneity in the spatial and temporal extent of LULCCs.…”

“…A recent report by Hailemariam et al [117] also concluded that population growth resulted in a high demand for cropland expansion, which in turn, has triggered a decrease in the areas of forest cover, shrubland, and grassland in the Bale mountain eco-region of Ethiopia. In a related study conducted in the Gilgel Tekeze Catchment of the northern Ethiopia highlands, Haregeweyn et al [118] suggested an integrated catchment management measures to minimize the adverse impacts of LULCC on sustainable hydrological system. Tadesse et al [119], in contrast, reported a regeneration of vegetation cover in the Yezat Watershed of northwestern Ethiopia, which was attributed to an integrated watershed management practices taken over the period between 2010 and 2015.…”

Hydrological Response of Dry Afromontane Forest to Changes in Land Use and Land Cover in Northern Ethiopia

“…This finding is supported by Berhane et al [39], who reported that forest cover of 35.1%, followed by shrubland (30.14%), occupied the largest portion of the land between 1985 and 2015, indicating an increment of forest cover (714 ha) and grassland (75 ha) in the Hugumburda forest of northern Ethiopia [13,39,47]. However, Haregeweyn et al [44] reported the major increments of cultivated land by 15.4% and settlements 9.9% at the expense of shrubland and grazing lands over the period of 1976-2003 in the Gilgel Tekeze catchment in the highlands of Northern Ethiopia [44,45]. The overall statistical accuracy assessment was performed on the resulting classified imagery.…”

Availability of Global and National Scale Land Cover Products and Their Accuracy in Mountainous Areas of Ethiopia: A Review

“…Of the 146 publications, 36 were from peer reviewed journals with environmental themes such as Science of the Total Environment [37][38][39][40]; Agriculture, Ecosystems and Environment [41][42][43]; Environmental Monitoring and Assessment [7,41,[44][45][46]; Environmental Systems Research [47][48][49]; Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 23 July 2018 doi:10.20944/preprints201807.0431.v1…”

“…This implies that authors find the LULC analysis quite important for water-related applications such as watershed management or surface and groundwater hydrology in Ethiopian river basins like the Upper Blue Nile, Tekeze, Awash, Baro, Ghibe and Rift Valley Lakes basins. Most studies were done in Upper Blue Nile River basin [37,40,43,45,47,[55][56][57][58][59][60][61][62], followed by studies in the Central and Rift Valley Lakes basin [63][64][65][66][67]. Given most of the reviewed studies focus on mid-to high-altitude regions, we evaluated the accuracy of six of the available national to global scale LULC products in the BMNP area, which ranges between 1,500 and 4,385 m a.s.l (see Table 4, Fig.…”