Land Use Evaluation over the Jema Watershed, in the Upper Blue Nile River Basin, Northwestern Highlands of Ethiopia

Abstract

Generating land capability class guidelines at a watershed scale has become a priority in sustainable agricultural land use. This study analyzed the area of cultivated land use situated on the non-arable land-capability class in the Jema watershed in the Upper Blue Nile River Basin. Soil surveys, meteorological ground observations, a digital elevation model (DEM) at 30 m, Meteosat at 10 km × 10 km and Landsat at 30 m were used to generate the sample soil texture class, average annual total rainfall (ATRF in mm), terrain, slope (%), elevation (m a.s.l) and land-use land cover (%). The land capability class was analyzed by considering raster layers of terrain, the average ATRF and soil texture. Geo-statistics was employed to fit a surface of soil texture and average ATRF estimates. An overlay technique was used to compute the proportion of cultivated land placed on non-arable land. As per the results of the terrain analysis, the elevation (m a.s.l) of the watershed is in the range of 1895 to 3518 m. The slope was found to be in the range of 0 to 45%. The amount of estimated rainfall ranged from 1640 to 131 mm with value declined from the lower to the higher elevation. Clay loam, clay and heavy clay were found to be the major soil texture classes. Four land capability classes, i.e., II, III, IV (arable) and V (non-arable), were identified with proportions of 28.56%, 45.74%, 22.16% and 3.54%, respectively. Seven land-use land covers were identified, i.e., annual crop land, grazing land, bush land, bare land, settlement land, forestland and water bodies, with proportions of 42.1, 35.9, 8.90, 8.3, 2.6, 2.1, and 0.2, respectively. Around 1707.7 ha of land in the watershed is categorized under non-arable land that cannot be used for annual crop cultivation at any level of intensity. Around 437 ha (3.5%) of land was cultivated on non-arable land. To conclude, the observed unsustainable crop land use could maximize soil loss in upstream regions and siltation and flooding downstream. The annual crop land use that was observed on non-arable land needs to be replaced with perennial crops, pasture and/or forest land uses.

Evaluation of the status of land use/land cover change using remote sensing and GIS in Jewha Watershed, Northeastern Ethiopia

“…This may be due to forest degradation and agricultural expansion. The results of the study are in conformity with researches undertaken in highland watershed as seen in [8,20].…”

Rainfall Variability across the Agro-Climatic Zones of a Tropical Highland: The Case of the Jema Watershed, Northwestern Ethiopia

“…In the Amhara Regional State, where the study site is situated, the average family size is estimated to be 4.6 people, while the population density is estimated to be~189.4 people km −2 [34]. The LULC types in the site are cropland, grazing land, settlement land, bare land, bush land, wood land, riverine trees, water bodies, and forest land [9]. The livelihood of the inhabitants is dependent on subsistence-scale mixed farming; i.e., food crop production and livestock rearing.…”

“…Ethiopia has shown considerable spatiotemporal differences in precipitation in the past [5,6]. The presence of other constraints such as inadequate farming technology, agricultural extension services, poor access to credit, poor financial market, poor infrastructure [7], soil degradation [8,9], and an incompetent institutional and administrative setup [5] have made the situation in the farming system more challenging.…”

“…Altitude is generally accepted to be the most common topographic variable used to explain spatial variations in precipitation due to precipitation enhancement through orographic uplift. However, the effects of altitude are not always straightforward [9]. In [6], it was indicated that relatively less-developed, semiarid, and arid regions of Ethiopia are highly vulnerable to climate change.…”

Agro–ecosystem sensitivity to climate change over the Ethiopian highlands in a watershed of Lake Tana sub–basin

“…Land is a source of water and soil resources that serves as a base for establishing a resilient livelihood system [59]. Land capability studies could be done considering a certain limitation of land depending on the context of the study site [40,60,61]. In the current study, LCC analysis was conducted taking into account classes of soil texture (%), slope (%) and elevation class (m a.s.l).…”