Papers by BROOK L E G E S E DADHE
Integrating GIS and Multi-Criteria Analysis for Sustainable Livestock Grazing: A Holistic Assessment of Biophysical and Socio-Economic Determinants in Semi-Arid Dawa Watershed of Ethiopia
Wiley , 2025
The degradation of rangelands in semi-arid areas threatens pastoral livelihoods and ecosystem ser... more The degradation of rangelands in semi-arid areas threatens pastoral livelihoods and ecosystem services, making it imperative that integrated approaches find a place in the sustainable land management program. In this regard, the study made use of GIS-based multi-criteria evaluation to determine livestock grazing suitability and degradation risks in the semi-arid Dawa watershed, integrating five relevant biophysical parameters (land use/cover, rainfall, water accessibility, slope, and soil type) with socio-economic indicators derived from expert informant surveys. Importantly, land use/cover classification recorded an accuracy of 98.3% (kappa = 0.97), confirming the soundness of the methodology. Among the species assessed, camels were found to have a fair share of appropriate rangelands, 72% moderately suitable, and 20% highly suitable, thus emphasizing the potential for specific management approaches targeting this species. Furthermore, with the three assembled socio-economic variables including service accessibility (β = 0.65), infrastructure quality (β = 0.61), and market accessibility (β = 0.40), multiple regression analysis showed these were useful in explaining 78.9% of variance in rangeland suitability. In a way, these results stress the important need to run environmental and socio-economic affairs in parallel to halt land degradation, improve ecosystem production, and sustain pastoral livelihoods in the long run. Thus, the study recommends an enhancement of infrastructure and market integration, coupled with specific zoning as the prerequisite sustainable land management practices in semi-arid rangeland situations.
Keywords: Agro-pastoral livelihoods | GIS-based multi-criteria analysis | land degradation | land management | pastoral ecosystems | socio-economic determinants
Climate changes alter regional hydrologic conditions and results in a variety of impacts on water... more Climate changes alter regional hydrologic conditions and results in a variety of impacts on water resource systems. This study aims to assess the streamflow response to Climate Change: the case of Tikur Wuha Sub-watershed, Rift Valley Basin of Ethiopia. In the study, the daily hydro-meteorological data values for the baseline period of 1981-2005 were used. Historical Representative Concentration Pathway (RCPs) data along with observed data of precipitation and temperature were used for extraction and bias correction using CMhyd tool. After evaluation of bias correction methods using RMSE, MAE and RE, the downscaled climate data such as, RCP4.5 and RCP8.5 scenarios was used for the future period assessment. Soil water assessment tool (SWAT) model were used to assess the streamflow response to Climate Change. The model calibration and validation results, using SWAT-CUP(SUFI-2), shows a good agreement with the observed flow with the coefficient of determination 0.79 and 8.6, and a Nash Sutcliffe efficiency was 0.56 and 0.64, respectively. The dynamically downscaled daily climate variables (precipitation and temperature) were used to simulate future projections of streamflow. Streamflow projections for future time periods showed that mean annual streamflow may increase by 15.
International Journal of creative research thought, 2020
This Paper analyzed the probable failure of a dam under a set of pre-defined scenarios, within th... more This Paper analyzed the probable failure of a dam under a set of pre-defined scenarios, within the framework of a case study, the
case subject being the Jema dam located at Amhara Region of Ethiopia. A probable maximum flood of Gilgel Abay River
(tributary of Jema River) has been computed using Hershfield (1961) and later modified (1965) is based on the general flood
frequency equation by Chow (1961). Breach parameters prediction, peak outflow hydrograph were determined by HEC-RAS
model based on available technical and geometric data. Different maps such as flood areal extent map, flood depth map and
velocity map have been produced by HEC-GeoRAS. Probable maximum flood of Gilgel Abay River by Hershfield’s technique
was found to be 1726.28 m3
/s. The maximum breach discharge resulted from HEC-RAS model was 79,886.37m3
/sec and the
maximum area inundated by this flood in downstream was found to be 41.6km2
. The areal maps show that the part of irrigation
command area at right side is a farm land while on left side is Bikolo Abay Town and settlement villages to be prone to flooding.
The depth and velocity of flood also depict that the downstream rural village near the river bank are under extreme hazard
category.Therefore, a further study regarding the economic and life damage consequences in detail has to be done.
Key words: Dam Breach, Flood Inundation Mapping, HEC-RAS, HEC –GeoRAS.
Annals of R.S.C.B, 2021
A survey was undertaken area to determine the quality of underground irrigation water, its effect... more A survey was undertaken area to determine the quality of underground irrigation water, its effect on soil properties in the irrigated areas. One hundred water samples collected from irrigated area of Nagaur district of Rajasthan revealed that 0.66 per cent water samples were good water, 1.33 per cent were marginally saline, 16.67 per cent were saline, 18 per cent were high SAR saline, 32 per cent were marginally alkali, 20
per cent were alkali and 11.34 were per cent high alkali categories, respectively. These results indicate that brackish water irrigation aggravates the degree of soil salinization and alkalization. Most of these waters had dominance of sodium followed by calcium, magnesium and potassium in cations and chloride as major anion followed by bicarbonate, carbonates and sulphate. The pH of irrigation water had significant and positive
correlation with pH and SAR of soil, whereas, significant but negative correlation was found with micro nutrient Zn, Cu, Fe, Mn and microbial biomass C, N and P. The EC of irrigation water had significant and positive correlation with EC of soil, whereas, significant but negative correlation was found with pH of soil.
The resulted significantly reduction of EC, pH, ESP and bulk density, improvement in infiltration rate and availability of N, P, K and micronutrients.
Key words:Bulk density, EC, ESP, pH, N, P, K, Zn, Cu, Fe and Mn
A survey was undertaken area to determine the quality of underground irrigation water, its effect... more A survey was undertaken area to determine the quality of underground irrigation water, its effect on soil properties in the irrigated areas. One hundred water samples collected from irrigated area of Nagaur district of Rajasthan revealed that 0.66 per cent water samples were good water, 1.33 per cent were marginally saline, 16.67 per cent were saline, 18 per cent were high SAR saline, 32 per cent were marginally alkali, 20 per cent were alkali and 11.34 were per cent high alkali categories, respectively. These results indicate that brackish water irrigation aggravates the degree of soil salinization and alkalization.Most of these waters had dominance of sodium followed by calcium, magnesium and potassium in cations and chloride as major anion followed by bicarbonate, carbonates and sulphate. The pH of irrigation water had significant and positive correlation with pH and SAR of soil, whereas, significant but negative correlation was found with micro nutrient Zn, Cu, Fe, Mn and microbial biomass C, N and P. The EC of irrigation water had significant and positive correlation with EC of soil, whereas, significant but negative correlation was found with pH of soil. The resulted significantly reduction of EC, pH, ESP and bulk density, improvement in infiltration rate and availability of N, P, K and micronutrients.
International Journal of Research and Analytical Reviews (IJRAR), 2020
Flooding is usually thought of as a result of heavy rainfall, snowmelt, land subsidence, rising o... more Flooding is usually thought of as a result of heavy rainfall, snowmelt, land subsidence, rising of groundwater, dam failures. Coastal flooding, river flooding, flash flooding, urban flooding , and snowmelt flooding are kinds of flooding. Among them, flash flooding and river flooding occurs often, and negatively impacts human lives and economic asset in Ethiopia. As flood risk and its impacts are increasing from time to time in Ethiopia, the main objective of this paper is to review flooding and it`s coping mechanisms in Ethiopia. The factors affecting flooding are the size of the catchments, the intensity of rainfall and amount of precipitation that fall under the watershed and tributaries, topography, the presence and absence of vegetation, anthropogenic activity within the catchment areas and catchment area are discussed within this paper. And also, the mechanism of reducing flood impacts like flood alert and metrological forecasting agency established but the cop ing and mitigation strategies are very low in Ethiopia. So that, forward suggestions are these strategies need to supplement one another, their coordination must include "multi-actor, multi-level, and multi-sector involvement and is realized for instance, by collaborative leadership. Stakeholder and community involvement and a standard knowledge basis also are fundamental. Check dams, terracing, bunds, percolation tanks, and storage tanks were proposed for various locations across the watershed as effective landscape-based flood risk mitigation strategies. Moreover, the coping strategies are very needed like insurance, perennial crops farming along with flood-prone areas and within the river's bank, and the waterway management is more needed to reducing the river flood inundate. This review recommends new policy approaches that will increase the effectiveness of the present flood coping strategies to sustainably address the impact of flooding on human health.
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Papers by BROOK L E G E S E DADHE
Keywords: Agro-pastoral livelihoods | GIS-based multi-criteria analysis | land degradation | land management | pastoral ecosystems | socio-economic determinants
case subject being the Jema dam located at Amhara Region of Ethiopia. A probable maximum flood of Gilgel Abay River
(tributary of Jema River) has been computed using Hershfield (1961) and later modified (1965) is based on the general flood
frequency equation by Chow (1961). Breach parameters prediction, peak outflow hydrograph were determined by HEC-RAS
model based on available technical and geometric data. Different maps such as flood areal extent map, flood depth map and
velocity map have been produced by HEC-GeoRAS. Probable maximum flood of Gilgel Abay River by Hershfield’s technique
was found to be 1726.28 m3
/s. The maximum breach discharge resulted from HEC-RAS model was 79,886.37m3
/sec and the
maximum area inundated by this flood in downstream was found to be 41.6km2
. The areal maps show that the part of irrigation
command area at right side is a farm land while on left side is Bikolo Abay Town and settlement villages to be prone to flooding.
The depth and velocity of flood also depict that the downstream rural village near the river bank are under extreme hazard
category.Therefore, a further study regarding the economic and life damage consequences in detail has to be done.
Key words: Dam Breach, Flood Inundation Mapping, HEC-RAS, HEC –GeoRAS.
per cent were alkali and 11.34 were per cent high alkali categories, respectively. These results indicate that brackish water irrigation aggravates the degree of soil salinization and alkalization. Most of these waters had dominance of sodium followed by calcium, magnesium and potassium in cations and chloride as major anion followed by bicarbonate, carbonates and sulphate. The pH of irrigation water had significant and positive
correlation with pH and SAR of soil, whereas, significant but negative correlation was found with micro nutrient Zn, Cu, Fe, Mn and microbial biomass C, N and P. The EC of irrigation water had significant and positive correlation with EC of soil, whereas, significant but negative correlation was found with pH of soil.
The resulted significantly reduction of EC, pH, ESP and bulk density, improvement in infiltration rate and availability of N, P, K and micronutrients.
Key words:Bulk density, EC, ESP, pH, N, P, K, Zn, Cu, Fe and Mn