Abebe Debele Tolche - Academia.edu (original) (raw)

Papers by Abebe Debele Tolche

Environmental sciences Europe, May 22, 2024

Environmental sciences Europe, Apr 29, 2024

Groundwater resources are essential for drinking water, irrigation, and the economy mainly in sem... more Groundwater resources are essential for drinking water, irrigation, and the economy mainly in semiarid environments where rainfall is limited. Currently, unpredictable rainfall due to climate change and pollution on the Earth's surface directly affects groundwater resources. In this area, most people depend on groundwater resources for irrigation and drinking purposes, and every summer, most of the area depends on groundwater in a semiarid environment. Hence, we selected two popular methods, the analytical hierarchy process (AHP) and multiple influence factor (MIF) methods, which can be applied to map groundwater potential zones. Nine thematic layers, such as land use and land cover (LULC), geomorphology, soil, drainage density, slope, lineament density, elevation, groundwater level, and geology maps, were selected for this study using remote sensing and geographic information system (GIS) techniques. These layers are integrated in ArcGIS 10.5 software with the help of the AHP and MIF methods. The map of the groundwater potential zones in the study area revealed four classes, i.e., poor, moderate, good, and very good, based on the AHP and MF methods. The groundwater potential zone area is 241.50 (ha) Poor, 285.64 (ha) moderate, 408.31 (ha) good, and 92.75 (ha) very good using the AHP method. Similarly, the MIF method revealed that the groundwater potential classes were divided into four classes: 351.29 (ha) poor, 511.18 (ha), moderate, 123.95 (ha) good, and 41.78 (ha) very good. The results were compared to determine which methods are best for planning water and land resource development in specific areas that have basaltic rock and drought conditions. Both groundwater potential zone maps were validated with water yield data. The receiver operating characteristic (ROC) curve and area under the curve (AUC) model results are found to be 0.80 (good) and 0.93 (excellent) using the MIF and AHP methods, respectively; hence, the AHP method is best for delineation of groundwater potential zone maps and groundwater resource planning. The present study's framework and the results will be valuable for improving the efficiency of irrigation, conserving rainwater and maintaining the ecosystem in India.

Environmental sciences Europe, Apr 24, 2024

Geomatics, Natural Hazards and Risk, Dec 21, 2023

Sustainability, Nov 27, 2023

Geomatics, Natural Hazards and Risk, Oct 18, 2023

Geocarto International, Oct 27, 2023

Environmental Sciences Europe, Jan 5, 2024

Research Square (Research Square), Nov 30, 2021

Background: Energy deeply influences the life of rural communities. The industrialized countries ... more Background: Energy deeply influences the life of rural communities. The industrialized countries depend primarily on modern energy while the developing countries like Ethiopia heavily rely on traditional biomass. Thus, in Ethiopia, the energy sector faces dual challenges: one limited access to modern energy and the second is heavy reliance on traditional biomass energy sources to meet growing energy demand. The modern energy of the country is predominantly from hydropower which accounts for 90% and fuelwood accounts for more than 80% of households' energy supply today, this leads to deforestation and severe land degradation in the country. Objective: This study aim at providing the way to diversify energy sources through integrated hybrid energy sources (wind, solar and diesel generator) to obtain a sustainable autonomous power supply system for remote site. 2 Method: Standalone hybrid system configuration was design by using HOMER software and finds an optimal combination of clean energy as well as comparing it with other energy sources for Adem Tuleman one of the remote sites in Ethiopia. HOMER is optimization tool to determine the possible optimal architecture and control strategy of the system. Results: The study found that the village had a 204.04 kWh/day average energy demand with a 31 kW/day peak load, a 4.5 kWh/day deferrable load, and 0.9kWh/day peak deferrable load. Simulation results demonstrated that the proposed system was a feasible solution to electrify Adem Tuleman. A financial analysis indicated that the project would have an initial

EGU General Assembly Conference Abstracts, Apr 22, 2016

Geology, ecology, and landscapes, Feb 23, 2020

The objective of this paper is to exploit the potential application of weighted index overlay ana... more The objective of this paper is to exploit the potential application of weighted index overlay analysis for assessing groundwater potential mapping at Dhungeta-Ramis sub-basin, Wabi Shebele basin, Ethiopia using remote sensing and geographic information system (GIS) technique. For this purpose, seven groundwater occurrences and movement controlling factors, including, lithology, slope, land use land cover (LULC), rainfall, lineaments, soil, and drainage density were mapped. Then, weight was assigned to thematic maps, and the groundwater prospective of the sub-basin is qualitatively classified into five classes, namely, very good, good, moderate, poor, and very poor which account for 2.22%, 26.93%, 56.74%, 13.84%, and 0.26% landscape, respectively. The cross-validation of the resultant model was carefully carried out using spring, hand-dug, and deep well data. The result reveals that 89% of springs were overlaying good and/or very good groundwater potential zones and 58% of deep well shows the same scenario, whereas 42% of deep well overlays moderate zone. As a result, the map generated using this platform could be used as a preliminary reference in selecting suitable sites for groundwater resource exploitation.

An improved general understanding of riverbed heterogeneity is of importance for all groundwater ... more An improved general understanding of riverbed heterogeneity is of importance for all groundwater modeling studies that include river-aquifer interaction processes. Riverbed hydraulic conductivity ‫)ܭ(‬ is one of the main factors controlling river-aquifer exchange fluxes. However, the meter-scale spatial variability of riverbed ‫ܭ‬ has not been adequately mapped as of yet. This study aims to fill this void by combining an extensive field measurement campaign focusing on both horizontal and vertical riverbed ‫ܭ‬ with a detailed geostatistical analysis of the meter-scale spatial variability of riverbed ‫.ܭ‬ In total, 220 slug tests and 45 standpipe tests were performed at two test sites along the Belgian Aa River. Omnidirectional and directional variograms (along and across the river) were calculated. Both horizontal and vertical riverbed ‫ܭ‬ vary over several orders of magnitude and show significant meter-scale spatial variation. Horizontal ‫ܭ‬ shows a bimodal distribution. Elongated zones of 2 high horizontal ‫ܭ‬ along the river course are observed at both sections, indicating a link between riverbed structures, depositional environment and flow regime. Vertical ‫ܭ‬ is lognormally distributed and its spatial variability is mainly governed by the presence and thickness of a low permeable organic layer at the top of the riverbed. The absence of this layer in the center of the river leads to high vertical ‫ܭ‬ and is related to scouring of the riverbed by high discharge events. Variograms of both horizontal and vertical ‫ܭ‬ show a clear directional anisotropy with ranges along the river being twice as large as those across the river.

Water Resources Management, Feb 1, 2023

Precise assessment, monitoring and forecasting of drought phenomena are crucial and play a 29 vit... more Precise assessment, monitoring and forecasting of drought phenomena are crucial and play a 29 vital role in agriculture and water resources management in the semi-arid region. In this study, 30 Standardized Precipitation Index (SPI) was used to predict the drought in the upper Godavari River basin, India. Ten combinations were used to predict three SPI timescales (i.e., SPI-3, SPI-6, and SPI-12). The historical data of SPI from 2000 to 2019 was divided into training (75 % of the data) and testing (25 % of the data) models for SPI prediction. The best subset regression method and sensitivity analysis were applied to estimate the most effective input variables for estimation of SPI 3, 6, and 12. The improved support vector machine using 36 sequential minimal optimization (SVM-SMO) with various kernel functions i.e., SMO-SVM poly kernel, SMO-SVM Normalized poly kernel, SMO-SVM PUK (Pearson Universal Kernel) and SMO-SVM RBF (radial basis function) kernel was developed to estimate the SPI. The results were compared and analyzed using statistical indicators i.e., root mean square error (RMSE), mean absolute error (MAE), relative absolute error (RAE), root relative squared error (RRSE), and correlation coefficient (r). The main results showed that the SMO-SVM poly kernel model precisely predict the SPI-3 (R 2 = 0.819) and SPI-12 (R 2 = 0.968) values at Paithan station; the SPI-3 (R 2 = 0.736) and SPI-6 (R 2 = 0.841) values at Silload station, respectively. 44 The SMO-SVM PUK kernel showed superiority in the prediction of SPI-6 (R 2 = 0.846) at Paithan station and SPI-12 (R 2 = 0.975) at the Silload station. The competition between SVM-SMO poly kernel and SVM-SMO PUK kernel was observed in the prediction of long setting time (i.e. SPI-6 and SPI-12), while SVM-SMO poly kernel is superior in the estimation of SPI-3 at both stations. The results of the study showed the efficacy of the SVM-SMO algorithm with various kernel functions in the estimation of multiscale SPI and can be helpful in decision making for water resource management and tackle droughts in the semi-arid region of central India.

Journal of Hydrology, Apr 1, 2018

Springer eBooks, 2022

A quantitative and qualitative understanding of the anticipated climate-change-driven multi-scale... more A quantitative and qualitative understanding of the anticipated climate-change-driven multi-scale spatio-temporal shifts in precipitation and attendant river flows is crucial to the development of water resources management approaches capable of sustaining and even improving the ecological and socioeconomic viability of rainfed agricultural regions. A set of homogeneity tests for change point detection, non-parametric trend tests, and the Sen's slope estimator were applied to long-term gridded rainfall records of 27 newly formed districts in Chhattisgarh State, India. Illustrating the impacts of climate change, an analysis of spatial variability, multitemporal (monthly, seasonal, annual) trends and inter-annual variations in rainfall over the last 115 years (1901-2015 mean 1360 mmꞏy-1) showed an overall decline in rainfall, with 1961 being a change point year (i.e., shift from rising to declining trend) for most districts in Chhattisgarh. Spatio-temporal variations in rainfall within the state of Chhattisgarh showed a coefficient of variation of 19.77%. Strong inter-annual and seasonal variability in regional rainfall were noted. These rainfall trend analyses may help predict future climate scenarios and thereby allow planning of effective and sustainable water resources management for the region.

Environmental Science and Pollution Research, Jan 17, 2023

Journal of African Earth Sciences, Aug 1, 2021

Climate change is widely accepted to be one of the most critical problems faced by the Huang-Huai... more Climate change is widely accepted to be one of the most critical problems faced by the Huang-Huai-Hai Plain (3H Plain), which is a region in which there is an over-exploitation of groundwater and where future warmer and drought conditions might intensify crop water demand. In this study, the spatiotemporal patterns of ET 0 and primary driving meteorological variables were investigated based on a historical and RCP 8.5 scenario daily data set from 40 weather stations over the 3H Plain using linear regression, spline interpolation method, a partial derivative analysis, and multivariate regression. The results indicated a negative trend in all the analysed periods (except spring) of the past 54 years of which only summer and the entire year were statistically significant (p < 0.01) with slopes of −1.09 and −1.29 mm a −1 , respectively. In contrast, a positive trend was observed in all four seasons and the entire year under the RCP 8.5 scenario, with the biggest increment equal to 1.36 mm a −1 in summer and an annual increment of 3.37 mm a −1. The spatial patterns of the seasonal and annual ET 0 exhibited the lowest values in southeastern regions and the highest values in northeastern parts of Shandong Province, probably because of the combined effects of various meteorological variables over the past 54 years. Relative humidity (RH) together with solar radiation (RS) were detected to be the main climatic factors controlling the reduction of ET 0 in summer, autumn, and the entire year on the 3H Plain. ET 0 in spring was mainly sensitive to changes in RS and RH, whereas ET 0 in winter was most sensitive to changes in wind speed (WS) and decreased due to declining RH. Under the future RCP 8.5 scenario, the annual ET 0 distribution displays a rich spatial structure with a clear northeast-west gradient and an area with low values in the southern regions, which is similarly detected in spring and summer. The most sensitive and primary controlling variables with respect to the increment of future ET 0 are in the first place RS and then mean temperature in spring, while they turn to be mean temperature and then RS in summer. In autumn, future ET 0 is most sensitive to RH changes. WS and RH are the controlling variables for ET 0 in winter. Annual future ET 0 is most sensitive to RH changes, and accordingly, RS is responsible for the predicted increment of the annual ET 0. Better understanding of current and future spatiotemporal patterns of ET 0 and of the regional response of ET 0 to climate change can contribute to the establishment of a policy to realize a more efficient use of water resources and a sustainable agricultural production in the 3H Plain.

Arabian Journal of Geosciences, Sep 1, 2022

The aim of this study was to determine suitable lands for agricultural use in the Yusufeli distri... more The aim of this study was to determine suitable lands for agricultural use in the Yusufeli district of Artvin city (Turkey), where the current agricultural land in the district center and 3 villages will be completely inundated while the land in 22 villages will be partially inundated due to three large dams currently being constructed. The ''Analytic Hierarchy Process (AHP)'' method, commonly used in land use suitability analysis, was utilized in this study. In application, the parameters of great soil group, land use capability class, land use capability sub-class, soil depth, slope, aspect, elevation, erosion degree and other soil properties were used. In determining the weights of the parameters, experts' opinions were consulted, and the agricultural land suitability map generated was divided into 5 categories according to the land suitability classification of the United Nations Food and Agriculture Organization (FAO). After deducting the forests, pastures and reservoir areas from the reclassified suitability map, it was estimated that 0.08% of the study area (177.87 ha) is highly suitable for agricultural production, while 1.55% (3578.33 ha) is moderately suitable and 6.3% (14575.91 ha) is marginally suitable for agricultural production. In addition, it was found that the proportion of land that is currently unsuitable for agricultural production is 2.24% (5183.63 ha), while the amount of land that is permanently unsuitable is 3.42% (7923.39 ha). It was also determined that the following facts were all effective factors in reaching these results: a substantial portion (approximately 85%) of the study area is covered with forests and pastures, the soil depth is inadequate for agricultural production, the slope in the study area is quite high and, accordingly, the erosion degree is high.

Water, Jan 27, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY