Browsing by Author "Korme, Tesfaye (PhD)"
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Item Application of Remote Sensing and Gis for Geological Investigation and Groundwater Potential Zone Identification, Southeastern Ethiopian Plateau, Bale Mountains and the Surrounding Areas(Addis Ababa Universty, 2002-06) Rango, Tewodros; Korme, Tesfaye (PhD)The application of remote sensing and GIS has found to be a quick and inexpensive technique in order to obtain the desired output efficiently. For the present study an attempt was made to map dykes, lithology and other thematic maps such as of drainage density, slope, elevation, lineament, rainfall, landcover and burrowing of rodents and then to integrate them in a GIS environment to get information about the occurrence of groundwater and used to select promising areas for further groundwater exploration. The present study was conducted on southeastern part of Ethiopia plateau, the Bale Mountains and the surrounding areas. Satellite image of Landsat ETM+ of all bands except the thermal bands were utilized for lithologic and geologic structures mapping. Topographic map at the scale of 1:50,000 were used to generate elevation contour at the interval of 20m. Slope map were derived from TIN (Triangulated Irregular Network), which is derived from elevation contour map. Spatial distribution of drainage density was derived by using three softwares AutoCAD map 2000 engineering software, Arcview3.2 and MapInfo professional 6.0. The burrowing of Rodents were mapped from field Knowledge and using 742(RGB) that shows areas of rodent burrowing activities. Secondary data of landcover, soil were also utilized. Groundwater potentiality in the area has been assessed through the integration of the different thematic layers that contributes for the natural recharging of aquifer. The predicted groundwater potential zones were divided into 5 classes from very good up to poor. Color composite, ratio and PCA (Principal Component analysis) were made to interpret the lithology of the area. Due to vegetation cover and similarities of reflectance of different rock units it was difficult to separate them. The field knowledge and some petrographic analysis support the identification of the lithology. Key words: dykes, lithology, groundwater potential zone prediction, Remote Sensing and GISItem Drought Vulnerability Assessment Using Geospatial Data and Modeling Techniques: a Case Study of East Hararge Zone, Ethiopia(Addis Ababa University, 2018-06-04) Tadesse, Chaltu; Korme, Tesfaye (PhD)Drought vulnerability assessment using Geospatial data and Modelling techniques: A case study of East Hararge Zone, Ethiopia Chaltu Tadesse Amante Drought is water related natural disaster, which affects a wide range of environmental factors. In 2015, eastern Ethiopia had experienced a severe drought. This drought had caused low crop production for both Belg and Summer harvests, poor livestock health and low water availability. This study investigated the effectiveness of Remote Sensing based drought indices as an indicator for drought assessment in arid and semi-arid areas, examined the relation between rainfall and vegetation indices and identified the most drought–vulnerable areas using geospatial data and modeling techniques in East Hararge Zone, Ethiopia which is a drought-prone area. To assess and examine spatiotemporal variation of seasonal drought patterns and severity, four drought indices namely, Aridity Index (AI), Water requirement satisfaction index (WRSI), Standard precipitation index (SPI) and Normalized difference vegetation Index (NDVI) are applied. SPOT and PROVA-V, MODIS, rainfall data for the years 2005-2015 were utilized as input data for the indices while crop yield data was used to validate the strength of indices in explaining the impact of drought. The result map was produced based on frequency maps of the four indices. This map shows that 40%, 54% and 6% of the total geographical area of the Zone were severe, moderate and mild vulnerable respectively. This result map could be valuable to make pre, and post–drought risk management plans by decision and policy makers.Item Evaluation Of Land Degradation And Landslide Using Integrated GIS And Remote Sensing Approach Around Sodo-Shone Area, Southern Ethiopia(Addis Ababa Universty, 2005-06) Teferi, Yodit; Korme, Tesfaye (PhD)In this study two major environmental hazards, namely land degradation and landslide have been investigated. These hazards have clear dynamic relationships given that both are chaotic phenomena that can be triggered by unstable equilibrium situation occurring drastically and abruptly to the environment. Southern Nation’s National Peoples Region is one of the most populated regions in the country. The area is situated in the western margin of the Ethiopian Main Rift system and it is structurally controlled and tectonically active. Therefore, the study area is an excellent site where natural and human induced or anthropogenic factors work jointly to result in such a staggering environmental damage. Generally, it is a place where most favorable factors of land degradation and landslide coincide in space. An integrated GIS and remote sensing approach was very helpful to study the intensity and extent of the two environmental hazards. The degradation rate that was calculated in areal base using cross classification of temporal data shows the degradation rate is becoming severe with time. The degradation rate that was 1.8 sq. km/year between 1984 and 1995 has increased in to 3.1 sq. km/year in recent times (till 2001). These figures show that the rate of degradation is increasing at an alarming rate. The amount of soil lost from the study area is estimated using cut and fill technique applied on 5 representative sites. Profiling was done using GPS reading taken at every 5-10m interval and organized in a database. The volume loss calculated shows that 2,485,818 m3 amount of soil is lost from 291,241 m2 area; with the net lose per area being about 8.53 m3. Factors that are found to be significant in triggering the Land degradation in the study area include structure, lithology, landuse/ landcover, slope, soil, drainage, and climate. Similarly these factors with addition of slope aspect play an important roll in aggravating the frequently occurring landslide. The presence of all the factors that are responsible for the staggering environmental hazard and their coincidence in space and time indicate that the area is highly prone to these hazards. Factors that are considered to be responsible for the two environmental hazards were weighted in hierarchical order using the MCE approach to produce susceptibility maps that express the likelihood occurrences of the hazards in the area on the bases of the local terrain conditionItem Evaluation of Land Degradation and Landsude Using Integrated Remote Sensing and Gis Approach Around Wolayita Sodo-Shone Area, Southern Ethiopia(Addis Ababa University, 2005-06) Teferi, Yodit; Korme, Tesfaye (PhD)In this study two major environmental hazards, namely land degradation and landslide have been investigated. These hazards have clear dynamic relationships given that both are chaotic phenomena that can be trigg~le e9..uilibrium situation occurring drastically and abruptly to the enVironment. ,. Southern Nation's National Peoples Region is one of the most populated regions in the country. The area is situated in the western margin of the Ethiopian Main Rift system and it is structurally controlled and tectonically active. Therefore, the study area is an excellent site where natural and human induced or anthropogenic factors work jointly to result in such a staggering environmental damage. Generally, it is a place where most favorable factors of land degradation and landslide coincide in space. An integrated GIS and remote sensing approach was very helpful to study the intensity and extent of the two environmental hazards. The degradation rate that was calculated in areal base using cross classification of temporal data shows the degradation rate is becoming severe with time. The degradation rate that was 1.8 sq. km/year between 1984 and 1995 has increased in to 3.1 sq. km/year in recent times (till 2001). These figures show that the rate of degradation is increasing at an alarming rate. The amount of soil lost from the study area is estimated using cut and fill technique applied on 5 representative sites. Profiling was done using GPS reading taken at every 5-10m interval and organized in a database. The volume loss calculated shows that 2,485,818 mS amount of soil is lost from 291,241 m'area; with the net lose per area being about 8.53 m~. ~i1 Factors that are found to be significant in triggering the Land degradation in the study area include structure, lithology, landusc/ landcover, slope, soil, drainage, and climate. Similarly these factors with addition of slope aspect play an important roll in aggravating the frequently occurring landslide. The presence of all the factors that are responsible for the staggering environmental hazard and their coincidence in space and time indicate that the area is highly prone to these hazards. Factors that are considered to be responsible for the two environmental hazards were weighted in hierarchical order using the MCE approach to produce susceptibility maps that express the likelihood occurrences of the hazards in the area on the bases of the local terrain condition.Item Evaluation of Land Degradation Around Deber Zeyit Area Using Rs and Gis Techniques(Addis Ababa Universty, 2005-07) Endale, Hanna; Korme, Tesfaye (PhD)Gully development dynamics that occurred from 1971 to 2002 around the Debre Zeyit area were evaluated using remote sensing and GIS in addition to field verification. The study was conducted in about 694-km2 area with in the East Showa Zone of the Oromia Region. The main objective of this study is to understand the rate, cause and extent of gully erosion around Debre Zeyit area in terms of change in landcover, development of infrastructure, soil type and geology of the area. Four sets of remotely sensed images, MSS-1973, TM-1986 & 1995 and ETM+ 2002 are used in evaluation of the change in landuse and landcover of the area with in of 13, 9 and 7 years gaps and Aerial photographs of 1971 as well as the 2002 ETM+ image are used in gully development rate mapping. In addition to this field measurement of gullies width and depth volume calculation is done to quantify the amount of soil lost by all gullies and rate of soil loss by new gullies with in 31 years gap. Results of landcover change analysis show cultivated land increased from 50% in 1971 to 55% in 1986 and to 67 and 69% in 1995 and 2002 respectively. The overall increase in cultivated land is about 19%, which was mainly at the expense of grasslands and dense shrub covers. The area which was mainly covered by the dense shrubs is changed to open woodland and cropland. The size of urban and water bodies increased from 1.04% to 1.7% and 0.73% to 1.02% percent due to population increase and construction of dams respectively. The area covered by wetland also show minor differences in size due to evaporation. New gullies are developing in areas where the original landcover is removed and where slopes are between 2 and 10 percent. In addition to this on the southern part of the study area construction of roads are important causes of gulling where the soil type and lithology are favoring erosion processes.Item Geospatial Approach for Groundwater Recharge Estimation Using Wetspass Model: A Case Study of Chemoga Watershed, Ethiopia(Addis Ababa University, 2018-05-03) Baychiken, Belete; Korme, Tesfaye (PhD)Geospatial Approach for Groundwater Recharge Estimation Using WetSpass Model: A Case Study of Chemoga Watershed, Ethiopia. Belete Baychiken, Msc. Thesis Addis Ababa University, May 2018 Groundwater recharge estimation is of critical importance for groundwater resources evaluation and management. There are several methods for water balance evaluation. Among which, WetSpass model is one, that has the ability to simulate spatially distributed recharges, surface runoff, and evapotranspiration for annually and seasonally averaged conditions. The spatial-temporal characteristics of the model allow distributed quantification of water balance components by preparing inputs in the form of digital maps using remote sensing, GIS tools, FAO databases, field reconnaissance and processing of meteorological and hydrological observations, that aimed at estimation of the annual and seasonal groundwater recharge, surface runoff and evapotranspiration amount in Chemoga watershed using WetSpass modeling method. Long-term hydrometeorological data and physical characteristics of the watershed such as land use/land cover, soil type, topography, groundwater level and slope are used as an input to the model. The long-term average annual rainfall of 1408.3 mm was distributed as 447 mm (31.8%) of surface runoff, 844.98 mm (60%) of actual evapotranspiration, and 116.3 mm (8.2%) of recharge, this recharge corresponds to 42,333,200 m3. Analysis of the simulated results tells that WetSpass works well to simulate the components of the hydrological balance for the Chemoga watershed.Item Geospatial Approach for Groundwater Recharge Estimation Using Wetspass Model: A Case Study of Chemoga Watershed, Ethiopia(Addis Ababa University, 5/3/2018) Baychiken, Belete; Korme, Tesfaye (PhD)Geospatial Approach for Groundwater Recharge Estimation Using WetSpass Model: A Case Study of Chemoga Watershed, Ethiopia. Belete Baychiken, Msc. Thesis Addis Ababa University, May 2018 Groundwater recharge estimation is of critical importance for groundwater resources evaluation and management. There are several methods for water balance evaluation. Among which, WetSpass model is one, that has the ability to simulate spatially distributed recharges, surface runoff, and evapotranspiration for annually and seasonally averaged conditions. The spatial-temporal characteristics of the model allow distributed quantification of water balance components by preparing inputs in the form of digital maps using remote sensing, GIS tools, FAO databases, field reconnaissance and processing of meteorological and hydrological observations, that aimed at estimation of the annual and seasonal groundwater recharge, surface runoff and evapotranspiration amount in Chemoga watershed using WetSpass modeling method. Long-term hydrometeorological data and physical characteristics of the watershed such as land use/land cover, soil type, topography, groundwater level and slope are used as an input to the model. The long-term average annual rainfall of 1408.3 mm was distributed as 447 mm (31.8%) of surface runoff, 844.98 mm (60%) of actual evapotranspiration, and 116.3 mm (8.2%) of recharge, this recharge corresponds to 42,333,200 m3. Analysis of the simulated results tells that WetSpass works well to simulate the components of the hydrological balance for the Chemoga watershed.Item GIS and Remote Sensing in Land Use Land Cover Change Detection in Finchaa Valley Area, East Wollega(Addis Ababa Universty, 2005-06) Kebebew, Zeleleke; Korme, Tesfaye (PhD)This study assessed land use/ land cover change of Finchaa valley area by integrating GIS and Remote sensing techniques in Finchaa valley area in between 1973 and 2003.The study compared four different techniques: image differencing, rationing NDVI image comparisons and post classification Comparisons. Image differencing and rationing proved not suitable for the study area. NDVI is found better for visual comparisons with its mean values. Post classification comparison is proved the best method for the study area. The result of the analysis indicates that generally vegetation cove is decreasing attribute to increase in crop land with accelerated rate of change, the development of mechanized state farm in between 1972 and 1986 and agroindusrial development since1991at accelerated rate of change with its related infrastructures but collapse of state farm in the valley. The change is directly related to socio-economic activities, fire and poor environmental management and inseparably connected to one another. From observation the change has negative implications on the environments particularly on land, vegetation and animal diversities. Therefore the ill environmental management strategy should be re evaluated to protect to protect vegetation cover and to keep the development sustainable.Item GIS and Remote Sensing in Land Use/ Land cover Change Detection in Finchaa Valley Area, East Wollega(Addis Ababa University, 2005-06) Kebebew, Zeleleke; Korme, Tesfaye (PhD)This study assessed land use! land cover change of Finchao valley area by integrating GIS and Remote sensing rechniques in Finchaa valley area in belll'een 1973 and 2003, The stud,' comparedfollr different techniques: image differencing, rationing NDV! image comparisons and posl classification Comparisons, Image differencing and rationing proved not suitable fiJr Ihe slwl\' area, SDVI isfollnd belter for visual comparisons with its mean \'{Ilues, Posl classification comparison is proved the best melhodfor Ihe stlldv area, The res lilt of Ihe analysis indicates thai generally \'egetalion cove is decreasing a/lribule ta increase in crop land with accelerated rate of change, Ihe de\'elopment of mechanized slate farm in heMeen 197_' and 1986 and agroindusrial development since! 991 at accelerated rate of change "'ilh ils re 'ated inji'astruclures bUI collapse of slale f arm in the valley. The change is directly related to socia-economic activities, fire and poor elIvironl11enlalll1anagell1ent and inseparably connect"d to one ana/her, From observational the change has negative implications on the environments particularly all land, vegetation and animal diversities, Therefore the ill environmental management strategy should be re evaluated fO pro/eel 10 protect vegetation e'er and to keep the development sustainable,Item Gis in Project Impact Assessment Southern Tsetse Eradication Project Humbo Woreda (Snnpr)(Addis Ababa Universty, 2005-07) Getahun, Dereje; Korme, Tesfaye (PhD)The objective of this study is to further expand the use of Remote Sensing and GIS techniques in the country, especially in the area of project planning, monitoring, evaluation and impact assessment in the agriculture sector. Impact assessment of the Southern Tsetse Eradication Project (STEP) was carried out using Remote Sensing and GIS techniques, by taking Humbo Woreda (SNNPR) as a case study. Landsat ETM+ image of the area was used and agricultural sample survey was conducted in 11 peasant associations in the study area. Pertinent questions categorized into household characteristics, agricultural data, tsetse fly and trypanosomiasis condition as well as environmental related issues regarding pre and post project periods were included in a structured questionnaire. Statistical comparison of with and without project situation of various parameters was made. These include size of cultivated land, amount of crop production, method of cultivation, number of livestock, oxen out put, situation of tsetse infestation and trypanosomiasis prevalence and environmental situations in the area, etc. Survey data was manipulated and spatially presented by creating a spatial database in GIS software and using spatial facilities such as grid interpolation, proximity analysis, density calculation, map query, grid analysis and layout facilities. The project had no socio-economic baseline data thus, farmers' recall method was applied as alternative source of information. In addition to this, due to the absence of recent satellite image, it was not possible to compliment the agriculture sample survey with remote sensing data. As a result it was not possible to assess the land use! cover and environmental change analysis at the desired level. Assessment based on the available information, showed that the so far undertaken tsetse control intervention by STEP has enabled to significantly reduce the tsetse and trypanosomiasis problem in the area. As a result, livestock health condition has improved while, livestock body and growth condition have not shown similar improvement mainly due to feed and water scarcity. There has been a clear shift from hand cultivation to the use of oxen power while average cultivated size and production of major cereals that normally require oxen power for their CUltivation has increased. The impact is more visible in kola areas, probably due to the f act that these areas had been highly affected by the problem and where most impact is expected as a result of the control intervention. The application of advanced survey and monitoring tools, including remote sensing and GIS, has in general, allowed appropriate situation analysis. Finally, it was recommended that any project need to undertake baseline as well as regular monitoring surveys enabling data collection for future project impact assessments and the use of recent satellite image for detailed land use! cover change analysis. Key words: STEP, Impact Assessment, Remote Sensing and GIS, Tsetse fly, Trypanosomiasis, Apparent FlyItem The Impact of Land Use/Cover Change and Climate Variabililty on Ground Water Recharge, a Case Study of Upper Gibe Watershed, Ethiopia(Addis Ababa University, 2019-05-04) Warku, Fikadu; Korme, Tesfaye (PhD)This study aimed to quantify the impact of land use/cover change and long-term climate variability on annual groundwater recharge of Upper Gibe watershed using Wetspass model. Understanding the spatial distribution of groundwater recharge with the response to Land use/cover change, hydro meteorological variability, soil texture, topography, and groundwater elevation parameters is important for management, proper utilization and future planning of water resources. Input data for the model were prepared in the form of grid maps using 30 m grid size and the parameter attribute tables were adjusted to represent the upper Gibe watershed condition using expert knowledge and scientific literature. The results of the model showed that the long-term temporal and spatial average annual rainfall of 1461 mm was partitioned to 292 mm (20%) of surface runoff, 818 mm (56%) of evapotranspiration, and 350 mm (24%) of recharge at first phase while annual rainfall of 1360mm was partitioned to 290 mm (21.32%) of surface runoff, 783 mm (57.57%) of evapotranspiration, and 287 mm (21.11%) of recharge at second. For the third phase, an annual rainfall of 1303 mm was partitioned to 292 mm (22.4%) of surface runoff, 790 mm (60.6%) of evapotranspiration, and 221 mm (17%) of recharge for the upper Gibe watershed. The analysis of the simulated result showed that WetSpass works well to simulate water balance components of upper Gibe watershed and is especially suitable for characterization the effects of land use/cover changes and hydro meteorological variability on the water resource in the watershed. The study result provide baseline information for water resource experts and policymakers of the region for further investigation of water resources, design, sustainable developmental activities and for land use managing and planning purpose.Item Impact of Land-Use/Land-Cover Changes on Land Surface Temperature in Arsi Zone, Eastern Ethiopia(Addis Ababa University, 2018-05-02) Abebe, Morka; Korme, Tesfaye (PhD); Haile, GetachewImpact of Land-Use/Land-Cover Changes on Land Surface Temperature in Arsi zone, Eastern Ethiopia Morka Abebe, Msc. Thesis Addis Ababa University, May 2018 Unmanaged Land-use/land-cover change is one of the main environmental problems and challenges, which strongly influences the process of urbanization and agricultural development. The world has faced with the problem of overwhelming increase in land surface temperature (LST) as compared from year to year. The present study has investigated the impact of land-use/land-cover (LU/LC) change on LST in administrative zone in Ethiopia. The research was conducted in Arsi zone, located in Oromia region, Eastern Ethiopian. Land-use/land-cover, LST and NDVI were extracted from Landsat TM (1997) and Landsat 8 OLI/TIRS (2017) using GIS and remote sensing tools. Land surface temperature was done using split window algorism. Changes in LU/LC, which occurred between 1997 and 2017 in the study area was evaluated and analyzed using geospatial tools and verified against field data. The result of LU/LC change indicated that farmland covered more than 40% during the study periods (1997–2017) and followed by shrub land covering more than 37%. The study indicated that most areas having lower LST in 1997 were changed to higher LST in 2017.This happened due to the increased in different LU/LC changes especially attributed to the decreasing of vegetation cover in the study area. By linking the LU/LC classes and LST parameter using zonal statistics as figure, it has been found that, LST has negative correlation with vegetation cover. Land surface temperature result showed that the eastern and some north western parts of the study area exhibited relatively higher temperature. This is mainly due to altitude, slope and LU/LC types and changes. On the other hand, the central parts and around mountains Chilalo,Kaka and Gugu area exhibited relatively low LST values ranging from 5.11°C to 9.02°C. This is mainly due to high NDVI value or denser vegetation cover. While the eastern and some north western part has high LST value reaching up to 44.90ºC. Therefore, the visual comparison of 1997 and 2017 images showed that the LU/LC type and NDVI status and condition play a major role in variability of LST values. Continuous land-use/land-cover change may not be stopped easily. However, different measures have to be taken by environmental experts and the concerned bodies to minimize the influence of changes in the LST on environments. This study showed that geospatial tools and techniques can give fast and reliable results for evaluating LST increases and variability at regional scale and its impact on the environment in a shorter analysis and evaluation.Item Impacts of Land-Use and Land-Cover Changes on Land Surface Temperature Distribution In Bahir Dar Town and Its Surroundings Using Remote Sensing(Addis Ababa University, 2018-06-02) Balew, Abel; Korme, Tesfaye (PhD)Spatio-temporal Land-Use and Land-Cover (LULC) changes has been affecting geo-environmental and climate change globally. These extreme changes affect Land Surface Temperature (LST). The present study analyzed the impacts of LULC changes on the distribution of LST in Bahir Dar town and its surrounding. Land-use and land-cover, Normalized Difference Vegetation Index (NDVI) and LST were analyzed from Landsat 5 TM (1987), Landsat 7 ETM+ (2002) and Landsat 8 OLI/TIRS (2017) using remote sensing techniques. Land-use and land-cover changes between 1987 to 2017 were analyzed using remote sensing techniques and the results were validated using ground truth data. Land surface temperature from Landsat 5 TM (1987) and Landsat 7 ETM+ (2002) was analyzed using a Mono-Window Algorithm (MWA). Split-Window Algorithm (SWA) used to generate LST from Landsat 8 TIRS (2017). The result indicates that LULC has been changing in space and time. During 1987-2017, cropland was the dominant land-use which was covered more than 50%. Settlement areas increased from 3.3% in 1987 to 9.13% in 2017. Service, industrial and paved surfaces areas also increased. However, wetland vegetation, shrubland, grassland, forest and water body are degraded. This study shows that LST has been increasing from 1987 to 2017 and its distribution varies spatially due to LULC variation, proximity to Lake Tana and Abay River, wind direction, and nature of topography and elevation. During the study periods, LST of Bahir Dar town and its surrounding varies from 12.35℃-43.01℃. Normalized difference vegetation index and LST have indirect relationship. Cropland located in the east, west, south and southwest parts of Bahir Dar town have high LST. Settlement areas located along Lake Tana and Abay River, and some places in Deq Istifanos Island and Kibran Gebriel Island have low LST. Most central parts of Bahir Dar town and Deq Istifanos Island relatively have high temperature. Land-use and land-cover is a serious problem and it cause raise in LST, particularly rapidly urban expansion increase urban heat island (UHI). Therefore, there should be sound environmental management and thermal refreshing mechanisms.Item Lithological and structural Mapping of the central and North Western part of Ethiopia in View of Petroleum Exploration(Addis Ababa Universty, 2005-06) Shiferaw, Zelalem; Korme, Tesfaye (PhD)Item Mapping and Estimating Above Ground Biomass and Carbon Stock Using Sentinel Imagery in Yayu Forest, South West of Ethiopia(Addis Ababa University, 2019-06-02) Muhe, Seid; Korme, Tesfaye (PhD)Accurate forest above-ground biomass (AGB) and carbon stock estimation is crucial for sustaining forest management and mitigating climate change to support REDD+ (reducing emissions from deforestation and forest degradation, plus the sustainable management of forests, and the conservation and enhancement of forest carbon stocks) processes. However the major challenge for REDD+ is to find an accurate method for biomass estimation. Thus, the main objective of this study is to assess the potential of texture analysis using grey level co-occurrence matrix derived from sentinel 1 C band GRD image and, vegetation indices and vegetation biophysical variables derived from Sentinel-2 medium resolution images in estimating AGB and carbon stock in Yayu tropical forest, south west of Ethiopia. Both Sentinel 1 ground range detected and Sentinel 2 multispectral instrument used for this study were acquired in February, 2018. Twenty two variables from sentinel 1 including polarization (VV and VH) and twenty variables from sentinel 2 including selected bands were used in this study. Forest stand parameter data such as DBH and tree height collected in 2016 were taken from office of Ethiopian Coffee Forest Forum and converted to AGB using available allometric equation. The correlation of biomass value measured in each plot and the radar information extracted using texture analysis of radar images, as well as variables extracted from optical image were assessed by the Pearson correlation coefficients. Regression modelling was applied based on chosen variables to estimate AGB for the whole study area and the estimated result was validated by considering the coefficient of determination between observed and predicted AGB. The strongest correlation (r = 0.65 - 0.74) was identified between sentinel 2 biophysical variables and AGB in the study area. Relatively weak to moderate correlations (r = -0.24 to 0.47) were found between sentinel 1 extracted variables and AGB. Band 4, IRECI, LAI, FCOVER and FAPAR were selected based on their correlation coefficient to develop AGB predictive model. The model has a coefficient of determination value of 0.74 and root mean square error (RMSE) of 0.16 ton/pixel. Forest above ground biomass and carbon stock map were produced by the developed model. Overall Sentinel 2 variables performed better in estimating AGB and carbon stock compared to sentinel 1 GRD image in the study area. Integrating field data with remote sensing method increases the accuracy of estimating forest AGB and carbon stock.Item Remote Sensing and Gis Approach for Estimation of Land Surface Temperature to Examine Urban Heat Island Effect on A City Scale; the Case of Hawassa City, Ethiopia(Addis Ababa University, 2018-05-04) Sisay, Dagnachew; Korme, Tesfaye (PhD)Estimation of Land Surface Temperature (LST) in a city scale is essential for various applications, especially for examining the Urban Heat Island (UHI) effect caused by different factors and identify the relationship of LU/LC types with LST. The integration of interpreted results obtained from Landsat 8 TIRS and MODIS night time data are helpful to identify the major causes for the spatial variation of LST. This helps to examine the heat island effect caused by the geological setting of an area located within the rift zones. Landsat 8 TIRS band 10 data was used to estimate LST of the area. An algorithm that was prepared for Landsat 8 band 10 were used by taking the NDVI method for the estimation of emissivity. The LU/LC maps of the area were prepared with better accuracy using on screen classification technique by identifying 18 different classes that have strong relation with the spatial variation of LST. The UGC types were identified and mapped by integrating computer aided and on-screen classification method using sentinel-2A data. The derived LST showed that the surface temperature of the city ranges from 20.6 to 41.30C and the minimum temperature of the area was observed within the lake and the surrounding areas such as the wetland. The maximum temperature was registered on the scattered and small hills (Tabor Ridge) and areas that are used for mining and some parts of bare lands including industrial park of the city. The spatial variation of LST in the city is the result of four (4) major factors namely: 1) geological setting (volcanic lava domes) and mining areas, 2) human induced activities, 3) the LU/LC type, 4) the nature of the rock (volcanic ash), for their immediate response as a result of absorbance of incident energy from the sun. The mapping of UGC for Hawassa city in detail was found to be good, though mapping and validation of smaller and scattered tree covers were difficult. Increasing of evergreen tree cover and rehabilitation of existing mining areas are among the recommended strategy to mitigate the UHI effects in the city. For future studies in areas that are susceptible to natural heat sources, the satellite data should have high spatial resolution and derived from multiple sensors and satellites that can provide better tools to understand the UHI effect considering the geological setting of the area.Item Rift Margin Development, the Case of Southern Afar Depression, DireDawa Area(Addis Ababa,University, 2003-11) Hagos, Miruts; Korme, Tesfaye (PhD)Southern Afar Rift margin is a 2S-30km wide zone separating the Somalian plateau from the Afar rift floor. It shows a complex fault pattern, characterized by the interplay of: (i) an E - W trending marginal fault system, (ii) a northwesterly major lineaments (faults) and (iii) a NE trending Nazareth fault system. The E - W oriented faults playa dominant role for the present morphology of the southern Afar rift margin and for the existence of highly tilted Mesozoic rocks. Rifting induced late Cenozoic volcanism in the southern Afar rift margin three main types. The oldest felsic rocks, aligned parallel with the boundary faults, are formed contemporaneously with these faults. The olivine free basalts and the Rhyolites are found with in the marginal half grabens. And the youngest volcanic rocks of the area are the Afar stratoid series, erupted during further episode of rifting and tilting. The marginal fault plane and bedding plane relationship of the area confirmed that the bed orientation is greatly controlled by the orientation of the faults. The strike of the beds and faults is nearly similar; however, their dip amount is inversely related and their dip directions lay opposite to each other. Systematic field observations and accurate measurements of the orientation of structural elements have enabled to identify the nature of fau lts at depth: the presence of roll-over anticline structures together with the subsidiary normal faults led the author to conclude that the nature of faults at depth is listric normal. The general fault pattern of the southernAfar rift margin, as well as mesoscopic fault analyses indicate the occurrence of a roughly NNE-SSW extension with small component of dextral shear motion along the Rift margin.Item Soil Erosion Modeling Using Remote Sensing and Geographic Information System: A Case Study of Awassa Area(2005-07) Hagos, Hamlmal; Korme, Tesfaye (PhD)Land degradation has been a major global issue because of its adverse impact on agronomic productivity, the environment, and its effect on food security and the quality of life. Soil erosion is the major form of land degradation in Ethiopia. This study is done in Awassa Catchment, which is the central part of the Main Ethiopian Rift. Assessment of soil erosion rate in the study area is done using the statistical and relatively simple soil erosion model that is USLE. All factors used in USLE were derived independently, while in reality the factors interact in a dynamic system and several assumptions have to be made to adapt the model to a given set of conditions. Based on the analysis of the data, 97.51% of the study area is characterized by low to moderate soil erosion rate (0-10.09 t/ha/yr) and 2.49% of the study area is characterized by high to extremely high soil erosion rate (10.09-201.79 t/ha/yr). Out of 97.51% of the study area that is characterized by low to moderate soil erosion rate, 88.05% of it is associated with slope gradient factor less than one. 49.32% of areas with erosion rate greater than 10.09t/ha/yr (30.92 km2) are associated with slope gradient factor greater than or equal to one. And 6.37% (1.97 km2) of those areas with erosion rate greater than 10.09t/ha/yr (30.92 km2) are related to slope length greater than or equal to 4.5. And areas with high to extremely high erosion rates are associated either higher slope gradient factor or with degraded bare land and grassland and shrub land cover. Out of the whole catchment, 30.24 km2 lies under high to extremely high soil erosion rate and this requires immediate conservation measures like planting trees which can hold the soil intact. According to the rates of soil tolerance limits that are developed for tropical soils (0.2 and 11 t/ha/yr), 97.51% of the study area is under tolerable soil erosion rate. But one thing to remember is that the USLE measures only rill and interrill erosion therefore the overall soil erosion rate especially in the Muleti area where ground cracks are observed could be much higher than the predicted by the USLE. Thus, estimation of soil loss from the ground cracks in Muleti area should assessed by other models. Therefore the analysis of high-resolution remote sensing data combined with further spatial information in a GIS environment provides an integrated and cheap tool for resource management within the scope of sustainable development.Item Spatila Modeling of Geo-Hazard Suceptiablity to Assess its Impact on the Major Infrastructure: the Case of Middle Awash Basin, Ethiopia(Addis Ababa University, 2019-06-02) Melkamu, Tewabe; Korme, Tesfaye (PhD)Geo-hazards, including earthquakes, ground fissuring, volcanic eruptions, and landslides, are crucial problems in Ethiopia causing heavy limitation on urbanization and infrastructural projects and, more in general, for the socioeconomic development of the country. Relatively speaking, the Main Ethiopia Rift Valley region is more susceptible to thus natural disasters. The production of susceptibility maps /hazard zonation mapping/ is the first step in managing a sustainable risk mitigation program in any geo-hazard -prone area. These study focused on Geo-hazard susceptibility mapping using Remote sensing and GIS technology, to assess the vulnerability of existing infrastructures at the middle Awash basin, Main Ethiopian Rift Valley. An attempt was made to map three geo-hazard susceptibilities namely; landslide, seismic, volcanism and associated of the three geo-hazards using Analytical Hierarchy Process method. For these purpose, eight spatial data layers were generated and evaluated. Thus are land use landcover, Faults, and lineaments; active volcanic vent, slope, topography, soil texture and lithology. The Data were combined based on their significance, to produce a susceptibility map of each hazard type. The result of the susceptibility mapping done for each hazard has been classified into four classes and their spatial area coverage also calculated. To validate the geo-hazard susceptibility generated by Analytical Hierarchy Process technique, differential interferogram (DInSAR) method were applied. The method was done by using a two year six months temporal baseline master and slave image co-registration. The two results (i.e AHP model and SAR result) were correlated using linear regression and Receiver Operating Characteristics curve analysis. From this; the result revealed that the performance of the model was acceptable. The hazard zones could practically be used to assess the vulnerability of existing infrastructure in the study area. Finally using the three combined hazard risk map the vulnerability of infrastructures and other property was assessed through spatial overlay in their location.Item Wetland Degradation Mapping and Evaluating Its Impacts on the Surrounding Environment, Using Geospatial Technique, A Case Study in Geba Watershed, Southwest Ethiopia(Addis Ababa University, 2019-05-03) Berhanu, Mintesnot; Korme, Tesfaye (PhD)Wetland is one of the world’s most significant ecosystems, threatened from both natural and human-induced activities. As a result, the overall objective of this study is to map, monitor, and evaluate the impacts of wetland degradation on the environment, the case of Geba watershed southwest, Ethiopia. Remote Sensing and Geographic Information System approach integrated with ground data calibration were used to evaluate and quantify wetland resources. To conduct this study Landsat Thematic Mapper (TM) images was acquired for 1985, 2000 and Landsat 8 Operational Land Imager (OLI) imagery for 2018. In addition, SRTM DEM was acquired from the archives of the United States Geological Survey (USGS) for the analysis. Three different approaches have been used for mapping and monitoring of wetlands. Pixel-based classification (Supervised classification), index-based classification (NDVI & MNDWI), SRTM Slope and (TWI)wetness index and image enhancement methods were used. The use of multi-spectral Landsat imagery, including SRTM DEM, combined with ground truth data and GIS produced acceptable results for the delineation and mapping of wetland degradation in the study area. The overall accuracy of the 3 aggregated wetland (1985, 2000 and 2018) in the study area was 86.66 percent with reasonable errors of omissions (7.54 percent) and low errors of commissions (13.33 percent). TWI and slope map enhance the detection of forested wetland in the study area. Based on the results, wetland areas of 31.115km2 (14.53%), was converted to agricultural land in the period of 1985 to 2000. Similarly, in the same fashion from 2000 to 2018, 17.515km2 (10.9%) of wetland converted to agricultural land. Hydro-chemical parameters indicate a significant difference in water quality of degraded and undegraded wetlands and there is a change in ground water table based deep-well data between drained and undrained wetland types. A considerable driving force for wetland degradation within the watershed was directly related to agricultural expansion and population increment. Climate variability has also its own impacts on the degradation of wetlands in the study area.