Institute of Technology
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Item LAND USE LAND COVER CHANGE DYNAMICS AND SOIL LOSS: GIS AND REMOTE SENSING BASED ANALYISIS, IN SHASHOGO WEREDA, HADIYA ZONE, SNNPRS, ETHIOPIA(Hawassa University, 2018-10-26) YOSEPH DEBOCH HANKOREThe relationship between land use land cover change dynamics and soil loss over the last four decades (1973-2015) was investigated using GIS and Remote Sensing data at Shashogo Wereda, Hadiya Zone, SNNPRS, Ethiopia. In order to achieve these, satellite data of Landsat 1 MSS for 1973, Landsat 5 TM for 1986, Landsat 7 ETM plus for 2000, and Landsat 8 OLI for 2015 have been obtained and pre-processed using ERDAS Imagine 2014 software. The Maximum Likelihood Algorithm of Supervised Classification has been used to generate LULC maps. Ancillary data were used to validate the classified LULC maps. For the accuracy of classified LULC maps, a confusion matrix was used to derive overall accuracy and results were above the minimum and acceptable threshold level. For change detection statistics, cross-tabulation matrices method was employed to identify gains and losses between LULC classes. The study analyzed the magnitude of spatial and temporal LULC changes for three consecutive periods; 1973 to 1986, 1986 to 2000, and 2000 to 2015. Moreover, the soil loss from the watershed was estimated using USLE employing GIS tools. Results of the study revealed that the study area has undergone substantial LULC changes. Over the 42yrs, the aerial coverage of cultivated land was increased from 43.9 to 63.0% between 1973 and 2015. Similarly, water body and wetland were increased from 0.6 to 3.9% and 4.4 to 6.7% respectively. Settlement area which was not found in the first and second period of study years, satellite image result have 2.9% proportion in 2015 LULC classification. On the other hand, grass land, bush land, and bare land were decreased from 16.1 to 6.5%, 28.6 to 12.4%, and 6.4 to 4.5% between 1973 and 2015, respectively. Following the land use change pattern, soil loss values were increased in 2015. The estimated soil loss rate in the watershed was 14.31t/ha/yr in 2015. The findings of this study suggested that the rate of LULC change over the study period, particularly intensively cultivated land, bare land, and soil erosion problems need to be given due attention to maintain the stability of the ecosystemItem GIS BASED SOIL LOSS ESTIMATION USING USLE MODEL FOR SOIL CONSERVATION PLANNING: IN KARESA WATERSHED, LOMA WOREDA, SOUTH WEST ETHIO(Hawassa University, 2017-10-10) BAGEGNEHU BEKELE MENGISTUSoil erosion is the most challenging and continuous environmental problems resulting in both on-site and off-site effects in the world particularly in Ethiopia. Karesa watershed is one of the most erosion-prone watersheds which received little attention. Managing the on site erosion is to reduce the negative impacts of downstream water resources and requires an understanding of the rates of soil loss as well as identification of the major controlling factors that enhance or retard these processes. This study was conducted to estimate average annual soil loss rate using Geographic Information System and Universal Soil Loss Equation Model adapted to Ethiopian condition. The following datasets were obtained from different sources for estimating annual soil loss such as 15 years mean annual rainfall data for estimating Erosivity factor, digital soil map for estimating soil Erodibility factor, 30m x 30m resolution Digital Elevation Model for estimating slope length and slope steepness (LS) factor, Landsat6ETM+ images with 30mx30m resolution for detecting Vegetation cover and Conservation practice factor. Raster calculator was used to interactively multiply and produce annual soil loss. The result reveals that 42,413.72 ton per year soil loss from 9939 ha entire watershed and 4.27 tons per hectare per year average annual soil loss rate. The mean annual soil loss rate was classified in to four erosion severity classes as very less, less, moderate and High . The result also implies, two slope classes (0-15% and 15-30%) were categorized under very less to less soil loss (0-6.25 tons ha-1 yr-1 ) which accounts an area of 9383.07 ha (94.4%) of the watershed areas and representing 81.13% of the total soil loss. On the other hand, the watershed slope classes (>30%) fell under moderate to High soil loss (6.25-25 tons ha-1 yr-1 ) together covers 555.93ha (5.6%) of the watershed areas contributing 18.82% of the total soil loss mainly due to cultivation of marginal land,Intensive cultivation, poor vegetation cover during critical rainfall period. Moreover, about 2,184.93 ha of the watershed area was highly affected by erosion which contributes 18,182.25 tones yr-1 (42.87%) total soil loss and requires integrated soil and water conservation measuresItem Land use/land cover change and soil erosion risk mapping in Shebedino woreda, Sidama zone, southern Ethiopia(Hawassa University, 2017-10-12) ADDISU AMARE HABTESoil erosion is one of the major environmental problems that threaten sustainable agricultural production. Estimates of soil erosion risks and changes in the land use land cover will assist effective and sustainable land management and soil and water conservation (SWC) measures implementations. This study reported assessments of Land use/land cover changes between periods of 1973 and 2014 using GIS and Remote Sensing technique of Shebedino woreda. The study also attempted to map soil erosion risk by water and estimated the rate of soil erosion using Universal Soil Loss Equation in combination with GIS and Remote Sensing applications. Two satellite imageries (Landsat MSS 1973 and Landsat ETM+2014) have been used for change detection. Ethiopia soil map and soil survey data, 23 years rainfall data, a digital elevation model image, and land cover map for the year of 2014 have been used to estimate rate of soil erosion. Subsequently, land use/land cover map of the year 1973 and 2014, and soil erosion risk map of the study area have been produced. The study revealed that in the last four decades significant changes have been detected on LULCC. Forest cover and grazing land significantly decreased at a rate of 184.22 ha/yr and 38.08 ha/yr respectively; on the other hand cultivated land has shown increment in area at a rate of 179.91 ha/yr; and settlement has shown increment as well. The soil erosion risk analysis result shows that the woreda exhibited soil erosion rate of between 0 to 50 tonnes per hectare per year. The total annual soil loss in the study area was about 77200.50 tonnes, with 3.92 tonnes per hectare per year of mean annual rate of soil loss. A significant increment (159 %) in total annual soil loss has been observed. The total annual soil loss amount increased to 77200.50 tonnes in 2014 compared to 31076.05 tonnes 1973 situation. Based on the finding of this study, it was concluded that there were significant land use/ land cover change happened in the woreda. Part of the worda is prone to soil erosion risks. Therefore, all woreda level actors should give emphases to the situation and devise appropriate interventions measures for better and effective management of land recourses