http://ir.bdu.edu.et/handle/123456789/2010 Sat, 13 Jan 2001 06:30:49 GMT 2001-01-13T06:30:49Z http://ir.bdu.edu.et/handle/123456789/16430 Assessing Land Use/Cover Dynamics on Soil Erosion and Sediment Yield in Barkana Watershed, Northeast Ethiopia Seid, Yimer Land use land cover (LULC) dynamics is the main environmental challenge that mainly affect soil erosion and sediment yield in Ethiopia. Thus, this study aimed to evaluate LULC dynamics on sediment yield and soil erosion in Barkana watershed. The main data sources for image analysis were Landsat TM (1993), ETM+(2008), and OLI (2023). While rainfall data, soil type and texture, Digital Elevation Model (DEM), and LULC data were used to generate the erodibility (R), erosivity (K), slope-length (LS), land cover (C), and management (P) factors for RUSLE Model. Soil erosion and sediment yield were estimated using the RUSLE, Sediment Delivery Ratio, and Sediment Yield (SD) algorithms. These data sets were analyzed using ERDAS Imagine and Arc GIS software accordingly. Moreover, a total of twelve key informant interviews (KII) were selected, three from the upper, four from the middle and five from the lower part of the watershed purposively depending on the spatial extent of these parts. The KII have been used to triangulate the secondary data analysis. The Maximum Likelihood Algorithm (MLA) of supervised classification was used to classify Landsat images from three separate time periods (1993, 2008, and 2023) into six key land use/cover classifications (agricultural, bare land, built-up, forest, grazing land, and shrubs). Consequently, throughout these years (1993 2023), forest, grazing land, and shrub declined by 3156.8ha (12%), 1584ha (6%), and 868ha (4%), respectively, while agricultural, bare land, and built up rose by 3742.5ha (14.3%), 488.2ha (2%), and 1378.5ha (5.3%). Throughout the study periods, the annual rate of change for different land uses and land covers varies. For instance, the yearly increases in built-up, bare land, and agricultural land were 0.48%, 0.06%, and 0.18%, respectively. In 1993, 2008, and 2023, the mean annual soil loss increased by 27.95, 41.98, and 59.34 t/ha/yr, respectively. The sediment yield increased by 8.6, 12, and 15.7 t/ha/yr during these times on the same trend. The average amount of soil erosion in 1993, 2008 and 2023 was employed to identify hotspot regions for watershed planning and management strategies. As a result, five priority classes (very high, high, moderate, low, and very low) are applied to the entire watershed. The first and second priority classes that needs attention together covered about 4,035ha (15.4%) of land. Moreover, the highest rates of soil erosion (more than 50 t/ha/yr.) were observed in very high, high, and moderate priority levels. As a result, these areas require quick attention. Sun, 01 Dec 2024 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/16430 2024-12-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/7544 GIS-Based Assessment of Water Supply and Loss in Water Distribution Networks • 006 The Case of Bahir Dar MELESE, MESHESHA Developing sustainable water supply systems appropriate to the needs ofthe customer and the water supplier capacity incofporated with the rapidly growing urban population is a challenge faced in developing municipalities. With limited financial resources to develop water utilities. demands for water supply and delivery services are growing rapidly. The current water supply system of Bahir Dar is yet to be fully developed, has inadequate distribution ofwater supply. as well as high water losses. "Although it is not po.ssible to have a leak~f;'ec network, it is possible to reduce the percentage ofwater losses and increase the supply wverage. Geographical Information Systems (GIS) h~e been integrated into the development of utilities greatly improving the operation an~ maintenance of the systems and the decision-making abilities of" utility developers. Therefore. we develop a GIS database jor the vvater distribution network components of" Bahr Dar town and evaluated both the supply coverage and water loss with primary and available secondary data in addition to spatial data. such as wflter supply layout. QuickBird satellite image. master plan of the town and GPS ;neasurements. Water production and water consumption aggregated Fom customers meter readings were used to evaluate the total water loss in the town. We jound that the average domestic per capita consumption of Bahir Dar town is j 8.98 llcld, which is lower than that ofthe minimum standards set as a basic need. The level ofconnection p~ family is 35% which implies that on averaf,e three families or 13 persons are sharing one connection or water tap. In spite oflow coverage. there is a high water loss .. -in the town. a mean total loss o/ahout -/3% This studv also analyzes the accessihility of" the distribution pipeline network to the center of" the residential huildings using u proximity spatial analysis tool. and the mean near distance is 274 meters long This study suggests that jor optimal water loss reduction and spatial comparison of/oss within the syste~1, it would be necessary to update the existing network data into a digital database, improve the billing system, establish water pressure managemi:'nt. implement proper maintenance and replacement of netvvorks, and diVide the existing system into subsystems and district meter areas. A thesis submitted to the school of graduate studies in partial fulfillment of the requirel~1ents for the degree of Master of Science in GIS and Remote Sensing: Wed, 02 Aug 2017 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/7544 2017-08-02T00:00:00Z http://ir.bdu.edu.et/handle/123456789/7543 Assesslllent of Forest Cover Dynanlics Using GIS and Remote Sensing in AdabaDodola, Bale Mountains Tsegaye, Sewinet Belay The dynamics of the forest cover in Bale Mountains was still poorly understood. The thesis use GIS and Remote sensing techn.ology to examine the forest cover in the . "- study area.. This study examined land cover dynamics of the Adaba Dodola in three sub periods; 1973 J986, 19'86 - 2000, and 2000 - 2006 and finally the period between 1973 and 2006. Super~ed classification of satellite imagery through maximum likelihood classifier was used ~o discriminate the four dominate land cover classes in the study area. Land cover change was varying during these sub-periods. In the past thirty three years .. there was a general decline of forest cover. The study also shows an increase in the area I ooverage of agricultural field. In the study area deforestation was severe along river valleys, near to settlement and roads. In this areas, agricultural field increases at the expense of forest cover. In • addition rate of forest cover change varies among sub-regions, which is the highest .. during 2000 - 2006 and the lowest in the period 1986 - 2000. As examined from images deforestation was severe in lower slopes. In slopes lower than t 5 degree agricultural field increases at the expense of grass and forest land cover. At the end recommendations are made. These recommendations are the implementation of ecologically and econorri1cally valuable land uses such as agro ecology and ecotourism. A Paper Presented In Partial Fulfillment of the Requirement for the Degree of Master of Science in Geoinformation (GIS) Wed, 02 Aug 2017 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/7543 2017-08-02T00:00:00Z http://ir.bdu.edu.et/handle/123456789/7510 GRICULTURAL LAND SUITABILITY EVALUATION FOR RAINFED CROPS USING GIS: ACASE STUDY OF DEBRE MEWI WATERSHED ADISALEM, ASEFA ASEFAW Land suitability evaluation is the base for land use planning and land management to enhance the sustainable use of land resources. Suitability evaluation for tef, maize and grass pea cultivation in r~fed agriculture was studied through a qualitative process of matching land charaC(teristics with crops requirements based on maximum limitation system. The present study ~ initiated with the main objectives of creating the digital elevation model, I identifying and mapping the major soils and LULC, classifying the watershed into land mapping units and finally producing suitability maps of the selected crops, which are c6ltivated in the Oebre Mewi watershed in the Amhara Region. The major variables used in this study include topography, climate, soil and LULC. Data of spatial vector and raster as well as the attribute of the major variables were collected from QuickBird2 satellite imagery, topographic sh~et, field observation and laboratory results. ArcInfo GIS 9.2 version was intensively used through the study. Most of the land units of the study area were found to be moderately suital?le for tef, the low lying land units highly suitable for grass pea and the well drained land units were moderately to marginally suitable for maize cultivation at a low level input use. While doing all these, the GIS-database was established and set in with a variety of datasets that can be easily update and enables to produce various types of maps and information about the Debre Mewi watershed. Thus, the study has showed GIS and RS techniques are powerful tools to integrate various data layers and to assess the potentials of land resources for scientific land use planning, decision making and resource management. Presented to the faculty ofSchool ofGraduate Studies ofBahir Dar University In partial ~fiI1ment ofthe requirements for the degree ofMasters of Science in Geo-Information (GIS) Tue, 01 Aug 2017 00:00:00 GMT http://ir.bdu.edu.et/handle/123456789/7510 2017-08-01T00:00:00Z