Soil degradation is wide spread and serious throughout the Ethiopian Highlands. It is also a major watershed problem in many developing countries causing significant loss of soil fertility, loss of productivity and environmental degradation. This research has, therefore, been carried out to evaluate the soil erosion risk and quantify the major land use land cover changes over the past 20 years in the Nashe watershed. The research integrates the Revised Universal Soil Loss Equation (RUSLE) with a Geographic Information System (GIS) and Remote Sensing (RS) to quantify the potential soil erosion risk and land use land cover changes. Rainfall data, soil data, DEM data and satellite image were used as input data sets to generate RUSLE factor values. Raster calculator was used to interactively calculate potential soil loss and prepare soil erosion risk map. For the land use land cover change calculation two satellite images of two year interval ( Landsat TM 1996 and Landsat 2016) has been utilized. As a result the potential soil erosion risk and land use land cover map of 1996 and 2016 of the study area was generated. The result showed that the potential annual soil loss of the watershed ranges from 0.00 to 243..065ton/ha/yr. and the mean annual soil loss rate is 45.7ton/ha/yr. Concerning the land use land cover change Grass land decline from (8.85%) to (6.85.4%), open forest changes from (47.10%) to (22.75 %) and settlement land changes from (4.42%) to (7.59%). On the contrary farm land changes from (27.18%) to (45.55%), bare lands increase from (5.40%) to (5.55%) and water body changes from (7.06%) to (12.10 %). By the LULC analysis it has been found that the grass land and forest land declined from 1996-2016. On other hand, the rest of the land cover types have increased.

The problem of environmental pollution and health hazards due to inappropriate solid waste disposal is critical in developing countries like Ethiopia, Nekemte town is one of the town in Ethiopia facing from environmental pollution due to lack of appropriate dumping site which leads pollution of surface and ground water and environment in and around dumping area. Therefore, the main objective of this study is selection of suitable site for disposal of solid waste using Geographic Information System (GIS) tools. Selection of the most suitable landfill site was determined through the integration of geographic information system (GIS) tools, multi criteria decision analysis and remote sensing techniques. To select suitable landfill site several parameters were considered such as slope, built up area, , road, surface water, land use/land cover, geology and soil. After analysis of suitability of solid waste disposal site using GIS tools and weighted analysis methods selected 36 areas for medium solid waste Bins. Suitability map was prepared by overlay analyses on GIS based Weighted Linear Combination analysis to select the suitable solid waste disposal sites and assigned as the value given 1; unsuitable, 2; less suitable, 3; moderately suitable ; 4; Suitable and 4; highly suitable were determined. Using this method selected 2 highly suitable areas for land fill and inclination area

Road constructing in Ethiopia is increasingly in demand to meet its medium and long term development programs. Most internal road of Oromia cities/town are cobblestone and gravel. Some portions along the alignment proposed and existing roads traversed low resistance of the subgrade that affect the stability of upper layers of cobblestones.  Structural failures are observed on cobblestones roads, would it be constructed by good quality or low quality of materials. Nekemte Cobblestones Projects have been started in 2014 widely which were failed in most area today as we observed that needs to be addressed and a corresponding remedial measures must be drawn. A possible remedial measures had been organized for every observed  failure  or  destroyed  to  obtain  normal  road  condition  of  the study  area. An assessment was made by using observation, interviews, laboratory and field test to determine the adequacy of the cobblestones, underlain material to serve as a subgrade for road construction based on project specifications and Ethiopian Road Authority (ERA) low volume road Specification. From the field tests and laboratory tests carried out, it is observed that the causes of cobblestone road failures of this road section are mainly due to the construction steps/sequence, quality of materials, road construction time, lack of proper design and quality control, absences of drainage structures, lack of highly compaction, lack of accurately fill fine aggregate and suddenly high loads vehicle applied on cobblestone road.