Evaluating Soil Loss Using Geographical Information System and Remote Sensing for Soil and Water Resource Conservation: The Case of Yisir Watershed, Northwestern Ethiopia

Soil erosion is more sensitive in the highlands of Ethiopia.  The purpose of this study is estimating soil loss rate using RUSLE model with GIS and remote sensing to identify erosion potential areas for soil and water resources conservation plan and to prepare soil loss risk map. LANDSAT image of the study area and Digital Elevation Model from http://earthexplorer.usgs.gov as taken in 2017. Collected data were processed and analyzed using Arc GIS10.2 version. Total average annual soil loss from the 2,120.33ha was estimated at 7161.06tons. The lower soil loss rate was 2.5t/ha/yr on plantation and natural forest, the maximum value was 100.62tons/ha/yr in steep slope cultivated land and average soil loss was 50.31 tons/ha/yr. About 6.35% of the area is under extremely very severe soil erosion rate. Level soil bund, graded soil, stone or stone faced soil bund, fanyajju, cutoff- drain in the above part of the catchment, waterway along the slope, trenches on grazing land, check dam SWC measures at Quala got, integrated physical with biological measures like tree Lucerne, Vetiver grass are the recommended SWC measures. This approach can be applied in other basin or watershed for assessment of erosion risk potential using GIS and RS, and this can be used as a preliminary watershed planning tool for decision makers in Ethiopia like Woreda Agriculture and Natural Resources management Office. Keywords: Ethiopia, GIS, RUSLE, Soil and Water Resource, Yisir Watershed DOI: 10.7176/JRDM/66-02 Publication date:June 30th 202

Watershed Management Performance Assessment Based on Land Condition Indicators (Laeya Watershed Case, Southeast Sulawesi Province

Laeya Watershed is one of the three Priority Watersheds in Southeast Sulawesi. Therefore, monitoring and evaluating watershed performance is very important to ensure that watershed management is sustainable. This study aims to assess the performance of watershed management based on indicators of land conditions in the Laeya Watershed, Southeast Sulawesi Province. The method used is a survey with a scoring technique using the parameters index of the percentage of critical land, vegetation cover, and erosion index to determine the carrying capacity of the watershed. The results showed that the carrying capacity of the Laeya Watershed was classified as very good with a score of 35 (<70), with each sub-criterion of critical land classified as very low with a score of 0.5, sub-criteria for vegetation cover classified as good with a score of 0.75 and sub-criteria the erosion index criteria are classified as very high with a score of 0.75. It can be concluded that the management performance of the Laeya watershed is very good

Review on Contribution of GIS and RS for Soil Degradation Assessment in Ethiopia

GIS and RS are an advanced tools and playing a great role in natural resource management, particularly for assessing soil degradation. Soil degradation is the chronic problem in the world including Ethiopia. To review the contribution of GIS and RS, data collected from secondary data sources then discussion made based on their key findings.Accordingly, a few authors have assessed soil degradation by using GIS and RS integrated with USLE in Ethiopia. According to their findings, land degradation in the form of soil erosion is a critical issue. It is triggering by water soil erosion. Because of soil erosion, the potential capacity of the soil highly deteriorated. The amount of soil loss estimated in a different place all above the maximum (22t ha−1 year−1) soil loss tolerant considered for Ethiopia. Consequently, it threatens economic growth, environmental resource, and social assets. Moreover, its severity is uneven in all parts of the country. Even though the study conducted on soil degradation by using GIS and RS technique, its contribution is yet not pronounced to government organizations, NGOs, policymakers, and decision-makers, environmentalist and researchers in reviewed form. This will be reducing the attention that could be given to it. Therefore, to tackle this issue, this paper aimed to review the GIS and RS contribution for soil degradation assessment in Ethiopia. Keywords: GIS, RS, Soil degradation, Soil loss, and effects DOI: 10.7176/JEES/9-12-01 Publication date: December 31st 201

토지이용 및 토지피복 변화에 따른 토양 유실량 평가: 에디오피아 데브레 마르코스 블루 나일 유역을 중심으로

학위논문 (석사)-- 서울대학교 대학원 : 농업생명과학대학 산림과학부, 2018. 2. Sangjun Im.Abstract Soil erosion has become one of the most important environmental problems in globally, particularly in Ethiopia. The past land use and land cover (LULC) changes suspected to be the main causes of soil erosion in the study area, where is the Debre-Markos Blue Nile (DMBN) basin. Therefore, the objectives of this thesis are to: (1) assess the LULC change by using ERDAS 9.2 from Landsat images (1987, 2002, and 2017) and (2) to identify the LULC changes that causes soil erosion and estimate the annual soil erosion hazard by using ArcGIS 10.1. To determine the LULC changes first, the study carried out a mapping of each LULC for 1987, 2002 and 2017 by using the Supervised Classification method of Landsat image. To improve classification accuracy and reducing misclassification, a training data was derived from Google Earths (GE) geo-browser it has high spatial resolution images which provide opportunity for detailed LULC. The Landsat images classification for 2002 and 2017 were based on GE, while 1987 Landsat image were referenced by 2002s GE and pre-classified images, since GE images acquired from 2002 in this study area. After classification, accuracy assessment for 2017 classified image were interpreted using both digitized reference points and field varification way points. In the second place, the study estimates annual soil erosion by water using Revised Universal Soil Loss Equation (RUSLE). The LULCs map utilized for the final analysis of annual soil loss. In addition, 20 years` mean annual rainfall data from Ethiopia Metrological Agency, soil map from FAO Digital Soil Map of the World, digital elevation model (DEM) and previous reports to identify the cover management and supportive practice were used for the erosion estimation. From the achieved map the overall accuracy of 2017 was 84.5% and a Kappa coefficient of 0.81 was recorded. The LULCs change comparisen between 1987 and 2017 indicate that, from the total area about ~29% experienced with changes. The classification result showed that from 1987 to 2017 the dominant agriculture land (~44%) increased by 2% while the second and third dominant grassland (26%) and woodland (25%) had significantly decreased by 1.87% and 3.57 % of its coverage respectively. Other LULC types with small coverage such as afro-alpine, forest, agriculture, natural forest, plantation, settlements and water body experienced increased rate. Moreover, the LULC changes in DMBN-basin also affected the total soil loss. Thus, the soil erosion yield increased 3.04% (9996 tons/ yr-1) in comparison between 1987 and 2017. As a result, the rill and inter rill soil erosion had greatest (over 95%) relation with the dominant agriculture and grasslands during 1987 - 2017. The soil erosion with respect to the agricultural lands showed an increment of 6.13% from the previous agricultural land. In other words, the annual soil loss due to grasslands became decreased by 3.93%. The study also identified the soil erosion severity level, which very slight and slight soil erosion categories (< 5tons ha-1 yr-1) in DMBN basin is about 76%. On the other hand, about ~23% of soil erosion rate was recorded above the tolerable limit, that categorized medium (~9%), high (~10%), severe (~2%) and very severe level (~1%). In addition, the annual soil loss rate of severe and very severe levels on the steeper slopes have decreased by a little change in vegetation coverage in 2017. However, the total soil erosion had increased due to medium slope areas, where the agricultural activities increased implementation. Overall, the LULC changes analysis and annual soil erosion estimation and mapping its distribution is important and effective for identifying natural resource prone areas. Therefore, the local experts and administrative bodies uses this information to prepare plan for those priority areas to conserve and monitor the degraded resources.1. Introduction 1 1.1 The Study Backgrounds 1 1.1.1 Statement of the Problems 4 1.1.2 Significance of the Study 5 1.1.3 Research Hypothesis, Questions, and Theory of the Study 6 2. Literature Review 8 2.1 Watershed in Ethiopia Context 8 2.2 Land Use and Land Cover and its Classification 8 2.3 Google Earth Base Classification 12 2.4 Soil Erosion by Water 14 3. Methodology 17 3.1 Study Area 17 3.2 Land Use and Land Cover Classification 18 3.2.1 Data Collection 18 3.2.2 LULC Classification Analysis. 20 3.2.3 Accuracy Assessments Samples 25 3.3 Revised Soil Loss Equation (RUSLE) 26 3.3.1 Rainfall Erositivity (R) Factor 27 3.3.2 Soil Erodibility (K) Factor 28 3.3.3 Slope Length Steepness (LS) Factors 30 3.3.4 Cover Management (C) Factor 32 3.3.5 Supportive Practice (P) Factor 32 4. Result and Discussion 35 4.1 Accuracy Assessment for LULC Classification 35 4.2 Land Use and Land Cover Change Analysis 39 4.3 Soil Loss Factors Maps 46 4.3.1 Cover (C) Factor Map 46 4.3.2 Rainfall Erositivity (R) Map 47 4.3.3 Soil Erodibility (K) Factor Map 49 4.3.4 Slope Length-Steepens (LS) Factor Map 50 4.3.5 Supportive Practice (P) Factor Map 51 4.4 Annual Soil Loss 53 4.4.1 Land Use and Land Cover Effects on Soil Erosion 54 4.4.2 The Slope Effect on Soil Erosion: 59 4.4.3 Soil Erosion Severity and Mean Annual Soil Loss 62 4.4.4 Comparison and Summary with Other Studies 66 5. Conclusions and Recommendations 68 5.1 Conclusions 68 5.2 Recommendations 70 References 73 Appendices 84 Abstract (In Korean) 91Maste

The Effect of Land Use Land Cover Change on Land Degradation in the Highlands of Ethiopia

Land use and land cover change through inappropriate agricultural practices and high human and livestock population pressure have led to severe land degradation in the Ethiopian highlands. This has led to further degradation such as biodiversity loss, deforestation, soil erosion and soil quality. Agricultural and economic growth in Ethiopia is constrained by the deteriorating natural resource base, especially in the highlands where 80% of the population lives. This threat stems from the depletion and degradation of the vegetation cover of the country. Loss of biodiversity is associated with land use/land cover changes that are related to a range of biophysical and socio-economic drivers. The implications of these changes suggest that the land use/cover changes have skewed to the rampant conversion of areas once covered with vegetation to cultivation without adequate use of soil and water conservation and rehabilitation practices. Understanding of the driving forces of land use and land cover change (LULC C) is essential for effective sustainable land resource management. Change in LULC can also negatively affect the potential use of an area and may ultimately lead to land degradation.  Improving the understanding of land use and land cover dynamics can help in projecting future changes in land use and land cover and to instigate more appropriate policy interventions for achieving better land management. Keywords: Deforestation, Ethiopia, land degradation, land use, soil quality

Land use/ cover changes, driving forces and influence on soil properties in Rib watershed, Ethiopia

Land use/cover (LULC) change has resulted from complex interactions of natural phenomena and human activities. Population growth coupled with economic growth has increased the demand of land resources for centuries and causing changes at various levels ranging from local to global scales. Land use practice affects the distribution and supply of soil nutrients to plants by altering soil properties. This study aimed at understanding the magnitude of LULC changes and its drivers. It also attempts to examine the influence of LULC on soil properties in Rib watershed. Satellite imageries of 1986, 1996, 2006, and 2016, field observation and four key informant interviews were employed. In addition, soil samples were taken over natural forest, grazing and cultivated lands in the two agroecological zones (Dega and High Dega) with five replications. The samples were taken at two depths: 0-15cm (surface layer) and 15- 30cm (subsurface layer) and mixed up to obtain composite and representative samples. Household survey was also employed to obtain data on farmers’ perception of drivers of LULC changes. Image analysis was accomplished on ERDAS Imagine and Arc GIS software to detect land use/cover changes. Descriptive statistics, pair-wise ranking technique, Multivariate analysis of variance (MANOVA), and Spearman’s rank correlation coefficient analyses in SPSS were employed. The findings of this study revealed an expansion of cropland and settlement, plantation, and bare land by 39.01, 24.88 and 5.62 ha/year, respectively between 1986 and 2016. On the contrary, natural forest, grassland, and grazing land have decreased by 30, 26.6 and 12.9 ha/ year, respectively. Plantation shows increasing trends in Dega agroecological zone, whereas in the High Dega cultivated/ farmlands & settlements, bare land has increased rapidly at the expenses of other LULC. Significant differences (p<0.05) were also observed in OC, Ca2+, clay, and silt fractions between the soils of natural forest, grazing land, and cultivated in the two agroecologies. Soils of natural forest has higher OC, OC stock and TN. For instance, soils of natural forest has higher OC stock (188.32 Mg/ha) as compared to soils of cultivated lands (72.75 Mg/ha). BD of cultivated land was significantly higher than natural forest and grazing lands. LULC changes were driven by increasing demands for new farmlands and increasing demand for eucalyptus wood in rural and urban centres. Moreover, weakness in law enforcement on natural resource conservation, low level of public participation in watershed management, and low level of livelihood diversification were among the drivers of change. Therefore, the study has suggested that the watershed ought to be enriched with of watershed restoration and natural resource conservation activities.Environmental SciencesPh. D. (Environmental Management

Prospects of sustainable land management amidst interlocking challenges in the Upper Beshillo Catchments, Northeastern Highlands of Ethiopia

Land degradation is a great threat to the Beshlo Catchment in Blue Nile Basisn, not merely as an environmental issue, but also a social and economic problem. In Gedalas Watershed (one of the micro catchments of Beshelo), land degradation, mediated by both biophysical and socio-economic drivers, is among the major environmental sustainability and social-economic development threats in the area. The threat is manifested in depletion of natural vegetations, water, soil and other natural resources; disruption of ecosystem functions, processes, integrity, and services. Given its particular vulnerability, watershed management activities have been in operation since the mid-1970s. Recently, the idea of Sustainable land management through integrated watershed development program has been initiated with the objective of reducing land degradation risks and ensuring food security at both the nationwide and family circle. Despite these investments and efforts, real evidences of success and failures of such efforts were not satisfactory explored. The objectives of this study were, therefore, to analyze the existing status and future prospects of sustainable land management and evaluates its implication on the environmental integrities and the local livelihoods specific to Gedalas watershed. For this effect, the study investigated the dynamics, deriving forces and implications of LULC, soil erosion and soil fertility status of the watershed, current status of watershed management practices, pertinent challenges and opportunities for practicing land management technologies and approaches that might help meet the sustainability requirements of SLM practices. In addition, the study explored factors that determine the willingness of farming households to undertake SLM practice. As the study carried in the coupled human-environment system of rural landscapes, interdisciplinary geographical approaches which integrats social and natural science methodologies were employed to deal with issues of land degradation-and-rehabilitation status comprehensively. The general findings of the study show that though it would be dificult to measure all the composite aspects of land degradation, some of the parameters considered in this study revealed that land degradation is a perpetuating challenge in the watershed. It is evidenced from the overall undesirable land use/cover changes i.e transition of 21.25% of Afro/sub alpine landscapes, 17.59% of the grasslands and 8% of shrub lands to either to cultivated land or settlement areas over the 1973–2017 period, which have unintended negative socio-ecological repercussions on the watershed; high annual mean soil loss value (which range from 37t/ha/year average values to 393 t/ha/yr soil loss rates on water courses) that exceed threshold level and a wide gap between the need for SLM and the actual achievement of SLM practices,including limited adherence to the idea behind contemporary land management policies and implementation principles and approaches. The study further revealed the presence of opportunities as well as a myriad of challenges that need to be tackled in order to achieve sustainable land management goals. The study colcludes that, though, some encouraging progresses have been observed in the SLM project sites; land degradation has remained a problem in the watershed. This calls for strenuous efforts to promote and assist wide scale adoption of SLM practices that address the pervasive land degradation problem and achieve land degradation neutrality as highlighted in sustainable development goals.Department of GeographyPh. D. (Geography

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Agricultural research, Research projects, Research policy, Research institutes, Impact assessment, Water management, Wetlands, Dams, Reservoirs

Improved water and land management in the Ethiopian highlands and its impact on downstream stakeholders dependent on the Blue Nile

Improved water and land management in the Ethiopian highlands and its impact on downstream stakeholders dependent on the Blue Nile – short title Upstream-Downstream in Blue Nile River project is one of the projects in the Nile Basin supported by the CPWF. It was implemented during from 2007 to 2009 through a partnership of 8 institutions. The Blue Nile is the major tributary of the Nile River, contributing about 62% of the Nile flow at Aswan. About two thirds of the area of this densely populated basin is in the highlands and hence receives fairly high levels of annual rainfall of 800 to 2,200 mm. However, the rainfall is erratic in terms of both spatial and temporal distribution with prolonged dry spells and drought often leading to crop failures. Currently, water resources are only marginally exploited in the upper basin but are much more developed in the downstream reaches. The population, located in the downstream part of the Blue Nile, is dependent on the river water for supplementary irrigation and energy production. Canal and reservoir siltation is a major problem, adding the burdens of poor riparian farmers. This project was envisaged to improve the scientific understanding of the land and water resources of the basin, and hypothesized that with increased scientific knowledge of the hydrological, watershed, and institutional processes of the Blue Nile in Ethiopia (Abbay), constraints to up-scaling adaptable best practices and promising technologies (technical, socio-economic, institutional) could be overcome, which will result in significant positive impacts for both upstream and downstream communities and state

Improved water and land management in the Ethiopian highlands: its impact on downstream stakeholders dependent on the Blue Nile; Intermediate Results Dissemination Workshop February 5-6, 2009, Addis Ababa, Ethiopia

River basin management, Watershed management, Farming systems, Water balance, Reservoirs, Water supply, Irrigation requirements, Irrigation programs, Simulation models, Sedimentation, Rainfall-Runoff relationships, Erosion, Soil water, Water balance, Soil conservation, Institutions, Organizations, Policy, Water governance, International waters, Institutional and Behavioral Economics, Land Economics/Use, Resource /Energy Economics and Policy,