http://ir.bdu.edu.et/handle/123456789/1680 2026-10-13T10:33:46Z http://ir.bdu.edu.et/handle/123456789/17108 Modeling Gully Erosion Vulnerability Areas in the Case of Abe Gerima Watershed, Amhara Region, Northwestern Ethiopia Dinku, Addisalem Gully erosion is a severe form of soil erosion that results in a wide range of environmental problems such as dams’ sedimentation, destruction of transportation and energy transmission lines, decreasing and losing farmland productivity, and land degradation. The main objective of this study was to map the areas prone to gully erosion, by using Frequency Ratio (FR) and random forest (RF) models. Moreover; multi- collinearity analysis was applied and 13 variables among 15 conditioning factors were selected to train the models for gully erosion susceptibility mapping (GESM). The conditioning factors include altitude, slope, aspect, plan curvature, profile curvature, drainage density, topographic wet index, precipitation, normalized difference vegetation index, land use/land cover, distance from the stream, distance from road, and soil-related variables. Model prediction potential was evaluated using the area under the curve (AUC) method. The RF model produced a higher accuracy with area under curve (AUC) an accuracy value of 89% and FR model prediction accuracy value was 77%. A detailed accuracy assessment using the Receiver Operator Characteristics (ROC) validation showed that the RF model is a reliable and accurate method for GESM than the FR model. Therefore, the RF model is useful in GESM and helps decision-makers in land-use planning and management. The outcome of this study can help managers in Aba Gerima to identify gully erosionprone areas which will help them to mitigate the gully erosion problem and prevent future gully erosion by taking preventive measures. 2024-11-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/17107 Effects of Land Use Type and Land Management on Soil Quality Indicators in Gerda Watershed, Northwestern Ethiopia Mera, Dejen Soil fertility loss is a major global issue, especially in developing countries, including Ethiopia. This is a significant concern for sustainable agriculture, threatening food security and ecosystem health. To minimize soil quality loss and protect ecosystem health, The Ethiopian government implemented land management practices, such as soil and water conservation, area exclosure, and planting highland bamboo (Oldeania/Yushania Alpina), to protect steep slopes, prevent soil erosion, and generate income in the Dembecha district. However, there is insufficient research on how bamboo forests and area exclosure affect soil quality indicators in the northwestern highland of Ethiopia. Therefore, this study is conducted to evaluate the effects of bamboo forests on soil quality indicators and to evaluate the effectiveness of land management practices (area exclosure for grazing land and bamboo forest, and integrated soil and water conservation practice for cultivated land) on soil fertility in the Gerda watershed, Northwestern Ethiopia. Soil samples were collected from treated and untreated sites of cropland, grazing land, and bamboo forest in the upper and lower slope positions. The collected data were analyzed following standard statistical procedures concerning treatment, land use type, and slope position by using SPSS software. Land management practice, land use types, and topography significantly (P < 0.05 to P < 0.001) influence almost all physicochemical soil quality indicators. Higher clay (36.6%), pH (6.77), organic matter (11.46%), total N (0.39 %), available P (9.25 ppm), CEC (45.38 Cmol (+) kg ) were obtained from the treated bamboo forest at a lower slope. Relatively higher bulk density (1.36 g/cm3) and sand content (54.33) were recorded from untreated cultivated land at the upper slope. This result implies that highly deteriorated soil quality indicators obtained from untreated cultivated land at the upper slope might be due to improper and intensive cultivation on steep slopes, and the application of inorganic fertilizer for a long period like urea, which leads to the removal of the fertile soil part. Generally, this result indicated that soil degradation can be minimized through enhancing land management practices like area exclosure, and integrated soil and water conservation practices to make sustainable agriculture in the watershed. -1 2025-05-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/17106 Assessment of Physical Soil and Water Conservation (PSWCP) Practices and Estimation of Soil Loss Using the RUSLE Model: Constraints and Challenges in The Debir Wonz Watershed, Yilmana Densa District, West Gojjam Zone, Amhara Wudu, Ayenew Due to several factors, most PSWC works have not fully achieved the intended objectives. The disparity between dimensions of the implemented PSWC work and the standard is the main factor. Water-induced soil erosion is the most prevailing form of land resource deterioration in the highlands of Ethiopia, where huge amounts of fertile soil are being lost annually. Most of the Debirwonz watershed was characterized by very severe to severe soil erosion rates, which are associated with the gentle slope. Data were generated through field observation, field measurements, and questionnaires. Measurements were taken from these soil bunds, trenches, waterways, cut-off drains, and check dams from three separate slope classes (lower, middle, and upper slope). The recommended value was analyzed using t-test statistics (p<0.05). The household survey data was analyzed by descriptive statistics using the basic Statistical Package for Social Science (SPSS-23), and the RUSLE model was used to estimate annual soil loss. Results showed that the measured mean dimensions of graded soil bunds, such as bund spacing, bund width, bottom embankment width,berm width, and height of embankment, were significantly different at 0.05 from the recommended dimensions at a 95% confidence interval (t<1.740) in the watershed. According to the result, 77.7% of the physical design of the implemented PSWC structures of spacing or horizontal distance constructed in the study area were meaningfully wider than the recommended standards and unfit to the standard, and 88.9% of the vertical intervals between soil bunds in the Debir-Wonz watershed were greater than the minimum technical standards. In addition, about 49.8% and 64% of the embankment bottom width of the soil bund and the length of the bund were without the standard. The mean annual soil loss rate in the watershed was estimated to be 0 to 815.99 t ha⁻ ¹yr⁻ ¹ with the average annual soil loss of 52.25 t/ha/yr. Major constraints such as 37.5% lack of labor and 22% technically difficult to implement 18.8% physical factor, 22.3% lack of technical skills, 19.6% lack of awareness, and 1.8% institutional factor are the major constraints in the study area. Through farmers come into view to face such problems. So, the study suggests that wellorganized training should be given for experts at different levels to fill the technical gap in their skills, and extension services like demonstrations should be held for all stakeholders before implementing the PSWC practice, and most PSWC practices lack the standard supportive activities, such as the cut of drain, check dam, biological work, frequent maintenance, and other dimensions. Hence, a well-appropriate design of physical soil and water conservation (PSWC) measures should be prioritized based on soil erosion severity levels. x 2025-06-01T00:00:00Z http://ir.bdu.edu.et/handle/123456789/17105 Investigating Water Hyacinth (Eichhornia Crassipes) Morphometric Characteristics and Harvesting Methods, Lake Tana, Northwest Ethiopia Mengistea, Hibre Water hyacinth (Eichhornia crassipes) is one of the major challenges in Lake Tana, negatively impacting the surface area coverage of the lake, and the wetlands around it. This study aimed to investigate water hyacinth's (WH) morphometric characteristics and harvesting methods in Lake Tana, in the northwest highlands of Ethiopia. An explanatory research design, satellite images, field observation, field measurement, and literature reviews were used. Descriptive statistics were applied to analyze the quantitative characteristics of WH morphometric characteristics. Stata was applied to compute the statistical analysis of the data. The results showed that the spatial distribution of the weed was 10.59 km² (1059 ha) in the dry season of 2024 (January) and 7.372 km² (737.2 ha) in the wet season of 2023 (August). WH showed a mean leaf length of 9.47 cm, leaf width of 10.6 cm, stem length of 33.63 cm, stem diameter of 2.3 cm, root length of 121.8 cm, root diameter of 8.5 cm, root shoot ratio of 3.7, leaf blade area of 57.8 cm², and leaf area index of 55374.03 cm². In addition, a mean of 21 leaves per plant and 47 plants per 1 m² was found. The average fresh and dry weight of WH was 62.09 kg/m² and 4.63 kg/m², respectively. The total wet biomass of WH in Lake Tana was 457,727.48t/year in the wet season of 2023 and wet WH biomass of 651945t/year in the dry season of 2024. On the other hand, the dry biomass of WH was 34,132.36t/year in the wet season of 2023 and 48,615t/year in the dry season of 2024. Furthermore, the net value of machine harvesting was $6,236,833.82/year. Monitoring water hyacinth’s morphometric characteristics and identifying cost-effective harvesting methods is crucial for effective lake management. Machine-based harvesting was found to be a cost-effective and preferable method. Although machinery harvested more biomass, integrated method is essential for effective WH harvesting, Lake Tana conservation, and sustainable management. 2024-10-01T00:00:00Z