Your search found 17 records
1 Shiono, T.; Kamimura, K.; Okushima, S.; Fukumoto, M. 2002. Soil loss estimation on a local scale for soil conservation planning. Japan Agricultural Research Quarterly, 36(3):157-161.
(Location: IWMI-HQ Call no: P 6409 Record No: H032681)
2 Sreedevi, T. K.; Shiferaw, B.; Wani, S. P. 2004. Adarsha watershed in Kothapally: understanding the drivers of higher impact. Patancheru, Andhra Pradesh, India: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT); Manila, Philippines: Asian Development Bank (ADB); Colombo, Sri Lanka: Comprehensive Assessment of Water Management in Agriculture. 19p. (Global Theme on Agroecosystems Report 10)
Watershed management ; Soil conservation ; Water conservation ; Productivity ; Income ; Pest control ; Runoff ; Soil loss ; Groundwater ; Cropping systems ; Economic impact ; Community development ; Villages ; Leadership ; Farmers’ attitudes / India / Andhra Pradesh / Kothapally Village
(Location: IWMI-HQ Call no: 333.91 G635 SRE Record No: H035878)
http://www.iwmi.cgiar.org/assessment/files/word/projectdocuments/icrisat/icrisatrep10_scr.pdf
https://vlibrary.iwmi.org/pdf/H035878.pdf
https://vlibrary.iwmi.org/pdf/H035878.pdf
(503.20 KB)
3 Awulachew, Seleshi Bekele; Tenaw, M. 2008. Micro watershed to basin scale impacts of widespread adoption of watershed management interventions in Blue Nile Basin. Paper presented at the Challenge Program on Water and Food (CPWF) Workshop on Micro-Watershed to Basin Scale Adoption of SWC Technologies and Impacts, Tamale, Ghana, 22-25 September, 2008. 6p.
Watershed management ; Sedimentation ; Runoff ; Soil loss ; Water balance ; Rainfall runoff relationships ; Models / Africa / Sudan / Ethiopia / Abbay-Blue Nile River Basin / Gumera River Watershed / Ribb River / Addis Zemen
(Location: IWMI HQ Call no: e-copy only Record No: H041747)
High population pressure, inappropriate agricultural policies, improper land-use planning, over-dependency on agriculture as source of livelihood and extreme dependence on natural resources are inducing deforestation, overgrazing, expansion of agriculture to marginal lands and steep slopes, declining agricultural productivity and resource-use conflicts in many parts of Blue Nile. Increased land degradation from poor agricultural practices and erosion results in increased siltation and the reduced water quality in the river basin. The rainfall, runoff and sediment are highly variable both in time and space. Poor water and land management upstream severely affect runoff characteristics and the quality of water reaching downstream. The result is a downward spiral of poverty and food insecurity for millions of people both within the upper catchment and downstream across international borders. Quantification of the erosion, sedimentation processes and evaluation of impacts of interventions are difficult tasks. This paper schematizes the Blue Nile Basin (BNB) at various spatial levels as micro watershed, watershed, sub-basin to basin. It is revealed that sediment in the river systems are temporally varying phenomenon and strongly related to the early onset of rainfall. The hydrographs of the systems shows that the peak of sediment reaches first followed by peak of rainfall and then runoff. Furthermore, the sediment cumulative curve shows that most of the sediment volume passes in the river in the first three months of the rainy season. The paper also considers a particular watershed to model runoff, sediment and impact of watershed intervention. The result shows that runoff can be reasonably simulated with calibration of R2=0.87 and validation of result of 0.82, and comparable sediment modelling results. The study also demonstrates, by undertaking spatial analysis using topographic, soil and land use parameters it is possible to identify the high sediment risk sub-watersheds. Impact of typical watershed intervention using various widths of vegetative filter and application on high erosion risk watersheds shows reduction of sediment yield from 52% to 74%.
4 Awulachew, Seleshi Bekele; Tenaw, M.; Steenhuis, T.; Easton, Z.; Ahmed, A.; Bashar, K. E.; Hailesellassie, A. 2008. Impact of watershed interventions on runoff and sedimentation in Gumera Watershed. In Humphreys, E.; Bayot, R. S.; van Brakel, M.; Gichuki, F.; Svendsen, M.; Wester, P.; Huber-Lee, A.; Cook, S. Douthwaite, B.; Hoanh, Chu Thai; Johnson, N.; Nguyen-Khoa, Sophie; Vidal, A.; MacIntyre, I.; MacIntyre, R. (Eds.). Fighting poverty through sustainable water use: proceedings of the CGIAR Challenge Program on Water and Food, 2nd International Forum on Water and Food, Addis Ababa, Ethiopia, 10-14 November 2008. Vol.1. Keynotes; Cross-cutting topics. Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food. pp.109-113.
River basins ; Flow ; Simulation models ; Watershed management ; Runoff ; Sedimentation ; Erosion ; Soil loss ; Soil degradation / Ethiopia / Sudan / Gumera Watershed / Abbay-Blue Nile River Basin
(Location: IWMI HQ Call no: IWMI 333.91 G000 HUM Record No: H041752)
http://cgspace.cgiar.org/bitstream/handle/10568/3706/IFWF2_proceedings_Volume%20I.pdf?sequence=1
https://vlibrary.iwmi.org/pdf/H041752.pdf
https://vlibrary.iwmi.org/pdf/H041752.pdf
(7.964MB)
5 Bui, Y. T.; Orange, D.; Visser, S. M.; Hoanh, Chu Thai; Laissus, M.; Poortinga, A.; Tran, D. T.; Stroosnijder, L. 2014. Lumped surface and sub-surface runoff for erosion modeling within a small hilly watershed in northern Vietnam. Hydrological Processes, 28(6):2961-2974. [doi: https://doi.org/10.1002/hyp.9860]
Watersheds ; Rain ; Runoff ; Erosion ; Land use ; Sloping land ; Sediment ; Soil loss ; Models ; Calibration / Vietnam / Dong Cao Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H046040)
(1.66 MB)
Developing models to predict on-site soil erosion and off-site sediment transport at the agricultural watershed scale represent an ongoing challenge in research today. This study attempts to simulate the daily discharge and sediment loss using a distributed model that combines surface and sub-surface runoffs in a small hilly watershed (< 1km2). The semi-quantitative model, Predict and Localize Erosion and Runoff (PLER), integrates theManning–Strickler equation to simulate runoff and the Griffith University Erosion System Template equation to simulate soil detachment, sediment storage and soil loss based on a map resolution of 30m 30m and over a daily time interval. By using a basic input data set and only two calibration coefficients based, respectively, on water velocity and soil detachment, the PLER model is easily applicable to different agricultural scenarios. The results indicate appropriate model performance and a high correlation between measured and predicted data with both Nash–Sutcliffe efficiency (Ef) and correlation coefficient (r2) having values>0.9. With the simple input data needs, PLER model is a useful tool for daily runoff and soil erosion modeling in small hilly watersheds in humid tropical areas.
6 Hussein, M. A.; Muche, H.; Schmitter, Petra; Nakawuka, P.; Tilahun, S. A.; Langan, Simon; Barron, Jennie; Steenhuis, T. S. 2019. Deep tillage improves degraded soils in the (sub) humid Ethiopian highlands. Land, 8(11):1-15. [doi: https://doi.org/10.3390/land8110159]
Agricultural production ; Deep tillage ; Soil degradation ; Humid zones ; Highlands ; Watersheds ; Conventional tillage ; Hardpans ; Sediment ; Rain ; Runoff ; Soil loss ; Soil moisture ; Infiltration ; Maize ; Crop yield / Ethiopia / Robit-Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049375)
(2.40 MB) (2.40 MB)
Intensification of rainfed agriculture in the Ethiopian highlands has resulted in soil degradation and hardpan formation, which has reduced rooting depth, decreased deep percolation, and increased direct runoff and sediment transport. The main objective of this study was to assess the potential impact of subsoiling on surface runoff, sediment loss, soil water content, infiltration rate, and maize yield. Three tillage treatments were replicated at five locations: (i) no tillage (zero tillage), (ii) conventional tillage (ox-driven Maresha plow, up to a depth of 15 cm), and (iii) manual deep ripping of the soil’s restrictive layers down to a depth of 60 cm (deep till). Results show that the posttreatment bulk density and penetration resistance of deep tillage was significantly less than in the traditional tillage and zero-tillage systems. In addition, the posttreatment infiltration rate for deep tillage was significantly greater, which resulted in significantly smaller runoff and sedimentation rates compared to conventional tillage and zero tillage. Maize yields were improved by 6% under deep tillage compared to conventional tillage and by 29% compared to no tillage. Overall, our findings show that deep tillage can be effective in overcoming some of the detrimental effects of hardpans in degraded soils.
7 Yaekob, T.; Tamene, L.; Gebrehiwot, S. G.; Demissie, S. S.; Adimassu, Zenebe; Woldearegay, K.; Mekonnen, K.; Amede, T.; Abera, W.; Recha, J. W.; Solomon, D.; Thorne, P. 2022. Assessing the impacts of different land uses and soil and water conservation interventions on runoff and sediment yield at different scales in the central highlands of Ethiopia. Renewable Agriculture and Food Systems, 37(S1):S73-S87. (Special issue: Restoring Degraded Landscapes and Fragile Food Systems) [doi: https://doi.org/10.1017/S1742170520000010]
Land use ; Soil conservation ; Erosion ; Water conservation ; Impact assessment ; Highlands ; Watersheds ; Runoff ; Sediment yield ; Discharges ; Soil loss ; Hydrological factors ; Rain / Ethiopia / Gudo Beret
(Location: IWMI HQ Call no: e-copy only Record No: H049533)
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/4F63E376EE1DAEB257043E7197E5B060/S1742170520000010a.pdf/assessing_the_impacts_of_different_land_uses_and_soil_and_water_conservation_interventions_on_runoff_and_sediment_yield_at_different_scales_in_the_central_highlands_of_ethiopia.pdf
https://vlibrary.iwmi.org/pdf/H049533.pdf
https://vlibrary.iwmi.org/pdf/H049533.pdf
(1.41 MB) (1.41 MB)
To tackle the problem of soil erosion and moisture stress, the government of Ethiopia introduced a yearly mass campaign where communities get together and implement various soil and water conservation (SWC) and water harvesting (WH) practices. Although the interventions are believed to have reduced soil erosion/sediment yield and enhanced surface and ground water, quantitative information on the impacts of various options at different scales is scarce. The objective of this study was to assess the impacts different land uses, SWC and WH interventions on water and suspended sediment yield (SSY) at plot and watershed scales in the central highlands of Ethiopia. Standard erosion plot experiments and hydrological stations were used to monitor the daily water and SSY during 2014 to 2017. The results show differences between treatments both at plot and watershed scales. Runoff and soil loss were reduced by an average 27 and 37%, respectively due to SWC practices at the plot level. Overall, SWC practices implemented at the watershed level reduced sediment yield by about 74% (in the year 2014), although the magnitude of sediment reduction due to the SWC interventions reduced over time. At both scales it was observed that as the number of years since SWC measures have been in place increased, their effectiveness declined due to the lack of maintenance. This study also revealed that extrapolating of plot data to watershed scale causes over or under estimation of net erosion.
8 Adimassu, Zenebe; Tamene, L.; Degefie, D. T. 2020. The influence of grazing and cultivation on runoff, soil erosion, and soil nutrient export in the central highlands of Ethiopia. Ecological Processes, 9:23. [doi: https://doi.org/10.1186/s13717-020-00230-z]
Grazing lands ; Cultivated land ; Soil fertility ; Nutrients ; Erosion ; Runoff ; Soil loss ; Land degradation ; Sediment ; Total nitrogen ; Phosphorus ; Potassium ; Highlands ; Watersheds ; Tillage ; Rain / Ethiopia / Galesa Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049738)
https://ecologicalprocesses.springeropen.com/track/pdf/10.1186/s13717-020-00230-z
https://vlibrary.iwmi.org/pdf/H049738.pdf
https://vlibrary.iwmi.org/pdf/H049738.pdf
(1.74 MB) (1.74 MB)
Background: Grazing by livestock and cultivation have been considered as two important causes of soil erosion and nutrient export. However, there has been limited evidence that grazing or cultivation matters to soil erosion and nutrient export in Ethiopia. Hence, this study was conducted in the Galesa watershed in Ethiopia to examine the effects of grazing and cultivation on runoff, soil loss, and nutrient export. Daily values of runoff, soil erosion, and nutrient outflow were measured for three consecutive years following standard procedures. Independent t test was performed to check if the means of runoff, soil loss, and nutrient loss from grazing and cultivated lands were significantly different. Moreover, repeated analysis of variance (ANOVA) was used to test if mean values of runoff, soil loss, and nutrient export varied significantly over the study years.
Results: Although the average annual runoff depth was 7.8% higher in grazing land (GL), soil erosion was significantly lower (39%) in GL as compared to cultivated land (CL). Similarly, sediment and runoff-associated annual losses of total nitrogen (N), available phosphorus (P), exchangeable potassium (K), and organic carbon (OC) were low in the GL treatments. Lowest losses of total N (9.30 kg ha-1 year-1 ), available P (0.83 kg ha-1 year-1 ), and exchangeable K (1.84 kg ha-1 year-1 ) were recorded in GL treatment. Likewise, lowest losses of sediment-associated total N (32.8 kg ha-1 year-1 ), available P (0.39 kg ha-1 year-1 ), exchangeable K (0.23 kg ha-1 year-1 ), and soil organic carbon (630 kg ha-1 year-1 ) were recorded from GL over the 3 years of experimentation.
Conclusion: Our results indicate that cultivation increased soil erosion as compared to grazing. Although there were significant reductions in soil erosion and nutrient export from grazing lands compared with cultivated lands, the absolute losses were still high. This implies the need for grazing land management using appropriate physical and biological erosion control measures to increase productivity and reduce soil erosion as well as nutrient export.
Results: Although the average annual runoff depth was 7.8% higher in grazing land (GL), soil erosion was significantly lower (39%) in GL as compared to cultivated land (CL). Similarly, sediment and runoff-associated annual losses of total nitrogen (N), available phosphorus (P), exchangeable potassium (K), and organic carbon (OC) were low in the GL treatments. Lowest losses of total N (9.30 kg ha-1 year-1 ), available P (0.83 kg ha-1 year-1 ), and exchangeable K (1.84 kg ha-1 year-1 ) were recorded in GL treatment. Likewise, lowest losses of sediment-associated total N (32.8 kg ha-1 year-1 ), available P (0.39 kg ha-1 year-1 ), exchangeable K (0.23 kg ha-1 year-1 ), and soil organic carbon (630 kg ha-1 year-1 ) were recorded from GL over the 3 years of experimentation.
Conclusion: Our results indicate that cultivation increased soil erosion as compared to grazing. Although there were significant reductions in soil erosion and nutrient export from grazing lands compared with cultivated lands, the absolute losses were still high. This implies the need for grazing land management using appropriate physical and biological erosion control measures to increase productivity and reduce soil erosion as well as nutrient export.
9 Zegeye, A. D.; Langendoen, E. J.; Steenhuis, T. S.; Mekuria, Wolde; Tilahun, S. A. 2020. Bank stability and toe erosion model as a decision tool for gully bank stabilization in sub humid Ethiopian highlands. Ecohydrology and Hydrobiology, 20(2):301-311. [doi: https://doi.org/10.1016/j.ecohyd.2020.02.003]
Gully erosion ; Erosion control ; Models ; Soil loss ; Soil stabilization ; Subhumid zones ; Highlands ; Watersheds ; Groundwater table ; Runoff ; Vegetation / Ethiopia / Blue Nile Basin / Debre Mawi Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049936)
(2.29 MB)
Gullies that are expanding at alarming rate are responsible for the majority of soil losses in the (sub) humid highlands of Ethiopia. Few affordable and effective methods for gully erosion control are available in the highlands. The objective of the study was to develop cost-effective measures to halt gully expansion by determining stable-bank conditions under a variety of environmental situations using the Bank Stability and Toe Erosion Model (BSTEM). The study was carried out in the sub humid Debre Mawi watershed, located 30 km south of Lake Tana. Input data for the BSTEM model were collected using field surveys and soil sampling. After the BSTEM was tested on actual measured soil data, soil cohesion and internal friction angle were calibrated against observed gully bank retreat. Using the calibrated parameters, the model evaluated the stabilization of the existing gully bank under different scenarios in which groundwater table, bank angle and bank height, tension crack depth, vegetation, and toe protection were varied. Finally, the head-cut of the study gully was treated based on the model recommendation. The simulated results showed that a 5 m deep gully was stable under fully saturated conditions when the bank toe is protected, its upper surface is vegetated, and its bank angles do not exceed 45°. If the depth of the gully is less than 5 m or if its water table is deeper than 0.5 m, only regrading the gully bank to an angle of 45° can stabilize the gully. BSTEM showed to be an effective tool that can be used to evaluate gully control measures.
10 Bogale, A.; Aynalem, D.; Adem, A.; Mekuria, Wolde; Tilahun, S. 2020. Spatial and temporal variability of soil loss in gully erosion in Upper Blue Nile Basin, Ethiopia. Applied Water Science, 10(5):106. [doi: https://doi.org/10.1007/s13201-020-01193-4]
Gully erosion ; Soil loss ; Soil conservation ; Water conservation ; Spatial variation ; Groundwater assessment ; Groundwater table ; Stream flow ; Sediment ; Watersheds ; Catchment areas ; Highlands / Ethiopia / Upper Blue Nile Basin / Chentale Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049937)
https://link.springer.com/content/pdf/10.1007/s13201-020-01193-4.pdf
https://vlibrary.iwmi.org/pdf/H049937.pdf
https://vlibrary.iwmi.org/pdf/H049937.pdf
(1.63 MB) (1.63 MB)
Gully erosion has many negative impacts on both cultivated and grazing lands in Ethiopian highlands. The present study was conducted in Chentale watershed, Ethiopia, to quantify the contribution of gully erosion, and to assess its temporal changes. Within the Chentale watershed, we selected a sub-watershed (104.6 ha) and nested gully catchment, and gauged for stream flow and sediment concentration data in 2015 and 2016. We measured gully dimensions before and after the onset of the rainy season in 2016 to determine soil loss due to gully erosion. The temporal changes of gully expansion were determined by digitizing gully plain area from Google earth images taken in 2005 and 2013. The results support that gullies were expanding at higher rate in recent years. Area covered by gullies in the watershed increased from 1.84 to 3.43 ha between 2005 and 2013, indicating that the proportion of the watershed covered by gullies was nearly doubled in the investigated period. The estimated soil loss from the main watershed and gullies catchment was 6 and 2 t ha-1 year-1 in 2015, and was 7 and 9 t ha-1 year-1 in 2016, respectively. The results support that gullies were the main contributors of soil erosion in the watershed, and that integrated soil and water conservation measures are required to reduce soil erosion.
11 Girmay, G.; Moges, A.; Muluneh, A. 2020. Estimation of soil loss rate using the USLE [Universal Soil Loss Equation] model for Agewmariayam Watershed, northern Ethiopia. Agriculture and Food Security, 9:9. [doi: https://doi.org/10.1186/s40066-020-00262-w]
Soil loss ; Soil erosion ; Universal Soil Loss Equation ; Models ; Soil conservation ; Risk assessment ; Land use ; Land cover ; Land degradation ; Watersheds ; Farmland ; Rain ; Geographical information systems / Ethiopia / Agewmariayam Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050035)
https://agricultureandfoodsecurity.biomedcentral.com/track/pdf/10.1186/s40066-020-00262-w
https://vlibrary.iwmi.org/pdf/H050035.pdf
https://vlibrary.iwmi.org/pdf/H050035.pdf
(5.16 MB) (5.16 MB)
Background:
Soil erosion and nutrient depletion threaten food security and the sustainability of agricultural production in sub-Saharan Africa. Estimating soil loss and identifying hotspot areas support combating soil degradation. The aim of this paper is to estimate the soil loss rate and identify hotspot areas using USLE model in the Agewmariam watershed, northern Ethiopia.
Methods:
Rainfall erosivity factor was determined from annual rainfall, soil erodibility factor from soil data, slope length and gradient factor were generated from DEM, cover factor and conservation practice factor obtained from land use cover map. Finally, the parameters were integrated with ArcGIS tools to estimate soil loss rates of the study watershed.
Results:
Mean annual soil loss rates were estimated to be between 0 and 897 t ha-1 year-1 on flatter and steeper slopes, respectively. The total annual soil loss was 51,403.13 tons from the watershed and the annual soil loss rate of the study area was 25 t ha-1 year-1. More than 33% of the study areas were above tolerable soil loss rate (11 t ha-1 year-1). The spatial risk categorization rate was 67.2% severe (> 51 t ha-1 year-1), 5.4% very high (31–50 t ha-1 year-1), 5.8% high (19–30 t ha-1 year-1), 3.2% moderate (12–18 t ha-1 year-1) and 18.3% slight (0–11 t ha-1 year-1).
Conclusion:
The results showed that the severity of erosion occurred on the steep slope cultivation, absence of conservation measures, and sparse nature of the vegetation cover. This area required immediate action of soil and water conservation which accounts for about 33.5% of the total watershed.
Soil erosion and nutrient depletion threaten food security and the sustainability of agricultural production in sub-Saharan Africa. Estimating soil loss and identifying hotspot areas support combating soil degradation. The aim of this paper is to estimate the soil loss rate and identify hotspot areas using USLE model in the Agewmariam watershed, northern Ethiopia.
Methods:
Rainfall erosivity factor was determined from annual rainfall, soil erodibility factor from soil data, slope length and gradient factor were generated from DEM, cover factor and conservation practice factor obtained from land use cover map. Finally, the parameters were integrated with ArcGIS tools to estimate soil loss rates of the study watershed.
Results:
Mean annual soil loss rates were estimated to be between 0 and 897 t ha-1 year-1 on flatter and steeper slopes, respectively. The total annual soil loss was 51,403.13 tons from the watershed and the annual soil loss rate of the study area was 25 t ha-1 year-1. More than 33% of the study areas were above tolerable soil loss rate (11 t ha-1 year-1). The spatial risk categorization rate was 67.2% severe (> 51 t ha-1 year-1), 5.4% very high (31–50 t ha-1 year-1), 5.8% high (19–30 t ha-1 year-1), 3.2% moderate (12–18 t ha-1 year-1) and 18.3% slight (0–11 t ha-1 year-1).
Conclusion:
The results showed that the severity of erosion occurred on the steep slope cultivation, absence of conservation measures, and sparse nature of the vegetation cover. This area required immediate action of soil and water conservation which accounts for about 33.5% of the total watershed.
12 Nepal, S.; Tripathi, S.; Adhikari, H. 2021. Geospatial approach to the risk assessment of climate-induced disasters (drought and erosion) and impacts on out-migration in Nepal. International Journal of Disaster Risk Reduction, 59:102241. [doi: https://doi.org/10.1016/j.ijdrr.2021.102241]
Climate change ; Disaster risk reduction ; Risk assessment ; Drought ; Soil erosion ; Vulnerability ; Migration ; Livelihoods ; Agricultural productivity ; Precipitation ; Spatial data ; Models ; Soil loss / Nepal / Ramechhap / Khaniyapani
(Location: IWMI HQ Call no: e-copy only Record No: H050406)
https://www.sciencedirect.com/science/article/pii/S2212420921002077/pdfft?md5=20cd30ca581cd4d6fc055f529d95a60b&pid=1-s2.0-S2212420921002077-main.pdf
https://vlibrary.iwmi.org/pdf/H050406.pdf
https://vlibrary.iwmi.org/pdf/H050406.pdf
(6.86 MB) (6.86 MB)
Out-migration is one of the most recognized adaptation practices when dealing with scarce resources and disasters. With the general objective of exploring migration as an impact of climate-induced disasters, our study was conducted in Khaniyapani, in the Sunapati rural municipality of Ramechhap district, Nepal. Disaster prioritization was conducted using the pair-wise ranking method, with results suggesting that drought and soil erosion are the most severe disasters in the study area. The severity maps were prepared using remotely sensed data. A Normalized Difference Drought Index and the Revised Universal Soil Loss Equation were used to produce the drought and erosion severity maps, respectively. Approximately 46.2% of the total study area was found to experience severe droughts, and almost 10% of the area had high soil erosion rates. In total, 100 out of 794 households were interviewed for a semi-structured questionnaire. Drought severity was found to directly impact livelihoods due to a decline in agricultural productivity, a decline in livestock, and drying of water sources. Out of 100 families, 64 practiced seasonal migration. A decline in agricultural productivity and livestock, and water scarcity were identified as the most influencing push factors. Excessive seasonal migration has reduced the resilience of these families. Drought-resistant land, water, and crop management techniques and practices, and alternative income-generating activities should be promoted to curb the seasonal migration.
13 Desta, G.; Abera, W.; Tamene, L.; Amede, T. 2021. A meta-analysis of the effects of land management practices and land uses on soil loss in Ethiopia. Agriculture, Ecosystems and Environment, 322:107635. (Online first) [doi: https://doi.org/10.1016/j.agee.2021.107635]
Land management ; Land use ; Land cover ; Soil loss ; Soil erosion ; Erosion control ; Environmental factors ; Soil texture ; Land degradation ; Soil conservation ; Slope ; Drainage ; Rain ; Farmland / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H050596)
(1.62 MB)
Over the last three decades, land management practices have been extensively implemented in Ethiopia. Different attempts have been made to assess the effects of land management practices on soil loss at plot scales under a range of climatic and land use conditions. However, the plot-level studies were mostly focused on limited sites and were inadequate to show the effects of land management and land cover practices across a range of practices and under various environmental contexts. A meta-analysis of 82 plot-level experiments in 59 sites was conducted to assessing the effects of land management practices and land use/cover types on soil loss relative to control practice. Random effects were accounted for the association of soil loss and environmental factors including mean annual rainfall, soil texture, and slope length. The results showed that there were significant mean soil loss differences among the categories of land management and land cover practices (p < 0.049). A large amount of residual heterogeneity (I2 = 92%) suggests that the groups of practices are heterogeneous. Mechanical erosion control and agronomic practices with the largest number of studies and somewhat area closure showed large heterogeneity across experiments.The overall mean soil loss ratio of mechanical (0.086, R2 = 81%), agronomic (0.21, R2 = 85%), and area closure (0.09, R2 = 52%) practices were significant to reduce soil loss. There was no residual heterogeneity exhibited across studies for the rest of four groups of practices. The mean soil loss ratio of mechanical practices under non-cropland, annual cropland cover, drainage, and non-cropland cover types were 0.12, 0.14, 0.27, and 0.29, respectively. Yet, with a certain level of inconsistency, the overall effects of all groups of land management and land cover practices were positive. In general, the sensitivity of environmental factors and their magnitude of association with soil loss ratio could imply that the effects of the range of land management practices and land cover types on soil loss are very contextual.
14 Sishu, F. K.; Bekele, A. M.; Schmitter, Petra; Tilahun, S. A.; Steenhuis, T. S. 2021. Phosphorus export from two contrasting rural watersheds in the (sub) humid Ethiopian highlands. Frontiers in Earth Science, 9:762703. [doi: https://doi.org/10.3389/feart.2021.762703]
Highlands ; Phosphorus ; Watersheds ; Rural areas ; Runoff ; Soil loss ; Precipitation ; Discharges ; Land use ; Sediment / Africa South of Sahara / Ethiopia / Dangishta Watershed / Robit Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050851)
https://www.frontiersin.org/articles/10.3389/feart.2021.762703/pdf
https://vlibrary.iwmi.org/pdf/H050851.pdf
https://vlibrary.iwmi.org/pdf/H050851.pdf
(4.00 MB) (4.00 MB)
Establishing worldwide sustainable and phosphorus efficient cropping systems is urgently needed because the supply of suitable phosphate rock is limited, and excess phosphorus in streams causes eutrophication. One of the impediments in the developing world for sustainable P practices is the lack of studies on P transport and its eventual disposition in the environment. One of these regions with few studies is the Ethiopian Highlands, with permeable volcanic soils. The objective was to establish baseline data on P watershed export in the (sub)humid highlands. Two contrasting watersheds were selected near Lake Tana. For 2 years, stream discharge and sediment, total P, dissolved P, and bioavailable particulate P concentrations were determined at the watershed outlet. The first watershed is the 57 km2 Dangishta, with lava intrusion dikes, forcing subsurface flow through faults to the surface and preventing gully formation. Subsurface flow was half of the 1745 mm annual precipitation, and surface runoff and erosion were minimal. The second watershed is the 9 km2 Robit Bata with 1,420 mm precipitation. The banks of several river banks were slumping. The upper part of the watershed generates saturation excess runoff. A hillslope aquifer in the lower part provided interflow. The average sediment concentrations of 10.5 g L-1 in the stream in Robit Bata (11 times that in Dangishta) reflected the sediments from banks slipping in the stream. The hydrology and the soil loss directly affected the phosphorus export. In Dangishta, the total P concentration averaged 0.5 mg L-1 at the outlet. In Robit Bata, the average total P concentration was 2 mg L-1 . The bioavailable particulate P concentration was only twice the concentration in the runoff water. The low phosphorus content of the subsoil slipping in Robit Bata moderated biologically available particulate P at the outlet. Average dissolved P concentrations for both watersheds were around 0.1 mg L-1 in the low range found in temperate climates. It reflects the difference in length of time that phosphorus fertilizers have been applied. Our research concludes that commonly implemented practices such as strengthening river banks and stabilizing gully might not lead to improved water quality in Lake Tana.
15 Umugwaneza, A.; Chen, X.; Liu, T.; Mind’je, R.; Uwineza, A.; Kayumba, P. M.; Uwamahoro, S.; Umuhoza, J.; Gasirabo, A.; Maniraho, A. P. 2022. Integrating a GIS-based approach and a SWAT model to identify potential suitable sites for rainwater harvesting in Rwanda. AQUA - Water Infrastructure, Ecosystems and Society, 71(3):415-432. [doi: https://doi.org/10.2166/aqua.2022.111]
Rainwater harvesting ; Geographical information systems ; Catchment areas ; Decision making ; Infrastructure ; Ponds ; Dams ; Runoff ; Sediment yield ; Soil erosion ; Soil loss ; Climate change ; Land cover ; Land use ; Models ; Calibration / Rwanda / Nyabugogo Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050951)
https://iwaponline.com/aqua/article-pdf/71/3/415/1026940/jws0710415.pdf
https://vlibrary.iwmi.org/pdf/H050951.pdf
https://vlibrary.iwmi.org/pdf/H050951.pdf
(1.13 MB) (1.13 MB)
The increasing demand of water results in the overexploitation of water resources. This situation calls for more effective water management alternatives including rainwater harvesting (RWH) systems. Due to the lack of biophysical data and infrastructure, the identification of suitable sites for various RWH systems is a challenging issue. However, integrating geospatial analysis and modeling approaches has become a promising tool to identify suitable sites for RWH. Thus, this study aimed at identifying suitable sites for RWH in the Nyabugogo catchment located in Rwanda by integrating a geo-information-based multi-criteria decision-making (MCDM) and SWAT (Soil and Water Assessment Tool) model. Moreover, the sediment yield was compared to the soil erosion evaluated using the Revised Universal Soil Loss Equation (RUSLE) owing to the lack of sediment concentration measured data. The results revealed that about 4.8 and 16.35% of the study area are classified as highly suitable and suitable areas for RWH, respectively. Around 6% of the study area (98.5 km2) was found to be suitable for farm ponds, whereas 1.6% (26.1 km2) suitable for check dams, and 25.9% (423 km2) suitable for bench terraces. Among 50 proposed sites for the RWH structures, 29 are located in the most suitable area for RWH. The results implicated that the surface runoff, sediment yield, and topography are essential factors in identifying the suitability of RWH areas. It is concluded that the integrated geospatial and MCDM techniques provide a useful and efficient method for planning RWH at a basin scale in the study area.
16 Fenta, H. M.; Aynalem, D. W.; Malmquist, L.; Haileslassie, Amare; Tilahun, Seifu A.; Barron, J.; Adem, A. A.; Adimassu, Z.; Zimale, F. A.; Steenhuis, T. S. 2024. A critical analysis of soil (and water) conservation practices in the Ethiopian Highlands: implications for future research and modeling. Catena, 234:107539. [doi: https://doi.org/10.1016/j.catena.2023.107539]
Soil conservation ; Water conservation ; Highlands ; Soil loss ; Erosion ; Sediment ; Ecosystem services ; Environmental monitoring ; Land use ; Crop yield ; Modelling / Africa / Ethiopia / Ethiopian Highlands
(Location: IWMI HQ Call no: e-copy only Record No: H052323)
(8.68 MB)
Soil and water conservation have been traditionally part of farming practices for thousands of years. Despite massive efforts to implement modern soil and water conservation practices (SWCPs) in the Ethiopian Highlands, soil erosion increased after the 1970s when social and political events led to a remarkable change in land use. This review aims to critically analyze the impact of conservation practices on soil loss and crop yield and highlight research and modeling gaps. In doing so, 120 published articles on experimental and simulated soil losses in the Ethiopian Highlands were retrieved from the refereed literature. We found that most published experimental studies evaluating SWCPs lasted less than five years in areas of less than 100 ha. Most modeling studies were over short periods, too; some models simulated soil loss over large areas. The literature analysis for these short-term experimental studies showed that SWCP decreased soil loss on individual sites and increased crop yield in semi-arid regions. Simulated sediment concentration increased as a function of watershed size, while observed soil losses did not follow this trend. Moreover, the decrease in soil loss due to the soil and water conservation practices on small plots was also greatly overestimated. Consequently, past research and current modeling techniques are inconclusive on the effectiveness of SWCPs in large catchments over periods exceeding five years and those with active gullies. Additional long-term experimental studies in catchments are required to evaluate whether SWCPs can decrease sediment loads.
17 Tullu, K. T. 2024. Assessment of soil erosion response to climate change in the Sululta Catchment, Abbay Basin, Ethiopia. H2Open Journal, 7(1):23-37. [doi: https://doi.org/10.2166/h2oj.2023.083]
Climate change ; Climate models ; Erosion ; Soil loss ; Assessment ; Geographical information systems ; Rainfall ; Runoff ; Land use ; Precipitation ; Farmland ; Grasslands ; Woodlands / Ethiopia / Addis Ababa / Abbay Basin / Sululta Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H052621)
https://iwaponline.com/h2open/article-pdf/7/1/23/1363084/h2oj0070023.pdf
https://vlibrary.iwmi.org/pdf/H052621.pdf
https://vlibrary.iwmi.org/pdf/H052621.pdf
(1.10 MB) (1.10 MB)
This study aimed to assess the response of soil erosion to climate change in the Sululta catchment using the Revised Universal Soil Loss Equation (RUSLE) integrated with the geographic information system (GIS). The current rainfall erosivity factor (R) was computed from the current rainfall data (1989–2018). Regional climate models (RCMs) under representative concentration pathways RCP4.5 and RCP8.5 were used for future rainfall projection (2021–2080) to determine projected rainfall R factor. Rainfall data, soil map, digital elevation model and land use/land cover data were used to evaluate RUSLE factors in the ArcGIS environment. The results of this study showed that the current average annual soil loss rate was found to be 5.03 tons/ha/year. The average annual soil loss may decrease by 2.78 and 0.80% in 2021–2050 and 2051–2080, respectively, under the RCP4.5 scenario compared to the current average annual soil loss. Under the RCP8.5 scenario, the average annual soil loss may increase by 7.75 and 2.98% in 2021–2050 and 2051–2080, respectively, from the current average annual soil loss. The result reveals that the average annual soil loss decreases in both time periods under RCP4.5 and increases in both time periods under RCP8.5.
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