Your search found 7 records
1 Mekuria, Wolde; Langan, Simon; Johnston, Robyn; Belay, B.; Amare, D.; Gashaw, T.; Desta, G.; Noble, Andrew; Wale, A. 2015. Restoring aboveground carbon and biodiversity: a case study from the Nile Basin, Ethiopia. Forest Science and Technology, 11(2):86-96. [doi: https://doi.org/10.1080/21580103.2014.966862]
Aerial parts ; Carbon sequestration ; Biomass ; Organic fertilizers ; Biodiversity ; Nile basin ; Ecosystem services ; Environmental degradation ; Plants ; Species ; Watersheds ; Vegetation ; Land degradation ; Land management ; Grazing lands ; Households ; Local communities ; Crop production ; Erosion ; Government agencies ; Non governmental organizations ; Case studies / Ethiopia / Nile Basin / Gomit Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H046886)
(0.43 MB)
In Ethiopia, exclosures in landscapes have become increasingly important to improving ecosystem services and reversing biodiversity losses. The present study was conducted in Gomit watershed, northern Ethiopia, to: (i) investigate the changes in vegetation composition, diversity and aboveground biomass and carbon following the establishment of exclosures; and (ii) analyse the economic returns of aboveground carbon sequestration and assess the perception of local communities on land degradation and exclosures. A space-for-time substitution approach was used to detect the changes in aboveground carbon, species composition, and diversity. Exclosures of 1-, 2-, 3-, 4-, 5-, and 7-years-old and a communal grazing land were selected. Household surveys, key informant interviews, and a financial analysis were used to assess the perception of local communities and the value of exclosure impacts, respectively. Significant (P = 0.049) differences in species diversity and considerable increases in aboveground carbon (ranged from 0.6 to 4.2 t C ha-1), CO2 storage (varied between 2.1 and 15.3 t CO2 ha-1), woody species composition, and richness (ranged from five to 28) were observed following the establishment of exclosures. Exclosures generated temporary certified emission reductions (tCER) of 3.4, 2.1, 7.5, 12.6, 12.5, and 15.3 Mg CO2 ha-1 after 1, 2, 3, 4, 5, and 7 years, respectively. The net present value (NPV) of the aboveground carbon sequestered in exclosures ranged from US$6.6 to US$37.0 per hectare and increased with exclosure duration. At a watershed level, 51.4 Mg C ha-1 can be sequestered, which represents 188.6 Mg CO2 ha-1, resulting in tCER of 139.4 Mg CO2 ha-1 and NPV of US$478.3 per hectare. This result would suggest that exclosures can potentially improve local communities’ livelihoods beyond rehabilitating degraded lands if carbon stored in exclosures is traded. Communities in the watershed demonstrated that exclosures are effective in restoring degraded lands and they are benefiting from increased fodder production and reduced impacts of soil erosion. However, the respondents are also concerned over the sustainability of exclosure land management, as further expansion of exclosures aggravates degradation of remaining communal grazing lands and causes fuel wood shortages. This suggests that the sustainability of exclosure land management can be attained only if these critical concerns are addressed by a joint effort among government agencies, nongovernmental organizations, and communities.
2 Gashaw, T.; Tulu, T.; Argaw, M.; Worqlul, A. W.; Tolessa, T.; Kindu, M. 2018. Estimating the impacts of land use/land cover changes on ecosystem service values: the case of the Andassa Watershed in the Upper Blue Nile Basin of Ethiopia. Ecosystem Services, 31(Part A):219-228. [doi: https://doi.org/10.1016/j.ecoser.2018.05.001]
Ecosystem services ; Economic value ; Land use ; Land cover change ; Estimation ; Watersheds ; Cultivated land ; Forest land ; Scrublands ; Grasslands ; River basins ; Models / Ethiopia / Upper Blue Nile Basin / Andassa Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H048818)
(1.40 MB)
Estimating the impacts of land use/land cover (LULC) changes in Ecosystem Service Values (ESV) is indispensable to provide public awareness about the status of ESV, and to help in policy-making processes. This study was intended to estimate the impacts of LULC changes on ESV in the Andassa watershed of the Upper Blue Nile basin over the last three decades (1985–2015), and to predict the ESV changes in 2045. The hybrid land use classification technique for classifying Landsat images, the Cellular-Automata Markov (CA-Markov) model for LULC prediction, and the modified ecosystem service value coefficients for estimating ESV were employed. Our findings revealed that there was a continues expansions of cultivated land and built-up area, and withdrawing of forest, shrubland and grassland during the 1985–2015 periods, which are expected to continue for the next three decades. Consequently, the total ESV of the watershed has declined from US$26.83 106 in 1985 to US$22.58 106 in 2000 and to US $21.00 106 in 2015 and is expected to further reduce to US$17.94 106 in 2030 and to US$15.25 106 in 2045. The impacts of LULC changes on the specific ecosystem services are also tremendous.
3 Wubaye, G. B.; Gashaw, T.; Worqlul, A. W.; Dile, Y. T.; Taye, Meron Teferi; Haileslassie, Amare; Zaitchik, B.; Birhan, D. A.; Adgo, E.; Mohammed, J. A.; Lebeza, T. M.; Bantider, A.; Seid, Abdulkarim; Srinivasan, R. 2023. Trends in rainfall and temperature extremes in Ethiopia: station and agro-ecological zone levels of analysis. Atmosphere, 14(3):483. (Special issue: Water Management and Crop Production in the Face of Climate Change) [doi: https://doi.org/10.3390/atmos14030483]
Extreme weather events ; Rainfall ; Temperature ; Trends ; Meteorological stations ; Agroecological zones ; Climate change adaptation ; Precipitation ; Spatial distribution ; Time series analysis / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H051768)
https://www.mdpi.com/2073-4433/14/3/483/pdf?version=1678174504
https://vlibrary.iwmi.org/pdf/H051768.pdf
https://vlibrary.iwmi.org/pdf/H051768.pdf
(9.01 MB) (9.01 MB)
Climate extreme events have been observed more frequently since the 1970s throughout Ethiopia, which adversely affects the socio-economic development of the country, as its economy depends on agriculture, which, in turn, relies heavily on annual and seasonal rainfall. Climate extremes studies conducted in Ethiopia are mainly limited to a specific location or watershed, making it difficult to have insights at the national level. The present study thus aims to examine the observed climate extreme events in Ethiopia at both station and agro-ecological zone (AEZ) levels. Daily rainfall and temperature data for 47 and 37 stations, respectively (1986 up to 2020), were obtained from the National Meteorology Agency (NMA). The Modified Mann–Kendall (MMK) trend test and the Theil–Sen slope estimator were employed to estimate the trends in rainfall and temperature extremes. This study examines trends of 13 temperature and 10 rainfall extreme indices using RClimDex in R software. The results revealed that most of the extreme rainfall indices showed a positive trend in the majority of the climate stations. For example, an increase in consecutive dry days (CDD), very heavy rainfall days (R20), number of heavy rainfall days (R10) and consecutive wet days (CWD) were exhibited in most climate stations. In relation to AEZs, the greater number of extreme rainfall indices illustrated an upward trend in cool and sub-humid, cool and humid, and cool and moist AEZs, a declining trend in hot arid AEZ, and equal proportions of increasing and decreasing trends in warm semi-arid AEZs. Concerning extreme temperature indices, the result indicated an increasing trend of warm temperature extreme indices and a downward trend of cold temperature extreme indices in most of the climate stations, indicating the overall warming and dryness trends in the country. With reference to AEZs, an overall warming was exhibited in all AEZs, except in the hot arid AEZ. The observed trends in the rainfall and temperature extremes will have tremendous direct and indirect impacts on agriculture, water resources, health, and other sectors in the country. Therefore, the findings suggest the need for identifying and developing climate change adaptation strategies to minimize the ill effects of these extreme climate events on the social, economic, and developmental sectors.
4 Gashaw, T.; Worqlul, A. W.; Lakew, Haileyesus; Taye, Meron Teferi; Seid, Abdulkarim; Haileslassie, Amare. 2023. Evaluations of satellite/reanalysis rainfall and temperature products in the Bale Eco-Region (southern Ethiopia) to enhance the quality of input data for hydro-climate studies. Remote Sensing Applications: Society and Environment, 31:100994. [doi: https://doi.org/10.1016/j.rsase.2023.100994]
Rainfall ; Temperature ; Models ; Evaluation ; Satellite observation ; Hydroclimate ; Precipitation ; Agroecological zones ; Meteorological stations ; Estimation / Ethiopia / Bale Eco-Region
(Location: IWMI HQ Call no: e-copy only Record No: H051974)
(7.50 MB)
The sparse distribution and lack of meteorological stations due to deficit infrastructure in developing countries is one of the limiting factors for hydro-climate studies, and dependency on globally available data is often prone to various level of errors. Thus, this study aimed to evaluate the performance of satellite/reanalysis rainfall and temperature products in the Bale Eco-Region (BER) in Southern Ethiopia. This study evaluated performances of three rainfall products such as the Climate Hazards Group Infrared Precipitation with Stations, version 2.0 (CHIRPS v2.0), Tropical Applications of Meteorology using SATellite and ground-based observations, version 3.1 (TAMSAT v3.1) and Multi-Source Weighted-Ensemble Precipitation, version 2.8 (MSWEP v2.8). The two temperature products evaluated in this study are ERA5 and Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA v2). Evaluations of these satellite/reanalysis rainfall and temperature products were undertaken against observed data (1995–2014) in temperate, sub-tropical and tropical agro-ecological zones (AEZs) across multiple temporal scales ranging from the daily to annual. For assessing the performances of satellite/reanalysis rainfall and temperature products, a point-pixel evaluation approach was undertaken using five continuous evaluation scores such as correlation coefficient (R), mean absolute error (MAE), root mean square error (RMSE), percent bias (PBIAS) and Kling–Gupta efficiency (KGE). Categorical sores such as Probability of Detection (POD), False Alarm Ratio (FAR) and Frequency Bias Index (FBI) were also used for assessing the rainfall products. The findings revealed that MSWEP v2.8 has better performance than CHIRPS v2.0 and TAMSAT v3.1 in temperate and tropical AEZs at the daily, dry season and annual time steps as well as in sub-tropical AEZ in dry season and annual temporal periods, but MSWEP v2.8 displayed comparable performance with TAMSAT v3.1 in the daily time step. CHIRPS v2.0 exhibit superior performance in the monthly time scale in the three AEZs as well as in the wet season in temperate and tropical AEZs, but TAMSAT v3.1 has outperformed than CHIRPS v2.0 in the wet season in sub-tropical AEZ. The finding also indicated that the capability of MSWEP v2.8 to detect the rainy days (79–86%) and frequency of rainy days (0.99–1.79) is better than CHIRPS v2.0 and TAMSAT v3.1, but TAMSAT v3.1 has shown the best performance for identifying the non-rainy days (14–38%) than MSWEP v2.8 and CHIRPS v2.0. With regard to temperature, MERRA v2 outperformed over ERA5 in temperate and tropical AEZs for estimating both maximum and minimum temperatures from the daily to annual time scales, but ERA5 has shown superior performance than MERRA v2 in the sub-tropical AEZ. In view of the finding, we concluded that the best performing rainfall and temperature products for each AEZ can be used for data scarce regions such as the BER. The findings of this study provide important insights about the need to identify best performing rainfall and temperature products for different AEZs to enhance the quality of hydro-climate study outputs in the decision-making process.
5 Aniley, E.; Gashaw, T.; Abraham, T.; Demessie, S. F.; Bayabil, H. K.; Worqlul, A. W.; van Oel, P. R.; Dile, Y. T.; Chukalla, A. D.; Haileslassie, Amare; Wubaye, G. B. 2023. Evaluating the performances of gridded satellite/reanalysis products in representing the rainfall climatology of Ethiopia. Geocarto International, 38(1):2278329. [doi: https://doi.org/10.1080/10106049.2023.2278329]
Rainfall ; Datasets ; Weather data ; Performance assessment ; Climatology ; Satellite observation ; Agroecological zones ; Precipitation / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H052402)
https://www.tandfonline.com/doi/epdf/10.1080/10106049.2023.2278329?needAccess=true
https://vlibrary.iwmi.org/pdf/H052402.pdf
https://vlibrary.iwmi.org/pdf/H052402.pdf
(3.33 MB) (3.33 MB)
This study evaluated performances of the Climate Hazard Group Infrared Precipitation with stations version 2.0 (CHIRPS v2.0) and Multi-Source Weighted-Ensemble Precipitation version 2.8 (MSWEP v2.8) products against observed data. Rainfall climatology was simulated for different agro-ecological zones (AEZs) of Ethiopia during 1991–2020 at different temporal scales. Performance evaluations were made using continuous and statistical performance measures as well as Probability Density Function (PDF). CHIRPS v2.0 for estimating monthly, seasonal, and annual rainfall totals, and MSWEP v2.8 for daily rainfall have shown better performance over all AEZs. The two products display comparable performance for detecting daily rainfall occurrences over alpine AEZ, but MSWEP v2.8 is superior in the rest four AEZs. CHIRPS v2.0 outperforms MSWEP v2.8 for detecting most of the daily rainfall intensity classes over all AEZs. The findings will play a noteworthy role to improve the quality of hydro-climate studies in Ethiopia.
6 Gashaw, T.; Wubaye, G. B.; Worqlul, A. W.; Dile, Y. T.; Mohammed, J. A.; Birhan, D. A.; Tefera, G. W.; van Oel, P. R.; Haileslassie, Amare; Chukalla, A. D.; Taye, Meron Teferi; Bayabil, H. K.; Zaitchik, B.; Srinivasan, R.; Senamaw, A.; Bantider, A.; Adgo, E.; Seid, Abdulkarim. 2023. Local and regional climate trends and variabilities in Ethiopia: implications for climate change adaptations. Environmental Challenges, 13:100794. [doi: https://doi.org/10.1016/j.envc.2023.100794]
Climate change adaptation ; Climate variability ; Trends ; Strategies ; Rainfall ; Temperature ; Agroecological zones ; Meteorological stations ; Spatial distribution / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H052409)
https://www.sciencedirect.com/science/article/pii/S2667010023001178/pdfft?md5=7a942050dc761a0e0ab04c909ca6637b&pid=1-s2.0-S2667010023001178-main.pdf
https://vlibrary.iwmi.org/pdf/H052409.pdf
https://vlibrary.iwmi.org/pdf/H052409.pdf
(4.10 MB) (4.10 MB)
Ethiopia is experiencing considerable impact of climate change and variability in the last five decades. Analyzing climate trends and variability is essential to develop effective adaptation strategies, particularly for countries vulnerable to climate change. This study analyzed trends and variabilities of climate (rainfall, maximum temperature (Tmax), and minimum temperature (Tmin)) at local and regional scales in Ethiopia. The local analysis was carried out considering each meteorological station, while the regional analyses were based on agroecological zones (AEZs). This study used observations from 47 rainfall and 37 temperature stations obtained from the Ethiopian Meteorological Institute (EMI) for the period of 1986 to 2020. The Modified Mann-Kendall (MMK) trend test and Theil Sen’s slope estimator were used to analyze the trends and magnitudes of change, respectively, in rainfall as well as temperature. The coefficient of variation (CV) and standardized anomaly index (SAI) were also employed to evaluate rainfall and temperature variabilities. The local level analysis revealed that Bega (dry season), Kiremt (main rainy season), and annual rainfall showed increasing trend, albeit no significant, in most stations, but the rainfall in Belg (small rainy) season showed a non-significant decreasing trend. The regional levels analysis also indicated an increasing trend of Bega, Kiremt, and annual rainfall in most AEZs, while Belg rainfall showed a decreasing trend in the greater number of AEZs. The result of both local and regional levels of analysis discerned a spatially and temporally more homogeneous warming trend. Both Tmax and Tmin revealed an increasing trend in annual and seasonal scales at most meteorological stations. Likewise, an increase was recorded for mean Tmax and Tmin in entire/most AEZs. The observed trends and variabilities of rainfall and temperature have several implications for climate change adaptations. For example, the decrease in Belg rainfall in most AEZs would have a negative impact on areas that heavily depend on Belg season’s rainfall for crop production. Some climate adaptation options include identifying short maturing crop varieties, soil moisture conservation, and supplemental irrigation of crops using harvested water during the main rainy season. Conversely, since the first three months of Bega season (October to December) are crop harvest season in most parts of Ethiopia, the increase in Bega rainfall would increase crop harvest loss, and hence, early planting date and identifying short maturing crops during the main rainy season are some climate adaptation strategies. Because of the increase in temperature, water demand for irrigation during Bega season will increase due to increased evapotranspiration. On the other hand, the increase in Kiremt rainfall can be harvested and used for supplemental irrigation during Bega as well as the small rainy season, particularly for early planting. In view of these findings, it is imperative to develop and implement effective climate-smart agricultural strategies specific to each agro-ecological zone (AEZ) to adapt to rainfall and temperature changes and variabilities.
7 Adem, A. A.; Wassie, T. M.; Gashaw, T.; Tilahun, Seifu A. 2024. Evaluation of exclosures in restoring degraded landscapes in the semi-arid highlands of northwestern Ethiopia. Catena, 237:107826. [doi: https://doi.org/10.1016/j.catena.2024.107826]
(Location: IWMI HQ Call no: e-copy only Record No: H052560)
(9.38 MB)
Land degradation is a severe environmental problem in the northern and northwestern Ethiopian highlands. As a response to increasing land degradation, rehabilitation of degraded grazing lands through exclosures (exclusion of farmers and domestic animals) has been undertaken. This study aimed to evaluate the effectiveness of 11 and 8-year exclosures in improving degraded landscapes in the Karita-Wuha and Dengora watersheds. It was assumed that the conditions on communal grazing lands at the time of the investigation corresponded to those at the establishment of exclosures. Vegetation was inventoried, and soil samples were collected and analyzed in 14 and 21 sampling sites selected from exclosures and communal grazing lands in Dengora and Karita-Wuha watersheds, respectively. Sampling plots (20 × 20 m) were established for soil sampling. In the two land uses, 10x10 m and 5x5 m sub-plots were used to survey trees and bushes/shrubs, respectively. Richness, diversity, evenness, and aboveground biomass (AGB) were evaluated using measurements from the vegetation inventory. Organic carbon (OC), total nitrogen (TN), and available phosphorus (AP) and their stocks were used as soil nutrient indicators. The result showed that exclosures aided in restoring vegetation in both watersheds and soil nutrient parameters in the Dengora watershed compared with communal grazing lands. In the Karita-Wuha watershed, there was significantly higher OC, TN, and their stocks in communal grazing land than exclosures (t-test, p < 0.05). These results are generally attributed to the fact that communal grazing lands were significantly degraded before exclosure and have yet to recover. As a result, exclosures of Dengora and Karita-Wuha watersheds were limited in restoring degraded landscapes. There have been differences in the effectiveness of < 11- and > 11-year exclosures in restoring degraded landscapes in the literature. The effectiveness of various aged exclosures in restoring degraded landscapes is likely variable and dependent on local biophysical parameters and land use systems.
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