The objective of this study is to investigate and perform long–term forecasting of both streamflo... more The objective of this study is to investigate and perform long–term forecasting of both streamflow and hydrological drought over Ethiopia. Observed streamflow and precipitation data are collected from 17 streamflow stations and 34 rainfall gauge stations to forecast future streamflow and hydrological drought from 2026 to 2099. Streamflow forecasting is performed using an artificial neural network (ANN) in conjunction with python software. Observed precipitation and streamflow data from 1973 to 2014 are used to train and test the ANN model by 70 and 30% ratios, respectively. After training the model, future downscaled precipitation data from regional climate models (RCM) have been used as input data to forecast future streamflow. Three RCM models were used to downscale historical and future climate data. RACMO is found a good downscaling model for all selected stations. The linear scaling bias correction technique results in less than 2% error compared to other alternative techniques. The result indicates that ANN is a good tool to forecast streamflow in areas having a good correlation between precipitation and streamflow such as Abbay, Awash, Baro, Omo Gibe, and Tekeze river basins. But in arid areas for example Genale Dawa, Wabishebele, and Rift Valley basins, the model is not suitable because the input data (precipitation) have high variation than the output variable (streamflow). In such areas, meteorological drought analysis and forecasting are better than hydrological drought analysis. Finally, future hydrological drought is analyzed using forecasted streamflow data as input to the streamflow drought index (SDI). The result indicates that 2028, 2036, 2042, 2044, 2062, and 2063 are the expected extreme drought years in most river basins of Ethiopia in the future. This shows that at least one extreme drought is expected in each decade in the future. Therefore, extensive research in drought analysis and forecasting is needed to develop an effective drought early warning system, and water resource management policy.
Drought is a complex natural disaster unlike flood, which covers a large area when it occurred. T... more Drought is a complex natural disaster unlike flood, which covers a large area when it occurred. This review was conducted on hydrological drought analysis and monitoring status in Ethiopia by reviewing the master plan of eight major river basins and previous research related to drought. A total of 24 article papers was reviewed and it is found that hydrological drought analysis studies cover only 8.33% of all of the river basins in Ethiopia. Researchers in the region have focused primarily on meteorological drought (37.5%) rather than hydrological and agricultural drought analysis. Although Ethiopia has long been dependent on rainfed agriculture for its economy and remains the primary livelihood of the population, the Ethiopian government has begun focusing on transitioning to an industrial economy, placing pressure on the water resource. In a region plagued by drought, drought analysis, and monitoring, drought early warning systems and effective mitigation measures are still limite...
The objective of this study is to investigate and perform long–term forecasting of both streamflo... more The objective of this study is to investigate and perform long–term forecasting of both streamflow and hydrological drought over Ethiopia. Observed streamflow and precipitation data are collected from 17 streamflow stations and 34 rainfall gauge stations to forecast future streamflow and hydrological drought from 2026 to 2099. Streamflow forecasting is performed using an artificial neural network (ANN) in conjunction with python software. Observed precipitation and streamflow data from 1973 to 2014 are used to train and test the ANN model by 70 and 30% ratios, respectively. After training the model, future downscaled precipitation data from regional climate models (RCM) have been used as input data to forecast future streamflow. Three RCM models were used to downscale historical and future climate data. RACMO is found a good downscaling model for all selected stations. The linear scaling bias correction technique results in less than 2% error compared to other alternative techniques. The result indicates that ANN is a good tool to forecast streamflow in areas having a good correlation between precipitation and streamflow such as Abbay, Awash, Baro, Omo Gibe, and Tekeze river basins. But in arid areas for example Genale Dawa, Wabishebele, and Rift Valley basins, the model is not suitable because the input data (precipitation) have high variation than the output variable (streamflow). In such areas, meteorological drought analysis and forecasting are better than hydrological drought analysis. Finally, future hydrological drought is analyzed using forecasted streamflow data as input to the streamflow drought index (SDI). The result indicates that 2028, 2036, 2042, 2044, 2062, and 2063 are the expected extreme drought years in most river basins of Ethiopia in the future. This shows that at least one extreme drought is expected in each decade in the future. Therefore, extensive research in drought analysis and forecasting is needed to develop an effective drought early warning system, and water resource management policy.
Drought is a complex natural disaster unlike flood, which covers a large area when it occurred. T... more Drought is a complex natural disaster unlike flood, which covers a large area when it occurred. This review was conducted on hydrological drought analysis and monitoring status in Ethiopia by reviewing the master plan of eight major river basins and previous research related to drought. A total of 24 article papers was reviewed and it is found that hydrological drought analysis studies cover only 8.33% of all of the river basins in Ethiopia. Researchers in the region have focused primarily on meteorological drought (37.5%) rather than hydrological and agricultural drought analysis. Although Ethiopia has long been dependent on rainfed agriculture for its economy and remains the primary livelihood of the population, the Ethiopian government has begun focusing on transitioning to an industrial economy, placing pressure on the water resource. In a region plagued by drought, drought analysis, and monitoring, drought early warning systems and effective mitigation measures are still limite...
Uploads
Papers by Admasu Gebeyehu