Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, Ethiopia
ABSTRACTModelling climate change impact is very important to reduce the crisis behind food security, drought, and loss of energy sectors. The impact on streamflow and hydrological components due to climate change was aimed to investigate by the SWAT model for this study. Two regional climate models...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2023-12-01
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| Series: | Water Science |
| Subjects: | |
| Online Access: | https://www.tandfonline.com/doi/10.1080/23570008.2023.2235161 |
| _version_ | 1797387108048961536 |
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| author | Bekan Chelkeba Fekadu Fufa Feyessa Wakjira Takala Dibaba |
| author_facet | Bekan Chelkeba Fekadu Fufa Feyessa Wakjira Takala Dibaba |
| author_sort | Bekan Chelkeba |
| collection | DOAJ |
| description | ABSTRACTModelling climate change impact is very important to reduce the crisis behind food security, drought, and loss of energy sectors. The impact on streamflow and hydrological components due to climate change was aimed to investigate by the SWAT model for this study. Two regional climate models (RCM) were selected according to their performance to calibrate and validate the streamflow. The Regional Climate Models’ performance in simulation of flow and the hydrological cycle was evaluated by statistical performance criteria. Digital elevation model (DEM), land use land cover and soil map, and streamflow data were collected and used as raw input for the model. Bias correction was made by using power transformation and variance scaling method for RCM against observed data. The result simulated with RACMO22T was best with (PBIAS = 0.23, NSE = 0.84, R2 = 0.79) for calibration, (PBIAS = 0.11, NSE = 0.88, R2 = 0.81) for validation. RCA4 model underperformed in simulating streamflow compared to RACMO22T with (PBIAS = 0.28, NSE = 0.78, R2 = 0.74) and (PBIAS = 0.18, NSE = 0.85, R2 = 0.78) for calibration and validation of the models respectively. The streamflow was projected and shows a slightly increasing trend respectively with 13.8 and 21.3 % for the 2030s and 2050s simulation years. But in the 2080s simulation periods, the simulated streamflow indicates a decreasing trend under representative concentration pathways (RCP4.5) by 12.5%. The overall result indicates both streamflow and runoff show a decreasing pattern in the end of this century under both scenarios. The spatial variability of hydrological components which contributes to streamflow was dependent on the subbasin characteristics. Furthermore, the simulated groundwater recharge (GW_Q), rainfall, water yields (WYLD), surface runoff (SUR_Q) and evapotranspiration (ET) were decreased by 4%, 17.7%, 20.8%, 27.7%, and 8.6% respectively for the baseline period. |
| first_indexed | 2024-03-08T22:19:08Z |
| format | Article |
| id | doaj.art-3bc971d993f14cc4ad0cda9f24a04b99 |
| institution | Directory Open Access Journal |
| issn | 2357-0008 |
| language | English |
| last_indexed | 2024-03-08T22:19:08Z |
| publishDate | 2023-12-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Water Science |
| spelling | doaj.art-3bc971d993f14cc4ad0cda9f24a04b992023-12-18T14:48:18ZengTaylor & Francis GroupWater Science2357-00082023-12-0137117919710.1080/23570008.2023.2235161Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, EthiopiaBekan Chelkeba0Fekadu Fufa Feyessa1Wakjira Takala Dibaba2Faculty of Civil and Environmental Engineering, Jimma University Institute of Technology, Jimma, EthiopiaFaculty of Civil and Environmental Engineering, Jimma University Institute of Technology, Jimma, EthiopiaFaculty of Civil and Environmental Engineering, Jimma University Institute of Technology, Jimma, EthiopiaABSTRACTModelling climate change impact is very important to reduce the crisis behind food security, drought, and loss of energy sectors. The impact on streamflow and hydrological components due to climate change was aimed to investigate by the SWAT model for this study. Two regional climate models (RCM) were selected according to their performance to calibrate and validate the streamflow. The Regional Climate Models’ performance in simulation of flow and the hydrological cycle was evaluated by statistical performance criteria. Digital elevation model (DEM), land use land cover and soil map, and streamflow data were collected and used as raw input for the model. Bias correction was made by using power transformation and variance scaling method for RCM against observed data. The result simulated with RACMO22T was best with (PBIAS = 0.23, NSE = 0.84, R2 = 0.79) for calibration, (PBIAS = 0.11, NSE = 0.88, R2 = 0.81) for validation. RCA4 model underperformed in simulating streamflow compared to RACMO22T with (PBIAS = 0.28, NSE = 0.78, R2 = 0.74) and (PBIAS = 0.18, NSE = 0.85, R2 = 0.78) for calibration and validation of the models respectively. The streamflow was projected and shows a slightly increasing trend respectively with 13.8 and 21.3 % for the 2030s and 2050s simulation years. But in the 2080s simulation periods, the simulated streamflow indicates a decreasing trend under representative concentration pathways (RCP4.5) by 12.5%. The overall result indicates both streamflow and runoff show a decreasing pattern in the end of this century under both scenarios. The spatial variability of hydrological components which contributes to streamflow was dependent on the subbasin characteristics. Furthermore, the simulated groundwater recharge (GW_Q), rainfall, water yields (WYLD), surface runoff (SUR_Q) and evapotranspiration (ET) were decreased by 4%, 17.7%, 20.8%, 27.7%, and 8.6% respectively for the baseline period.https://www.tandfonline.com/doi/10.1080/23570008.2023.2235161Bias correctionclimate changeRCMspatial variabilitySWAT model |
| spellingShingle | Bekan Chelkeba Fekadu Fufa Feyessa Wakjira Takala Dibaba Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, Ethiopia Water Science Bias correction climate change RCM spatial variability SWAT model |
| title | Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, Ethiopia |
| title_full | Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, Ethiopia |
| title_fullStr | Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, Ethiopia |
| title_full_unstemmed | Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, Ethiopia |
| title_short | Climate change in the upper Awash subbasin and its possible impacts on the stream flow, Oromiyaa, Ethiopia |
| title_sort | climate change in the upper awash subbasin and its possible impacts on the stream flow oromiyaa ethiopia |
| topic | Bias correction climate change RCM spatial variability SWAT model |
| url | https://www.tandfonline.com/doi/10.1080/23570008.2023.2235161 |
| work_keys_str_mv | AT bekanchelkeba climatechangeintheupperawashsubbasinanditspossibleimpactsonthestreamfloworomiyaaethiopia AT fekadufufafeyessa climatechangeintheupperawashsubbasinanditspossibleimpactsonthestreamfloworomiyaaethiopia AT wakjiratakaladibaba climatechangeintheupperawashsubbasinanditspossibleimpactsonthestreamfloworomiyaaethiopia |