Modifying the water table fluctuation method for calculating recharge in sloping aquifers
Study region: Robit Bata and Dengeshita watersheds, Upper Blue Nile basin, Ethiopia Study focus: Sustainable development of groundwater in the Ethiopian Highlands requires recharge measurements. The Water Table Fluctuation (WTF) method has been used to measure recharge. Lateral flow in sloping hills...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-04-01
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| Series: | Journal of Hydrology: Regional Studies |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214581823000125 |
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| author | Abdu Y. Yimam Feleke K. Sishu Tewodros T. Assefa Tammo S. Steenhuis Manuel R. Reyes Raghavan Srinivasan Seifu A. Tilahun |
| author_facet | Abdu Y. Yimam Feleke K. Sishu Tewodros T. Assefa Tammo S. Steenhuis Manuel R. Reyes Raghavan Srinivasan Seifu A. Tilahun |
| author_sort | Abdu Y. Yimam |
| collection | DOAJ |
| description | Study region: Robit Bata and Dengeshita watersheds, Upper Blue Nile basin, Ethiopia Study focus: Sustainable development of groundwater in the Ethiopian Highlands requires recharge measurements. The Water Table Fluctuation (WTF) method has been used to measure recharge. Lateral flow in sloping hillside aquifers violates the assumptions on which the original WTF method is based. We modified the original WTF method to include lateral flow controlled by gravity. New hydrological insights: Previously it was shown that the sum of recharge over the travel time in a sloping aquifer is equal to the base flow. Since recharge cannot be measured directly, the recharge calculated with the modified WTF method was tested using baseflow measurement in two contrasting highland watersheds, Robit Bata and Dengeshita, where groundwater depth and streamflow data were monitored from 2015 to 2018. Baseflow was determined with the one-parameter digital filter technique. Predicted and observed monthly baseflow agreed well with R2 > 0.9 and RMSE < 20 mm during calibration and validation. Recharge in Robit Bata, in which the aquifer underlays 55% of the watershed, was 293 mm a−1 of 1378 mm a−1 precipitation. In Dengeshita, where the entire watershed has an aquifer, the average annual recharge was 525 mm a−1 of 1550 mm a−1. Our findings indicate that the modified WTF method is simple and practical for determining aquifer recharge for highlands and other sloping aquifers. |
| first_indexed | 2024-04-09T23:44:04Z |
| format | Article |
| id | doaj.art-b24884f43fb4472d9ce1f4c66ea0eda5 |
| institution | Directory Open Access Journal |
| issn | 2214-5818 |
| language | English |
| last_indexed | 2024-04-09T23:44:04Z |
| publishDate | 2023-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Hydrology: Regional Studies |
| spelling | doaj.art-b24884f43fb4472d9ce1f4c66ea0eda52023-03-18T04:41:11ZengElsevierJournal of Hydrology: Regional Studies2214-58182023-04-0146101325Modifying the water table fluctuation method for calculating recharge in sloping aquifersAbdu Y. Yimam0Feleke K. Sishu1Tewodros T. Assefa2Tammo S. Steenhuis3Manuel R. Reyes4Raghavan Srinivasan5Seifu A. Tilahun6Faculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, EthiopiaFaculty of Chemical and Food Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, EthiopiaFaculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia; Corresponding author.Faculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia; Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USASustainable Intensification Innovation Lab and Department of Agronomy, Kansas State University, Manhattan, KS 66506, USADepartment of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA; Temple Research and Extension Center, Texas A&M University, College Station TX, USAFaculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia; Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA; Corresponding author at: Faculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia.Study region: Robit Bata and Dengeshita watersheds, Upper Blue Nile basin, Ethiopia Study focus: Sustainable development of groundwater in the Ethiopian Highlands requires recharge measurements. The Water Table Fluctuation (WTF) method has been used to measure recharge. Lateral flow in sloping hillside aquifers violates the assumptions on which the original WTF method is based. We modified the original WTF method to include lateral flow controlled by gravity. New hydrological insights: Previously it was shown that the sum of recharge over the travel time in a sloping aquifer is equal to the base flow. Since recharge cannot be measured directly, the recharge calculated with the modified WTF method was tested using baseflow measurement in two contrasting highland watersheds, Robit Bata and Dengeshita, where groundwater depth and streamflow data were monitored from 2015 to 2018. Baseflow was determined with the one-parameter digital filter technique. Predicted and observed monthly baseflow agreed well with R2 > 0.9 and RMSE < 20 mm during calibration and validation. Recharge in Robit Bata, in which the aquifer underlays 55% of the watershed, was 293 mm a−1 of 1378 mm a−1 precipitation. In Dengeshita, where the entire watershed has an aquifer, the average annual recharge was 525 mm a−1 of 1550 mm a−1. Our findings indicate that the modified WTF method is simple and practical for determining aquifer recharge for highlands and other sloping aquifers.http://www.sciencedirect.com/science/article/pii/S2214581823000125BaseflowGroundwater rechargeWater table fluctuationSloping aquiferEthiopian highlands |
| spellingShingle | Abdu Y. Yimam Feleke K. Sishu Tewodros T. Assefa Tammo S. Steenhuis Manuel R. Reyes Raghavan Srinivasan Seifu A. Tilahun Modifying the water table fluctuation method for calculating recharge in sloping aquifers Journal of Hydrology: Regional Studies Baseflow Groundwater recharge Water table fluctuation Sloping aquifer Ethiopian highlands |
| title | Modifying the water table fluctuation method for calculating recharge in sloping aquifers |
| title_full | Modifying the water table fluctuation method for calculating recharge in sloping aquifers |
| title_fullStr | Modifying the water table fluctuation method for calculating recharge in sloping aquifers |
| title_full_unstemmed | Modifying the water table fluctuation method for calculating recharge in sloping aquifers |
| title_short | Modifying the water table fluctuation method for calculating recharge in sloping aquifers |
| title_sort | modifying the water table fluctuation method for calculating recharge in sloping aquifers |
| topic | Baseflow Groundwater recharge Water table fluctuation Sloping aquifer Ethiopian highlands |
| url | http://www.sciencedirect.com/science/article/pii/S2214581823000125 |
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