Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa
An integrated hydrogeological modelling approach applicable to hard-rock aquifers in semi-arid data-scarce Africa was developed using remote sensing, rainfall-runoff modelling, and a three-dimensional (3D) dynamic model. The integrated modelling approach was applied to the Hout catchment, Limpopo Pr...
| Main Authors: | , , |
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| Format: | Journal Article |
| Language: | Inglés |
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Springer
2019
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| Online Access: | https://hdl.handle.net/10568/101281 |
| _version_ | 1855526121589702656 |
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| author | Ebrahim, Girma Yimer Villholth, Karen G. Boulos, M. |
| author_browse | Boulos, M. Ebrahim, Girma Yimer Villholth, Karen G. |
| author_facet | Ebrahim, Girma Yimer Villholth, Karen G. Boulos, M. |
| author_sort | Ebrahim, Girma Yimer |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | An integrated hydrogeological modelling approach applicable to hard-rock aquifers in semi-arid data-scarce Africa was developed using remote sensing, rainfall-runoff modelling, and a three-dimensional (3D) dynamic model. The integrated modelling approach was applied to the Hout catchment, Limpopo Province, South Africa, an important agricultural region where groundwater abstraction for irrigation doubled during 1968–1986. Since the 1960s, groundwater levels in irrigated areas have displayed extended periods of decline with partial or full recovery in response to major decadal rainfall events or periods. The integrated dynamic 3D hydrogeological flow model, based on the One-Water Hydrologic Flow Model (MODFLOW-OWHM), helped to understand recharge and flow processes and inform water use and management. Irrigation abstraction was estimated based on irrigated crop area delineated using the Landsat Normalized Difference Vegetation Index (NDVI) and crop water requirements. Using groundwater level data, the model was calibrated (2008–2012) and validated (2013–2015). Estimated mean diffuse recharge (3.3 ± 2.5% of annual rainfall) compared well with estimates from the Precipitation Runoff Modelling System model. Recharge and groundwater storage showed significant inter-annual variability. The ephemeral river was found to be losing, with mean net flux to the aquifer (focused recharge) of ~1.1% of annual rainfall. The results indicate a delicate human-natural system reliant on the small but highly variable recharge, propagating through variable pumping to an even more variable storage, making the combined system vulnerable to climate and anthropogenic changes. The integrated modelling is fundamental for understanding spatio-temporal variability in key parameters required for managing the groundwater resource sustainably. |
| format | Journal Article |
| id | CGSpace101281 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| publisher | Springer |
| publisherStr | Springer |
| record_format | dspace |
| spelling | CGSpace1012812025-02-19T13:42:22Z Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa Ebrahim, Girma Yimer Villholth, Karen G. Boulos, M. hydrogeology integrated management modelling sustainable agriculture groundwater management groundwater recharge groundwater extraction water use water levels water requirements catchment areas semiarid zones aquifers rainfall-runoff relationships remote sensing vegetation climate change precipitation pumping An integrated hydrogeological modelling approach applicable to hard-rock aquifers in semi-arid data-scarce Africa was developed using remote sensing, rainfall-runoff modelling, and a three-dimensional (3D) dynamic model. The integrated modelling approach was applied to the Hout catchment, Limpopo Province, South Africa, an important agricultural region where groundwater abstraction for irrigation doubled during 1968–1986. Since the 1960s, groundwater levels in irrigated areas have displayed extended periods of decline with partial or full recovery in response to major decadal rainfall events or periods. The integrated dynamic 3D hydrogeological flow model, based on the One-Water Hydrologic Flow Model (MODFLOW-OWHM), helped to understand recharge and flow processes and inform water use and management. Irrigation abstraction was estimated based on irrigated crop area delineated using the Landsat Normalized Difference Vegetation Index (NDVI) and crop water requirements. Using groundwater level data, the model was calibrated (2008–2012) and validated (2013–2015). Estimated mean diffuse recharge (3.3 ± 2.5% of annual rainfall) compared well with estimates from the Precipitation Runoff Modelling System model. Recharge and groundwater storage showed significant inter-annual variability. The ephemeral river was found to be losing, with mean net flux to the aquifer (focused recharge) of ~1.1% of annual rainfall. The results indicate a delicate human-natural system reliant on the small but highly variable recharge, propagating through variable pumping to an even more variable storage, making the combined system vulnerable to climate and anthropogenic changes. The integrated modelling is fundamental for understanding spatio-temporal variability in key parameters required for managing the groundwater resource sustainably. 2019-05 2019-05-16T07:19:53Z 2019-05-16T07:19:53Z Journal Article https://hdl.handle.net/10568/101281 en Open Access Springer Ebrahim, Girma Y.; Villholth, Karen G.; Boulos, M. 2019. Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa. Hydrogeology Journal, 17p. (Online first) doi: 10.1007/s10040-019-01957-6 |
| spellingShingle | hydrogeology integrated management modelling sustainable agriculture groundwater management groundwater recharge groundwater extraction water use water levels water requirements catchment areas semiarid zones aquifers rainfall-runoff relationships remote sensing vegetation climate change precipitation pumping Ebrahim, Girma Yimer Villholth, Karen G. Boulos, M. Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa |
| title | Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa |
| title_full | Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa |
| title_fullStr | Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa |
| title_full_unstemmed | Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa |
| title_short | Integrated hydrogeological modelling of hard-rock semi-arid terrain: supporting sustainable agricultural groundwater use in Hout catchment, Limpopo Province, South Africa |
| title_sort | integrated hydrogeological modelling of hard rock semi arid terrain supporting sustainable agricultural groundwater use in hout catchment limpopo province south africa |
| topic | hydrogeology integrated management modelling sustainable agriculture groundwater management groundwater recharge groundwater extraction water use water levels water requirements catchment areas semiarid zones aquifers rainfall-runoff relationships remote sensing vegetation climate change precipitation pumping |
| url | https://hdl.handle.net/10568/101281 |
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