The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation Systems
This study evaluates the cause of salinization in an irrigation scheme of 100 ha supplied from a reservoir. The scheme is located in Gumselasa catchment (28 km<sup>2</sup>), Tigray region, northern Ethiopia. The catchment is underlain by limestone–shale–marl intercalations with dolerite...
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MDPI AG
2021-03-01
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| Series: | Agronomy |
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| Online Access: | https://www.mdpi.com/2073-4395/11/3/512 |
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| author | Michiele Gebrehiwet Nata T. Tafesse Solomon Habtu Berhanu F. Alemaw Kebabonye Laletsang Reneilwe Lasarwe |
| author_facet | Michiele Gebrehiwet Nata T. Tafesse Solomon Habtu Berhanu F. Alemaw Kebabonye Laletsang Reneilwe Lasarwe |
| author_sort | Michiele Gebrehiwet |
| collection | DOAJ |
| description | This study evaluates the cause of salinization in an irrigation scheme of 100 ha supplied from a reservoir. The scheme is located in Gumselasa catchment (28 km<sup>2</sup>), Tigray region, northern Ethiopia. The catchment is underlain by limestone–shale–marl intercalations with dolerite intrusion and some recent sediments. Water balance computation, hydrochemical analyses and irrigation water quality analyses methods were used in this investigation. Surface waters (river and reservoir) and groundwater samples were collected and analyzed. The water table in the irrigated land is ranging 0.2–2 m below the ground level. The majority of groundwater in the effective watershed area and the river and dam waters are fresh and alkaline whereas in the command area the groundwater is dominantly brackish and alkaline. The main hydrochemical facies in the groundwater in the effective watershed area are Ca-Na-SO<sub>4</sub>-HCO<sub>3</sub>, Ca-Na- HCO<sub>3</sub>-SO<sub>4</sub>, and Ca-Na-Mg-SO<sub>4</sub>-HCO<sub>3</sub>. The river and dam waters are Mg-Na-HCO<sub>3</sub>-SO<sub>4</sub> and HCO<sub>3</sub>-SO<sub>4</sub>-Cl types, respectively. In the command area the main hydrochemical facies in the groundwater are Ca-Na-HCO<sub>3</sub>-SO<sub>4</sub> and Ca-Na-Mg-SO<sub>4</sub>-HCO<sub>3</sub>. Irrigation water quality analyses revealed that salinity and toxicity hazards increase from the effective watershed to the irrigated land following the direction of the water flow. The results also showed that the analyzed waters for irrigation purpose had no sodicity hazard. The major composition controlling mechanisms in the groundwater chemistry was identified as the dissolution of carbonate minerals, silicate weathering, and cation exchange. One of the impacts of the construction of the dam in the hydrologic environment of the catchment is on its groundwater potential. The dam is indirectly recharging the aquifers and enhances the groundwater potential of the area. This increment of availability of groundwater enhanced dissolution of carbonate minerals (calcite, dolomite, and gypsum), silicate weathering and cation exchange processes, which are the main causes of salinity in the irrigated land. The rising of the brackish groundwater combined with insufficient leaching contributed to secondary salinization development in the irrigated land. Installation of surface and subsurface drainage systems and planting salt tolerant (salt loving) plants are recommended to minimize the risk of salinization and salt accumulation in the soils of the irrigated land. |
| first_indexed | 2024-03-10T13:22:53Z |
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| series | Agronomy |
| spelling | doaj.art-123d2bb491884086a15e6012d7505c832023-11-21T09:49:51ZengMDPI AGAgronomy2073-43952021-03-0111351210.3390/agronomy11030512The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation SystemsMichiele Gebrehiwet0Nata T. Tafesse1Solomon Habtu2Berhanu F. Alemaw3Kebabonye Laletsang4Reneilwe Lasarwe5Department of Land Resource Management and Environmental Protection, College of Dryland Agriculture and Natural Resources, P.O. Box 231, Mekelle University, Mekelle, EthiopiaGeology Department, University of Botswana, Private Bag UB 00704, Gaborone, BotswanaDepartment of Land Resource Management and Environmental Protection, College of Dryland Agriculture and Natural Resources, P.O. Box 231, Mekelle University, Mekelle, EthiopiaGeology Department, University of Botswana, Private Bag UB 00704, Gaborone, BotswanaGeology Department, University of Botswana, Private Bag UB 00704, Gaborone, BotswanaGeology Department, University of Botswana, Private Bag UB 00704, Gaborone, BotswanaThis study evaluates the cause of salinization in an irrigation scheme of 100 ha supplied from a reservoir. The scheme is located in Gumselasa catchment (28 km<sup>2</sup>), Tigray region, northern Ethiopia. The catchment is underlain by limestone–shale–marl intercalations with dolerite intrusion and some recent sediments. Water balance computation, hydrochemical analyses and irrigation water quality analyses methods were used in this investigation. Surface waters (river and reservoir) and groundwater samples were collected and analyzed. The water table in the irrigated land is ranging 0.2–2 m below the ground level. The majority of groundwater in the effective watershed area and the river and dam waters are fresh and alkaline whereas in the command area the groundwater is dominantly brackish and alkaline. The main hydrochemical facies in the groundwater in the effective watershed area are Ca-Na-SO<sub>4</sub>-HCO<sub>3</sub>, Ca-Na- HCO<sub>3</sub>-SO<sub>4</sub>, and Ca-Na-Mg-SO<sub>4</sub>-HCO<sub>3</sub>. The river and dam waters are Mg-Na-HCO<sub>3</sub>-SO<sub>4</sub> and HCO<sub>3</sub>-SO<sub>4</sub>-Cl types, respectively. In the command area the main hydrochemical facies in the groundwater are Ca-Na-HCO<sub>3</sub>-SO<sub>4</sub> and Ca-Na-Mg-SO<sub>4</sub>-HCO<sub>3</sub>. Irrigation water quality analyses revealed that salinity and toxicity hazards increase from the effective watershed to the irrigated land following the direction of the water flow. The results also showed that the analyzed waters for irrigation purpose had no sodicity hazard. The major composition controlling mechanisms in the groundwater chemistry was identified as the dissolution of carbonate minerals, silicate weathering, and cation exchange. One of the impacts of the construction of the dam in the hydrologic environment of the catchment is on its groundwater potential. The dam is indirectly recharging the aquifers and enhances the groundwater potential of the area. This increment of availability of groundwater enhanced dissolution of carbonate minerals (calcite, dolomite, and gypsum), silicate weathering and cation exchange processes, which are the main causes of salinity in the irrigated land. The rising of the brackish groundwater combined with insufficient leaching contributed to secondary salinization development in the irrigated land. Installation of surface and subsurface drainage systems and planting salt tolerant (salt loving) plants are recommended to minimize the risk of salinization and salt accumulation in the soils of the irrigated land.https://www.mdpi.com/2073-4395/11/3/512groundwaterirrigationsalinitysodicitytoxicity |
| spellingShingle | Michiele Gebrehiwet Nata T. Tafesse Solomon Habtu Berhanu F. Alemaw Kebabonye Laletsang Reneilwe Lasarwe The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation Systems Agronomy groundwater irrigation salinity sodicity toxicity |
| title | The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation Systems |
| title_full | The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation Systems |
| title_fullStr | The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation Systems |
| title_full_unstemmed | The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation Systems |
| title_short | The Contribution of Groundwater to the Salinization of Reservoir-Based Irrigation Systems |
| title_sort | contribution of groundwater to the salinization of reservoir based irrigation systems |
| topic | groundwater irrigation salinity sodicity toxicity |
| url | https://www.mdpi.com/2073-4395/11/3/512 |
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