Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia
Intense anthropogenic activities in arid regions remarkably affect groundwater by causing phreatic decline and water environmental deterioration. A systematic understanding of groundwater hydrochemical evolution and recharge is critical to regional water, ecological and agricultural security in arid...
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| Format: | Article |
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MDPI AG
2024-03-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/16/5/763 |
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| author | Yuan Yao Chenwei Tu Gaojia Hu Yuhan Zhang Hanyuan Cao Wanrui Wang Weihua Wang |
| author_facet | Yuan Yao Chenwei Tu Gaojia Hu Yuhan Zhang Hanyuan Cao Wanrui Wang Weihua Wang |
| author_sort | Yuan Yao |
| collection | DOAJ |
| description | Intense anthropogenic activities in arid regions remarkably affect groundwater by causing phreatic decline and water environmental deterioration. A systematic understanding of groundwater hydrochemical evolution and recharge is critical to regional water, ecological and agricultural security in arid regions, but is not well known in arid oasis–deserts. This research identified groundwater recharge processes and assessed the impact of anthropogenic activities on groundwater hydrochemical evolution in a representative oasis–desert in Central Asia using stable isotopic indicators (δ<sup>2</sup>H and δ<sup>18</sup>O) and hydrochemical data. Results indicated that the normalized difference vegetation index (NDVI) and cultivated land area exhibited a significant increasing trend during 2000 to 2020. Stable water isotopes and the ionic composition of both groundwater and surface water exhibited obviously spatial heterogeneity and seasonal variation. Generally, the spatial distribution pattern of major dissolved ions for shallow groundwater was consistent and increased along the groundwater flow direction from midstream to downstream. Surface water and groundwater were both characterized by higher δ<sup>18</sup>O and total dissolved solids (TDS) in the non-flood season than those in the flood season. Shallow groundwater had a larger seasonal variation in δ<sup>18</sup>O and TDS than other water components. Groundwater level in monitored wells generally presented a decreasing trend from 2018 to 2021, accompanied by a decrease in phreatic water TDS and NDVI in the desert area. Gypsum dissolution and weathering of silicate and halite had an important role in forming groundwater hydrochemistry. Anthropogenic activities significantly affected groundwater hydrochemistry and recharge. Shallow groundwater received its primary recharge from surface water and lateral groundwater flow, constituting 73% and 27% of the total recharge, respectively. Agricultural activities and groundwater overexploitation were the main factors for variations in groundwater level and quality in the oasis area, and directly affected groundwater and natural vegetation in the desert area. The results would be helpful to deeply understand groundwater hydrochemical evolution and cycling, and beneficial for groundwater efficient utilization and desert ecosystem restoration in the arid areas. |
| first_indexed | 2024-04-25T00:19:12Z |
| format | Article |
| id | doaj.art-9acc2ec3a26a48468a038305cca60494 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-04-25T00:19:12Z |
| publishDate | 2024-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-9acc2ec3a26a48468a038305cca604942024-03-12T16:57:59ZengMDPI AGWater2073-44412024-03-0116576310.3390/w16050763Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central AsiaYuan Yao0Chenwei Tu1Gaojia Hu2Yuhan Zhang3Hanyuan Cao4Wanrui Wang5Weihua Wang6College of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, ChinaCollege of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, ChinaCollege of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, ChinaCollege of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, ChinaCollege of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, ChinaCollege of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, ChinaState Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, ChinaIntense anthropogenic activities in arid regions remarkably affect groundwater by causing phreatic decline and water environmental deterioration. A systematic understanding of groundwater hydrochemical evolution and recharge is critical to regional water, ecological and agricultural security in arid regions, but is not well known in arid oasis–deserts. This research identified groundwater recharge processes and assessed the impact of anthropogenic activities on groundwater hydrochemical evolution in a representative oasis–desert in Central Asia using stable isotopic indicators (δ<sup>2</sup>H and δ<sup>18</sup>O) and hydrochemical data. Results indicated that the normalized difference vegetation index (NDVI) and cultivated land area exhibited a significant increasing trend during 2000 to 2020. Stable water isotopes and the ionic composition of both groundwater and surface water exhibited obviously spatial heterogeneity and seasonal variation. Generally, the spatial distribution pattern of major dissolved ions for shallow groundwater was consistent and increased along the groundwater flow direction from midstream to downstream. Surface water and groundwater were both characterized by higher δ<sup>18</sup>O and total dissolved solids (TDS) in the non-flood season than those in the flood season. Shallow groundwater had a larger seasonal variation in δ<sup>18</sup>O and TDS than other water components. Groundwater level in monitored wells generally presented a decreasing trend from 2018 to 2021, accompanied by a decrease in phreatic water TDS and NDVI in the desert area. Gypsum dissolution and weathering of silicate and halite had an important role in forming groundwater hydrochemistry. Anthropogenic activities significantly affected groundwater hydrochemistry and recharge. Shallow groundwater received its primary recharge from surface water and lateral groundwater flow, constituting 73% and 27% of the total recharge, respectively. Agricultural activities and groundwater overexploitation were the main factors for variations in groundwater level and quality in the oasis area, and directly affected groundwater and natural vegetation in the desert area. The results would be helpful to deeply understand groundwater hydrochemical evolution and cycling, and beneficial for groundwater efficient utilization and desert ecosystem restoration in the arid areas.https://www.mdpi.com/2073-4441/16/5/763groundwater dynamicstable isotopeshydrochemistryrechargeagricultural activitiesoasis–desert region |
| spellingShingle | Yuan Yao Chenwei Tu Gaojia Hu Yuhan Zhang Hanyuan Cao Wanrui Wang Weihua Wang Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia Water groundwater dynamic stable isotopes hydrochemistry recharge agricultural activities oasis–desert region |
| title | Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia |
| title_full | Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia |
| title_fullStr | Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia |
| title_full_unstemmed | Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia |
| title_short | Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia |
| title_sort | groundwater hydrochemistry and recharge process impacted by human activities in an oasis desert in central asia |
| topic | groundwater dynamic stable isotopes hydrochemistry recharge agricultural activities oasis–desert region |
| url | https://www.mdpi.com/2073-4441/16/5/763 |
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