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| DOI：10.13522/j.cnki.ggps.2025124 |
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| Temporal dynamics of groundwater depth and its driving factor in the Hetao Irrigation District |
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Du Yanxia, Zhang Yiqiang, Wang Yunjie
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Bayannur Hydrology and Water Resources Survey Center, Linhe 015000, China
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| Abstract: |
| 【Objective】Groundwater dynamics in irrigation districts are sensitive to anthropogenic management and agricultural activities. This paper analyzes the temporal groundwater variation in the Hetao Irrigation District, as well as its regional implications.【Method】The arithmetic mean method was used to describe the changes in groundwater depth, Yellow River water diversion, irrigated area and water consumption based on data measured from 1980 to 2023 from 150 boreholes in the region. Correlation and regression analyses were used to elucidate the driving factors of the variation in the groundwater depth.【Result】There was a marked shift in pattern of temporal groundwater depth variation around 2015. From 1980 to 2014, groundwater table rose mainly in March and declined in November. From 2015 to 2023, groundwater table declined in September and rose in the subsequent May. Three factors influenced groundwater variations: ①Sustained decrease in Yellow River water diversion, which reduced groundwater recharge; ②adjusted irrigation schedules with advanced irrigation timing and increased water application, which slowed groundwater table decline and even resulted in net groundwater recharge in May. ③A combination of reduced autumn irrigation area and Yellow River water diversion, which, combined with postponed autumn irrigation from mid-October to late November, resulted in a substantial drop in groundwater level. Moreover, the optimized cropping restructure - featuring a reduction in wheat cultivation and an increase in autumn crops such as corn and sunflower-altered the timing and intensity of crop water consumption, which in turn changed the temporal groundwater depth change pattern.【Conclusion】The temporal change in groundwater table rising and declining in the Hetao Irrigation District was induced by anthropogenic activities. Changes in Yellow River water diversion, cropping structure and irrigation management collectively reshaped local groundwater variations. The shift from water-intensive wheat to drought-resistant corn, sunflower and other crops changed the seasonal pattern of crop demand for water, and improved irrigation arrangement altered the balance between groundwater recharge and discharge, as well as the associated water-salt migration. |
| Key words: Hetao Irrigation District; groundwater table depth; wet and dry seasons; Yellow River diversion volume；cropping pattern; impacts |
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