不同河渠水位条件下壤砂土上升毛管水运动特性——以叶尔羌河灌区为例

Subjects: Geosciences >> Hydrology submitted time 2023-03-28 Cooperative journals: 《干旱区研究》

陈永宝 胡顺军 张书杰 裴明松 张巧丽

Abstract： River canal leakage is the main mode of surface water replenishment to soil water for desert riverbank ecological protection, plant water absorption, and utilization. It is also an important cause of soil salinization during increased groundwater level periods. Therefore, studying the movement of groundwater and soil moisture under the condition of canal leakage recharge in arid areas can be crucial not only for constructing a benign ecological circulation system dominated by water environment, but also for preventing soil salinization. This study used laboratory simulation experiment to analyze the capillary water movement characteristics in loamy sand under different water levels in Yarkant River irrigation area. Results showed a decreasing trend in the capillary water supply rate, which could be subdivided into three stages, including rapid decrease, linear decrease, and stable- state, while the average stable recharge rate 0.02 mm · min- 1 was detected. The rising height of capillary water and rising rate both had parabola relationships with the recharge time. Validation of the linear relationship between capillary water recharge and rising height of capillary water under different canal water levels revealed that the slope (B) was equal to the difference between the mean soil water content (θmean) and initial water content (θi), while B values under different canal water levels ranged from 0.3155 to 0.4046 cm3·cm-3, with a mean value of 0.3695 cm3 ·cm- 3. A linear correlation was detected between capillary water supply rate and the reciprocal value of rising height of capillary water. The improved Green-Ampt model could successfully be used to simulate capillary water rise process in a homogeneous loamy sand. Overall, these results could potentially provide clues for studying the restoration and reconstruction of ecologically protected plants in canals, and for the prevention of soil salinization in arid areas.

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