| 摘要: |
| 【目的】揭示干旱区降雨或灌溉条件下的包气带水分运移规律。【方法】利用原位观测和同位素示踪方法对银川平原永宁引黄灌区的降雨特征和降雨、灌溉水、土壤水、地下水同位素组分进行了分析。【结果】2019年4—10月降水量为157.3 mm，6月降水量最大，占全年降水量的55%，总体上表现为短历时的小到中雨。土壤水δD和δ18O的最大值随着土层深度的增加而减小，0~50 cm土壤水氢氧同位素的标准差大于70~270 cm的标准差。5月7日、6月25日、6月27日降水对0~50 cm土层的贡献比例分别为13.7%、14.8%和83.9%。灌溉水在0~50 cm土层的贡献比例为49.3%~100.0%，70 cm以下的贡献比例为14.3%~46.6%。【结论】降水入渗的影响范围在30~50 cm以内，灌溉入渗的影响范围达到270 cm，土壤水蒸发消耗主要发生在0~50 cm土层。 |
| 关键词: 包气带; 土壤水; 水分运移; 氢氧同位素; 银川平原 |
| DOI：10.13522/j.cnki.ggps.2020055 |
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| Tracing Water Infiltration in Soils with Isotopes in the Yongning Irrigation District in the Yellow River Basin |
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ZHAO Zhipeng, YANG Lihu, GONG Liang , LI Bingliang, MA Xuedong , XU Yingchun, LIU Haiyan
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1.Geological Bureau of Ningxia Hui Autonomous Region, Yinchuan 750021, China; 2. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; 3. Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101400, China; 4.Ningxia Geological Survey Institute, Yinchuan 750021, China; 5. School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China
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| Abstract: |
| 【Background】Rainfall and irrigation are two factors mediating water movement in soil, but how the exogenous water percolates in soil remains elusive.【Objective】We took Yinchuan plain in the Yellow river basin of China as an example, tracing water infiltration in soil using isotopes in attempts to help improve agricultural water management in this region.【Method】We observed and analyzed in 2019 isotope contents in rainfall, irrigation water, soil water and groundwater in this region.【Result】The overall rainfall from April to October was 157.3 mm, with maximum rain falling in July which accounted for 55% of the annual precipitation. Most rainfalls were small to moderate. The maximum δD and δ18O concentrations decreased downwards along the soil profile, and the standard deviation of the isotope concentrations in water in the top 0~50 cm soil was higher than that in the subsoil. Precipitation falling on 7 May, 25 June and 28 June contributed 13.7%, 14.8% and 83.9% to the water in the top 0~50 cm of soil, respectively. On average, irrigation water contributed 49.3%~100.0% to the water in the top 0~50 cm of soil, and 14.3%~46.6% to the water in soil below the depth of 70 cm.【Conclusion】 The rainfall infiltrated into the soil to a depth of 30~50 cm depending on rainfall intensity, while irrigation water could percolate as deep as 270 cm. Evaporation was mainly from the water in the top 0~50 cm of soil. |
| Key words: unsaturated zone; soil water; hydrogen and oxygen isotopes; soil water movement; Yinchuan plain |
