| 引用本文: | 窦 旭,史海滨,李瑞平,等.暗管排水控盐对盐渍化灌区土壤盐分淋洗有效性评价[J].灌溉排水学报,2020,39(8):102-110. |
| ,et al.暗管排水控盐对盐渍化灌区土壤盐分淋洗有效性评价[J].灌溉排水学报,2020,39(8):102-110. |
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| 摘要: |
| 【目的】解决盐渍化灌区土壤盐渍化较严重问题，明确暗管排水控盐对土壤盐分淋洗效果的影响。【方法】以
灌区下游乌拉特灌域为研究区，通过野外实测和室内试验分析结合，采用经典统计学与地质统计原理，分析收获后、
春灌前后暗管排水土壤盐分统计特征和空间异质性，及其土壤盐分和盐分离子脱盐效率和暗管排水对地下水埋深的影
响。【结果】暗管排水 0~20、20~40、40~100 cm 土壤平均脱盐率分别为 61.14%、52.78%、40.37%，随着土壤深度的增
加，脱盐率减小。春灌后土壤盐分变异系数降低、空间自相关性增强，说明春灌后土壤盐分空间异质性均有所下降。
土壤中除 CO 3 2- 表现为上升趋势外，其余各离子均表现为下降趋势，且 HCO 3 - 脱盐率最小，几乎不变，土壤各盐分离子
脱盐率大小表现为：Cl - >K + +Na + >SO 4 2- >Mg 2+ >Ca 2+ >HCO 3 - 。暗管排水地下水埋深在灌后 7 d 开始下降，且下降速率较快，
排水明沟深 1.5 m，对地下水埋深的控制效果较好。【结论】利用暗管排水均能降低土壤含盐量，弱化土壤含盐量的空
间异质性，土壤盐分由“高盐异质性”向“低盐均质性”转变，有效降低土壤盐分离子量，避免盐渍化过程中离子平
衡失调，防止盐类向单一化方向发展。利用暗管排水技术降低河套灌区土壤盐分，控制地下水埋深，保证作物正常生
长，防止土壤次生盐渍化具有重要意义；暗管排水技术可在河套灌区农业生产中推广应用。 |
| 关键词: 暗管排水；土壤盐分；盐分离子；空间变异；地下水埋深 |
| DOI：10.13522/j.cnki.ggps.2019265 |
| 分类号: |
| 基金项目: |
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| Assessing the Efficiency of Subsurface Drain in Controlling Soil Salinization in Hetao Irrigation District |
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DOU Xu, SHI Haibin , LI Ruiping, MIAO Qingfeng, TIAN Feng, YU Dandan, ZHOU Liying
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College of Water Conservancy and Civil Engineer, Inner Mongolia Agriculture University, Hohhot 010018, China
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| Abstract: |
| 【Background】Soil salinization could cause soil desertification and land degradation, and it is a major
ecological concern affecting sustainable agricultural production almost in every country around the world. Hetao
Irrigation District is located in an arid and semi-arid region in Inner Mongolia, and it is one of the three major
irrigation areas in China. Precipitation in the region is low while evaporation is high, leading to sever soil
salinization and hampering sustainable agricultural development in the region. Open ditch drainage has been widely
used to control groundwater table and alleviate soil salinity in the district, but it often results in slope collapse in
addition to its waste of valuable land. It is also ineffective to control soil salinization due to its low efficiency in
draining water. Subsurface drain can resolve these problems while in the meantime improving soil physical and
chemical properties. 【Objective】The purpose of this paper is to assess the efficacy of subsurface drains in alleviating
soil salinization induced by irrigation in Hetao Irrigation district.【Method】We took Wulate area to the downstream
of the district as an example. Data measured from field and laboratory were analyzed using the principles of classical
statistics and geostatistics method, from which we obtained the statistical characteristics and spatial heterogeneity of
soil salt at harvest, before and after the spring irrigation, respectively. We also analyzed the effects of soil salt and its
ion composition on efficiency of the subsurface drain in desalinizing soil.【Result】The average desalination rate in
the 0~20 cm, 20~40 cm and 40~100 cm of soils was 61.14%, 52.78% and 40.37%, respectively. Subsurface drains
reduced the coefficient of variation while increased spatial autocorrelation of soil salt, indicating that irrigation after
spring reduced heterogeneity of the salt distribution. Except for CO 3 2- , the drains reduced the concentration of other
ions although HCO 3 - remained almost unchanged. The decrease in ions can be ranked in the order of
Cl - >K + +Na + >SO 4 2- >Mg 2+ >Ca 2+ >HCO 3 - . Groundwater table started dropping seven days after irrigation and soil
desalination was fast in this period. In comparison, open ditch 1.5 m deep was also effective in controlling
groundwater table.【Conclusion】Subsurface drains increased soil desalination, reduced spatial heterogeneity of soil
salt and contents of most ions. It also alleviated ion imbalance in salinization and prevented development of
salinization dominated by a few ions. Overall, subsurface drains can control groundwater table and reduce soil
salinity thereby safeguarding crop growth in Hetao Irrigation district |
| Key words: subsurface drain; soil salinity; salt ions; spatial variation; groundwater table depth |
