| 引用本文: | 刘燕楠,孙贯芳,毛 威,等.基于地统计分析的河套灌区土壤水盐空间变异规律分析[J].灌溉排水学报,2022,41(9):101-109. |
| LIU Yan’nan,SUN Guanfang,MAO Wei,et al.基于地统计分析的河套灌区土壤水盐空间变异规律分析[J].灌溉排水学报,2022,41(9):101-109. |
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| 摘要: |
| 【目的】研究干旱盐渍化灌区不同深度土壤水分和盐分的空间变异规律。【方法】以内蒙古河套灌区隆胜井渠结合区为研究区，通过野外取样和实验室分析结合，应用经典统计学和地统计学方法研究了根系层（0~60 cm）及深层土壤（60~120、120~180 cm）土壤含水率和含盐量的空间变异性、空间格局及二者之间的关系，并探究了地下水埋深和地下水矿化度对土壤含盐量的影响。【结果】①土壤含水率在垂向上大小关系为0~60 cm<60~120 cm<120~180 cm，土壤含盐量为0~60 cm>60~120 cm>120~180 cm。土壤含水率和含盐量的变异系数和块金系数自上而下逐层减小，变程逐层增大。根系层的土壤含水率和含盐量均具有中等程度的空间相关性，深层土壤含水率和含盐量的空间相关性较强。②各层土壤含水率的变异系数和块金系数小于土壤含盐量，变程大于土壤含盐量，二者之间的空间格局存在显著的正相关关系。③研究区各层土壤含盐量均与地下水埋深呈指数相关关系，与地下水矿化度呈幂函数关系。当地下水埋深大于2.5 m时，总体土壤含盐量较低，且各层含盐量变化较小。【结论】研究区土壤盐分呈表聚型，其空间特征和分布格局与土壤含水率有着密切的关系。调控地下水埋深是灌区控制土壤盐渍化的关键措施，为有效控制土壤盐渍化，建议地下水埋深控制在2.5 m以下。 |
| 关键词: 河套灌区；土壤水盐；地统计学；空间变异；地下水环境 |
| DOI：10.13522/j.cnki.ggps.2021621 |
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| Geostatistical Analysis of Spatial Variability of Soil Water and Salt in Hetao Irrigation District |
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LIU Yan’nan, SUN Guanfang, MAO Wei, CHENG Xiaoyao, ZHU Yan, YANG Jinzhong
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1. The State Key Laboratory of Water Resource and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China;
2. Institute of Soil and Water Conservation, Northwest Agriculture and Forestry University, Yangling 712100, China;
3. Zhongnan Municipal Administration General Design Institute Co. Ltd., China Municipal Engineering, Wuhan 430101, China
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| Abstract: |
| 【Background and objective】Soil salinity is an abiotic stress affecting agricultural production worldwide, especially in countries in arid and semi-arid regions. Soil salinity is closely correlated to soil water, both varying erratically over space and time. Understanding their spatial variability is essential to improving water use efficiency and alleviating soil salinization. This paper aims to analyze the spatial variability of soil water and salt at different soil depths, their relationship in Hetao Irrigation District, as well as their dependence on groundwater depth and salinity.【Method】The study site is at Longsheng, a typical well-canal conjunctive irrigation area in the irrigation district. Soils were sampled from the root zone (0~60 cm), subsoil (60~120 cm) and deep soil (120~180 cm), and the moisture and salt contents in each sample were measured using standard laboratory methods. Their spatial variations were analyzed using classical statistical and geostatistical methods. The relationship between groundwater and soil salinity was calculated using the Pearson correlation analysis.【Result】① The averaged soil water content at different soil depths were ranked in the order of 0~60 cm<60~120 cm<120~180 cm, while the averaged soil salt content were ranked in the order of 0~60 cm>60~120 cm>120~180 cm. The variation coefficient and nugget coefficient of soil water and salt content decreased monotonically with soil depth, while their spatial autocorrelation distance increases monotonically with the depth. Soil water and salt content in the root zone showed moderate spatial autocorrelation, while in deep soil they showed a strong spatial autocorrelation. ② The variation coefficient and nugget coefficient of soil water in each soil layer are smaller than that of soil salt, while its variation range is larger than that of soil salt; there was a strong negative correlation between them. ③ Soil salt in each soil layer is exponentially related to groundwater depth, but is a power-law function of groundwater salinity. When the groundwater depth is greater than 2.5 m, the soil salt content is low and the soil salinity only slightly changes with groundwater depth.【Conclusion】Salt accumulates mainly in the root zone and its spatial distribution is closely related to soil water content. Groundwater depth is the major controlling factor of soil salinity, and to reduce the risk of soil salinity, the groundwater depth should be controlled below the depth of 2.5 m. |
| Key words: Hetao Irrigation District; soil water and salt; geostatistics; spatial variation; groundwater environment |
