干旱区研究 ›› 2023, Vol. 40 ›› Issue (10): 1615-1624.doi: 10.13866/j.azr.2023.10.08 cstr: 32277.14.j.azr.2023.10.08

• 水土资源 • 上一篇    下一篇

石羊河下游民勤盆地土壤盐分空间分异特征

刘新(),郝媛媛(),花立民   

  1. 甘肃农业大学草业学院,草业生态系统教育部重点实验室,国家林业草原高寒草地鼠害防控工程技术研究中心,甘肃 兰州 730070
  • 收稿日期:2023-03-08 修回日期:2023-06-27 出版日期:2023-10-15 发布日期:2023-11-01
  • 作者简介:刘新(1997-),男,硕士研究生,主要从事土壤恢复生态遥感工作. E-mail: liuixn74851686@163.com
  • 基金资助:
    国家自然科学青年基金项目(41907406);甘肃农业大学科技创新基金项目(GAU-KYQD-2018-23)

Spatial differentiation characteristics of soil salinity in Minqin Basin, downstream of Shiyang River, China

LIU Xin(),HAO Yuanyuan(),HUA Limin   

  1. College of Patacultural Science, Gansu Agricultural University, Key Laboratory of Grassland Ecosystem, Ministry of Education; Engineering and Technology Research Center for Alpine Rodent Pest Control, National Forestry and Grassland Administration, Lanzhou 730070, Gansu, China
  • Received:2023-03-08 Revised:2023-06-27 Published:2023-10-15 Online:2023-11-01

摘要:

明晰土壤盐分空间变异性是土壤盐渍化程度研究和盐碱地改良的前提。本研究选取干旱内陆河流域石羊河下游民勤盆地为研究区,通过对0~30 cm土层土壤盐分原位数据统计学特征、空间自相关性、变异性和分布格局的分析,探讨民勤盆地土壤盐分空间异质性变化规律,以期为研究区土壤盐渍化治理提供理论依据。结果显示:(1)实测土壤盐分含量和变化范围均随土层加深而变小,且均呈偏正态分布。(2)Moran’s I 指数均呈“∽”型波动趋势且值域范围随土层加深而变大,正(负)空间自相关性均随距离的增大而减小(0~10 cm负的空间自相关性相反)。(3)变异函数均以指数模型为最好,R2随土层加深而变大(0.62→0.69→0.81),RSS均是0.0002,C0/(C0+C)和A0变化规律一致,随着土层加深空间异质性由弱到强烈再到中等。(4)插值精度10~20 cm > 20~30 cm > 0~10 cm。3个土层土壤盐分均存在空间分异特性,水平方向(同一土层)上,盐渍化程度均自西南向东北逐渐增加;垂直方向(不同土层)上,分布规律由简单到复杂,从聚集状态(0~10 cm)逐渐趋于斑块化(10~20 cm)和斑点化(20~30 cm)。非盐化土(<1.50%)和4种不同程度盐渍土在3个土层中均有分布,盐渍土面积中度(>70.00%)>强度(约20.00%)>轻度(约9.00%)>盐土(<0.50%)。

关键词: 土壤盐分, 空间变异, 地统计学, 民勤盆地, 石羊河下游

Abstract:

Clarifying the spatial variability of soil salinity is the aim of soil salinization research and saline-alkali land improvements. In this study, the Minqin Basin in the lower reaches of the Shiyang River in the arid inland river basin was selected as the study area. By analyzing the statistical characteristics, spatial autocorrelation, variability, and distribution patterns of soil salinity in situ data of the 0-30 cm soil layer, the changes in the spatial heterogeneity of soil salinity could be explored to provide a theoretical basis for soil salinity in the study area. The measured soil salinity content and its variation range both decreased as the soil layer increased, and both were in a skewed normal distribution. Moran’s I index showed a “∽” type fluctuation trend, and the range of values increased with the soil layer, and the positive (negative) spatial autocorrelation decreased as the distance increased (negative spatial autocorrelation of 0-10 cm was opposite). The exponential model was the most suitable for use with the variogram. The R2 increased with soil depth (0.62→0.69→0.81), and the RSS was 0.0002. Variation rules of C0/(C0+C) and A0 were consistent, and the spatial heterogeneity ranged from weak to strong to moderate with soil depth. Accuracy of the interpolation was 10-20 cm > 20-30 cm > 0-10 cm. The soil salinity of the three layers had spatial differentiation characteristics, and the degree of salinization increased gradually from southwest to northeast in the horizontal direction (the same soil layer). In the vertical direction (different soil layers), the distribution patterns changed from simple to complex, and gradually tended to patches (10-20 cm) and spots (20-30 cm) from the aggregation state (0-10 cm). Nonsalinized soil (<1.50%) and four different levels of saline soil were distributed in the three soil layers, and the area of saline soil was moderate (>70.00%) > strength (approximately 20.00%) > mild (approximately 9.00%) > saline soil (<0.50 %).

Key words: soil salinity, spatial variation, geostatistics, Minqin Basin, downstrearm of Shiyang River