典型干旱区绿洲春季土壤盐分空间分布特征分析

Spatial Distribution characteristics of Soil Salinity in an Oasis of Typical Arid Regions in Spring

  • 摘要: 干旱区绿洲春季土壤盐渍化问题十分严重。以新疆第二师31团灌区为例,在GIS技术的支持下,运用经典统计学和地统计学方法,对春季灌区内不同深度土层的盐渍化特征与空间分布格局进行分析,探讨了这一地区土壤盐渍化规律,为当地农业生产和土壤改良提供了理论依据。结果显示:春季灌区内土壤pH值范围在8.01 ~ 8.32,总体呈碱性;土壤盐分呈表聚型,盐分阳离子以K+和Na+为主,阴离子在耕地土壤以SO42−、在非耕地土壤以Cl为主;盐分类型耕地以氯化物-硫酸盐型为主,非耕地以硫酸盐-氯化物型为主。不同深度土层土壤盐分含量在水平方向均具有较强的变异性且大多具良好的空间相关性;其中,40 ~ 60 cm土层土壤盐分含量空间相关性强烈,0 ~ 20 cm、20 ~ 40 cm、80 ~ 100 cm土层空间相关性中等。在垂直方向上,0 ~ 20 cm、40 ~ 60 cm土层土壤盐分含量较高,在1.59 ~ 8.91 g kg −1之间;20 ~ 40 cm、80 ~ 100 cm土层盐分含量相对较低,在2.44 ~ 3.95 g kg −1之间。在水平方向上,不同深度土层的土壤盐分含量空间分布状况基本一致,研究区中部及东北部盐分含量相对较高,且由中部向两侧逐渐递减。中部荒漠化程度高,地势低洼之处盐分含量达3.00 ~ 8.91 g kg−1;西北和东南部盐分含量相对较低,在1.59 ~ 3.00 g kg −1之间。

     

    Abstract: The problem of soil salinization in the oasis of the arid area in spring is very serious. In order to study the characteristics and spatial distribution of soil salinization in a typical oasis area. The pH and salts at different soil depths in the irrigation areas were analyzed by using classical statistics, geostatistical and GIS methods in the 2nd Division, 31st Regiment, Xinjiang. The results showed that the pH values of soils in the irrigation area ranged from 8.01 to 8.32 and was alkaline in general. The salt in spring was accumulated in soil surface. The main cations of soil salt composition were K+ and Na+. The main anion was SO42− in the cultivated soil and was Cl in the uncultivated soil. The arable and non-arable lands were mainly belonged to chloride-sulfate type and sulfate-chloride type, respectively. The contents of soil salts at different depths were strongly different and most of them showed good spatial correlations. The soil salt content at the 40-60 cm soil layer showed a strong spatial correlation. The contents of soil salt in the 0-20 cm, 20-40 cm, and 80-100 cm depths showed a moderate spatial correlation. The contents of soil salts were higher at the 0-20 cm and 40-60 cm depths, ranging from 1.59-8.91 g kg−1, and were lower at the 20-40 cm and 80-100 cm depths, ranging from 2.44-3.95 g kg−1. The spatial distributions of salt contents within the same soil depths were basically same. The areas with high soil salinity were mainly distributed in the middle and northeast of the study area and in the area with high desertification and low terrain, with 3-8.91 g kg−1 salt contents. The soil salt contents were gradually decreased from the middle to the two sides, and was relatively low (1.59-3 g kg−1) in the northwest and southeast of the study area.

     

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