玛纳斯河流域土壤盐渍化影响因素研究

为了探讨区域盐渍化过程和分布特征,本文通过野外调查和室内分析,研究了新疆玛纳斯河流域海拔高度、地貌类型、地下水埋深、土地利用类型和不同种植年限对土壤盐分含量变化的影响。结果表明:玛纳斯河流域土壤盐分含量随海拔高度的变化呈现先降低后升高再降低的趋势,高盐分含量主要集中在海拔350~400 m,海拔高度与土壤盐分含量之间没有很好的变化趋势;土壤盐分含量在不同地貌类型的分布状况为:冲积洪积扇缘带冲积平原中部冲积平原下部冲积洪积扇中部干三角洲地区,冲积洪积扇缘带与冲积平原中部的土壤剖面盐分有表聚和底聚现象,冲积平原下部土壤剖面中间层盐分含量较高;地下水埋深对土壤盐分含量变化影响明显,随着地下水埋深的变浅,土壤盐分含量显著增加;不同土地利用方式下,土壤含盐量具有显著性差异,荒地土壤盐分含量最高,表层和底层盐分高于中间层,耕地0~100 cm土层盐分含量均较低;随着滴灌年限的增加,0~100 cm土层盐分含量均呈现降低趋势,滴灌1年与3年表层盐分含量差异不显著,其他土层差异显著,滴灌8年与10年的各层土壤盐分含量差异均不显著。综上,玛纳斯河流域土壤盐分含量受地貌类型、地下水状况、土地利用类型和滴灌年限因素影响显著,盐分在土壤剖面上也表现出不同的分布特征。

Factors Influencing Soil Salinization in Manasi River Basin,China

The objective of this study is to learn more about the distribution of salinized soil in the Manasi River Basin and the factors influencing soil salinization in the region. The following factors are considered:elevation, landform, groundwater depth, land use, and years of drip irrigation. The results showed that soil salt content increased as elevation increased to 350~400 m and then declined. However, the differences in salt content among different elevations were not significant. Soil salt content decreased in the following order:edge of the alluvial fan>central part of the alluvial plain>lower part of the alluvial plain>center of the alluvial fan>dry delta. At the edge of the alluvial fan and in the central part of the alluvial plain, soil salinity was greatest in the uppermost and lowermost depths of the soil profile. In the alluvial plain, the middle depth had the highest salt content. Groundwater depth had significant effect on the soil salt content. The soil salt content increased significantly as groundwater depth increased. There was significant difference in soil salt content among land use types. The salt content was highest in wasteland soil. The middle soil depth under wasteland had less salt than the upper and lower soil depths. In the cultivated field, the soil salt content in the 0~100 cm depth was low. As the number of years of drip irrigation increased, soil salt content in the 0~100 cm depth decreased. Soil salt content in the surface depth after 1 years of drip irrigation was not significantly different from that after 3 years drip irrigation. Soil salt content after 8 years of drip irrigation was not significantly different from that after 10 years of drip irrigation. In conclusion, soil salt content in the Manasi River Basin was significantly affected by landform, groundwater depth, land use, and the number of years of drip irrigation. These factors also significantly affected the distribution of salt in the soil profile.