渭河两岸缓冲带的土壤有机质含量分布特征及其影响因子

Distribution Characteristics and Influential Factors of Soil Organic Matter Content at Buffer Zone Along Weihe River

选取陕西省内渭河沿岸南北3 000 m缓冲区为研究区,利用野外调研、室内实验处理并应用GIS、ENVI、SPSS等软件,分析了土壤有机质的空间分布特征及影响因子,为渭河沿岸生态环境治理与修复提供理论依据。结果表明:渭河沿岸土壤有机质平均含量范围6.3~22.5 g/kg,有机质含量较低。渭河沿岸缓冲带区内南北两岸土壤有机质含量在1 000 m范围内随着距离的增加而增加,1 000 m范围外随距离增加而减少或基本不变;渭河沿岸的土壤有机质平均含量上游最高,下游次之,中游最低。土壤有机质的影响因子有地形因子(高程、坡度)、植被覆盖度和土壤质地。其中土壤有机质与高程、植被覆盖度(NDVI)和土壤颗粒中粉砂百分含量呈正相关,特别是高程因子与土壤有机质表现为显著相关;而土壤有机质与坡度、土壤颗粒中砂粒百分含量呈负相关。

In order to provide theoretical bases for the rational management and remediation of ecological environmentalong the Weihe River in Shaanxi, this study targeted at 3000 m-buffer zone along the Weihe River and the spatial distributioncharacteristics of soil organic matter （SOM） content and its influential factors were analyzed by field survey and laboratorymeasurement with the application of GIS, ENVI, SPSS and other software. Results showed that SOM content was low along theWeihe River, meanly ranged from 6.3 to 22.5 g/kg; On both north and south sides along the Weihe River, SOM content increasedwithin 1 000 m away from the river bank, and then reduced or remained unchanged outside 1 000 m range; The average SOMcontent was highest in upstream, followed by downstream and by midstream. Topographic factors （elevation, slope）, NDVI andsoil particle composition were influential factors of SOM. SOM had positive correlations with elevation, NDVI and siltpercentage, while it had negative correlations with slope and silt percentage.