An attempt to monitor seasonal dynamics of soil salinization in the Yellow River Delta region of China using Landsat data

Abstract

Abstract. Monitoring seasonal dynamics of soil salinization is necessary with distinct seasonal climates. The article is to explore the optimal inversion models of soil salinity content (SSC) in different seasons and to achieve the spatial distribution and seasonal dynamics of SSC in Kenli district in the Yellow River Delta (YRD) region of China. Based on the Landsat data in 2013, the improved vegetation indices (IVI) were constucted, which were then applied in the SSC inversion model construction. Finally, the SSC optimal model in each season was extracted, then, the spatial distributions and seasonal dynamics of SSC in four seasons were analysed. The results indicated that the support vector machine (SVM) method resulted in the best inversion models. The SSC best inversion model of spring was also determined as the optimal model of winter, similarly, the best model of autumn was also as the optimal model of summer. The SSC exhibited a gradually increasing trend from the south-west to the north-east in Kenli district, and its seasonal dynamics were as that soil salinity accumulates in spring, decreases in summer, rises in autumn, and peaks in winter. This work would provide data support for the treatment and utilization of saline alkali soil in the YRD region.