Study on spatial variability evaluation of hydrometeorological elements based on TOPSIS model

Abstract

The spatial variability evaluation of hydrometeorological elements under the impact of climate change and human activities is important for the water utilization and management in the river basin. In this study, a case study is conducted in the Daqing River Basin (DQRB) of China. The spatial variability index system is constructed in the DQRB, and the spatial variability characteristics are comprehensively analyzed and evaluated by geostatistical method and technique for order preference by similarity to an ideal solution (TOPSIS) model. The results show that (1) the nugget-to-sill ratios of the models selected for different hydrometeorological elements in plain and mountain areas are all less than 75%, indicating that the spatial structure of hydrometeorological elements has moderate or strong spatial autocorrelation (SPA). Moreover, the spatial heterogeneity is strongly influenced by structural property (STP). (2) The variability is mainly caused by variability component (VAC) and anisotropy (ANI), and the variability intensity (VAI) is the least likely to occur in the spatial variability. (3) The hydrometeorological elements in plain and mountain areas are mainly characterized by moderate or moderate-strong spatial variability. Meanwhile, the temperature and evaporation in plain area are more likely to have strong spatial variability, with comprehensive evaluation scores of 0.691 and 0.634, respectively. It shows that the effect of regional climate change is significant, and the plain area is more affected and should be paid more attention to. This study can provide a new idea for quantitatively evaluating the spatial variability of hydrometeorological elements in other regions.