Analysis of macro and micro freezing characteristics of gravelly soil.

To investigate the mechanism of effect of different gravel contents on freezing characteristics of gravelly soil, macroscopic and microscopic experiments were combined. Unidirectional freezing experiment and NMR experiment were conducted on gravelly soil, with gravel contents of 0%, 10%, 20%, 30%, 40% and 50%. In unidirectional freezing experiment, final temperature, stratified moisture content and frost swelling of the samples showed a parabolic pattern with an upward opening about the gravel admixture.

Spatial-Temporal Sensitivity Analysis of Flood Control Capability in China Based on MADM-GIS Model.

To facilitate better implementation of flood control and risk mitigation strategies, a model for evaluating the flood defense capability of China is proposed in this study. First, nine indicators such as slope and precipitation intensity are extracted from four aspects: objective inclusiveness, subjective prevention, etc. Secondly, the entropy weight method in the multi-attribute decision making (MADM) model and the improved three-dimensional technique for order preference by similarity to ideal solution (3D-TOPSIS) method were combined to construct a flood defense capacity index evaluation system.