A study of the evaluation of geo-hazards development degree based on time-space coupling

The geo-hazards comprehensive evaluation index system was established in the early stage of the team, and the number, the number density, the volume and the volume density, which reflect the spatial dimension, are used to evaluate the development degree of geo-hazards, excluding the evaluation factors reflecting the time dimension. In this paper, disaster years reflecting the time dimension are introduced to enrich the development degree evaluation system of geo-hazards. The median logarithmic method and probability density distribution are respectively used to processing data of disaster years and volume, and the entropy weight is used to determine the weight of evaluation factors. The evaluation models are established and the evaluation results are divided into four levels by the slope method, reflecting the development status of disasters. The geo-hazards occurred in 31provinces in China (excluding Hong Kong, Macao and Taiwan) from 2011 to 2020 are taken as examples, the development degree of geo-hazards (landslide, collapse and debris flow) is evaluated and divided according to this method. The results show that the geo-hazards high development areas cover 323 counties in total, involving 19 provinces, mainly occurring in Southeast China, Southwest China and Northwest China. The sub-high development areas cover 566 counties in total, involving 25 provinces, mainly occurring in Southwest China, South Central China and Southeast China. The moderately development areascover 623 counties in total, involving 30 provinces, mainly occurring in Northwest China and North China. The low development areas cover 1336 counties in total, involving 30 provinces, mainly occurring in North China, Northeast China and East China. When compared with the national disaster prevention deployment situation or the geo-hazards distribution, the evaluation results are in good agreement with the reality. In addition, through field investigation, the evaluation results are more consistent with the actual situation.