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

Abstract

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 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 most of Hunan, western and eastern Hubei, southeastern Jiangxi, eastern Guangdong, central and western Fujian, eastern Sichuan, northern Chongqing and southern Gansu. The sub-high development areas occupy 566 counties in total, involving 25 provinces, mainly occurring in most of Sichuan, western and southern Yunnan, southeastern Hunan, northern Hubei, most of Jiangxi and Guangdong, Guangxi, Fujian and Zhejiang, southwestern Guizhou, southern Shaanxi and eastern Jilin. The moderately development areas cover 623 counties in total, involving 30 provinces, mainly occurring in most of Xinjiang, Tibet, Gansu, Hebei, Shanxi and Henan. The low development areas occupy 1336 counties in total, involving 30 provinces, mainly occurring in Qinghai, most of Tibet, northern Gansu, Inner Mongolia, Heilongjiang, western Jilin and Liaoning, eastern and southern Hebei, Shandong, eastern Henan, central and northern Anhui and Jiangsu. 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 scientific and reasonable than before.