Types of geological disasters

In the classification of geological disasters, according to the field investigation data of 293 landslides, 52 collapses and 5 1 unstable slopes that cause disasters or have potential hazards, natural geological phenomena such as landslides and collapses that do not cause disasters or have potential hazards are not considered.

According to the Specification for Detailed Investigation of Landslide, Collapse and Debris Flow Disasters issued by China Geological Survey in 2005 (1: 50000), combined with the actual situation in the investigation area, the main types of geological disasters are divided into three categories: landslide, collapse and unstable slope, and the basic types are further divided into 38 categories, such as soil landslide, shallow landslide and traction landslide. Table 3-5 lists the names of the main types, classification indicators and their development percentage in the total number of types. Landslide occurrence time (Figure 3-2), landslide stability (Figure 3-3), landslide thickness (Table 3-6), landslide scale grade (Table 3-7), collapse formation mechanism (Figure 3-4), main reasons for slope instability (Figure 3-5), landslide sliding surface position (Table 3-8) and collapse formation mechanism.

Table 3-5 Classification and Main Types of Geological Hazards (and Hidden Dangers)

sequential

Figure 3-2 Proportional Pie Chart of Landslide Occurrence Times

1- ancient landslide; 2- Old landslide; 3- Modern Landslide

Figure 3-3 Histogram of landslide stability ratio

1-unstable; 2- basically stable; 3- stability

Table 3-6 Statistics of Landslide Thickness

Table 3-7 Statistics of Landslide Scale and Grade

Figure 3-4 Proportional Histogram of Collapse Formation Mechanism

1-dump type; 2- sliding type; 3- expansion type; 4- split type; 5- staggered type

Figure 3-5 Pie Chart of Main Causes of Unstable Slope

1- human engineering economic activities are the main activities; 2- Natural causes are dominant.

Table 3-8 Landslide Classification Table by Development Position of Sliding Surface

Table 3-9 Classification of Formation Mechanism of Regional Collapse