## 3 Results
### Engineering geology
#### 3.3.1 Geological Disasters and Disaster-Inducing Factors  
The Qinghai-Tibet Plateau's geomorphological pattern--characterized by interlaced mountain ranges and lake basins--combined with complex geological structures, hydroclimatic conditions, and anthropogenic engineering activities, jointly shapes the unique spatial distribution characteristics of collapses, landslides, and debris flows (CLD), which exhibit pronounced spatial heterogeneity. As shown in Table 2, Comprehensive Zones I-III represent high-density hazard areas, with CLD densities of 1.10, 1.21, and 1.04 events per 100 km\({}^{2}\), respectively, accounting for a combined 84.32% of all hazard events. Zone IV exhibits a moderate density of 0.30 events per 100 km\({}^{2}\). This pattern closely correlates with geological structures and topographic conditions. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Zoning of Disaster-Inducing Environments** & **Area/km\({}^{2}\)** & **Collapse** & **Landslide** & \begin{tabular}{c} **Debris** \\ **Flow** \\ **(One)** \\ \end{tabular} & \
\begin{tabular}{c} **Small** \\ **Plan** \\ **(One)** \\ \end{tabular} &
\begin{tabular}{c} **Density/** \\ **Place** \(\times\) \\ **(100 km)\({}^{-2}\)** \\ \end{tabular} & **Percentage/\%** \\ \hline Alpine Valley Freeze–Thaw & & & & & & & \\ Tectonic Zone (I) & 532,429 & 910 & 1012 & 3960 & 5882 & 1.1 & 42.51 \\ Alpine Canyon Tectonic-Erosion & & & & & & & \\ Zone (II) & 396,643 & 963 & 1739 & 2105 & 4807 & 1.21 & 34.74 \\ Alpine Freeze–Thaw Tectonic & & & & & & & \\ Active Zone (III) & 85,036 & 168 & 334 & 380 & 882 & 1.04 & 6.37 \\ Faulted Basin Weather & & & & & & & \\ Fragmentation Zone (IV) & 303,823 & 180 & 89 & 632 & 901 & 0.3 & 6.51 \\ Permafrost-Vaathered Rock Belt (V) & 254,436 & 255 & 34 & 213 & 502 & 0.2 & 3.63 \\ Permafrost-Nival erosion Zone (VI) & 394,924 & 124 & 58 & 343 & 525 & 0.13 & 3.79 \\ Alpine Hard Rock Freeze–Thaw & & & & & & & \\ Debris Zone (VII) & 462,211 & 29 & 5 & 109 & 143 & 0.03 & 1.03 \\ Alpine Lake Basin Saline Soft & & & & & & & \\ Rock Zone (VIII) & 149,773 & 69 & 7 & 119 & 195 & 0.13 & 1.41 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Statistical table of geological hazards in integrated zoning (I–VIII). Figure 8: Map of engineering geology factors in disaster-inducing environments. (**a**) Distribution of CLD hazards and their correlation with engineering geology; (**b**) relationship between engineering geological zoning and CLD hazard quantity/density. Comprehensive Zone I, located in the Himalaya-Gangdese Mountains, is shaped by the ongoing collision between the Indian and Eurasian plates, resulting in densely developed fault systems, fragmented rock masses, and extreme topographic relief--all of which provide abundant material sources and gravitational potential for collapses and landslides. Zone II, situated in the Hengduan Mountains and western Sichuan region, is defined by the deeply incised valley landscape formed by the \"Three Parallel Rivers\" geomorphology, and is highly prone to debris flows triggered by concentrated monsoonal rainfall [56]. Zone III, in the Qilian Mountains, frequently experiences CLD events due to active tectonic fragmentation combined with localized precipitation and snowmelt processes [57]. Zone IV, positioned along the margins of the Qaidam-Gonghe-Huangshui Basin, is characterized by intense weathering and an abundance of loose clastic material; under the influence of snowmelt and short-duration heavy rainfall, debris flows and collapses are readily triggered [58]. In Zone V (Eastern and Western Kunlun Mountains), intense tectonic uplift and freeze-thaw weathering have led to the accumulation of thick surficial debris layers. Under the joint action of glacial meltwater and sudden precipitation, debris flows and periglacial collapses and landslides frequently occur [59; 60]. By contrast, Zones VI-VIII, located in the Qiangtang Plateau, Karakoram, and Tanggula Mountains, are characterized by gentler terrain and sparse human activity, resulting in significantly lower hazard densities.