## 4 Characterization of the Evolution of the Landslide Disaster Chain
### Types of Landslide Disaster Chain Evolution  
Multiple secondary disasters have been created as a result of landslide catastrophes, producing a chain-type evolution network comprising several disasters. [PERSON] [51] classified various disaster chain developments into a chain-type disaster chain, a dispersed disaster chain, a centralized disaster chain, a shuttle-type disaster chain, and a network-type catastrophe chain. The Baige landslide disaster chain is made of cascade, dispersed, focused, and shuttle catastrophe chains, according to a review of historical landslide incidents on the Qinghai-Tibet Plateau.  
(1) Cascade disaster chain  
A cascading catastrophe chain is a sort of unidirectional continuation of the evolution of a single hazard type that produces other types of danger during the evolution of the hazard. As illustrated in Figure 6, following the Baige landslide, the landslide mass carried dirt and stones into the Jinsha River channel, leading to the obstruction and diversion of the river channel and the formation of a barrier lake. This, in turn, resulted in a downstream flood disaster when the lake water breached its barriers. The preceding tragedy is the beginning point for the following disaster in a cycle of cascading disasters. Controlling the emergence of the aforementioned disaster or cutting off the link between the two disasters might help to avoid the development of subsequent disasters.  
(2) Dispersed disaster chain  
A dispersed disaster chain represents a type of disaster chain evolution in which hazards branch into various sub-hazards that extend outward like veins. As shown in Figure 7, the release of water from the dammed lake reservoir occurred after the obstruction of the Jinsha River channel, giving rise to floods, debris flows, secondary landslides, and surges. In a dispersed disaster chain, source hazards can lead to multiple forms of hazard concurrency, and by controlling the originating hazard from occurring or cutting of the connecting edges, subsequent hazards will not occur.  
(3) Centralized disaster chain.  
Concerning the manifestation of the evolutionary network, the focused disaster chain and the dispersed disaster chain exhibit a reciprocal relationship, branching into numerous  
Figure 6: Cascading landslide disaster chain.  
Figure 7: Dispersed landslide disaster chain.  
secondary disasters during their evolution into a comprehensive and highly destructive disaster format. As shown in Figure 8, after the Baige landslide, secondary disasters such as mudslides, rock flows, and floods continue to induce secondary disasters, resulting in damage to power facilities, shipping accidents, animal husbandry, and business stoppages. This series of disaster events has jointly evolved into economic loss events. In the concentrated disaster chain, a single control of a disaster event or connecting edge cannot prevent the occurrence of subsequent disaster events. Given the challenge of entirely averting the emergence of all disaster elements, it is often necessary in practice to manage the consequences of each disaster event to mitigate the extent of harm.  
(4) Shuttle disaster chain  
The shuttle-type disaster chain is distinguished by the mutual interweaving, intersection, and transition of multiple disaster types during its evolution, while still preserving the cumulative trend of multiple disaster species. As shown in Figure 9, the rupture of the barrier lake dam triggered a secondary landslide disaster, which, in turn, triggered a debris flow. Both of those events could lead to transportation gridlock and power disruptions, jointly triggering a series of disasters such as delayed rescue, railway accidents, and communication accidents, forming a potential risk of casualties. The form of a shuttle disaster chain is intricate, with multiple disasters frequently occurring in tandem, influencing, intersecting, and interpenetrating each other.  
Figure 8: Centralized landslide disaster chain.  
Figure 9: Shuttle landslide disaster chain.