## 5 Study on the Evolution Network Model of the Landslide Disaster Chain  
### Construction of a Landslide Disaster Chain Evolution Network Model  
The evolution network structure of the landslide disaster chain is intricate, encompassing a variety of causal relationships, including one cause and one effect, one cause and multiple effects, and one effect and multiple causes [52]. Through an analysis of the chain's evolutionary stages and the types of the Baige landslide on the Jinsha River, we have identified 31 disaster elements that are part of the landslide disaster chain (Table 2). A complex network structure composed of multiple nodes and directional connecting edges is selected as a research tool, and the relationship between a disaster event and each disaster event is abstracted into the points and edges of the network, that is, 31 nodes represent 31 landslide disaster crisis elements, 77 directional connecting edges represent the development relationship between crisis elements, and directional arrows represent the disaster evolution direction. Therefore, an undirected disaster network, that is, a landslide disaster chain evolution network model, is constructed, as shown in Figure 10. A node in the network represents a disaster event, and the loss caused by the disaster is measured by the degree of the node. The degree of the node reflects the impact of the disaster event, including the loss of the disaster and the relationship between the disaster and other disasters. \begin{table}
\begin{tabular}{c c c c c} \hline
**Node** & **Disaster Event** & **Node** & **Disaster Event** & **Node** & **Disaster Event** \\ \hline V1 & Landslide & V12 & Dam break & V23 & Farmland destruction \\ V2 & Debris flow & V13 & Overflow & V24 & Plague/infectious disease \\ V3 & Microseism & V14 & Bank collapse & V25 & Industrial/enterprise shutdown \\ V4 & Blocking the river & V15 & Water supply accident & V26 & Shipping accident \\ V5 & Beach risk & V16 & Crop yield reduction & V27 & Livestock industry suffers \\ V6 & Swell & V17 & Secondary landslide & V28 & Bridge washout \\ V7 & Barrier lake & V18 & Backwater & V29 & Destroy water conservancy facilities \\ V8 & Cutoff & V19 & flood & V30 & Economic loss \\ V9 & Washed vegetation & V20 & Road damage & V31 & Casualties \\ V10 & Downstream water hazard & V21 & Electrical disruption & & \\ V11 & Damaged soil surface & V22 & House destruction & & \\ \hline \end{tabular}
\end{table} 
Table 2: Risk evolution disaster events of landslide disaster chain. The adjacency matrix is a representation of connections between vertices, and it serves as a two-dimensional array for storing the connecting edges between vertices. This matrix allows for the rapid identification of connection relationships between two nodes, simplifying the calculation of each node's degree. It can be divided into directed adjacency and undirected adjacency by analyzing the disaster events included in the disaster chain of the evolutionary network model and the connection between events and extracting the 31 \(\times\) 31 \"node connecting edge\" adjacency matrix (Figure 11). The rows and columns of the matrix correspond to 31 disaster nodes (V1 to V31), and the adjacency matrix clearly illustrates the undirected relationship between the 31 hazard events. If there is a triggering  
Figure 10: Evolution network model of the landslide disaster chain. (Note: Due to the prompt evacuation of personnel, no casualties resulted on Baige slope. However, given that other landslides could potentially result in casualties, the dotted line is employed to denote the connecting line of events related to casualties in the model). relationship between disaster event \(V_{i}\) and disaster event \(V_{j}\), the corresponding matrix unit is 1. If there is no triggering relationship between disaster event \(V_{i}\) and disaster event \(V_{j}\), the corresponding matrix unit is 0.