# Spatial Evolution Analysis of Tailings Flow from Tailings Dam Failure Based on MacCormack-TVD
## 4 Tailings Industrial Area Slope Maps and Dam Failure Simulation Conditions
### Initial Conditions of the Model
The evolution of the dam failure tailing sand flow can be seen. In the dam failure just started within 12 s of the tailing sand flow along the collapse of the caliber of the direction of movement into the first larger corner, due to the corner of the west side of the mountain height being lower, while the tailing sand flow velocity is larger, resulting in the formation of tailing sand flow diversion here due to the narrower ditch and the drop of about 90 m, the tailing sand flow velocity increased rapidly. At the flow distance of more than 350 m after the ditch, the topography gradually became gentle and open. After the flow distance exceeded 350 m, the topography gradually became smooth and open, and at this time, due to the faster speed of the tailings flow just washed out, it did not form an obvious accumulation of tailings flow directly to the pumping pool. Then, the arrival of the tailings flow rate is reduced, and there is an obvious accumulation in this location; the accumulation of tailings at this location impedes the subsequent transport of tailings, slowing down the flow rate and deposition of tailings, while the tailings head of the flow still continues to move downstream. There is the emergence of inundation areas 400 m from the tailings dam ditch entrance to the tailings dam's 400 m ditch mouth at the center of the expansion to the four sides; a ditch inundation area to the west back to 3000 s from \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Degree of Danger** & **Risk Level** & \begin{tabular}{c} **Maximum** \\ **Flow Depth** \\ **H (m)** \\ \end{tabular} & \begin{tabular}{c} **Logical** \\ **Relationship** \\ \end{tabular} & \begin{tabular}{c} **Flow Intensity V \(\times\) H (m/s), Flow** \\ **Velocity \(\times\) Flow Depth** \\ \end{tabular} & **Description** \\ \hline High & 3 & H\(\geq\) 3 & Or & vh \(\geq\) 3 & \begin{tabular}{c} Injuries, destruction of houses, serious \\ damage to facilities \\ \end{tabular} \\ \hline Medium & 2 & 1\(\leq\) H \(<\) 3 & And & 1\(\leq\) vh \(<\) 3 & \
\begin{tabular}{c} Injuries to people, damage to houses, \\ damage to other facilities \\ \end{tabular} \\ \hline Low & 1 & 0.2\(\leq\) H \(<\) 1 & And & 0.2\(\leq\) vh \(<\) 1 &
\begin{tabular}{c} Small probability of injuries, damage to \\ houses and other facilities. \\ \end{tabular} \\ \hline Ultra-low & 0 & H \(<\)0.2 & Or & vh \(<\)0.2 & Safe area \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Classification of the disaster degree risk level of the project. Figure 12: Tailings pond disaster level cloud map. the beginning of the dam failure reaches a temporary balance, to stop continuing to the west and north expansion of tailings which continue to expand to the west. According to the results of the analysis of the degree of disaster and the impact of the downstream settlements, it is necessary to increase the safety protection measures in the affected area. The project expansion tailings dam breach tailings flow did not threaten the tailings pond downstream of the mining settlement area, and for a 700,000-ton resource utilization project, the degree of risk is acceptable.