System Dynamics Flood Modeling Framework for Dam Failure Evacuation Planning in Developing Countries

摘要

Currently, available flood modeling approaches require High-Performance Computing (HPC) software and high-resolution terrain data. Developing countries with unstable dams face challenges in accessing these technologies and acquiring the required data elements. This project developed a dynamic flood modeling methodology, using established hydrological assumptions, that implemented simulation and optimization models to determine safe evacuation routes by using public datasets, publicly available technical expertise, and common computing capabilities. The Péligre Dam in Haiti was the case study site since data from an HPC model was available for results comparison. QGIS was used to extract the “water flow factors” which are: (i) channel slope, turns, and shape; (ii) major channel obstructions and channel terrain; (iii) floodplain shape; and (iv) major floodplain obstructions and floodplain terrain. A system dynamics model was created to simulate water flow as a function of time using Vensim. This model used the water flow factors as inputs and produced the following key outputs: (i) volumetric flow rate $(mathrm{Q}_{mathrm{i},mathrm{t}})$, (ii) water height over time $(mathrm{h}_{mathrm{i},mathrm{t}})$, (iii) time when actual flooding begins (ChannelMAX), and (iv) time of maximal flooding (FloodplainMAX). The results were plotted, and the root mean square errors were calculated to visualize the extent to which the results from the systems dynamics model compare with the HPC software results. Evacuation routes were modeled with the shortest path algorithm by minimizing the feasible travel distance between at-risk populated areas and safe-high-ground areas with route constraints based on the system dynamics model’s output. The validity of the results demonstrates that the proposed methodology can adequately model inundation and reliable evacuation routes for dam failure scenarios in developing countries.