Rapid urban expansion into flood-prone areas and the disruption of natural drainage routes have increased Tetouan’s vulnerability to heavy rainfall, particularly in low-lying areas connected to the Martil River basin, a scientific study has found. The study, titled “Urban Flood Risk Assessment for Urban Planning Using Two-Dimensional Hydraulic Modeling: The Case of Tetouan, Morocco,” examined […] The post Study: Rapid urban growth leaves Tetouan more vulnerable to flooding appeared first on HESP
Rapid urban expansion into flood-prone areas and the disruption of natural drainage routes have increased Tetouan’s vulnerability to heavy rainfall, particularly in low-lying areas connected to the Martil River basin, a scientific study has found.
The study, titled “Urban Flood Risk Assessment for Urban Planning Using Two-Dimensional Hydraulic Modeling: The Case of Tetouan, Morocco,” examined the city’s exposure to extreme rainfall events using two-dimensional hydraulic modeling.
The researchers found that Tetouan’s surrounding terrain, characterized by steep slopes, accelerates and concentrates surface runoff toward the Martil plain. During periods of heavy rainfall, this flow could exceed the capacity of existing stormwater drainage networks, according to the study.
Researcher Salah Eddine Zahli used the HEC-RAS hydraulic modeling software to assess flood risks, along with the ArcHydro tool to process terrain and drainage-network data.
The study modeled two flood scenarios: one corresponding to a rainfall event with a 50-year return period and another based on a 100-year event, allowing researchers to assess the city’s exposure to extreme rainfall.
The simulations showed significant differences in flood intensity across the city, with several urban areas identified as particularly vulnerable. Water depths in some locations could approach 2 meters during extreme rainfall events, the study found.
Water flow speeds could also exceed 2 meters per second in some areas, highlighting the danger posed not only by the volume of water but also by the force and speed of flooding to people, property and infrastructure.
The findings indicate that flood risk is influenced by more than rainfall levels alone. Terrain, urban expansion, changes in land use, the obstruction of natural drainage channels and limited stormwater infrastructure all contribute to the city’s vulnerability, according to the study.
The research produced a series of flood-risk indicators and maps, including maps showing water depth, flow velocity and overall risk levels. These tools can help identify the urban areas most exposed to flooding.
Zahli said the findings could support urban planning by incorporating flood-risk maps into decisions on where to allow future development and directing new projects and infrastructure away from areas most vulnerable to inundation.
The modeling could also help improve stormwater drainage networks, identify locations requiring urgent intervention and strengthen preparedness for extreme rainfall events, potentially reducing damage and improving the city’s ability to respond to floods.
The study concluded that reducing flood risks in Tetouan will require a comprehensive approach extending beyond the expansion of drainage networks. It called for tighter controls on urban development in vulnerable areas, preservation of natural drainage routes, improvements to hydraulic infrastructure and the integration of digital flood-risk maps into urban planning and development decisions.
The post Study: Rapid urban growth leaves Tetouan more vulnerable to flooding appeared first on HESPRESS English - Morocco News.
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