Simulation of overflow thresholds in urban basins: Case study in Tuxtla Gutierrez, Mexico

The space-time dynamics and the effect of urban growth on territory transformation were simulated withIber2D to analyze flooding events in the lower basin of the Sabinal River, Mexico. We classified the main coverages and land uses of the study area. Soil roughness and water infiltration in the soil were evaluated. Both values were used as input data in a simulation model withIber2D to analyze and compare the levels of water height and maximum flood level area with different precipitation values in two reference years, 1986 and 2014. Residential use land cover increased considerably while tree, pasture and agricultural use covers decreased. Consequently, in 2014, precipitation of similar magnitude led to higher values of direct runoff, increasing water levels and therefore the risk of overflowing. The water levels and moments of river overflow provided feedback for flood-risk warning systems and tools to monitor basins lacking adequate infrastructure.