Mexico City (CDMX) is located in an endorheic basin historically prone to flooding and waterlogging, the recurrence and magnitude of which have intensified in recent decades. However, flood risk assessment tends to focus primarily on the occurrence of intense rainfall to explain this phenomenon. The main objective of this study is to demonstrate that the risk of flooding in Mexico City (CDMX) depends not only on intense rainfall, but also on changes in hydrological vulnerability resulting from the loss of natural vegetation cover. The curve number (CN) method is used to determine hydrological vulnerability and flood risk in CDMX, integrating environmental information and precipitation values. Changes in surface runoff are also determined for 10 watersheds located west of Mexico City, considering urbanization in 1992 and 2021, as well as a non-urbanized scenario. The results indicate that hydrological vulnerability and flood risk increased from acceptable levels to “high” and “very high” levels, mainly in regions where urbanization increased and natural vegetation decreased. It was also identified that, under different levels of precipitation, agricultural and urban land cover have considerably lower infiltration capacities compared to natural land cover, such as forests, which infiltrate more than half of the precipitation. Finally, the increase in surface runoff in the watersheds located west of the city is closely related to the urbanization process and the physical characteristics of the territory. It was also observed that a degraded watershed can generate approximately 90% more runoff than a non-urbanized watershed.
Zúñiga et al. (2026) studied this question.