Implications of maximum daily precipitation on streamflow of a watershed: a case study in Zacatecas, Mexico

ABSTRACT

In this article, we present the results of the analysis of a flood event that occurred on 18 July 2008 in the town of Tlaltenango, Zacatecas, Mexico. The flood was caused by a storm that reached an accumulated precipitation of 145 mm/day. The event was caused by the passage of hurricane Fausto that produced an intensification of moisture transport to the mainland channelled by topography. The storm event was simulated using the Mesoscale Model version 5 (MM5). The hydrologic model Hydrologic Engineering Center (HEC)-1 was then employed to determine the run-off hydrographs and streamflows. Finally, the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model predicted water levels by integrating information about channel geometry and characteristics such as roughness. The numerical results show that the map of the flooded area as simulated by the HEC-RAS model matches the observed inundation extent for this event well. The calculated values for water levels were quite similar to those directly recorded by civil protection authorities in the urban area. Despite the recent history of recurring flood events, plans and strategies have not been implemented to reduce flooding.

Keywords:

• Flood event
• hydraulic modelling
• heavy rainfall