Flood management in el-Qa'a watershed, Lebanon-using the hydrological model HEC-HMS

Abstract EN

El-Qa'a city, which is located in the northeastern part of Lebanon, is subject to destructive flash floods due to rainstorms events with high intensity and short duration.

Torrents coming from the nearby valleys cause severe damage to houses and properties in the city.

Moreover, floods cause inundation of surrounding agriculture lands resulting in destroying agriculture crops which are the main source of income for the population in that city.

In addition to intense rainfall, misuse of land, absence of land management, uncontrolled grazing practices, and high land degradation are factors which not only contribute to the problem of flash floods, but also leading to a high risk of rapid desertification in the area.

The size of the catchment area contributing to the flash flood of El-Qa'a city is around 18.74 Km2 with an average annual rainfall of 208 mm.

In this catchment, 4 locations which could be potentially used for establishment of pond were proposed.

HEC-HMS model was employed to determine these ponds’ impacts on the flow regime.

Results showed that the constructing of two ponds with total storage volume of 98000 m3 could reduce peak flow by 50%.