Keywords
hydrological modelling, ungauged basins, remote sensing, snow melt
Start Date
1-7-2006 12:00 AM
Abstract
Development of methodologies to achieve a priori parameter estimation of hydrological models is fundamental in ungauged basins. This study shows that a semi-distributed physical model can be applied to ungauged watersheds in Lebanon and its parameters can be estimated using physical approach and remote sensing techniques. Most of the Lebanese coastal watersheds are affected by an important seasonal snow cover. The snowmelt contributes up to about two thirds of the total yearly discharge of the catchments. Most snowmelt water infiltrates the limestone and discharges at several karsts springs. A physical model based on the snowmelt mechanisms using the standard energy balance approach and a degree-day melting model allows simulating several spring discharges within the Nahr el Kelb and Nahr Ibrahim catchments. The snow cover area was calculated by combining TM5 images with a digital elevation model, and field observations made every three days, from 1400 to 2300 m altitude. Each subbasin is semi-distributed and divided into zones according to altitude. Therefore, this model was applied to Afqa spring, and the physical parameters were estimated. This model was validated on four other springs considered as ungauged basins.
River Flow Simulation within Ungauged Catchments in Lebanon using a semi-distributed rainfall-runoff model
Development of methodologies to achieve a priori parameter estimation of hydrological models is fundamental in ungauged basins. This study shows that a semi-distributed physical model can be applied to ungauged watersheds in Lebanon and its parameters can be estimated using physical approach and remote sensing techniques. Most of the Lebanese coastal watersheds are affected by an important seasonal snow cover. The snowmelt contributes up to about two thirds of the total yearly discharge of the catchments. Most snowmelt water infiltrates the limestone and discharges at several karsts springs. A physical model based on the snowmelt mechanisms using the standard energy balance approach and a degree-day melting model allows simulating several spring discharges within the Nahr el Kelb and Nahr Ibrahim catchments. The snow cover area was calculated by combining TM5 images with a digital elevation model, and field observations made every three days, from 1400 to 2300 m altitude. Each subbasin is semi-distributed and divided into zones according to altitude. Therefore, this model was applied to Afqa spring, and the physical parameters were estimated. This model was validated on four other springs considered as ungauged basins.
