Physically based distributed hydrological modelling of the Upper Jordan catchment and investigation of effective model equations

摘要

Sufficient freshwater availability in the water scarce environment of theUpper Jordan Catchment (UJC) is a central prerequisite for peacefulagricultural and industrial development. Hydrological modelling is requiredto understand terrestrial water balance and to provide scientifically soundestimates on water availability.

This article aims at two related objectives: First the water balance of theUJC, a hydrogeologically complex catchment located at the borders of Israel,Syria and the Lebanon, is investigated. It is for the first time that aphysically based model is set up for this region that accounts both for theentire terrestrial water balance and in particular for thegroundwater-surface water interaction. It is shown that the model is able todescribe observed river discharges satisfactorily.

Secondly, it is investigated if observed and simulated runoff components canbe explained by simple lumped approaches based on 1) linear filter theoryand 2) neural networks and what the number of degrees of freedom for therunoff components is. It is exemplary shown for the Ayun subcatchment of theUJC that the simulated river discharge, the direct runoff component and the interflowrunoff component as modelled by the physically based distributedhydrological model WaSiM can be described by simple effective equations with only3 to 5 degrees of freedom. Application of simple lumped approaches toobserved river discharge values showed much weaker performance.