Conceptual hydrological approach to a geologically complex basin with scarce data: the Hula Valley, Middle East

The Hula Valley in the Middle East is a cross-border hydrogeological system. A highly complex hydrogeological framework and the absence of production or even observation wells poses difficulties in modeling this hydrogeological basin. Various tools were used to overcome the scarcity of data and the hydrogeological complexity to create a reliable conceptual hydrological model. The isotopic δ¹⁸O ratio was used to distinguish between two hydrogeological units in the alluvium fill of the valley, which are recharged from the different regional and local aquifers surrounding it. Abundant gas boreholes that discharge a mixture of natural gas and groundwater were equipped, measured and sampled to obtain valuable hydrological data such as hydraulic head and transmissivity of the hydrogeological units in the valley. These findings were integrated with geological analyses of the subsurface flow domain to construct the first conceptual hydrological model of the unclear Hula Valley groundwater flow system. The described methodology to overcome lack of hydrogeological data might be relevant to complex hydrogeological basins worldwide with scarce hydrological information.