AN APPLICATION OF A PHYSICALLY BASED SEMIDISTRIBUTED MODEL TO THE BALQUHIDDER CATCHMENTS

A physically based semi-distributed model, TOPMODEL, is applied to the two catchments at Balquhidder. The model uses a topographic index whi ch highlights hydrologically significant areas within the catchments. The model is used to simulate runoff and to compare the behaviour of t he two catchments. The results indicate that a large proportion of str eam water is generated from saturated contributing areas (source areas ); the Monachyle has higher contributions of water of this type. The r esults may also indicate that the hydrology of the Monachyle catchment has changed following agricultural improvement by increased drainage; a damped subsurface response is observed.