Item Description

The experiments are performed in a rectangular stainless steel tank filled with a granular medium, where a permeable catchment area has been formed. The inclination of the catchment is simulated by providing inclination of the catchment using stainless steel sloping system.

A series of spray nozzles are used to simulate the rainfall. A valve controls the number of spray nozzles in operation, making the rain fall on either all or half of the catchment and thus enabling a moving storm to be simulated and/or the lag time on the hydrograph to be varied. The tank is well equipped with the methods of filling and draining.

Two wells are provided in the middle of the tank and a row of piezometer tapings are connected to a water manometer to enable the water table profile to be determined. Water supply is drawn from the large reservoir tank by using a high-pressure pump and is then delivered to either the spray nozzles and/ or the end(s) of the tank via a system of valves. The supply to each ends of the tank can be independently varied and the total flow is measured by a gap meter.

A calibrated weir adjacent to the reservoir tank allows the measurement of the runoff from the catchment and the flow of the wells. The apparatus is a freestanding self-contained unit, and require only a main electrical connection for operation. A suitable grade of sand is also included.