Hydrographs are an important tool for the representation of hydrological data such as precipitation, groundwater levels or discharges.
HM 141 produces precipitation of varying duration and intensity. The storage capacity of soils with different saturation is also examined. Using various drainage methods, it is possible to demonstrate the correlations between precipitation and seepage.
The trainer includes a tank with a sand filling, which is flowed through by water. The water is supplied to the tank via a precipitation device with two nozzles that can be adjusted separately via valves. To study different drainages, the water is drained either via a drainage pipe or a drain chamber, which is separated from the experimental section by a screen.
The draining water is distributed over 17 transparent chambers. This creates a profile over time of the water drain. The water levels are measured and plotted in a hydrograph.
Drip pans can be used to demonstrate the lag of the drainage through rainwater retention basins.
The water supply is controlled by a valve and read on a flow meter. The timed discharges are adjusted via electronic timers.