RHU Unité de l'hydrologie des Précipitations

The main element of the Rainfall Hydrographs Unit,"RHU", is a tank mounted on a frame. The tank can be filled with sand. There are removable curtains to prevent splashing.

There are two square pattern spray nozzles at the top that supply water to the sand. Water, before being sprayed, passes through a flow control valve, a flowmeter and a solenoid valve controlled with the electronic console.

The drainage of the system is driven towards one end of the tank, through which water leaves towards a collection and measurement system, mounted on another frame. The collection system consists of a vessel divided internally into 17 storage compartments and a central drainage channel. Its frame includes a drive motor that allows its displacement to a controlled velocity under the tank outlet, thus enabling an immediate visualization of the hydrograph. The motion time of the system is measured and visualized in the console to be able to obtain an immediate hydrograph of the drainage in function of time.

The unit includes several accessories to analyze the surface retention, the storage effect in depressions and land drainage.