Why can’t scientists directly monitor and measure the real effects of rain in the countryside? “The greatest soil loss and erosion accompany or follow rainstorms and sudden violent storms. These phenomena are not captured by mean statistics, and we cannot predict their occurrence in advance, let alone control their parameters. Since we are in point of fact unable to control the wind and storms, we have built, like other colleagues in our field, a rain simulator.”
Structure of the simulator
The actual technical design was preceded by complex physical considerations. Did you know that the speed of a raindrop depends on its diameter? Big raindrops fall faster due to gravity, but gradually a speed limit is reached at which the forces of gravity are matched by forces of friction. This ultimate speed is reached during a fall from a height of approx. 9 metres. No device used so far uses the real impact speeds of raindrops. However, compensation in the form of increased water flow may have a negative effect on results.
In order to approach real-life conditions as closely as possible, scientists at BUT have constructed a simulator which looks more or less like a 9 m tall shower stall. Through a simple yet sophisticated structural design, which we have industrially protected, scientists let water fall from the “shower head”. Based on precise calculations, flow is deflected so that it “rains” evenly. The equipment enables the intensity of rain to be regulated. Artificial rain falls on a soil sample lying 9 metres below, where we can monitor soil loss and erosion processes, the soaking capacities of different soil covers and other properties. The artificial terrain can be tilted at various angles, which is used for modelling erosion on a slope. In the laboratory, extra layers may be added to the sample and e.g. vegetative cover may be grown on it, or can be removed directly from the examined locality.
The obtained data and models can be used e.g. in formulating recommendations for anti-erosion measures in the landscape. The real rain simulator is the result of an applied research project carried out in cooperation with the company Dekonta, a.s.
The introductory image Rain Drops by weimieweim is under the license of CC BY-2.0
