The disintegration of the Earth’s surface by flowing water results in soil erosion (loss of soil). At present, this loss of soil can be determined in two ways – particularly by using a model calculation which only gives a model value of the mean loss of soil and which depends on the setting of the input parameters. However, the actual loss of soil at a particular location is not determined, which is many times higher. The real input parameters are very often difficult to determine, so the mean values ascertained for the whole Czech Republic are chosen. Values for the model soil loss acquired this way are generally used to identify the locations of sites endangered by erosion.

Another method which can be used for detecting soil loss caused by water erosion is to use a device – the so-called erosion meter. For this purpose an erosion meter, consisting of a wooden crossbar fitted at both ends on props that touch the terrain surface. The crossbar has holes drilled through it. Through the drilled holes a needle is gradually lowered onto the ground, and its descent down to the surface is recorded. In this way one needle is lowered through each hole and the length of the descent through the hole is recorded, all of which is extremely time-consuming.

One disadvantage in using this method is that the holes in the crossbar are long distances apart, due to which we do not get an accurate profile of the ground surface. Other drawbacks of the device lie particularly in that it only can measure big rills on the soil surface, is very imprecise and can be used for measuring only a small number of profiles of soil surface. In addition, taking measurements with this device is extremely labour intensive, prone to a high error rate due to manual lowering, reading and extracting of the needle, it also does not allow uses to document the measured profile in a simple and comprehensive way and transfer such data for digital processing. No other device which would be able to take direct measurements in the terrain and thus quantify the amount of eroded soil is available in the Czech Republic.

However, a new measuring device, protected as a utility model, has been developed at the Institute of Landscape Water Management at the Faculty of Civil Engineering of BUT by a scientific team headed by Doc.Ing. Miroslav Dumbrovský, CSc. This device eliminates the drawbacks of currently used devices and enables volumetric quantification of the manifestations of water erosion in a more precise, simple, repeatable, documentable and easy-to-evaluate way.

The advantage of this newly developed erosion meter is above all that in contrast to the well-known wooden erosion meter, it allows the measured profile, including small rills, to be measured quickly, thanks to the density of measuring needles and the ability to simultaneously lower and lift them. This new measuring device can also locate the surface of terrain of the measured profile and thus quantify the volume of eroded soils, or loss of soil from a particular location. Another advantage of the device is that measuring using the new erosion meter is very easy and fast. Moreover, the measured values are immediately visible in graphic form on the scale, can be documented by an image recording device, and can be easily adapted for processing and evaluation by computer.

Fig. 1: View of the device with raised measuring needles.

Fig. 2 View of the device with lowered measuring needles.

Fig. 3 View of the device in the measuring position showing the measured profile using the measuring needles in the scale.

Interest in this measuring device is expected in particular from government institutions or land offices, where the new erosion meter could be used for quantifying the volume of eroded soil. The newly developed erosion meter is protected as a utility model.