Soil Erosion and Flood Risk Management

Three main gully types were selected to describe the variety of the morphological features of the 20
investigated gully profiles. It was found out, that one of the main factors, which can change the gully
genesis, is the variation of slope inclination.
At the slope area with a high amount of bedrock occurrence the starting point of the rills and the gully
heads were located. In this area the slope inclination is very high. This could be the reason why the
investigated gully is in this part deep and side erosion take place. After a few meters downhill the
gully began to meander and deposition of sediments starts to decrease the depth of the gully.
The first cross profile was taken a few meters after the two rills enter in the gully head. The slope in
this area is very steep with bedrock. The gully walls are high (ca. 4.0 m) and the average width at the
bottom of the gully is small (ca.3,50 m).
The cross profile 12 was measured after a road crossed the gully. The slope was 5° and in the case of
storm water, the street on the left side was flooded (notice that the picture and the cross profile were
taken in the direction to the hill). It is visible that the water formed some new rills on the street (Fig.
10 and 11).
Fig. 10: Cross profile 12
The profile 13 (figure 11) describes a part of the gully, where the slope is gentle and the gully change
into the sheet flow type. Another gully entered in this gully system near the St.Kelvin academy. The
pathway of the storm water entered in this place in a large sheet flow area (Map 8) and crosses the
street afterwards.
The cross profile 17 (figure 12 describes the gully formation a few meters after a culvert which was
constructed one year ago. The vertical erosion was more pronounced than the horizontal erosion. That
can take place when the water discharge is very high. The water came from the area with the sheet
flow pattern and was concentrated in front of the construction.
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