Landslide monitoring on the example of the shallow slope deformation near Třebenice in the České středohoří Mts., Czech Republic
Abstract
This contribution presents the continuous results of surveys and long-term monitoring of the slope deformation near Třebenice town in the northwest of the Czech Republic. The landslide is situated near the border of the České středohoří volcanic complex and sedimentary Bohemian Cretaceous Basin.
Landslide area has a character of shallow slope deformation in clayey and other sediment rocks with different permeability. Total area is around 28 ha.
The partial reactivations of the slope deformation were periodically observed in the past. The last extensive reactivation is documented in 80's of the last century - particularly the inner landslide near crossing of the regional railway and road (ca. 4 ha).
We observe the partial reactivations in connection with above-average precipitation in May and June 2013. These reactivations are particularly evident on the recent deformation of the road surface in the landslide area.
The road surface deformation is newly monitored by geodetic methods (combination of trigonometric measurements and measurement of cracks by caliper). The changes of distances are around 1-2 mm/month.
The other landslide activity is monitored by long-term control measurement of groundwater level and by extensometric tape for measurement of surface deformation. The fluctuation of groundwater level and seasonal influences affect surface deformation.
The movement of landslide mass depends mainly on soil saturation and seasonal effects. This data can be correlated with climate information (especially precipitation) from a nearby permanent meteorological station of IRSM CAS p.r.i.
The variability of data and long time series allows finding correlations between climatic effect and their influence on groundwater level fluctuation and dynamics of landslide mass.