Rock Fall Risk Management in the Bohemian Switzerland National ...

Z. Vařilová & J. Zvelebil Rock Fall Risk Management in Bohemian Switzerland National ParkFig.2: A. A map showing the distribution of areas prone to creation dangerous rock falls within the National Parkterritory. B. Inventory map of unstable rock objects endangering the Hřensko village with an assessment of theiractual instability in a four-degree scale. C. An example of numerical evidence of individual unstable object inselected part within the Hřensko village area.data processing, and on-line, interactive resultvisualizations has been introduced.D) Different developmental stages of the processof rock fall preparation, including the earlywarning precursors of rock fall immediateoccurrence, are detected using characteristicdifferences in slope movement dynamics.Quite reliable diagnostics of immediate dangerstate (with reading and evaluation intervals inseconds), as well as its short and medium timeforecasting (from days to 2 years) are at ourdisposal now (cf. Fig. 3; Zvelebil & Moser 2001).Phenomenological models, which are predominantlyused for monitoring data evaluationand rock fall danger assessment and whichhad been mainly empirically based (cf. Zvelebil1995, 1996), have been now accompanying bymathematically rigorous numerical analysesand modelling according the latest challengesof complex dynamical systems theory (Palušet al. 2004). For wider practical use of the laerand of their result visualisations, as well asfor improvement of implementation of theprogressive information technologies enablingit all, a four years project of establishing andtesting of the unique, highly automated expertsystem for safety evaluation of monitoring datahas started in the National Park this year.Set of possible stabilising technologies has beenoptimised regarding as monitoring resultsand actual danger of rock fall occurrence andits possible negative consequences, and alsoas regarding their economical and technicaldemands of each method in question withregards to demands of nature preservation.Two basic types of remedial technologies havebeen use there:1) The simple one – which is possible to accomplishby hand-work, using technically verysimple and relatively cheap means. Specialposition within the simple technologies holdsFerrantia • 44 / 200555