Geoinformation Analysis of Factors Affecting Wind Damage in the Šumava National Park

This project forms part of the "Remotely Accessed Decision Support System for Transnational Environmental Risk Management" (STRiM) project undertaken within the framework of the European Union's INTERREG IIIB CADSES programme. The test took place in a 70 km² test area within the western part of the Šumava National Park. It is commonly known that windthrow occurs frequently in the Šumava Mountains, and it tends to occur in particular areas. The intensity of windstorms and the amount of damage caused appear to be relatively constant. In the case of Šumava, such meteorological hazards frequently become biotic hazards as they are often followed by bark beetle infestations. We hypothesise that, in particular areas, the incidence of windthrow, the amount of harm done, and the cost of alleviating that damage are in close relationship with natural factors prevalent in the area and with previous human intervention (forestry) in the landscape. Analysis of such factors, and a comparison with actual data on windthrow, showed that a) the most damaged stands were generally found on gently sloping sites of 8-15 degrees; b) the leeward side of elevations were more heavily damaged; c) non-natural forest stands were subject to more damage; d) damage increased with increasing stand density; e) middle-aged stands of around 12 years were at greatest risk; and f) the most damaged portions of the test area were located at sites with normally drained and deep soils. Further, landscape relief and active surface character appeared to play an important role in modifying wind speed and direction, thereby increasing the wind's devastating power.