Assessment of rockfall potential in the Kula (Manisa, Turkey) Geopark Region

Abstract

The term Geopark is an interrelated phenomenon of geology, landscape, civilisation and society. One of the first Geopark areas in Turkey will be founded in the Kula district of Manisa. This region is an impressive area with its archaeological, historical and tourism-related features and its geological characteristics, such as cinders and maars, tectonic structures and earth pillars. Moreover, the earth pillars in the region present high-rockfall potential due to their geometric and lithologic peculiarities, formed by erosional processes. The present study aims in investigating the rockfall potential in this area by means of experimental investigation and numerical analyses. Extensive field studies including determination of earth pillar locations with rockfall potential, geological description of the earth pillars, scan-line surveys on discontinuities, identification of slope profiles, measurement of actual fallen block dimensions and sampling procedures were carried out. The eight earth pillar profiles were analysed to determine the run-out distances of basalt blocks and seven blocks were found to be capable of reaching the transportation line. For future protection purposes, barrier designs were suggested by computer analyses. Additional analyses were performed to determine rockfall-prone areas, taking into consideration the mapped rockfall source areas. Based on these analyses, the transportation line is threatened by potential rockfall. These results are in accordance with conclusions of the runout distance analyses. As a consequence, environmental aspects and rockfall phenomenon of the Kula Geopark Region must be taken into consideration during the planning process. It should also be pointed out that we have to own the values of geological heritages and to protect them based on the scientific and rational approaches.