Coastal Dune Changes under Natural/Human Hazards

Most sand dunes in Bulgaria are protected areas and national reserves because they are unique ecosystems and habitats. However, dunes have been exposed to an extended anthropogenic pressure in particular over the last decades. Despite coastal dunes change under natural processes and hazards (during storms, erosion etc.) they can naturally rebuild and recover. By contract, the impact of increased urbanisation in the coastal zone of Bulgaria has implied in large geomorphological changes and constant reductions of total dune landscape. Sand dunes presently comprise only about 10% of the entire 432 km long coastline of Bulgaria. For protecting dunes and guiding land managers there is a need for identification of landscape changes for a certain period of time and accurate delineation of sand dune areas. The present research is intended to trace changes of dune areas along the Bulgarian coast for nearly 3 decades (1983-2011) and to examine the many coastal hazards related to natural processes and human-induced effects of urbanisation and tourism. This time interval includes also the period of extensive tourism boom and over urbanisation of the coastline, and therefore reflects the largest dune alterations and reductions. To analyse these changes, topographic maps and modern aerial digital photographs and orthophotos were used, as well as results of field works and direct observations. Based on the landscape change analyst in GIS environment the study also explores the role of different natural and human hazards in driving the observed dune alterations and/or irreversible destruction. The main reasons for identified dramatic dune changes are mostly associated with uncontrolled beach and dune overbuilding by housing and tourism infrastructure (huge hotels, second homes, parkings etc.) and are related to mismanagement of these very natural resources and a lack of coastal setbacks all along the beach and dune areas in Bulgaria.