Natural Conditions and Anthropogenic Change of the Coastal Zone in the Area of Kacha Village

Abstract

Development of not yet used parts of the coastal zone poses the task of developing appropriate management principles based on scientific ideas and forecast. The aim of the work is to characterize natural conditions, features of lithodynamics and anthropogenic impact on the coastal area adjacent to the village of Kacha (Sevastopol region); using this site as a case, to demonstrate the problems arising out of economic development; and to give recommendations for rational use of natural resources. The data of repeated geomorphological surveys, observations of the coastline dynamics at the controls, measurements of the beach profiles were analyzed using the results of tacheometric and photogrammetric surveys, satellite images, and other materials. Geological and geomorphological conditions and lithodynamics are considered in detail. In the area under study, a complex pattern of redistribution of sediment volumes is observed; it is characterized by a significant seasonal and interannual variability of alongshore sediment migrations. The average rate of the cliff edge retreat is 0.43 m/year in the northern part of the site, 0.04 m/year in the central part and 0.10 m/year in the southern part. At the same time, the central part of the cliff falls due to soil crumbling in the absence of landslides. According to satellite data, over a 2 km area centered at the Nemetskaya Clough, average displacement of the cliff edge was about 0.27 m/year in the period from 2004 to 2016. The most probable average annual value of sediment input due to destruction of cliffs is about 6,000 m 3 /year. Provided earlier in the literature, the values of the cliff retreat and sediment influx due to its destruction are not confirmed by the data of long-term observations and seem to the authors to be significantly overestimated. Specific cases of hazardous exogenous processes (landslides) and current anthropogenic impact on the coastal zone are considered. Specific recommendations are given for further economic development of the coastal zone.