Coastal changes and land use alteration on Northeastern part of Turkey
Abstract Coasts, not only today but throughout history, have been valuable, important and attractive areas for mankind. Unfortunately, the link between coasts and user has not been stayed in balance due to growing pressure from increasingly diverse human activities. Anthropogenic pressure on coastal areas is rising because of the fact that people are tend to settle by the coast for some reasons such as better transportation, nutrition and commerce. Many conflicts were observed during the establishment of mega cities on coastal zones. Unfortunately, sustainability is generally neglected through the solution process of the coastal problems. Even though, it is a relatively late step, the recent initiatives have a potential to decrease the anthropogenic pressure on coastal zones in Turkey. To achieve the best management strategy, there should be a well established connection between science and policy. Therefore novel technologies should be used for better monitoring and mapping the coastal zones. Coastline mapping is one of the fundamental steps of Integrated Coastal Zone Management (ICZM) planning. In this study, coastal zone of the Trabzon city which comprises approximately 110 km length including central district and 9 coastal counties was investigated in terms of decadal coastline changes and associated land use/cover (LULC) types. Automatic extraction of the coastline was achieved by applying proposed methodology on multispectral Landsat TM/ETM images. To obtain the LULC classes, Support Vector Machine (SVM) algorithm was implemented and four classes, water, vegetation, impervious surface and bare soil were identified. Finally all graphical data was transferred and analyzed within GIS environment. The coastline changes were evaluated by using a GIS tool of Digital Shoreline Analysis System (DSAS). DSAS results revealed that, the net coastline change was reached up to 88.2 m in central region of Trabzon. It was found that during the time span (1984–2011) coastal agricultural lands were intentionally converted to impervious surfaces. The ratio analyses of the study area showed that impervious surface area was doubled for the last 27 years. The coastal zone of the region can be characterized with “accretion” type zone. The geomorphologic character, linear-littoral development of the city and recently completed North Anatolian highway might be dominant effects in shaping the coastal zone character. In conclusion, decadal change analyses prove that the coastal zone of the city is under severe anthropogenic effects as it can be observed in some other coasts of Turkey.