Rare vegetation change detection in the Gobustan Conservation Area, Azerbaijan

The Gobustan State National Park (Conservation Area) is a nationally important desert/semi-desert located west and south-west of Baku, Azerbaijan. In 2007 Gobustan was declared a UNESCO World Heritage Site considered being of “outstanding universal value” for the quality and density of its rock art engravings. The Study Area at Gobustan contains a wealth of historical and archaeological sites and is also known for its rare vegetation. The desert communities in the Gobustan State National Park (GSNP) represent the most ecologically important habitat. The great age of many of the desert communities and their slow growth rate further enhance their botanic significance. Climate change and various anthropogenic activities are causing large losses to natural habitats in this area. The importance of this habitat type is one of the reasons that the Gobustan desert has been proposed as the State National Park, so that some level of protection is offered to this desert. Plant communities such as these, which develop very slowly are particularly susceptible to this disturbance and are easily lost, taking many years to recover (at least 10-12 years). Remote sensing technology in combination with geographic information system (GIS) can render reliable information on rare vegetation cover. The analysis of the spatial extent and temporal change of rare vegetation cover using remotely sensed data is of critical importance to rare vegetation monitoring. For this study, out of various change detection techniques, spectral change analysis method with special emphasis on vegetation indices was selected. The Normalized Difference Vegetation Index (NDVI) was used for rare vegetation change detection in this study because of its acceptable accuracy and ability to detect the green vegetation. NDVI values which extracted for SPOT5 images from 2004 and 2007 years were compared statistically. The statistical analysis carried out on the NDVI values in different years showed tha- - t the reduction of NDVI values was significant. The application of indices NDVI series of images supported by the results of the classification supervised generated in GIS indicates the vegetation degradation in the Study Area. This study showed that rare vegetation distribution was significantly decreased in the areas which have been affected by anthropogenic and natural activities in this area. The results indicates that major changes in the study area from 2004 to 2007 involved decrease in vegetation cover types including Alhagi pseudoalhagi (-10.89%), Salsola Nodulosa/Artemisia Lerchiana/Salsola Dendroides communities (-20.58%) and Suaeda Dendroides (-8.94%); and increase in Tamarix (+17.99%) and Bare ground (+4.35%).