Satellite-based investigation of drought effect on vegetation health index: Beyşehir-Kaşakli Sub-Basin, Turkey

In this study, drought status analyses of Beyşehir-Kaşaklı Sub-Basin were carried out in the 35-year period (1984-2018) using remote sensing techniques, and accordingly, climate change factors were investigated. In this context, Landsat TM, ETM+, and OLI/TIRS were used. LST, NDVI, VCI, TCI, and VHI indexes were used as satellite-based drought monitoring techniques. Drought analyses were examined separately both for the basin in general and for the immediate surroundings of the Beyşehir and Seydişehir districts, the two largest districts of the basin. According to the results of drought categories evaluated by the VHI, Beyşehir and its surroundings and the entire basin underwent the highest droughts in 1985, 2000, and 2006. For Seydişehir and its surroundings, 1985, 1996, and 2000 were found to be the highest drought years. In addition, we sought to determine by variance analyses whether there is a statistically significant difference between the result values of VHI for different years. When the results of parametric and non-parametric variance analyses are examined, both variances show a statistically significant difference between VHI values for different years according to the analysis method.