Evaluation of long-term meteorological drought in the Aras and Coruh Basins with Crossing Empirical Trend Analysis

Abstract

Drought is one of the most devastating disasters. Although the devastating effects of drought appear after many years, it is possible to evaluate drought based on meteorological parameters to control these negativities. In recent years, graphical trend analysis methods have been used to evaluate drought using meteorological parameters. The Crossing Empirical Trend Analysis method is the most recent trend analysis method and one of these graphical methods. Using monthly total precipitation data measured between 1969 and 2020 at 12 different meteorological observation stations within the borders of the Aras and Coruh basins, located northeast of Turkey, the basin's meteorological drought analysis was analyzed through the standardized precipitation index. In the study, the trend of meteorological drought in the basin was determined using the CETA method. As a result of the study, it was determined that there was an increasing trend in the majority of drought values in the Slope Upper and CETA Pivot analysis and a decreasing trend in the Slope Lower values. According to the Sen Slope analysis, there was no significant change in trends (34% increased, 35% decreased, and 31% no trend). Ardahan station is the most sensitive station regarding meteorological drought among the stations examined. It was concluded that the months with the highest increase trend in the Aras and Coruh basins are May, June and November.