Drought analysis of the Van lake basin by using different drought indexs

In this study, drought analysis for the basin was calculated using 50 years (1968-2018) data of 14 meteorological stations in the Van Lake Basin area. For this analysis, 4 different drought analysis methods were determined and the results obtained from these methods were compared. On the other hand, calculations were made with 3 different trend analysis methods to examine the change of precipitation and temperature data of the stations in the basin over the years. In addition, the distribution of the drought values obtained on the basin by these calculations is shown in the basin map by coloring with the interpolation method in the geostatic analysis mode with the help of ArcGIS program. According to the results obtained, it was concluded that 28% of the basin was slightly rainy, 45% was slightly dry, and 19% was moderately drought. Among the indices used in drought analysis calculation, the Standard precipitation index was shown to provide the most reliable and most accurate result. The average monthly precipitation in the basin is calculated to be 48 mm. Considering the results of the trend analysis of precipitation and temperature data, which are the two main parameters of drought, it can be said that there is a slight decrease in the change of precipitation across the basin over the years. However, it was observed that there was an increasing trend in temperature values.