Drought monitoring in the Lake Urmia basin in Iran

Abstract

Drought is a reptile phenomenon that is caused by rising temperatures and decreasing rainfall than normal. This phenomenon has a significant impact on the human lives and other organisms. We tried to study the drought status by using the MATLAB software and integrated SEPI in two 3- and 9-month scale in the lake of Urmia. For this purpose, we used the climate data of 5 synoptic stations of Lake Urmia (Tabriz, Maragheh, Urmia, Saghez, Mahabad). The findings of the study indicate that the Standardized Evapotranspiration and Precipitation Index (SEPI) reflects the characteristics of both the Standardized Precipitation Index (SPI) and Standardized Evapotranspiration Index (SEI) indicators, and also introduces the temperature as one of the effective parameters in the change of drought severity in drought conditions; therefore, the study of drought using SEPI is better than that using SPI. Drought investigation indicates that the drought trend is increasing based on SEPI in the Lake Urmia. Temperature is also increasing more intensively. The longest period of drought persistence occurred at the Urmia station on a 3-month scale from June to December 1995 to December 2016 for 24 months in the Lake Urmia basin. The highest drought incidence rate was observed at the Saghez station at the 3-month scale and the lowest in Maragheh.