Investigation of the Hydrological Drought of Groundwater Using HDMI Index in Urmia Plain

Since groundwater is very important in meeting the water consumption needs of different sectors, as a result, managing and planning the consequences of drought on underground resources is considered one of the important and vital issues in the planning and administration of countries. For this purpose, in this research, using the combination of quantitative indicators of drought GRI (Groundwater Resources Index), SDWI (Standardized Well Discharge Index) and qualitative index MSECI (Modified Standad Electrical Conductivity Index) to the Hydrological drought management index HDMI in Urmia Plain during the years 2003 to 2018. The monitoring results of this drought management index in Urmia Plain show that the longest drought duration observed according to this management index is 7 years, which started from 2012 and continued until 2018, and the most severe drought observed in 2018 was -2/2. In order to observe the drought trend on the drought indicators, Mann-Kendall test was used. The results show that with the continuation of the current trend in the region, the value of the GRI index will reach less than -2 by 2026 and the HDMI drought management index will reach less than -6 by 2031. It is a sign of the state of non-exploitation and the exposure of underground resources to severe drought. If the current situation continues, it will be impossible to sustainably use the underground resources of the Urmia Plain.