Investigation of Relation between Meteorological and Hydrological Drought in Sistan Plain

Drought is a natural and repeatable disasterwhich affects all climates. Because of the intrinsically dry climate and low precipitation in Sistan plain, the main water resources are surface water originated from a neighboring country. This study investigates the relationship between meteorological and hydrological drought in Sistan plain.
At first, meteorological and hydrological drought were investigated by indices including moving average, SPI and SDI in Sistan plain. Moreover, the relationship between them was evaluated for 45 years.
Results show that indices of meteorological and hydrological droughts do not match with each other in the entire of the study period, but there is a significant relationship between them during dry years. It was also observed that a drought period started in 1999 and continued until 2012.
Discussion and Therefore, due to low volume and high coefficient of variations of rainfall and vital role of surface flows in the supply of water in the plain, hydrological drought shows conditions of drought is better than the meteorological drought in Sistan plain.