Mahbubeh SabziEtivand - Department of Earth Sciences, Institute for Advanced Studies in Basic Sciences(IASBS), Zanjan, Iran
Masoud Saatsa - Department of Earth Sciences, Institute for Advanced Studies in Basic Sciences(IASBS), Zanjan, Iran

Drought is an important factor of climate change and it has been defined as a period of time that the moisturecontent is less than normal weather conditions. In hot and dry climate, drought monitoring process is needed todetermine and analysis of the intensity, duration and frequency of drought. In this study, the basic drought factorshave been investigated in Zanjan plain based on the climatological data of Zanjan synoptic station from September1969 to August 2013.In this study, after plotting unit hydrograph, the wet and drought years have been specified using deciles index (DI).Then Markov Chain Model is used to predict and assess drought occurrence probability. The extracted balanceprobability matrix shows the change of probability of a wet year in normal mode is maximum and equal to 0.5. Theminimum change of probability is calculated for a wet year in wet mode. The results show that in the next 10 years,the probability of drought occurrence will be 0.18 per year and its duration will be 1.37 years.

Aquifer; Zanjan; Drought; Markov Chain