بررسي دوره هاي خشكسالي با استفاده از تجزيه و تحليل داده هاي هيدرومتئورولوژي

Determination of the drought periods by analyzing the hydrometeorological data

This article presents an overview of the water resources available in Iran on one hand and Urmia lake catchments area, situated on the North-West of this country on the other. Water balances are presented for the Urmia lake catchments area and the water supply and consumption patterns in the Iranian main river basins. The drought periods occurrences have been analyzed using the forecasting methods and correlation laws between the discharges and the precipitation data measurements for the Adji-chai river, which is a river most representative of the Arid and Semi-arid region. The results obtained from using forecasting methods in data analysis indicated that drought phenomenon in Tabriz region and in general in Iran, is resulted from irregular time and spatial precipitation distributions in one hand, and severely negative fluctuations in precipitations and consequently highly reduced river flows on the other.