Geographical Research

Heavy rainfall is the causes of the crisis. In recent years extreme floods have occurred in the Behesht Abad basin in Chahar Mahal and Bakhtiar province،Iran in 2.10.2006 with a moment discharge of 605m3 .This case study lies in the period of 1984-2010 and is selected for synoptic and thermodynamic condition studies. The meteorologically studied variables and thermodynamic charts indicate potential wet temperatures that would enhance circumstances for a storm.Bradbury and Rackliff Indexes show values of -2.15 and 33.67 that indicated a high instability in basin region. In addition، pressure synoptic analysis showed that 500 mb synoptic conditions are favorable for the occurrence of flooding is in accordance with expanding Atlantic – Europe down words polar shift. The dominant meridional pattern over the Mediterranean region and Middle East is formed over the Mediterranean and the West، with an intense fall over Iran. Bradbary and Radcliffe the indexes are fit for forecasting heavy rainfall that may lead to flooding.