Analysis of Drought Return Period in East and South East of Iran

The Average annual and monthly rainfall of limited projects Stations were surveyed in statistical periods 30 years (1970-1999) to analyze droughts of south and South-East of our country. At first the average annual rainfall was estimated in a drought period according to statistical rules and best-selected distribution. Then the map of chosen area was provided based on the estimated rain fall rate to average annual of each station for return period (P/P.Mean). Due to provided maps may recognize when drought with a T return period occurs in whole area and then which area has more critical weakness. Ofcourse, each area would have more critical condition that has weakness with more diversity to their mean long time weaknesses. Using dimensionless statistical series criteria may evaluate drought area with similar T return period intensity.