Studying the effect of hydro-climate factors on natural hazards in Golestan province with emphasis on flood

Natural disasters are the major problems that mankind unable to prevent their occurrence despite increasing progress. It has been determined that 31 out of 40 natural disasters occur in Iran as one of the most vulnerable countries. However، this research tried to risk zoning of natural hazards in Golestan province and determination of the number of people living in each urban and rural area population. This study was done in order to investigate index of flood rising by using annual maximum instantaneous data DOE and data of monthly and annual rainfall measurement stations during the statistic period in 1986-2009. Also، the flood rise was determined with a return period of 25-year discharge maximum moment for each station by using “Hager” relationship in Golestan province. Then، plan of flood hazard risk zonation was drawn based on “Krijing” method. The results showed that the maximum and minimum of flood rise are for Pasposhte station in Minoodasht Township and Bandar Torkaman station (6/3 and 36/0) respectively. According to findings، 20. 5% of Golestan province was classified as very high-risk zone; 20. 7% high-risk zone; 39. 6% medium flood risk and 19. 2% in low-risk zone. The results were as follows: about 18/6% of rural population was in very high-risk zone and 14/5% in high-risk zone; 11/9% was in medium flood risk and 6/6% in low-risk zone; also، about 9/9% of urban population was very high-risk zones; 10/2% in high-risk areas، 18/9% within medium flood risk، also %9/1 was in low-risk zone in the province. According to the results، it is concluded that Golestan province is in high risk of flooding، about 31/1% of rural population are in very high and high risk zones in terms of human and financial. Thus، it is necessary to identify and prioritize management programs due to high-risk zones areas