期刊名称:Research Journal of Environmental and Earth Sciences
印刷版ISSN:2041-0484
电子版ISSN:2041-0492
出版年度:2013
卷号:5
期号:09
页码:537-547
出版社:Maxwell Science Publications
摘要:Hurricane is one of the climate risks that are always led to life and financial losses. The purpose of this study is to predict the incidence of hurricanes at Zahedan city based on statistical analysis and synoptic analyses of this phenomenon. For this reason, the data related to wind survey of synoptic stations of Zahedan in 1983-2011 were collected. First, the accuracy and homogeneity of data were conducted using Run Test. Then, the hurricanes that their average annual incidence was between 3-5 times per year were selected based on partial series analysis model and the basic wind speed was determined 22 m/sec. After creating data matrix in Mat lab, the number of severe winds identified during the statistical period was 79 storms which their frequency has been increased in recent years. Results have shown that the storms with a speed of more than 26.4 m/s in 2-year period with a 50% probability and the storms with a speed of more than 36.52 m/s in a hundred-year return period can be occurred. Although the strongest winds occur in spring, January is the most incidence of occurring storms. Also the cyclone shows 80% of hurricanes northward. For example, the synoptic pattern of the storms occurred in 4 April 2002 and 2 April 2002 using maps of mean daily pressure, temperature, Zonal and Meridional winds at two sea levels and 850 hPa. The patterns indicate establishing low-pressure nuclear and locating 1000 hPa tabs on the region. Creating two high pressures, one on Zagros and the other Asian high pressure makes possible the conditions to intensify pressure gradient, making steep and severe pressures in the region, conditions are occurred by the winds exceeds more than 40 m/s. in this condition, Zahedan region is the maximum temperature of the surrounding in which severe temperature conflicts predominated on the region.