تحلیـل آمـاری، همدیدی طـوفان‌های گردوخاک در جنـوب‌شـرق ایـران (مطـالعـه‌ی مـوردی: منطقـه‌ی سیستـان)

1- Introduction Sand storms are the most important environmental issues in the special zones of the world. Dust storm called to an event that lead to disturbance winds and by moving a lot of dust to the air, decreases the horizontal sight to 1000 m. this phenomenon influenced by special atmospheric condition that every year have serious damages to farms, installations, roads, traffic and transportation and with air pollution made respiratory problems and … . Studies that have done in relation with abundance of dusty days in Iran showed that central holes have the most dusty days, so that in blowing zone of 120 days winds of Sistan, the abundance of occurrence of mentioned days reaches to 150 days in the year. 2- Methodology The study has done based on meteorology codes during the period (1979-2008) for statistical, synoptically analysis of sand storms of Sistan zone, and has used from horal statistics of speed and direction of wind in synoptic station of Zabol and atmospheric pressure maps, geo potential height, temperature, pattern of current, the same speed line, wind direction at two levels of Sea level and 850 Hecto Pascal that have made daily. After setting of matrix table of data, by using of SPSS software, the data become sort. For selecting of days with dusty storms, based on definition of global meteorology organization, base speed and horizontal sight were 15m/s and less than 1000 m, respectively. Dusty storms reported based on weakness and strength, by special meteorology codes (codes of 30 to 35) in meteorology data. Thus, days with the mentioned conditions, considered as a dusty days and statistical analysis have done on them. In same sight analysis used of environmental to circular approach. related maps of starting and peak days of storm , from daily data of infra assays : pressure, temperature, current lines, direction and speed of wind, in two level of the earth and 850 hectopascal overlay technique. The zonation of suitable site for landfill has been determined. In addition, using the numerical method TOPSIS options for solid waste landfill in Sabzevar was ranked. Accuracy of two methods was assessment based on effective site selection criteria for the municipal solid waste landfill. Each of the options proposed by the two methods were reviewed and analyzed. 3- Discussion The AHP evaluation criterion is used to select the suite site for sanitary disposal landfill. The Saaty (1980) developed method was applying in TOPSIS method. In this method, the ideal values are set as the maximum or the minimum value which belongs to an alternative for a particular criterion. In this study, the weight assigned to the criteria was then weighted in GIS software layer multiplied by the number of zone map for urban landfill. This zone with prioritized by two-methods AHP and TOPSIS finally reviewed and evaluated according to these criteria, prioritize options given by both methods and criteria. 4- Conclusion and suggestion Results of this study indicated that TOPSIS method proposed options for reasons long distance from the place of waste production, located in the suburban of Sabzevar city, and alignment with the prevailing wind direction, are unqualified for the construction of landfill facilities. According to this study, Priorities that determined by the method of hierarchical analysis for landfill, are more suitable.