مجله مدیریت مخاطرات محیطی
سال سوم شماره 2 (تابستان 1395)

Aerosols are among the most important of atmospheric pollutants and they are observed  like the microscopic particulate matter (solid and liquid) in the lower parts of the troposphere. From environmental standpoint, have priority the investigation of hazards due to aerosols distribution and predict the movement mechanism of them and will be studied with an emphasis on the Middle East. The main purpose of this study was introduce the new method based on remote sensing results and analysis of fractal statistics until in addition to investigate the origin of aerosols, make survey the movement mechanism and pattern of their distribution in large areas of North Africa and the Middle East. The research results indicate that the pattern of aerosols distribution in Middle East is followed from non-linear patterns with chaotic specifications. To prove it, is used from MODIS sensor Images belongs to America's space agency [NASA] until the needed photo-maps are produced that consists of aerosols optical thickness (AOT), changes in nitrogen dioxide (NO2) and carbon monoxide (CO). Spatial analysis of data and seasonal - annual compare of them with together, is represent a exponential relative relationship in aerosols dispersion pattern. So with use of variance-distance equation ( Mark and Aronson (1984)), besides demonstrating the relationship between atmospheric pollutants Iran, Iraq and Saudi Arabia with climatic changes in North Africa, two climatic regime of hot and cold, were compared according to the energy content and chemical composition of different seasons. In practice, bodieds of aerosols and industrial pollutants of area is functional of seasonal changes and chaotic behavior of them in the cool months is greater than the warm months. Therefore, the environmental hazards of winter regimes is more than of summer regimes. Also, changes the fractal dimension (especially at the brownian distribution level of optical thickness), the possibility of check the remote sensing criteria has provided on the based of  the fractal geometry principles,whereby, has been introduced the  new approach to predict the cumulative behavior and movement pattern of aerosols in Middle East .

The waste pollution is sources environmental problems. These do pollution water resource, air and soil. In additional, they do destructive landscapes and pestilential in the regional. Therefore, the placement is a policy for solid waste landfill. In this research, we are going to find suitable placement for landfill in the Ardal region. This region is important for water resources and natural landscape. We are used of data geo data base  such as DEM, river, spring, wells, soil, land use ,forest, transfer energy(gas, power electric line),population settlement and geology .In addition, we used of AHP and geo-statically methods. The results shown that distance of population settlements, forest, land use and water resources are important for election placement of solid waste in Ardal region. Also, in this region are five classes for landfill. These classes are very suitable (10.8 km2), suitable (17.3 km2), relatively good (4.8km2) and unsuitable (1055.3km2).So, rural management must consider these conditions for landfill solid waste in Ardal regional.

The drought status studies as a natural hazard in different areas in order to develop plans to deal with drought and risk management is very important. They are lots of indices for drought assessment which based on climatic effective quantities. Check simultaneously occurrence situation of drought indices categories can be a useful framework for conformity assessment profiles. The aim of this study was to compare two methods, TOPSIS ranking method and standardized precipitation index (SPI) for drought condition in Khouzestan province and their performance in this review. In another part of the study, the sensitivity of TOPSIS method to determine that which of four climatic parameters are affecting climate drought or wet has been done and provided as tables. In this study it is found that these two methods to determine the intensity and condition of drought, are good and have similar performance but for measure the intensity of wet, standard index (SPI) isn’t useful. In fact, This method just determine that, the target year is wet or not. For example, the lowest value for this index was -3.04 which is related to Abadan station at 1390 and this number indicates severe drought, also the highest value was 1.33 which is related to Ahwaz station so it located in normal (wet) category. TOPSIS ranking method in addition to determine the intensity of the drought, also can present the condition of wet years numerically. According to calculations, 1390 was the driest year between all stations and 1371 was the wettest year for all stations. Also, To determining The sensitivity of TOPSIS method, it was found that the most sensitive parameter among the climatic parameters, related to the number of rainy days and low sensitivity is for relative humidity between all the parameters.

Iran because of its natural characteristics and morphology has been exposed to many natural hazards. Mass movements and slope instability are major dangers to human activity that often leads to loss of economic resources, damage to property are established. These issues need mass movement’s hazard zonation as the first step in the right environmental management explains this phenomenon. The study aimed to zonation of mass movement’s hazard in Venus watershed of Fars Province.  At first important factor affecting the data layers 10 in the mass movements such as lithology, slope, elevation, current use of the land, rainfall, temperature, slope, distance from roads, distance from fault, and distance from the river preparation and were digitized. Then, using aerial photo interpretation and field work, all the mistakes in the field, identifying and maps were presented.  The integration of independent and dependent variables of mass movements and the weighting factor classes in each class, based on the models of intelligence value, density and LNRF took place. Finally hazard map for a mass movement to integrate the various layers of weightlessness on different models.  The results show that the method further intelligence value in terms of compliance with the mass movements of high-risk zones as well as the ability to separate classes of risk, performance is better than the other two methods, especially methods LNRF.

Thunderstorms are destructive climatic phenomena that, recognition of mechanism, genesis and development of the thunderstorms could can be special very helpful in order to play against and reduce losses. In this study examined thunder storms with rainfall exceeding 10 mm in a 14-year period (2000- 2013) the Ahwaz region. Early identify the code for this event and then extract 10 mm of rain And were taken mean daily data of sea level pressure from NCEP / NCAR reanalysis data in 32 days. Finally, using principal component analysis (PCA) and cluster analysis, were classified circulation patterns of sea level which played a role in a rain thunderstorms. The study showed that the Ahwaz region of thunderstorm, has followed by general pattern. In the first pattern, in the SLP, low pressure systems Sudan with trough 1012 millibar with the passage over the Red Sea and the Persian Gulf advected hot and humid air to the study area and at 850 and 500 millibar level, the Ahwaz region is located in front of the trough 1500 geopotential heights and 5760 geopotential meter respectively.In the precipitation of this pattern, instabilities has continued to 500 millibar level. In the second pattern, the anticyclone tongue (flank) 1016 millibar that had spread from the East with the passage of the sea of Oman and the Persian Gulf led to the moisture advection was from study area and the 850 millibar level the study area located in front of the trough with geopotential height of 1500 to 1510 meter. Both the precipitation pattern, main source of moisture provide by Warm seas of the South and the major factor of uplifting provide by the western trough.

The present study aims to shed lights on the way "climate-related usual and disastrous events" are forecast by Iran Meteorological Organization and how they are covered by IRIB. This research is carried out through a "content analysis" of news items broadcast various provincial newscasts as well as Channel One's 21:00 newscast and IRINN's 13:00 newscast during Persian years of 1393, 1394 and 1395. The results of each newscast have been compared. For practical aims, as survey was conducted and the views of meteorological experts as well as news editors-in-chief with regard to the way weather-related news events are managed were gathered consequently. The findings indicated that the rhetoric and terminology used in almost half of the weather reports on dangerous and disastrous events were not "sensitizing and warning". 22 percent of critical events were not forecast in the Meteorological Organization's announcement and 33 percent of weather reports were not consistent with the organization's forecast announcements. In 92.5 percent of weather reports, no experts and employers-at-risk were interviewed for training implications. The forecasts of 58.5 percent of dangers were reflected as usual weather events with low priority at the end of newscasts and with the same amount of time (55 percent of weather reports on usual events and 47 on critical events lasted from one to two minutes). Literature review shows that no other study has been carried out on the subject in IRIB. Therefore, the present research is a new and innovative.