نشریه پژوهشهای تغییرات آب و هوایی
پیاپی 2 (تابستان 1399)

Iran is a large country with a wide climate diversity and up to 80 percent of territory of Iran is located in the arid and semi-arid region with. Numerous observations and various modeling confirm that the Earth's climate is getting warmer. Such condition leads to increase of heat waves and heat stress. Over the last fifty years the average temperature of Iran up to 1.4 degree per decades has increased. The aim of this study is to investigate the heat stress by indicators (pHSI) and physiological pressure (pPhS) in the Caspian Sea region during past (1997-2017) and future (2020-2040) to evaluate the effect of global warming on thermal stresses in this the region of interest. Current study is based on the Regional Climate Modeling System (RegCM – V.4.6). The RegCM is used for downscaling of GFDL-ESM2M general circulation model (GCM). The evaluation is based on three RCP's emission scenarios includes RCP2.6, RCP4.5 and RCP8.5. The observational period is 1997-2017 and future period is 2020-2040. The indexes for evaluation of heat stress is physiological strain (pPhS) and heat stress index (pHSI). The results of this study show that in the winter during the observational period (1997-2017) in the study area, the thermal stress index (pHSI) indicates a slight cold stress, which the maximum is related to Rasht station and the minimum is related to Babolsar station. Such conditions, however, with lower pHSI values ​​for the next period are also observed in all three scenarios of RCP2.6, RCP4.5 and RCP8.5. The Physiological Pressure Index (pPhS) shows that there is a mild cold pressure in all stations studied during the winter in the basic period, and in the future decades this index will increase in all scenarios. In the spring, the physiological pressure index will be neutralized (partial pressure). In the summer, mild heat pressure was observed throughout all station during observational period and the intensity of this heat pressure will increase between 2020 and 2040. In autumn, the results show a mild cold pressure for the observation (base) period, which will be an increase in the physiological pressure index (pPhS) index in Anzali, Ramsar and Rasht stations in the future, and a decrease in the future index value in Gorgan station.

Nebkhas affected by wind erosion in areas that have been and are vegetated form that is a function of wind regime, sediment load available habitat plant species and vegetation types are the Thus. This hill is the layering of sedimentary layering due to loss of moisture from the leaves of the tree or shrub and environmental conditions and characteristics of each type has its own environmental. This study tries to examine the environmental conditions in the Western lut Desert edge pay for the layering of sediments in the area are used Nebkhas layers. This research descriptive - analytical based on method field data, statistic and the library. That first field trip to the study area, nebkhas of using transects and plots were determined and then measure the morphometric characteristics of the species tamarix aphyla nebkhas. Next, a layer about 4 nebkhas, area sampling was carried out in different parts of the region and in the Laboratory, measurement of seed and plant material found in each of the samples was carried out to analyze the data collected. The results of the study indicate that the depth of about 2 meters elevation, area studies, about 5 layers can be detected that 5 layer is the result of a joint study on all nebkhas area is divided into 5 consecutive. Survey of sediment and organic matter in each layer that is present in the first period, which coincides there is a stable environment, but environment conditions in the second period, the first period was fluctuation. Peaceful environment in the region faced in the third period, but the fourth and fifth conditions in the region suggests that fluctuation. The fourth period of the oscillations was weaker than the processes in the context of the fifth round of stronger processes.

The purpose of this research is to identify the change of climatic components of spatial zones in Isfahan province. In this study, by using factor-cluster analysis has done climatic regionalization of the Isfahan province. This method selected for all climatic variables influencing in the climatic regionalization, for implementation this study, the wrought matrix for selected stations and parameters affecting the climatic, at size 29 * 24, including 24 synoptic stations in the province and adjacent areas, and 29 parameters were affecting the climate. Due to the nature of the research were used normal annual data for analysis and because of differences in scale variables measured were used of the standard value variables. Also from IDW Interpolation methods for creating nodes and the kriging method was used to create arenas. Results of the factor analysis showed that the five factors Height-Coldness-Precipitation, Thunder-Precipitation, Cloudiness-Humid, Humid and Dust more than 92% of can explain the behavior of climatic of the province. Using cluster analysis on the factors mentioned in Isfahan province was divided into seven climatic regions.

The evolving trend of rural and agricultural societies in North Central Iran in the late fourth millennium BC stopped suddenly and population declined dramatically. This cultural decline continued until the end of the Bronze Age, and by the mid-second millennium BC, the Iron Age cemeteries appeared largely without the settlement and agricultural activity, with a different culture. Given the material culture of these societies, the cemeteries appear to have belonged to pastoral-nomads. These tribes are believed to have migrated from the northern latitudes to the Iranian plateau, probably due to climate and environmental change. However, it also appears, due to extreme weather events related to the 5.2, 4.2 and 3.2 ka BP climatic events, such as severe droughts and torrential rains, native societies of North Central Iran affected by famine, diseases, violence, migration and mortality, using strategies of resilience and adaptation, such as the overall change of subsistence system from sedentary-farming to nomadic-pastoral/hunting, were trying to resist the adverse conditions. Here, it has been attempted to study the long-term cultural decline in North Central Iran, using the paleo-climate and paleo-environment conditions of the region. The results show that the abrupt climate change played a direct and important role in cultural changes and social, economic, political evolution.

International environmental law is one of the new branches of international law that created after the international community felt threatened by climate change and among codification numerous international treaties it quickly stabilized itself over other international law.In this article, we first briefly analyze the most important international agreements related to climate change, as well as the most important legal measures in the Iranian legal system to protect the environment and reduce greenhouse gas emissions.In the next step, the obligations of different countries about climate change are studied and the obligations of various internal institutions are analyzed and in the last stage, the gaps and deficiency of these obligations in international law and internal law of Iran are expressed.The findings of this study show that the promotion of the status of environmental treaties to human rights treaties can strengthen the position of these treaties in international law. Also, structural and legal reforms in internal law will lead to the development and promotion of environmental standards in Iran.

Consequences of climate change affect many aspects of human societies. Unfortunately, the impacts of climate change has less studied and analyzed In terms of security. One of the important effects of climate reimpacts is the impact on water resources of different regions. Access to proper water resources is one of the biggest challenges in the present century, as it is limited to water resources, and the consumption and demand of it is always increasing. Hence, the situation of water resources will play a significant role in the formation of relations flow and development movement in Iran's geographic space. Due to the growing importance of water competition, identification of the positive and negative capacities of the country's hydropolivalent can be used to provide the macro and micro strategies.The present study is applied in terms of purpose. With descriptive approach following the systematic analysis of the spatial status of water resources (aqueous flows from neighboring countries and precipitation). It tries to analyze the challenges of dehydration and security consequences of water resources, especially in boundary and border areas.Dehydration and water crisis in Iran are the result of physical and economic factors resulting from poor management of water resources. Other factors such as annual rainfall, persistent drought, limited water access, population increase, climate change, water distribution, different spatial dispersion, water efficiency in different sectors of agriculture and lack of sustainable water planning can not be ignored.The above factors lead to a gradual reduction in agricultural activities, increasing tension and involvement over water resources, increasing unemployment and expanding poverty cycle, migrating to major cities and margins, emptying the land of the population, increasing trafficking, dissatisfaction.