جستجوی مقالات مرتبط با کلیدواژه « climate zoning » در نشریات گروه « جغرافیا »

City is a living, dynamic being evolving over time in the context of physical and anthropogenic components and complex relationships between them. It is the reflection of the role and attitude of man-kind influenced by social, economic, political, cultural and geographical factors and conditions. Increased population and density in urban areas have far-reaching consequences, such as increased consumption of natural resources, land-use changes, climate change, and disruptions in the exchange of material and energy. Consequently, cities face many issues and problems, the most important of which are issues related to urban design. These include poor ventilation, high heat load, air pollution caused by the physical characteristics of cities, and insufficient attention to the capabilities, natural characteristics and climate of the region and the city.

The present study seeks to prepare an urban climate analysis map to study and analyze spatial and climatic information collected from Tehran. Urban Climate Map (UCMap) is an information-based and analytical tool that combines factors of urban climate with urban planning factors and some environmental conditions to provide an image of urban climate issues in a two-dimensional environment. Urban climate map consists of an urban climate analysis maps (UCAnMap) and an urban climate recommendation map (UCReMap). Urban climate analysis maps apply various spatial information layers of heat load maps such as building volume, urban topography and green space along with layers of land cover, natural landscape, and proximity to open spaces in dynamic capacity maps. The proposed model is generally based on the evaluation and analysis of variables affecting climatic conditions. Based on six layers of building volume, land cover, topography, proximity to open spaces, green space, and natural landscape, maps were prepared in Arc/GIS10.4.1 environment for Tehran urban area. To eliminate the unit and reach comparability and overlap, the layers were standardized and used to prepare maps of ambient heat load and dynamic capacity.

Three layers of building volume, topography, and green space were weighted and combined to create a heat load map. The other three layers of land cover, natural landscape, and proximity to open spaces were also combined to create a dynamic capacity map. Afterwards, these two maps were combined to create an UCAnMap. The resulting map was close to the on the ground realities. For example, building volume has a negative effect and increases heat load in urban areas. On the other hands, green space reduces heat load and has a positive effect. The central and southwestern parts of the city have a high heat load and core areas of the urban heat island have been calculated and obtained in these areas. The resulting map was classified into 8 categories to create urban climate analysis map of Tehran.

Results indicated that 59% of the urban area in Tehran, mostly located in the northern part of the city, has a good cooling and ventilation condition while 19% of the study area, mainly in the central, southern, and southwestern parts, faces heat stress and lacks an appropriate air ventilation condition. 22% of the study area, scattered all over the city but mostly located in the northern, western and eastern parts, faces an intermediate condition. According to the calculated heat load map, the central, southern, and western parts (in region 21) of the study area face a high and unfavorable ambient heat load. And many parts of the 4th, 1st, 2nd, 5th, and 22nd urban districts are characterized with low ambient heat load and favorable climatic conditions.

The excessive emission of greenhouse gases in recent decades and the ongoing changes in the climate have changed the meteorological parameters and, accordingly, the climatic zones. In this study, the future prospect of climatic zones and the risk of desertification in the watershed of Karun basin was investigated using UNEP index and LARS-WG6 microdirection model and HadGEM2-ES model under the RCPs emission scenarios for three periods 2021-2040, 2041-2060, and 2061-2080. The results pertaining to all three future periods and RCPs release scenarios showed that the long-term average annual precipitation will decrease between 1.9 and 14.6% compared to the base period, but the annual average minimum temperature will be between 1.2 and 3.4 °C, maximum temperature between 1.3 and 3.7 °C and the annual average of evaporation and transpiration will increase between 4.7 and 12.3% compared to the observation period. In the upcoming period and based on the emission scenarios, dry climate (the risk of very severe desertification) and semi-arid climate (the danger of severe desertification) increase 3.5% and 4.4%, respectively, and semi-humid (moderate desertification) and humid (no desertification) and very humid (moisture and wet climate) decrease 4% and 4.7%, respectively. However, semi-humid climate zones (low risk of desertification) with 0.8% will be less severe. Under the pessimistic scenario, the semi-arid climate region will reach its maximum level among the publishing scenarios in the near future with 12.4%. Therefore, this displacement in the boundaries of climatic classification will increase the desertification of Karun basin in the upcoming period.

Identifying homogeneous climatic zones plays an important role in the success of regional development programs. The climate system is composed of various elements, factors, and variables that together form the climatic components of a region. Multi-characteristic and multivariate methods can combine and overlap the types of elements and variables effective in constructing the climate with appropriate weights in the climatic zoning area. In the present study, climatic zoning of the Caspian region was performed using factor analysis and cluster analysis. For this purpose, a 30*30 matrix consisting of 30 meteorological stations and 30 climatic and environmental variables was formed. The results of factor analysis showed that the climate of the region is affected by 5 factors including precipitation-humidity, temperature, wind, sunlight, and environmental factors. These factors explained a total of 92.5% of the variance of the data. Then, cluster analysis was performed by the hierarchical integration method of Ward on the five mentioned factors. The results showed four climatic zones including humid, semi-humid, semi-arid, and arid in the study area.

Climate zoning is the identification of zones with the same climate. With the expansion of quantitative methods, traditional methods of cluster classification have been replaced by new methods, such as various interpolation methods in the field of climatological zoning studies. In this study, we evaluated the zoning of radiation effects on the administrative spaces of Kerman city. Accordingly, the ordinary Kriging interpolation method is used along with circular, Gaussian, and spherical models for data interpolation with error criteria including root square error (RMS), its standardized value (SRMS), standard mean (Ms Mean Mean), and Mean Square Error (ASE). These factors are intended for accuracy evaluation. This research is a descriptive-analytical study on the basis of spatial analysis using the GIS system. The results of the final maps produced for climate zoning (radiological factors) showed that the angle of the sun shine is right in the equinoxes and horizontal in the revolutions. Therefore, radiation is more in the offices uptown and less in the ones downtown. The latter case is due to the presence of mountains in the south of the city. Also, solar radiation is maximal in the northern and eastern regions while it is the lowest in the west and the south. In proportion to the AD months and with regard to the amount radiation in offices in equinoxes and revolutions, it was found that the Gaussian distribution spectrum and the angle of radiation have the greatest effect on the offices in the north of the city, which is due to the position of those buildings to the sun.

The aim of current research is atmospheric hazards climate zoning in Iran Northwest. So meteorological organization data were used in cases such as mean temperature , minimum temperature , maximum temperature, precipitation in monthly and daily scale for 13 synoptic stations in range of East Azerbaijan province, West Azerbaijan province) and Ardebil province during 26 years. (1990-2015) in this research , it was investigated 10 main atmospheric hazards such as famine or drought , hailstone,, heavy snow , thunder storm, severe precipitation, margin precipitation , blizzard , fogging , dust storm in range of Northwest bound. Then happening frequency maps were prepared with separating form for hazards by using Geographic information system. (GIS) Also spatial zoning maps were prepared for every class. Finally by combining all of hazards investigation; it was prepared Northwest region atmospheric hazards extensive map. Results show that, East, Southeast, center and West parts in Northwest region are located among most hazard zones based on happening frequency. But Northeast parts and zones have the least hazards. Also results express that blizzard and dust storm are main atmospheric hazards at Northwest regionThe highest hazard frequency in Northwest region relate to blizzard with 4148 hazards during 1990-2015 study period. The highest blizzard frequency in Ahar station is observed with 514 hazards. The second hazard in Northwest relate to dust phenomenon with 1948 cases. The highest frequency of mentioned case was observed in Maragheh station with 410 hazards. The third case in Northwest relate to thunder storm phenomenon with 1773 hazards. The sixth case relate to icing phenomenon with 1315 hazards meaning. The highest icing frequency is observed in Khalkhal station with 144 hazards. The seventh case relate to hailstone phenomenon at Northwest with 341 hazards. The highest of hailstone frequency is observed in Maragheh station with 56 hazards. The eighth case relate to fogging phenomenon with 333 hazards. The highest of fogging is observe in Ahar station with 135 hazards. The ninth case relate to famine or drought phenomenon at Northwest with 168 hazards. The highest of famine or drought frequency is observed in Urmia and Ardebil stations with 16 hazards totally. The highest margin precipitation is observed in Parsabad station with 19 hazards. The lowest frequency of margin precipitation relate to Makou and Khalkhal stations with 4 hazards totally.

Using advanced statistical methods such as multivariate statistical analysis, one way is to separate areas from each other. In the present study, based on hierarchical cluster analysis methods and compare the different methods, Annual and monthly data for 9 stations for 10 years (2000-2009) Taked of Lorestan province meteorological Department, and the analysis Done. The purpose of this study addition to showing how cluster analysis process, Climatic zoning Lorestan province is Include four Area: 1-Semi humid, temperate summers, very cold winters (Alashtar, Azna ...) 2- Semi-moist, relatively warm summers, cold winters (Aligoodarz, Boroujerd ...)3- Semi-humid, hot summers, temperate winters (Khorramabad and Kouhdasht)4- Semi-dry, hot summers, relatively cold winters (Poldokhtar). Zoning of Province has been by using ARC GIS.