JOURNAL OF GEOGRAPHICAL SCIENCES
Year:2006 | Volume:5 | Issue:6-7|Papers Count:9

In this research, climates of Northwest of Iran have been zoning by make used of Geographical Information System (GIS) software (Arc info & Arc view) and utilized numerical ability of Litynski climatic classification method. First, isopleths for each climatic factor on the bases of Litynski method by Arc info, Arc View and SPSS software were calculated. Then every climatic factors classifed based on defined classes in used method. Finally were extracted six climatic maps. The results show there are 21 climatic subtypes in Northwest of Iran. The statistical mode of climatic zones is 221132-10 class that its areas is 267 km2 or 25.4% of total areas.

Pakdasht is located in southern foothills of Alborz mountain. Its area estimated 604 km2. It possesses high agricultural potential. Its close proximity to Tehran (20 km) has turned it into one of the most attractive migrant center. This unprecedented migration rate in turn, has led to the unpleasant urban physical expansion and agricultural destruction.Thus, the major objective of this study is first to investigate the physical characteristics of the region. This is followed by creation of land use map in order to detect all of the physical changes toward subsequent needed planning management.The research method of this study is followed by production of topographic map of the region along with the corresponding satellite images. As a second step, this map were digited. Through application of GIS, this led to production of elevation maps showing both degree and direction of the elevation of the region. As a further step, relevant processing were done on the satellite images through application of Geomatica software. Superwised classification and maximum likelihood were applied in order to produce land use map.This study suggests that the northern part of the region essentially is not suitable for human habitation in general and agricultural activities in particular. However, southern part possesses high physical poterntials regarding human habitation. This part has drawned a lot of migrants and therefore needs particular attention regarding management issue. According to the finding, the dominant land use is idle lands (50.55). This is followed by agricultural lands (39.33) and area under construction (9.22). The area of Pakdasht was 430 hectare prior to 1379. This changed into 734 hectare in 1383. This dictates its physical expansion equal to 304 hectare.

The climate, the natural environments of Iran and tribal and nomadic system provided the grounds for the tribes to dominate the political and governmental system of this country in the course of history. The spontaneous invasion of the tribes and nomads and the flow of the population to the sedentary societies institutionalized their effects on the political and governmental pattern of Iran. Thus, this paper attempts to study the structure of tribal community and its effects on the political and governmental system of this country.

Understanding the Earth system and, in particular, its climate, remains one of the major intellectual challenges faced by science. The processes influencingclimate, the mechanisms through which they act, and the responses they generate are, in general, as complex and poorly understood as they are important. Because observational records of climate processes span only the most recent years of Earth's history and, in many instances, are known to be markedly affected by anthropogenic influences, paleorecords of past climates are exceedingly important to the development of scientific understanding of local, regional and global climate systems. Of the various paleorecords available to science, ice cores provide the most direct and highest resolution view of the paleoatmosphere.

In this research the empirical transmission probability matrix in the Different Parts of Iran has been produced with precipitation data recorded in the 26 synoptic stations in a 50 years period. For producing the drought transmission data matrix, has been used the Log-Normal that fitted to the data in different groups and regarding to the climate specification of the previous year the analogous groups were created. Then with calculating the maximum correction factor of the parameters m and d, the log-normal distribution was fitted to the drought data. By using the one-step and multi-step transmission probability matrix, the formation of drought variations was predicted with means of the past and present conditions of the climate. It will be possible to predict the droughts in the next 5 year with this empirical transmission probability matrix.

In this research, using TOPSIS parameter, drought phenomenon is determined and ranking. For this prepuce, using four climatically parameters: rain, temperature, relative humidity and the number of raining days, droughts in Synoptic station, far a 24-years statistical period (1980-2003) was determined and ranking. In TOPSIS method, using more climatically parameters, in relation to old simpler methods, drought phenomenon is noted with systematic interaction. At the end, far testing the proposed method, output data of SIAP and TOPSIS methods are compared far all of the country station.Results are in good agreement with predicted information. For example, the correlation of these two methods for the output at Khuzestan station was calculated as r= /9.

Desertification and Kavir progress are known as the most important problem in arid regions.Within this context, regional studies indicated that expansion of Kavir-e-Mighan toward its sorrounding areas are destroying all vital values and transformed them to be favourized areas supporting fauna and flora. Human based activites, geomorphological and climatic modification are mainly responsible for this catastrophic situations. Mighan basin (5440 km) situated in north-east of Arak. Nevertheles, some elevated uplands with more than 3000 m pf altitude bring humidity covering this region.The effects of plants cover in Mighan is notable and any strategy focusing vis a vis to vitalize and expand them help to stop Kavir impacts. Nitraria schoberi is a plant which can be observed commonly in this region and must be considered as a good mean to prevent Kavir expansion and also well known for its resistance against harsh and saline lands.

The assessment of Newtowns either with planned cities or the cities without planned is very important phenomenon for programmers. In this situation, the success and failure of these types of cities will be seen very clearly. Also, there are some positive approaches, but some other finding indicate that new towns have no regard able success without zoning approaches. With regards to relationship between city and rural and also looking to the quality of discipline governed upon city and rural in Iran, the zoning approaches is very important parameter. Political situation about the building of new towns regardless to zoning approaches are the main reason for the failure of these cities. To sum up, zoning approaches as a methodological framework for assessment of the newtowns are suggested here as a very important study for officials and public in general.