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Arasbaran is one of most important regions in terms of agriculture, economics and tourism in northwest of Iran that it usually receives the most yearly spring precipitation. To recognize the synoptic patterns of the 500 hpa, geopotential  height data were driven for coordinates 00-70 ˚ E and 15- 65˚N in rainy springs (1972-1976-1979-1981-1986).To select the most important component using principal components  analysis, a matrix S mode with dimensions 386×610 was used. The results showed that more than 92% of the total variance can be explained by 13 components. After clustering procedure on the 13 components, six circulation patterns were obtained. In 5 cases of the extracted patterns, there's a really high center of east Mediterranean and south east Europe, the most important component was detected during the wet spring. Other major factors will be referred to the short-wave atmospheric middle level that at this time of year is usually active between the Caspian Sea and the Black Sea and cause wet periods in spring in this area.The systems accompanying low active centers of located in Central Asia and their short waves bring instability and precipitation in the spring to this area.

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Introduction and Objectives: Unbalanced distribution facilities and services on Economic, Social and between regions, need to the planning and balanced spatial development the spatial structure of the country is inevitable This study aimed to determine the level development of the provinces of Iran and rank them based on the level of development and different levels of development of the country From 1345 to the present to help make the planning system and national policy has been done.

Methods: This study is based on cognitive research and in terms of the goal of the evaluation research method - comparative. The population according to the latest political divisions of 31 provinces and indexes evaluated 33 indicators in four dimensions (Economic, infrastructure-physical, socio-cultural and health), respectively. For data analysis, factor analysis and cluster analysis techniques were used.

Findings: The results show, between the provinces in terms of development, there are differences and inequalities. So that in Tehran alone during the decades the highest level of development and Sistan and Baluchestan province are the lowest and most disadvantaged. Comparison provinces during different periods of development of the center over the periphery of inequality.

Conclusion: According to the results of research to reduce disparities between provinces The placing of the country due to the talent and potential of each region and prioritizing disadvantage and less developed provinces in the planning of regional demands. 

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Early heat waves are extreme events that cause heavy losses in plant and animal life and cause many social and economic problems for communities. The purpose of this study was to identify synoptic patterns and statistical analysis of preterm heat waves in northwestern Iran. To do this, the maximum daily temperature data of March 14th was used for fourteen synoptic stations in the northwest of the country during the statistical period (1333-1393) Hijri Shamsi. Then, on the basis of the threshold, the Baldy index was selected for 61 days of heat wave. All statistical characteristics of the data were processed in SPSS software. They were The elevation data of the middle atmosphere of the atmosphere was extracted from a NCEP / NCAR database on a network with an arc 2/5 × 2/5 degree on the 0 to 70 degree eastern longitude and 0 to 60 degrees north latitude. The matrix was made up of 864 columns in 40 rows, with rows of days with thermal waves and elevation data on the columns on the middle of the atmosphere. The analysis of the basic components was performed on the algebraic data matrix matrix And 12 components that account for about 93 of the variations in pressure levels above 500 hp, were identified. To identify the coherent patterns, cluster analysis was performed on the scores of the components by the WARD integration method. Five types of pre-heat generation waveform patterns were identified. The results of this study showed that the premature heat waves in the northwest of Iran are due to high altitude formation in southern Arabia, the Aden valley and the center of Sudan at a level of 500 hpa and the formation of Sudan's low pressure in the sea level and the discharge of its tabs to the north and northeast of the region The case study (Northwest of Iran) also includes events occurring.