GEOGRAPHICAL RESEARCH QUARTERLY
Year:2005 | Volume:37 | Issue:52|Papers Count:13

The covariance coefficients of precipitation for 26 weather station from1985-1999 within northwest and west of Iran were subjected to Principal Component Analysis (PCA) and cluster analysis.The PCA extracted principal components as, summer precipitation, the original seasonal concentration of precipitation, locational  subsidence of precipitation.The components classified with Ward clustering analysis yielded four precipitation regions.  

This research started with the question of what relation exists between the filling of localism and nationalism in Tabriz. The procedure used in this study is measurement and the instrument was data collection using a questionnaire .The population in this research were literate people residing in Tabriz . Using a random cluster sampling procedure, 224 subjects were selected as the statistical sample group for this research .Then questionnaire were distributed among the literate residents of Tabriz .The results of data analysis indicated that the rate of nationalism in Tabriz city was much stranger than localism. The test of secondary hypothesis showed that despite the weakness of the sense of localism, some factors such as relative deprivation, relationship of the same root ethnics beyond the border can strengthen its effects and some such as Shiite faith, national and religious celebrations can reinforce its nationalism.

Sabzpushan Mt. is an anticlinorium located in the Suthwestern area of Shiraz,within the so-called “Zagros Folded Belt’’. Its axial trend has been diverted from the general NW-SE trend of the Zagros, e.g. from the trend of the two adjacent anticlines (Figure1). It has been rotated in a clockwise direction. A transverse strike–slip fault divides the Sabzpushan Mt. into a bigger northwestern and a smaller southeastern blocks. Qualitative and quantitative methods of morphotectonics illustrate different rate of uplift in different parts of the Mountain. SL– index contour map of the anticline   displays that on the widened central part, uplift is symmetric with reference to the axis of the anticline but it is more prominent adjacent to the transverse strike–slip fault. Drainage pattern study of the different parts of this anticline demonstrates that the trend of the anticline axis offsets at the central part. Statistical joint analysis of the different parts show that a local compressional stress trending N660 E has caused a clockwise rotation of the total axial trend of the anticline,a right–lateral  movement of Sabzpushan transverse fault, and many other structural and morphotectonic changes.

The present study aims to investigate the drought phenomena and its short occurrences in Khorasan region. To achieve these goals, two methods have been  utilized. To study the drought conditions of the region; monthly precipitation statistics of 34 stations from 1968-1997 was taken into account. In the next stage, to obtain short period occurrences of the drought, Two State First Order Markov chain has been used.  In this method, the daily precipitation data obtained from five representative stations in different parts of the province was helped to derive climatic characteristic associated with occurrences of short dry and wet spell such as stationary and simple probability, day frequencies,the length of wet and dry spells and weather cycle. Then, having computed the frequency of dry period, probability of occurrences of these periods and their return periods. The analysis results of the process of monthly precipitation trough method cleared the condition of different years in terms of drought and wet year. The analysis showed that 57 percent of stations in 1970 suffered from severe drought. On the contrary, the recived precipitation of all stations in 1991 was higher than normal level. It should pointed out that 76 percent of these stations spent a wet year with different intensities. The exact determination of probability of two sequential dry days have, differences between simple and stationary probabilities, the occurrences of wet and dry days and also the frequency of dry spell can be accounted among the significent result of this study. This study also showed that the probability of susequent dry spell fluctuated from 71 to 98 percent. No noticeable difference was observed between the simple and stationary drought of the stations. Interms the frequency of dry days, the average number of dry days will be 20 or more during the whole seasons.

These essay has prepared with using the Landset imagery (1/1000000 scale); topograpy maps (1/250000 scale) and field works. The valley fills and fans-forming are two important landscape of fluvial landforms in Lout plain.Average Lout unit height is about 980m and has many big, small, old and new fans. The old fans are higher, the new fans are lower and sometime deposited on old fans. Source of many parts of Landforms in Lout plain (more than half) are  depositional-fluvial kind. In this essay we examine 3 groups of fluvial processes, wind and fans changes. Aeolian processes in the Lout are trenching and building of recent alluvial material at the toe and headfans.

This research was conducted to study droughts and forecast precipitation and temperature in Birjand area . First monthly total precipitation and mean temperature of the station during 1955-2001 period  were analyzed .After testing randomness, homogeneity, and stationary of the monthly precipitin and temperature series , the Box-Jenkins ARIMA model was implemented to the series .              The accuracy of the resulted models was checked by some indexes such as AIC  and SBC criteria.The final model for precipitation of Birjand is (0,1,1) (0,1,1) and for the temperature of the station is (1,1,1) (0,1,1).  

Geological and stratigraphical structures affect the balance of network drainages. Indeed, between all factors which determine the characteristics of drainage network, lithology and tectonic are very important. These factors control the part of drainage network from the erosion point of view. In finding their way, rivers always choose the weak points of the formations. In addition, faults, fissures and cracks in stones are the best places for overlapping and evolution of drainages. Due to extensive expansion of rivers and the plentiful ness of small anticlines in the north-east of Elborz, the way of drainages evolution and the effectiveness of anticline geomorphology of this area in the drainage pattern have been investigated. Geomatica software was used as the main tool of the study. order to analyze the effective variables. More over, Thematic Mapper (TM) and Enhanced thematic Mapper plus (ETM) satellite images and also radar images were used as a tool for indirect observation and numeric data analyses. Comparing the results of quantitative data analyses with geological maps show that in the north east of Elborz, the rivers have crossed the anticlinals and created the cluses. The results also show that the major part of these geomorphological landforms have been almost smoothed during the time and under the effect of extensive erosion dominating north and north east of Elborz. Although, these created cluses are not visible in satellite images, and quantitative comparison with geological maps and field data, using structural reconstruction technique. Reveals the existence of such old cluses and shows the performance of transversal networks in this system.   

In order to detect different precipitation regimes of Iran monthly precipitation observations from Jan 1951 through Dec 1999 have been analyzed. Using this data set 588 monthly digital maps with a spatial resolution of 15×15 Km have been calculated. Dividing monthly precipitation over each pixel to annual precipitation of that pixel provide the basic data for detecting precipitation regimes. An agglomerative hierarchical cluster analysis then applied to a random sample extracting from relative precipitation matrix.  This analysis shows that there are three main precipitation regimes in Iran: winter regime, winter-spring regime and fall regime. Temporal distribution of precipitation in Iran depends mainly on latitude. Meanwhile local geographical features play a crucial role in secondary characteristics of precipitation regimes.

Landslide is one of the natural hazard which mainly occurs in mountainous areas. It gives sudden changes to the morphology of the ground and causes drastic damages to residential areas, roads, and farmlands, that is xhy governments and scientific and research centres have pahd special attention to the phenomenon of landslide and some measures have been taken to identify and control them. In 1374, Abkar, a village of Farsan city Chahar–Mahal Bakhtiary province–was buried down with its50 inhabitants due to the landslide (Ghobadi, M.H.,1381,P.164). In the area under study, specially in the northern ranges of cherkindag, which looks to Bazargan plain and New Maku, paleo and New landslide can be seen. Fortunately, since the area is for from the residential area, in has not produced serious problems for the people. The aim of the present article is identifying the area with a landslide potential. Therefore, using topographical maps and considering the methodspresented by Anbalagan, I would provide a zonation plan of the landslide hazard to let the planning and designing managers, provided with an exact understanding and identification of these area, could consider the geomorphological risks in using them.

In view of Iran,s being located on one of the tow seismic belts of the world as well as the very existence of copious geologic fault, the occurrence of earthquake in the plateau of Iran is but a natural phenomenon. Iran is one of the ten cataclysm–generating countries and the sixth in number of the world earthquake - generating countries. That is why earthquake inflicts high death toll of human lives. Moreover the seismic zone encompasses 90% of the territorial area of our country . But what is more important in this regard, is the regrettable location of cities and metropolises (such as Tehran, Tabriz…) that have been built on or within the vicinity of geologic fault and, as a result, are unquestionably prone to earthquake menace.This is because Iran is one of the countries that have taken on their formation through innumerable geologic faults whose movements cause the release of stored energy leading to reccurrence of earthquake meting out heavy human casualty and immense property losses in urban areas. In this paper, endevours will be made to probe into the cause of earthquake generation in the plateau of Iran and the negative effects of activities of faults on some of the cities taken as models and recall the dangers entailed therein.

During the twentieth century of A.C. Khouzestan the most strategic province if Iran, more than any other provinces of this country, has been exposed to separatism. Arab governments, Specially Iraq, have been the greatest planner and obstinate spporter of separation of this part of Iran. Being Arabs and particularly historical desire of the magority of this province inhabitance for separation has been the most important excuse and proof supporting this plan. This research tries to analysis the divergence and convergence degree of Khouzestan Arabs with regard to the major constructing political core of country an national aspiration as well. 

 Lack of proper distribution of educational space in Zanjan has caused many problems. Among them uncompatibility undesirability and lack of enough capacity of educational space are important factors. Inaddition educational space lacks standard factors, so I tried to elaborate these factors by case study and data gathering by GIS and Arc/info software. Graphical data was fed in Arc files then by ordering Buld and clean , desired map for building coverage was obtained. The next stage analizing Arcview soft ware , Then by applying calculat Density, Bufferring, Network program,…at last proper pattern for settleing highschool egucational space in Zanjan was done and this will facilate all Zanjan students access to the schools.