فصلنامه تحقیقات جغرافیایی
سال بیست و نهم شماره 4 (پیاپی 115، زمستان 1393)

Daily precipitation data from APHRODITE''s Water Resources with a spatial resolution of 0. 25˚for 57 years has been used to detect the trend of precipitation in Azerbaijan Republic. First of all monthly، seasonal and yearly maps and regional mean time series calculated. According to the annual map mean annual precipitation of the country is about 410 m. m there are two precipitation maximal is Azerbaijan; one in northern part (Şahdağ and Bazardüzü) and the other one in south Western part of the country (Lankaran region). Throughout the country precipitation maximum occurs in spring and winter. Trend analysis of annual time series shows a decreasing trend that is significant in 96 percent confidence level. The same situation is true for summer and winter.

One of the most variability of atmospheric parameter is precipitation، which changes seasonally. It is important to understand exact characteristic of rainfall seasonal variable. Therefore، it is avoidable to study rainfall season in Hamedan province، because Hameden is one of the important centers of agriculture in Iran. In this research، the seasonal variability of rainfall is considered in Hamedan province. For this object، precipitation data spanning 30 years (1979-2009) were analysed to determine the onset and cessation، trend and seasonal variability of rainfall، based on the daily rainfall for there separated decades. The result of this study show the duration of rainfall is from early falls until end of spring in the first decade. This result indicated the duration of rainfall is long. In the second decade، there is no significant change in rainfall season، but only in some part of the province، the rainfall duration is shortfall and in the other part is long falls. Nevertheless، in the third decade there is considerable movement، i. e. the onset of rainfall duration has been in winter and cessation of rainfall duration has been in summer. It express that rainfall season has moved to summer slowly. The trend of rainfall duration has increasing trend. On the other hand، the duration length of rainfall is longer than before. In order to classify، rainfall seasonal variability is interpolated and the cluster analysis is done base on the “Oghlidos distance” and “Ward” integrated method. According to this method، Hamedan province is classified to 3 groups. The first group indicates the shortfall in the most parts، the second group indicates rainfall season onset is moved to winter، and in the third part the rainfall season hasn’t had change.

Nomad’s livelihood is based on continuous migration between summer and winter pastures to obtain forage for their animals and access to contented weather. This living way has long history in Iran which formed in accord with climate. In recent century، modernization has been caused many changes in traditional living way of nomads. Therefore، nomads have no more their role and function as in the past. One of changes in nomads’ living way is about migration time which usually leads to early entering in rangelands. This has deteriorative effect on rangelands. Present article delivers results of a survey research on factors affecting early migration of nomads and early entering of their animals in summer pastures of Fars province. Findings indicated that early entering in summer pastures are a common phenomenon among nomads. The mean of days which nomads enter early in summer pasture is 13 days. This mean are 17. 5، 2. 1 and 41. 4 days for nomads of Qhashqay clan، Khamseh clan and Mamasani clan respectively. Most nomads have migrated their animals from winter pasture to summer pastures by walk. This way of migration، in comparison to migration by machine، has resulted in decreasing the days which nomads enter early in summer pasture. The results also indicated that nomads have low sense of security in migration time. From point of their view، the? plant and drought could increase the days of entering early in summer pasture for 18 and 26 days respectively. Nomads also believed that fresh water and animal forage deficiencies are important determinant factors in early migration of nomads.

The present study carried out to identify neo tectonic activity of the Gorgan River basin in Golestan province، in North of eastern Alborz range is investigated by four geomorphic indices including the stream– gradient index (SL)، drainage basin asymmetry (Af)، reveres symmetry of topography (T) and mountain front sinuosity (Smf). Result from the analysis is accumulated and expressed as an index of relative active tectonics (Iat)، which divided into four classes from relatively low to highest tectonic activity. The high class values low tectonic activity for Iat mainly occur in the south and southwest of the Gorgan River Drainage Basin، while the rest of the study area has classes of Iat suggesting moderate to low tectonic activity. The results of this study، show that high values of T-vectors are related to Gorgan River are resulted from Caspian، segments of North Alborz and Khosh yeilagh faults activity. In this area increase trend of tilting collimate with faults can be reason the existence of an active tectonics region in the west part of the eastern Alborz. Other results of this study show low Smf and high SL values. The rate of tectonic activity in this area will increase from north to south. This increase can be related to the position of peaks stream length-gradient index along the fault and segment fault. Also value of drainage basin asymmetry is calculated for all of the sub catchments greater or less than 50 that shows tilt for each stream toward West or East. Length of the T- vector in eastern Alborz proportionate with measure of tilting and class of active tectonics. On the other hand، other results of this research are high levels of tilt and drainage basin asymmetry. The results of the review to propose the relative active tectonics index in the region، represent areas with focus on low tectonic activity in the central part of Gorgan Drainage Basin، while other areas have moderate to high categories were tectonic activity which indicates the study area is neo tectonically active.

Hydrograph analysis is a complex problem in a variety of water resources investigations and its estimate is critical in the assessment of low flow characteristics of river for use in water supply، water management and pollution assessment. The paper describes different methods of base flow separation based recession analysis from daily river flow records and distinguishes the most suitable method in some hydrometric stations of Azarbaijan province. An automated base flow separation with different parameters –with different parameters of 0. 9 to 0. 975- and local minimum techniques has been tested against correlation method of master recession curve with base flow index. unnecessary of calibration in this algorithms is made easy to use them and Finally، use of digital filter with the parameter set to 0. 925 was found to be a most accurate method of base flow separation in study region. Also، Recession constants have fluctuations between 0. 65 to 0. 83 which reveal role of ground water and base flow in river recharging. Continuous investigations of daily flow data in long term duration is another benefit of this algorithm that can be used for leaching control and pollutions entry into soil in environmental plannings.

In this study، we used monthly Palmer Severity Drought Index (PDSI) data of National center of oceanic atmospheric administration (NOAA) during 1/1950 to 12/2005 (56 year). The time and space resolution of data is monthly and 2. 5*2. 5 degree respectively. Therefore 26 pixels located in Iran political boundary. A matrix 26*672 carried out that pixels located on rows and month located on column. The cluster analysis by Ward method showed that Iran classified to four regions. The most drought severity occurred during year 2000 in northwestern of Iran. It seems that location of regions related to the atmospheric passing route on Iran and their effective radius. There is a significant correlation between teleconnection patterns and drought in Iran. The effect of teleconnection patterns is different for regions. In total، in autumn there is a highest correlation between teleconnection patterns and Drought.

Modeling and prediction of land use/cover changes is an essential need for planning sustainable use of land in country like Iran with its high level of changes in land uses and land covers. This study aimed to analyze the capability of CA Markov prediction model and Landsat satellite images for land use/cover change detection within the framework of “Iran at 1404 prospective” in Esfarayen region، North Khorasan province for year 2025. The results of CA Markov modeling showed a reduction about 5000 and 400 ha in irrigated agricultural lands and rangeland class in 2025، respectively. Furthermore، the model predicted that the poor rangeland class and Esfarayen city will be increased 30 and 450 ha in 13 years from 2009 to 2025. According to the results، if current land use continues to intensify regardless of sustainable development considerations، severe degradation in the natural resources of the study area is unavoidable in the future. Overall، the results demonstrate that satellite remote sensing data and CA Markov model can be successfully used to predict land use/ cover changes and the extracted maps can help policy makers to make better decision for the future of the region.

Iran country due to laying in the desert belt on the northern hemisphere، are dry and desert climate of many parts of it Predominate. Due to the same location in the atmospheric loss of human life and animal life and it has an important role. And according to the moisture sources in the country and located outside of the atmospheric loss from year to year fluctuations have other roles pluvial systems are more bold. One of the important mechanisms that cause instability and density will be cyclones. Therefore recognition of cyclonic centers and cyclogenesis can in environmental studies، planning and management of water resources and natural disasters، weather forecasts and the country sociol-economic development is necessary and important. Therefore، for identify and positioning cyclonic action is used from reanalysis data geo-potential height NCEP/NCAR with 6-hour time resolution (00، 06، 12، 18 z) and spatial resolution 2. 5× 2. 5 degree for the 1371 Solar year (93-1992). for Cyclone identification in six levels 1000، 925، 850، 700، 600، 500 hecto pascal Two conditions are considered Which include the: 1- geo-potential height pixel resurvey than every eight neighboring surrounds is low. 2- Large gradient geo-potential height on the Cornell Equal to or greater than 100 meters is 1000 km. In this study، first cyclonic centers according to the provisions are intended Identify and then monthly، seasonal and annual plans، drawn and cases were analyzed. According to the calculations performed were determined The maximum cyclone frequency in the first nine months in The 500 hpa level and three months in winter in level 1000 hpa and low they in the levels both 850 and 700 hpa Occurred. Also cyclogenesis centers of the cyclones they affect the country are include Genoa cyclogenesis area، Italy southern، Sicily and Sardinia Islands، southern Greece، Adriatic Sea، West Spain، Libya and Algeria، Iceland and are Pakistan. Finally، a correlation between frequency percentage cyclone monthly with an average monthly precipitation country established Shows that The highest correlation is in hpa 1000 level and in other levels correlation value decreases. finally، Can be said that there is between frequency percentage cyclones with rainfall average country a positive correlation.

Identification of spatial-temporal anomalies sea level pressure in part of northern hemisphere was the main aim in this research. For this purpose six hourly data used from the to eastern longitude and to northern latitude. In this location، there are 825 pixels to geographical degree. Therefore، database extent created. In this matrix، 825 are number of the pixels at that location and 90520 is number of six hourly scout of the sea level pressure during 62 years (1948-2009). Using these data، monthly anomalies sea level pressure obtained for every pixel. Frequency lesser and higher then long term mean calculated such as the negative and positive anomaly to sequence. For every month anomaly map of the sea level pressure have been drawled. The results showed that frequency of negative anomalies of the sea level pressure، almost during from November to April in most parts of Iran have been more then 50 percent and also during May to October lesser from 50 percent.

Tectonic، plays a key role in the evolution of morphology and can be distinguished with morphotectonic، rivers and structural parameters. An analysis of morphometric parameters illustrates that the development of them is associated with faults activities and rocks resistance. Morphotectonic analysis also supplies seismotectonic setting for a region. For appropriate and survey tectonic activities of Piranshahr fault in south west of Azarbaijan province as Northest part of Zagross Main Recent Fault، the morphotectonic indices contain: Ratio of Valley-mouth width to Valley Height، Ratio of Valley-floor width to Valley Height، Ratio of Vc and Mountain Front Sinuosity has been calculated. The results of several indices are incorporated to highlight tectonic activity and provide an assessment of a high degree of morphotectonic، Neotectonic activities. Piranshahr fault with 95 km length produced a seismic hazard magnitude ~ 6. 9 in Richter scale.

One of the most important problem and issues in metropolises is natural hazards and the earthquake is the most important of them in developing countries. According to this theme، comprehensive disaster management especially earthquake is an important factor to safe people life and evaluate risks by complete and update information bank، exact and modern hardware and GIS and Karmania Hazard softwares. This paper discusses with regard to the earthquake damage of Kerman and active faults evaluates vulnerability of the 13 operational area. In this method (survey)، by the Karmania Hazard software and GIS، landuse damage and the number of casualties are calculated; and then the efficiency rate of all kinds of emergency centers will be evaluated. 13 area is the old region of Kerman city that is included of different kinds of emergency center، one fire station، 14 health center and 10 police centers. By evaluating reports and vulnerabilities map results of simulation an earthquake with 6. 3 (Ms) of magnitude caused by Koohbanan fault in Karmania Hazard software، except 7 hospitals the other emergency centers will be unusable; And because the population is more than 28000، there will be no enough area and open spaces for emergency and temporary housing and no enough space to set up search and rescue centers. The main problem here is old houses and mazing and narrow paths that hinders and rescue procedure and increases the dead persons numbers.

Selecting sites for various uses is one of the final stages in land use planning. Given the fact that the favorable establishment of uses، which is influenced by a variety of factors، is the main reason that helps lower the costs، the site selection of land uses in Rural Development Plans should be able to maintain its favorable position over time with the minimum changes so as to ensure the sustainability of Rural Guidance Plans. The main goals of this paper is to assess the degree of satisfaction rural communities of the proposed sites in Rural Guidance Plans in sample villages of Khaf County. The data of the study، which drew on a descriptive-analytical method، were mainly gathered based on field studies and a questionnaire that was distributed among 253 subjects in 10 rural settlements، which had experienced Rural Guidance Plans about a decade ago. Face validity was confirmed by experts and its reliability by performing pre-test and analysis of the questionnaire data and the calculation of Cranach''s alpha coefficient (0. 854) were approved. Research instrument is questionnaire. Data analysis was conducted using SPSS software and ARC GIS software were used to assign weight to the indexes and prepare maps respectively. The results show that the proposed localization of User-conductor designs to fit the needs of rural communities، physical needs and is consistent with ecological. And we can say that in this aspect، most villagers have expressed satisfaction with the implementation of the proposed use. In contrast، the base for the social and economic dimensions، respectively is -3. 098 and -2. 723. Indicates that the social and economic indicators in preparing and conducting projects in this area، little attention has been made and people have the lowest levels of satisfaction.

The main purpose of this article is، showing similar fluctuation of temperature series and their consistency with what happened in the global level. In addition، it determines new estimates of regional seasonal and annual temperature trends over Iran، after the detection of artificial and natural non homogenous points of 33 synoptic stations for the period of 1960 2010. The 22 stations with shorter records are used only to confirm variability during overlapping periods as evidence. Due to similarity of the results of homogeneity tests and also to prevent of complexity، assessing of data homogeneity have been surveyed only by using the results of Standard Normal Homogeneity test (SNHT)، expert judgment and Metadata. The results showed، the country may be segmented to 10 such regions in terms of trends and variability of temperature. In addition، it was shown، the country with having different climatic type and with facing similar natural fluctuation، have experienced similar variability and fluctuation of temperatures in all regions at nearly equal rates of 0. 4-0. 5 and 0. 2-0. 3 (°C /decade) for annual minimum and maximum temperature، respectively in Iran. Non homogeneities in the temperature series relate mostly to relocation and changes of environmental conditions at individual stations. In the case of ignoring these non homogeneities، it is appeared errors in the statistical characteristics of temperature، Furthermore، it will be followed uncertainties in spatially averaged trends. The finding in earlier work of a few individual stations with negative trends is found to be due to artificial effects like relocation.

Development of tourism activities motivated tourist attractions often subject to diverse natural، cultural، and historical. Leading countries in terms of tourism or natural landscapes such as lakes، sunny beaches and high mountain snow، or the old historical terms or in terms of its other elements and create some artificial gravity and create the organizational structure and provide Broad context of bringing investments have been able to demand a wide range of tourist needs answered، the impact and achievements as well as its benefit. This study evaluated classification level and spatial distribution of Attraction Brnhvh factors in attracting tourists in the city Dalahoo villages in Kermanshah province was investigated. With normal cognitive abilities Vjazbh numerous regional and environmental planning for sustainable development of tourism in the correct area is essential. In this study، a descriptive - analytical Vpymayshy is achieved with the method of applying TOPSIS، one of the decision model Chndshakhsh (MADM) to study the spatial distribution and grading of villages and attractions in the city has paid to attract tourists. The results show that the village is Ban Ryjab yolk area equal to the highest ideal index + cli 71 / 0 in the other districts in attracting tourism has had.

Summer heat and drought conditions، especially in the southern half of Iran''s air sovereignty is recognized. In order to investigate the synoptic conditions - scanning the effect of unusual rain event for summer 12 to 6 September 2008 (22-16 September 1387) in the southern Zagros range، environmental approach to sightseeing and daily statistics recording station 270 Days of rain detected. Then، sea level pressure، geopotential height، wind، and humidity level of 500 hPa moisture convergence from the databases of the National Center for Atmospheric Research predicted environmental and United States (NOAA) mining and anomaly parameters according to the average 65-year term (2012 - 1948) were calculated and compared with the conditions of the day. So dominant pattern of rainfall associated with the monsoon days، the general rule and it depends on the same pattern as the cold season patterns. Deviation from the mean sea level pressure in the low pressure and high pressure in the North Caspian Sea، Persian Gulf and the resulting pressure gradient along the Zagros Mountains and formed over the region lives in front of an obstacle in the direction of ups and downs westerly winds anomally In addition، the negative 500 hPa level rise caused by moisture entering the Mediterranean and Red seas، and the resulting rainfall is provided.

In this paper occurrences of precipitation in Iran was analyzed according to random processes by the applying of markov chain model. In order to do that occurrence and non-occurrence of rainfall of asfezari data base for the period of 1961/3/21 to 2004/12/31 was used. This data are for 7187 pixel and 15991 days. By using markov chain model first order two state dry and wet frequency matrix was made. And then by the method of maximum likelihood transmission probability matrix was developed. By Chi-square goodness data following from chosen model was confirmed. By frequently powering this matrix stable probability and daily return period of rainy and non-rainy states was estimated. Period of daily returns and non-rainy days was estimated 7 and 1 respectively. So probability of precipitation was 0.1449 and probability of non-occurrence was estimated 0.8551. Return period of precipitation with lasting 1 to 3 days was calculated for all the months. The maximum likelihood of occurrence with precipitation was in March with the amount of 0.27. The shortest return period. The Shortest return period with lasting of 1 to 2 days was in February and March with the amount of 5.6 and 3.7 respectively.

Landslide like phenomena such as earthquake، flood، and volcano eruption are considered as the important natural events which happen every year in the mountainous and the elevated regions of the country and incur substantial damages and losses. Today، in the countries involved with the issue of earthquake sliding، there is an increasing tendency in evaluating and zoning of the danger and damages resulting from this phenomenon. Various factors such as topography، petrology، climatology، etc. are effective in the instability of the ranges and in various ways causes then instability of the ranges. In this study، in order to realize the rate of instability in various parts of the region based on Anbalagan. Firstly، the total area under study are divided into 26 work units and then the factors affecting the sliding are evaluated separately and the numerical value of each one was obtained and eventually the total scores were gathered. Based on the scores obtained، the plan of sliding ground was drawn for the total region. Studying the map suggests the fact that this region is divided into four areas in terms of landslide; the zone has been allocated with a high degree of danger of 31. 13 sq. km. from the total area of the region or 18. 52 % of the lands located near the villages and the roads. The region with high degree of danger 37. 30% in the area of study، the zone with medium danger of 23. 8 %، and a zone has been allocated with low degree of danger 20. 38 % from the region.