نشریه جغرافیا و برنامه ریزی محیطی
سال بیست و سوم شماره 3 (پیاپی 47، پاییز 1391)

Introduction The cloudiness effects on the climate in the southern coasts of Caspian Sea through increasing of humidity, precipitation and cloudiness cooling. Spreading of Caspian Sea in the north of area and Elborze Mountains in the south of area cause suitable conditions to generate heavier precipitation in the southern coasts of the Sea when low pressure systems pass from area or high pressure systems are located in around of Caspian Sea. The previous researches showed that convective clouds are the most important cause to generate heavier precipitation but non convective clouds can produce this group of precipitation if they accompany with convective clouds. In this research, kinds of low clouds which produce heavy and super heavy precipitation events were studied. 2- Methodology Precipitation events are computed on the basis of daily precipitations (1982 to 2003). Precipitation events were divided into 2 groups heavy and super heavy precipitations after sorting with regard to 25 and 50 percent probability. Then, the classes were grouped into two classes convective and non convective clouds based on clouds synoptic indices. Clouds synoptic indices 2, 3, 8 and 9 show convective clouds as well clouds synoptic indices 4, 5, 6 and 7 show non convective clouds. Convective and non convective clouds which generate heavy and super heavy precipitation events analysis and compare were used METEOSAT 5 images were used to survey and determinate clouds location in different geographic places. 3- Discussion Precipitations in the southern coasts of Caspian Sea are different from of the rest of places in Iran both amount and duration. Synoptic and dynamic conditions particularly sea surface temperature over the Sea and cold advection from north to south can be the most important factors to produce the clouds. The previous studies have indicated that the main cause to generate heavier events is convective clouds. The results show that the area is divided into 3 regions on the basis of formation conditions of clouds and its daily and monthly regimes in general. The first region is the west and middle coasts of Caspian Sea. Cumulonimbus clouds (type 3 and then 9) produce heavier precipitation and the frequency of convective clouds in heavy group is less than super heavy group. Frequency maximum is at 03 and 15 oclock GMT in different months for heavy precipitations group. The second region is the east coasts of Caspian Sea. The convective clouds are the main cause to generate heavier precipitation events and its frequency is more than non convective clouds. The most frequency of convective and non convective clouds is between 03 and 15 oclock GMT. The third region includes mountainous parts in the middle of area. Cumulonimbus clouds (type 3) which are locally and not spread produce heavier precipitations. 4- Conclusion convective precipitations particularly cumulonimbus clouds are the main cause to generate heavy and super heavy precipitation events originally in the southern coasts of Caspian Sea even though non convective have been spread throughout of sky. Non convective clouds have the main role in heavy precipitation than super heavy precipitation. Cloudiness percent and monthly regime aren’t similar in different regions as cloudiness in the west region is more than the east and mountainous places. The frequency maximum is 03 and 12 GMT for convective and non convective clouds respectively.

Introduction Developing the cities and it’s influences on the spatial structure of megalopolises has always been one of the most important factors for the planners. Among the most important factors directing the development of the cities, are natural factors such as climatic ones which have been less considered in the country as yet because of various factors like economic benefits resulting from immethodical construction of the buildings. Since this carelessness has caused an unwise and easy-going development of Tehran megalopolis in unsuitable geographic directions, so this research intends to accomplish the optimum site selection for physical development of Tehran megalopolis based on climatic elements and geographic factors. 2- Methodology Topographic maps of the region which mainly consist some parts of Tehran and Alborz provinces on a scale of 1:250,000 were prepared and the region boundary was defined on them. In the next step, the climatic data of six meteorological stations was taken from the Iranian Meteorological Organization and, after reconstruction, was considered through the similar time range of 1984 to 2005. Then, using ArcGIS software and on the basis of the climatic and geographic factors, various layers affecting the site selection including topography, digital elevation model (DEM), slope percent and aspect, solar radiation angle, temperature means (minimum, maximum and daily), mean diurnal temperature difference, 24 hrs. maximum precipitation, and mean wind speed were made and entered into the software. Pixels’ values in the climatic layers were calculated via spline interpolation method or regression equations. Then the resulted raster layers, after the reclassification of their pixels’ values, were weighed and overlayed using Spatial Analyst (SA) and Spatial Analytical Hierarchy Process (SAHP) models and thus the final maps of the physical development suitability of these two models were obtained. On the other hand, two Landsat ETM-7 images prepared from Iranian Space Agency and some geometric corrections were made on them using PCI (Geomatica) software in UTM WGS84 projection. Before geometric corrections, because of temporal differences of images, radiometric corrections were made on them too. radiometric correction or normalization means the reconstruction of image values so that there is a linear and similar relation between pixels and their real radiations in the whole imaging area. The result was the Normalized Difference Vegetation Index (NDVI) map and the land use map. As the last step, the final site selection maps were presented via overlaying the NDVI and the land use maps with final maps of each two SA and SAHP models. 3– Discussion Based upon the distribution of the development suitability zones in the site selection maps, the most unfavorable areas have been developed in the high slope sections of the north of the region in the SA model. According to this model, about 8500 km2 of the region has not any special limitation for the development. In the SAHP model too, the most important limitation in the way of the development is the high slope sections of north of the region. The most suitable areas with almost 1400 km2 area stands in the south, west and the submontanes of north and northwest of the region. Partly suitable areas with the area equal to 5300 km2 have been developed in the central and southern parts of the region. The comparison of the final maps of two models reveals that the most suitable areas in the SAHP model have lesser extent than in the SA model. 4– Conclusion Considering the bare land expansion which is mainly developed in the south of region and overlaying it with suitability zones of the SA and SAHP models and in order to protect the vegetation cover specially in the western parts of the region, among the three suitable zones for physical development of the city, the south direction is the most favorable direction and the western and southwestern regions respectively stand in the next precedences. In order to get a more comprehensive study in this regard, the other natural factors such as geologic, geomorphologic, hydrologic and human factors must be taken into account too.

The increasing growth of urban and rural development has caused some natural anomalies in the Earth's inhabitants. Mass movements, especially landslides, are one of the most damages of them that have had the increasing momentum together human manipulation in natural systems in recent decades. So that it is one of the principal geomorphic processes in the mountainous areas. Landslide phenomenon occurring in many parts of the world and Iran in the favorable conditions causes the destruction of vegetation, orchards, farmlands, and even human casualties. According to estimates, landslides have imposed much financial damages about 500 milliard Rials to Iran, annually. Burying of Abikar village of Charmahal-o-Bakhtiari Province in spring 1997 year is one of the clear samples of landslide human damage. Among these, the Lorestan Province is one of the most susceptible sites of landslide occurrence in Iran. The occurrence about 274 landslides in Lorestan Province, with extent 1400km2 equivalent %4.8 of its area confirm this claim. Since the exact predication of landslides occurrence isn’t possible by human sciences, thus, we can prevent from the damages of this phenomenon by identification of landslide susceptible areas and prioritizing them. Landslide hazard zonation maps can help the environmental designers and engineers to select a suitable place for development projects implementation. The results of these studies can be used as fundamental information by environmental managers and planners. The purposes of this study are the recognition of effective factors in landslide and the zonation of Khoram Abad City in terms of the occurrence of this phenomenon using the AHP model and GIS technique. Therefore, selection of criteria and standards, providing of factors raster layers, determining of relative and final weight of factors, overlaying of layers and preparing landslide hazard zonation map are the major objectives of this research to determine sensitive sites that have the maximum occurrence probability of landslide.

Veladareh basin is located in the eastern site of Sabalan volcanic massive and north of Sarein town in the north west of Iran. The length of Veladareh River is 37.75 kilometer and its drainage basin area is 37.3 square kilometer. This basin is part of Qaraso and the Arax river basin. Veladareh basin is located at 38° 10' 17" to 38º 13' 21" northern latitude and 47º 58' 10" to 48 º 9” eastern longitude. The purpose of this study is investigation of erosion and sediment estimating in the Veladareh basin. 2- Aim of this study is estimation of erosion rate in the Veladareh basin. For arrive to above aim the Veladareh basin was divided to four sub-basins. Erosion rate was estimated on one of the sub basins using by Erosion Potential Method (E.P.M). In order to perform a conservation soil and nominate struggle methods with erosion and decrease of sediment yield must be estimated total volume of yearly sediment rates. To achieve this goal estimated 4 erosion factors include Erosion coefficient of basin (Ψ), Land use index (), Susceptibility of rocks to erosion) Y) and mean gradient of basin (I) in the four sub basins. 3– Base of four above agents we are estimated Erosion intensity coefficient from formula 1 in the work units (Refahi, 1375: 257). Z = Y. (Ψ+). Just as show in table 3 and fig. 6, erosion intensity coefficient is different between. 62 in the north Erdymosa catchment and. 77 in the Arandareh catchment. Between the four above effective agents role of gradient is higher than others agents, that is caused erosion intensity is different in this basin. Erosion intensity in Arandareh catchment has 2 erosion classes and in the others sub basins have 3 erosion classes. For estimate of yearly especial erosion in E.P.M method is used fomola2 (refahi, 1375: 259). = T. H. π. Just as show in table 4, especial erosion in the whole Veladareh basin is 777.7 m3/km/y or 10.3 ton per hectare. Arandareh catchmen between sub basins has higher especial erosion (1099 m3/km2/y or 14.3 ton per hectare) than that others catchments, because of high branching ratio, high erosion coefficient and high gradient; but Erdymosa catchment has lower especial erosion(660 m3/km2/y or 8.6 ton per hectare), because of low gradient. To estimate of annual erosion rates in basin area is used formola4 (Refahi, 1375: 261): Just as show in table 4, whole basin can produced 29008 m3 sediments during year. The highest produced sediment was related to Arandareh catchment (10331 m3/y) because of setting in mountainous area, high gradient and high area (9.4 km2). The lowest rate of produced sediment was in north Erdymosa sub basin (5676 m3/y), because of gentle gradient and low area (7.8). 4– Conclusions of study show that violence of erosion is intense in Arandareh subbasin (upper part of the basin) due to high gradient in this part. But in the lower part of basin (Veladareh, Erdymosa and north Erdymosa subbasins) rate of erosion is low; because in this part gradient is few. Rate of especial erosion in whole of basin and per catchments of Arandareh, Veladareh, Erdymosa and north Erdymosa in order to arrange have been calculated 10.3, 14.3, 8.7, 8.6 and 8.6 ton in hectare in year. Potential of sediment discharge in whole of basin and sub basins in order to arrange have been estimated 29008, 10331, 7912, 5676 and 5179 cubic meter in the year. Excessive of especial erosion and potential sediment discharge in Arandareh catchment, than others sub basins is much of gradient and susceptibility of rocks. Whereas in the others catchments (Veladareh, Erdymosa and north Erdymosa) factor of gradient decrease effect of others agents in viewpoint of sediment yield and have been decrease a potential sediment discharge in these catchments.

In recent decades, rapid growth of urban population,rural-urban migrations & urban regions natural population growth, made very difficults for big cities & metropolises of our country. Before of this time Cities that had little growth, with very new difficults faced. One of the Maine needs of urban populations is fine access to urban sevices. Accabilitiy is one of the Maine characterizes of a good city and can divide to diver shape of access such as activities, goods, resources and services. 2- Primary, Effective alternatives of post center site selection converted for information layer with shape file format. In next stage, best buffer for any layers determined and for each considered range weigth between 1(lowest value) & 5(higthest value). Because the entire information layer that used isnt equall effect in post center site selection and because to be many Layers, compare & determine value of each seems very difficult, so AHP technique used for weigthing and combaine layers. The export of this stage is land zoning for locating post centers in 5 ranges with amount of goodness: very much, much, mediane, low & very low. So, in order to determining poor regions, network analysis tools in GIS environment used and 750 meters of standard buffer access for exist centers designed and with period rank planning, the best sites for construction post centers in 3 periods(low, mediane & long) determined. 3- In case study (zone 5 & 6 of Isfahan city), that 5 post services center exist, bad spatial distribution & locating near of the maine roads, created very difficults for settelers for access to this services. So in this research primary effective factor in post center site selection distincted that involved information layer such as radiant access, access to roads, nearest to attractive centers such as: educations, military, cultural, religious centers, center of regions and far from exists post centers. So using analytical hierarchy process technique compared these layers and for each layers one weigth in base amount of important considered. That far from exist post center gained highest value and radiant access of each center post gained lowest value. Then weigthed sub alternatives form each aleternatives for amount of importance using analytical hierarchy process technique. The weigths that gaind for each alternative and sub alternative used in stage of combining in GIS environment and finaly leveling of area surving for amount of goodness achived in order construction new post centers. Because the goal of research is construction post center ranking, so with attention to amount of lands goodness, with considering 750 meters access buffer, new post centers in 3 period (low, mediane, high times) porposed. 4- Results of this research shows that exist post centers in zons 5&6 of Isfahan city, haven’t good distribution and don’t considered exist alternatives for post centers site selection in their locating and exist center instead locating in center of neighborhoods & zones of city and corporate with other land uses, located near the maine roads that this forther more condemn extera finances for citizens, caused more attract people to near of this roads and created terafic challenges. So in order to doing exist standards with determine buffers with750 meters for each center, in one term with low, mediane & long periods, oltimately 10 new post center in optimal sites porposed that in low period 2 center, median period 3 center and finaly in long period 5 new post center porposed.

Nowadays, tourism as a dynamic industry and unique characteristics includes an important part of economic activities and production in the developed and developing countries. This industry covers all the phenomena and relationships resulting from the interaction of tourists, suppliers and vendors of tourism products, governments and host communities, in the process of attracting and welcoming of tourists. Results and achievements of the tourism industry involve considerable results such as aspects of employment and its impact on development and economic -social functions mentioned in a region or country. For the city of Shiraz that has numerous cultural attractions and historical and natural potential, development of tourism industry can be very helpful. 2-

The methodology of this research was based on descriptive-analytical methods. For collecting information and data required, documentation and field studies such as interviews and using these data, the attractions, facilities, services and tourism situation in region has been investigated. Then, the SWOT analysis matrix was used for data analysis and presentation of tourism development strategies in the Shiraz city. 3-

The Shiraz city due to good weather and having historical and unique civilization sites is one of tourism centers in national and international levels. These city due to Persepolis neighborhood, each year hosts a large number of domestic and foreign tourists. Moreover, Shiraz has valuable natural potential. But so far, this city failed to their real position in tourism field, especially in terms of attracting tourists and the number of tourists to achieve stability coefficient. In this paper, SWOT strategic planning process has been used for analyzing the functioning of tourism in Shiraz. A four-stage process of strategic planning including: first, external (opportunities and threats) and internal (strengths and weaknesses) factors evaluation matrix; second, analysis of strategic factors; third, external and internal matrix and matrix of quantitative strategic planning and finally, appropriate strategies for development of tourism in the city of Shiraz, has designed and presented. Moreover, after consideration of relevant information, the major external and internal factors were identified in the matrix were evaluated. Number of external factors determined to be 19. From this amount, 9 factors cause tourism opportunities of Shiraz and 10 threatened it. Firstly, the factors that led to the opportunity and then those that threaten the Shiraz tourism sector are located in the matrix. Number of domestic factors also determined to be 22 including the strengths and weaknesses of tourism in Shiraz. So that, firstly 11 strength factors and then 11 weakness factors of tourism are placed in the matrix, then using the expert viewpoints and comments of those interviewed, individual affecting factors were heightened. Finally, by adjusting the strategic planning and internal and external factors that are the base in the strategies planning, the SWOT matrix was extracted and accordingly, quantitative strategic planning, appropriate strategies and priorities matrices of tourism development are identified. 4-

In the present study, using strategic planning process, the abilities and functions of tourism and develop these functions, the action and determine strategies to provide practical solutions for Shiraz tourism development. In this process, with assessment capabilities and opportunities of Shiraz tourism, findings indicate that tourism planning strategies acceptable in this city, conservative strategies would be planned in first priority and second priority planning aggressive strategies. Thus, first WO primary strategies and then SO strategies were selected in the SWOT matrix priorities. In fact WO2 conservative strategy with 6.16 scores represents the best strategy on tourism development will be considered in Shiraz. To achieve this, the strategy to familiarize hotels and travel agencies managers with new methods of advertising and marketing of tourism, increase awareness of tourism interested in the unique attractions of Shiraz city and surrounding areas. Consequently increase the number of tourists and increase tourists to stay in the city is practical. However SO1 invasive strategy with 7.3 scores is considered as the most effective strategy for the conservative strategy. To achieve goals and enjoying the tourist development strategy, strengthening and increasing the amount of facilities and services offered alongside the importance of tourism attractions and resources in national and international levels, with the aim of attracting more tourists, especially the satisfaction of foreign tourists in order to introduce position of historic -civilization sites of Shiraz to other countries are recommended with the aim of attracting even more foreign tourists and create sustainable employment and income on the other hand.

Tourism and journey industry are one of the most varied industries in the world. Tourism as a social-cultural phenomenon is considered as the widest form of human transportation. Increasing growth of 20th century has made many pundits to call it as tourism century. This industry has many effects on economic, social and cultural areas such as foreign exchanges, incomes, engagement, prices; dispense of incomes, migration, distribution the jobs, customs and arts. Considering the significance of tourism, the main goal of this essay is the satisfaction of foreign tourism in to the Iranian hosts in the extension of tourism industry. In this research the basic main is to persuade the tourism. 2- In order to achieve this aim, we have two attributive ways (based on a historical study) and ground study. Statistic society of this research includes of foreign tourism from five continents of the world that with the economic, social, cultural and sport goals travel to the Iran. 385 tourism was been chosen as a best individual for evaluation from satisfactory from 6 introduce, resident, the general behavior, clean the street from anything, percept driver license, respect to the others and precept in the clean the street from individuals. 3– The results of the study showed that level of tourist satisfaction and the willingness of tourists to travel have high status. So the operators of public participation in protecting the global environment, cultural heritage and nature as an effective agent can help to develop the country's tourism industry. Achieving sustainable development in the countries involved in planning and implementing projects is essential. In this respect, we can organize tourism activities. In addition, many of the problems of agriculture and industry, social, economic and eliminates the problem of youth employment. Development of tourism in Iran, the government has an important role in the overall policy of the Government in this regard would be helpful. To investigate possible solutions should be considered from different perspectives of the tourism industry Charhandyshy for each of them and the obstacles in the way. 4– As a results 86% from tourism were very satisfy to the Iranian person and 95% like to travel to the Iran again. And the correlation coefficient between two variety the sense of satisfactory and the tendency to the travel to the Iran for second time is the considerable correlation r=582% and observe meaningful surface (p=0.000). Because this coefficient is positive and show the right relation between two variety, to the attention the measure of appointment coefficient (R2=0.34) about 0.34% from variety like to travel to the Iran again. So, when ascendant the measure of the sense of satisfaction of tourism than to the Iranian people increased the tendency to the travel to Iran for second time.

Climate change could be studied by detection of amount and tempo-spatial pattern of climatic elements. Precipitation is one of important climatic elements that could be studied. Precipitation is one of the most variant climatic elements that could have negative consequences on environment, society, economic and even culture of human society. Accordingly the changes and looking for change and variability of precipitation take the attention of climate experts. This is because of the importance of this sort of studies on climate forecasting and water resources management as well as environmental, economical and agricultural planning. Precipitation as one of fundamental elements in climate has increased by 0.1% in middle and high latitude especially during 20th century. Meanwhile in subtropical lands (Northern latitude of 10-30 degree) decreasing in precipitation by 0.3% has been reported, also there are increasing by 0.2%-0.3% in tropical regions (Mosmann et al. 2004). In addition there are negative trends of precipitation in Mediterranean basin since 1950s. Because of this spatial differ in precipitation changes and in order to precise exploring the changes, a dozen of studies have been accomplished. 2- In this paper long term and oscillatory behavior of precipitation in the Northwest of Iran has been evaluated. The area under investigation is about 12654.4 square kilometers and contains four province including west and east Azarbayjan, Ardabil and Zanjan. It occupied about 7.7% of all country. The average elevation of northwest of Iran is about 1830 meters above sea level. The highest area is about 4500 meters above sea level. In order to do this research, daily precipitation data of 260 stations during 1966-2005 have been analyzed. The length of recorded data have been used in this study wasn’t equal, so it had created a map for every single day using the stations that was available. This stage has been accomplished by Kriging interpolation method. Accordingly 15052 daily precipitation maps by 100*100 pixel resolution were created. To create the 40 annual maps, these maps were used. So the investigated area was covered by 5374 pixels. Finally the matrix of data by dimensions of 5374*41 has been established. The analyses of two approaches were accomplished on this matrix. They are as follow: 1- The trends of annual precipitation have been analyzed using linear non – parametric regression model. 2-annual cycles of precipitation have been estimated using spectral analyses. The cycle that has largest difference with null continuum, is chosen as the significant cycle. Finally, all result of above two stages is presented in related maps. 3– Annual precipitation of northwest of Iran is about 360.9 mm. precipitation mean is spatially different from 200 mm (northeast of area in Dashte-Moghan) to 800 mm (in southwest of area. Accordingly spatial coefficient of variations is about 24.1%. The area with low precipitation is most extending than the area with high precipitation. For example about 58.8% of northwest of Iran has achieved the precipitation lower than its spatial average. The annual precipitation of northwest of Iran (except of small parts in southwest and north) during the studied period has experienced decreasing trend. The amount of decrease in about 84.5% of area is about 3 mm per year. This kind of trends has been occurred especially in eastern and southern halves. Across west to east and toward the mountains the amounts of trend is decreased. About 16.8% of area is covered by Non –significant trends that contain Dashte-Moghan and western mountains. The region under increasing trends is about 8% of the area in which the trends is about 5-9 mm per year. In the 58%-71% of the area, precipitation has experienced the values more than long term average during the first three decades. Meanwhile during the forth decade the area with precipitation lower than long term average has increased by 72%. By using spectral analyses technique on precipitation data, significant oscillations in 2-3, 3-5, 5-11 and 11 years have been discovered. Major area experienced 5-11 years oscillations. As it has reported by many experts these oscillations periods are due to macro-scales circulations between atmosphere and hydrosphere e.g. quasi binomial oscillation is related to ENSO phenomenon. 4– Based on what discovered in this paper it has been cleared that long-term mean of precipitation in 84.5% of northwest of Iran has been decreased. The increased trends values of precipitation are happened in southwest. The decreasing in precipitation is due to last decade in which the area with low precipitation has increased by 72%.Spectral analyses showed significant oscillations in 2-3, 3-5, 5-11 and 11 years. Major area experienced 5-11 years oscillations. As it has reported by many experts, these oscillations periods are due to macro-scales circulations between atmosphere and hydrosphere e.g. quasi binomial oscillation is related to ENSO phenomenon.

The issue of passive defense has a long history especially in construction of urban spaces as well as public buildings. The accuracy of this claim can be found in Initial wars of Islam and defensive measures such as digging ditches, making a fort. Considering the improvement in technology and its effect on the development of WMD, the need for improvement in considerations of passive defense for reducing casualties of war is more felt. Since Iran is a country with strategic objectives and strategies such as: authoritarianism, self-seeking, preservation of territorial integrity, political independence, the pattern of local development, etc. and also due its location in the Middle East and having unique geopolitical, geostrategic, geo-economic opportunities, applying a defensive consideration in urban development is very important. In this study, hazard zones in the country were identified and also sensitive buildings of Shahriyar were determined. Doing so, we can prevent financial and physical damages, of parts which are more prone to damage, before the occurrence of war. 2-

This study is applied and the general approach is descriptive-analytical. The studied area is the zone of Shahriar in general and its official area in particular and the population was a number of experts in the public sector (municipalities), private sector (consulting engineers and engineering offices), government sector (Government agencies) and the public. In order to better recognize the current status and understand the necessity to investigate the passive defense preparations, raw data were collected from the latest census of the country in 2006 and considering the comprehensive studies of Shahriar and getting the relevant maps from the urbanization and housing ministry, the location of the official cite of Shariar was determined in natural, economic and social dimensions and finally, using the matrix table, different levels of decision-making process in devising developmental projects were specified and presented.

planning and urban green spaces location in our country as an important element of the user and the environment can Signify Greatly Them an- made environments, as Favorable community and with reduce the damaging effects of expansion of industry and improper use of the technology and raise the level of aesthetics cause increase the quality of life and identity of its residents. It can also improve the chaotic scenes so that the importance of the intuitive user and its compatibility with the environment should be balance and obviously it to unite the city's landscape and visual composition is necessary. Thus there is a need for existence of parks and green spaces as an existence needing of communities for improve quality life of people living and as a major factor increasing a good balance in the environment should be the top priority in urban planning development. Noorabad City has been flourishing in this research study. The time now is facing a severe shortage of urban green spaces. This research wants to consider and analyze the green space land use of Noorabad city with contributed existence analysis in GIS And finally locate new green spaces, however small step to be taken to solve the problems of city's green spaces. 2-

The research method used is descriptive analysis, That use city map with scale of 1/5000 through a detailed study of the city and the observed field Collect the required information using GIS software and to help analyze hierarchical Data processing and analysis were performed according to the standards of urban planning and in the end will determine the appropriate location for urban green space.

Potential evapotranspiration () is one of the most important component of hydrological cycle for irrigation systems scheduling, preparing input data for water balance hydrological models, and assessment of hydrological effect of climate change. One of the major issues of human societies in the present century is global warming due to green house gases increasing and water resources crisis. As a result, climate change may have significant effects on some of the hydrological parameters such as runoff, evapotranspiration, soil moisture and groundwater. Also, evapotranspiration is most important component of hydrological cycle after precipitation and usually crop water requirement determined using. Any change in climatological parameters due to global warming will affect evapotranspiration too. Eventual global warming may increase dry conditions in the world with increase of evapotranspiration and intensification of desertification. Therefore, Earth’s global warming may change the hydrological cycle components and global water resources will re-distribute in the time and place. This may intensify desertification in arid and semi arid countries such as Iran. 2- In this study values computed using the Blaney- Cridle method for the 6 synoptic stations located at southern part of Aras river basin in the period 1986-2008 (23 years). Furthermore, trend of and some meteorological variables (precipitation, maximum temperature and minimum temperature) which affect it were analyzed in both annual and seasonal time scales. Data used for computing involves: mean daily temperature, minimum relative humidity, wind speed (m/s) and sunshine hours. For trend computing, the effects of autocorrelation cofficients until 31 lags were included. Then trend analysis was performed with conventional MK method (for series with insignificant autocorrelation) and modified MK (for series with significant auto correlation). Mann – Kendall method is one of the most commonly used non parametric tests for considering trend in different hydrological and climatological variables. Test statistic Z was obtained from Mann-Kendall equations compared with normal Z in significance level. If Mann-Kendall test statistic absolute value, Z, was more than 1.645 then the trend (increasing or decreasing) considered being significant in 10% level. If it was more than 1.96, trend considered being significant in 5% level and if it was more than 2.33 then trend level will be 1%. In addition to trend test, slope of trend line also estimated using the Sen’s slope estimator. 3- Results indicated that variation trend of as one of the main components of hydrological cycle at southern part of Aras river basin has spatial and temporal variations. Among all stations, Khoy experienced the most sever significant increasing trend (P<0.05) at annual time scale. At this station strong decreasing trends detected for minimum relative humidity, which was stronger than other stations. At this station some parameters related to air temperature and wind speed showed increasing trends. trend line slope estimated about 25 mm/year at the mentioned station. Increasing insignificant trends detected for at Makoo and Ahar stations at annual time scale. At this station decreasing trend for relative humidity experienced. Other station’s trend was detected to be decreasing (but insignificant). At seasonal time scale, combinations of both positive and negative trends observed for stations. Khoy station’s seasonal trend for all seasons was positive (autumn was significant at 5% level) and at Parsabad station was negative (but insignificant). Among considered parameters, trends of sunshine hours at all stations were significant at both seasonal and annual time scales. Minimum, maximum and mean air temperature in annual time scale at all stations had increasing trends. Trends of autumn precipitation at all stations were decreasing. Decreasing trends observed for wind speed at all stations (except Jolfa and Parsabad) at annual time scale. 4- Results showed that among all stations, Khoy had highest significant increasing trend which is due to significant increase in wind speed, sunshine and significant decrease in relative humidity values. Maximum value of trend line slope at this station observed at annual time scale which was estimated equal with 25 mm/year. Among all stations the strongest decreasing trend slope belonged to Parsabad station (at annual time scale) equal with 8.4 mm/year. Among parameters which their effects considered on evapotranspiration more variation related to autumn sunshine hours in Ardebil station which is about 3.7 hours/year. The most decreasing precipitation trends observed at Ahar and Parsabad station which the slope of trend line was about 2.4 mm/year.