فصلنامه مطالعات جغرافیایی مناطق خشک
پیاپی 21 (پاییز 1394)

Oilseeds after Cereals make up the second world food supply. Sesame is one of the oldest cultivated plants and possibly the world's oldest oil plants. Nowadays, sesame is used as a source of edible oil. Sesame home is warm and semi-warm areas, but its cultivation spread to temperate regions (Weise, 2000). To effectively and efficiently use the available water sources to meet the possible variation of cropping pattern, studies of crop water requirements for upland and paddy crops based on derived crop coefficient are crucial (Sheng et.al, 2006). Irrigation is a vital input in the agricultural productivity and agricultural growth. More than 80% of available water resources worldwide as well as in India are being presently utilized for irrigation purposes (Pradeep, 2015). World sesame cultivation in 2007 amounted to 3.7 million hectares and 3.3 million tons of production have been reported.
Research Sabzevar City has expanded from 56° ཀ to 58° ཋ E and 35° ཚ to 36° ' 58 N and has an elevation of 977 meters above sea level and with an area of 20502 square kilometers is located in West of Khorasan Razavi. To estimate crop water requirements and irrigation water requirements CROPWAT model was used. In this study, for the calculation of reference evapotranspiration, FAO - Penman-Monteith equation is used. To calculate the reference evapotranspiration using FAO-Penman-Monteith equation, climate data such as minimum and maximum air temperature, relative humidity, sunshine hours and wind speed is required. Other inputs of the model is cultivation pattern, the plant coefficient, the area under cultivation (1 to 100 percent of area), irrigation scheduling, soil type, the available soil moisture, root depth and water content in the soil.
Discussion and According to the obtained results, the mountainous regions of northern Sabzevar in all phases have the lowest water requirement and southern regions have the greatest need of water. The results also showed that by moving from north to south, water requirement increases. Most of the irrigation requirement is related to the early and middle stages of growth. Soil moisture curve shows the least amount of soil moisture occur on the intermediate and final stages of product development. Results also showed that the crop coefficient in the middle stages of growth season is the highest value. The lowest water requirements occur in the final stages of growth season. The results indicated that the irrigation depth is occurred two to three months after the date of sesame cultivation.
Based on the results of the model, sesame crop water requirements in Sabzevar plain because of low rainfall and high temperature during the year and the long-term of the dry period shows a high level. The results showed that sesame plants to complete their growth needs to at least 20 times irrigation. It should be noted that to prevent soil crusting and emergence of a plant, round and deep of irrigation in the early stages of growth is low, but with the passage of time from planting date and getting to the middle phase of growth, both irrigation and water depth increases. Given that the final stages of development and ripening seeds in Sabzevar is consistent with the onset of the dry season, soil faced with moisture deficit and continuing of this process causing plant stress and lack of growth. Because the sesame plant is resistant to drought, in plain of Sabzevar produces good and economic products. In term of climatic conditions and compatibility of this product with environment, sesame can be cultivated but in the southern areas, it needs to repeat more frequently.

Assumptions about relationship between spatial structure and regional disparities reduction once has attracted the attention of policy makers and scholars alongside with the introduction of polycentric development policies in Europe and national level during the recent decades. Accordingly the present article attempted by examining the economic and experimental test of such assumptions in the country to establish a foundation for supporting the polycentric development policies. In this regard a review on economic growth models show that these theories paid a little heed to the development of city structure and the role which it can play in the reduction of regional disparities. So, there is a weak theoretical base of relations between regional economic growth, polycentric and disparities as assumed by many policies. This study tried to find out an experimental basis for this relation. The main question is that whether a polycentric urban structure is really effective on the reduction of regional disparities?
Research The present research is applied by aim and regarding to its nature and procedure include a correctional study. In this regard, to answer the main question of the study; in first step the different provinces of country are measured for their level of polycentricism. Then by using the secondary data of regional disparities of each province extracted from statistical records from Statistical Center of Iran; the correlation between two components were determined using Pearson method. For more detail analysis; firstly the correlation among the components, polycentric indicators and regional disparities were illustrated in 2012 and in next stage such correlation between components and polycentric indexes and the level of variations of each regional disparity index was shown in 2005 and 2012. In this study, the primate city index, focal analyses were applied for measuring the dimensions of polycentricism. Also, Gini coefficient, dispersion index and the poor's share of consumption were used to show the disparity.
Results and Findings: The results from 31 provinces of the country showed no evidences regarding to the association between the spatial dispersion of cities or balanced distribution of centers and in general polycentric/mono-centric can reduce disparities in the region. So that all obtained figures were less than 0.35. This means that correlation coefficient among the variables explained even less than 0.4 percent of their variations. Also the direction of correlation supported mono-centric urban systems. Other variables illustrated even lesser associations such as coefficient of correlations for polycentric/mono-centric development, the variation of Gini coefficient, dispersion index and the share of consumptions of poor. These findings confirmed the results of Sandberg and Meijers (2008) which showed weak connection between polycentric development and regional disparity in European countries. But in the present research there was a weak indirect correlation between polycentric and regional disparity. However these findings showed a less direct significant link of spatial structure on the trend of reduction of spatial disparities; however it supported the polycentric system slightly. While the results of Sandberg and Meijers indicated the positive role of mono-centric system on the reduction of regional disparities. Also assessment of relationship between regional disparity and the most polycentric and mono-centric of different provinces indicated an important point. So that this not only showed the significant and considerable correlation (0.546) between two components but it supported the polycentric structures strongly. While the correlation of disparities and distribution of center size increased the figure to 0.7.
It now can be concluded that at least in the case of Iran; contrary to some assumptions under influence of early intervention and current technological and structural changes; it does not confirm that the concept of inequality and periphery will become more spatial issue. So there is a need of deeper knowledge to theoretical and its backup like regionalism to adopt "polycentric development". From this perspective, further attention should be given to institutional approaches and capacity in the analysis of regional issues like disparity. However the results of these studies have not been able to provide empirical justification for the claim that polycentric development can reduce disparity and lead to solidarity; but it can shift the attention of commentators towards theoretical foundations of polycentric development and the change from a descriptive-analytical conception to a normative concept; and from a mere spatial term to a network of cooperation and coordination. So it seems essential other researches to concentrate not only on the economic- geographical aspects but on institutional and its relations with the claims of polycentric development; certainly such studies could help better understanding of development policies for implementation in the country.

Drought as one of the most dangerous natural disaster, a wide range of climates and ecosystems, impact and threat to households and communities that depend for livelihood is agriculture. The consequences of the drought could lead to instability rural livelihoods. Dolatabad district in the central city of Jiroft in Kerman province, including rural areas, the incidence of consecutive droughts in recent decades, major losses for farmers and livestock of the villagers living in it are often brought. while the management and how to deal with this phenomenon as whether from the authorities and the villagers themselves and principles when faced with the mainly for Traditional reaction. The purpose of this study was to assess the risk of drought in Dolatabad village using risk management and sought to answer this question is the most important risks and consequences of drought in the eyes of officials and villagers have what?
The present investigation has a descriptive- analytical nature. Data as library and field. Semi-quantitative risk assessment of drought in the area studied by 30 experts and experts in the Department of Natural Resources and Agricultural Jihad Organization of Jiroft and Jiroft city Kahnooj and officials (Dhyaryha and members of the Islamic Council) sample villages (Dolatabad, Aliabad, abasabad and Saghari) as canvassed, was done. So that the list of risks and consequences of drought in the area studied was extracted, then all of the risks and consequences of the index and prioritization, and ultimately results data are shown in a radar chart.
Discussion and The results of the research suggests that total unemployment and loss of job opportunities and out of the agricultural sector the the highest priority of experts and those in power and officials in the villages of your sample is assigned to the case study and the incidence of mental and emotional disorders and increased migration to the cities raising the level of in the diagram curve final prioritizing risks of droughts have (according to the consequences) and In a nutshell increase the risk of drough.
Jiroft township with regard to the climatic conditions and features of the hydrological and meteorological, witnessed a drought in several times. In the rural areas did not escape the phenomenon of drought have had a high potential vulnerability to it, so in order to reduce the impact of relevant, holistic approach was required to all aspects, including economic, managerial, organizational, institutional, cultural, ecological and include policy and so on. In such a situation a Drought Risk Management or a series of measures that before it is carried out by the drought and in the course of action and surprise to the lowest possible rate observed. Because assessments undertaken in the field of drought, suggests that crisis management actions are reactions to hasty, inadequate and ineffective led. The results showed that the total unemployment and loss of job opportunities and out of the agricultural sector the highest priority of experts and those in power and officials in the villages of your sample is assigned to the case study and the incidence of mental and emotional disorders and increased migration to the cities raising the level of in the diagram curve final prioritizing risks of droughts have (according to the consequences) and In a nutshell increase the risk of drought. Therefore, the priority actions should be based on addressing these issues in the region. The first steps should be to reduce unemployment, to prevent the loss of jobs and made out of agriculture caused by drought, Further in this regard should be the most vulnerable areas of the region are identified and measures to inform and to be more prepared in this area. The results can be combined with the results of the estimate of damage in the region and the measures to be taken in the right place. Due to this that all measures for the entire region is essential, taking advantage of the risk management model can be used makes it possible to build up to prioritize actions, right where the greatest need to run there, and ultimately doing vulnerability reduced drought against the villagers. Keywords: Risk, drought, risk management, the city of Jiroft.

Today tourism industry is as an important source of income in the world and yet effective factors which are contributing to the cultural exchange countries has the largest movement of people in peace time and one of the most promising development activities that are referred to as the gate of development. Tourism is a complex and contradictory phenomenon. It’s a beneficial industry, balanced economic development in the regions. In recent decades the development of the tourism industry make it as one of the main economic activities of developed countries , have led planners to increase tourism income, paying attention to two important issues: first the satisfaction of tourists and to promote the enjoyment and quality of the tourism experience and second trying to protect the interests of host communities. Currently many countries get their economic and social benefits from tourism and used tourism revenues for infrastructure development in the region. Tourism is one of the most developed industries in the second half of the twentieth century and is often used as a key for economic growth in both developed and developing countries. In fact the main objective of the internal and external tourism development is the socio-economic development of target areas. The importance of tourism in the modern era, more than anything, depends on the economic cycle which has a high potential in terms of dynamic, local and international economy. The criteria for determining the center of tourist areas and a needed infrastructure and adjusting the inequalities is among the region. In 2000, about 700 million tourists have visited around the world. According to the latest report of World Tourism Organization (WTO) France is the most visited in terms of the issue among international travelers (75million tourist) and the United States with ($74.5 billion) has the highest tourism income in the world. Mediterranean country such as Turkey has the highest record in past four years. Tourism industry can bring many benefits for different communities. These five main interests include: infrastructure development, transportation, energy and communications, processing and supporting area for the development of industry, agriculture construction, nutrition and services, attracting direct and indirect foreign investment, paving the ground for an increase in national income, the development of employment opportunities and creating positive changes in the other parts of the economy using multiplication factor of tourism industry. The appropriate atmosphere of tourism in production and reproduction of region influence on economic and cultural development. For better understanding the atmosphere, the constructive process of physical including infrastructure and tourist services (hotels, restaurants, stores, etc.) visiting places (monuments, recreation, cinema, theater, museums, religious places, etc. ) social and cultural characteristics and behavioral area is very important. This study is aimed to rate the cities of Semnan province in terms of tourism infrastructure and investigate the influential factors in attracting urban tourism. Factors include accommodation facilities, including hotels, inns, and restaurant catering units between roads, the offices of passenger services, the number of commercial cultural and artistic exhibitions, public parks and tourist area among Semnan province which has been analyzed. Tourism is presented as a multi-purpose activity. In this study is to pay attention to tourism infrastructure and their spatial distribution within the cities of Semnan province rather than rating and ranking the city in terms of tourism. In this way we can realize the comparative comparison and tourist attractive and the performance of tourist atmosphere. Besides the spatial pattern of tourism infrastructure provided for balanced development.
With an emphasis on systematic approach, in this paper the analytical method was used. This means that at first the required information and statistics related to the tourism infrastructure among the cities of province were collected. Then through MCDM models, we ranked the cities and determining the important coefficient of infrastructure criteria
Discussion and This study is aimed to rate the cities of Semnan province in terms of tourism infrastructure and investigate the influential factors in attracting urban tourism. Factors include accommodation facilities, including hotels, inns, and restaurant catering units between roads, the offices of passenger services, the number of commercial cultural and artistic exhibitions, public parks and tourist area among Semnan province which has been analyzed. Tourism is presented as a multi-purpose activity. In this study is to pay attention to tourism infrastructure and their spatial distribution within the cities of Semnan province rather than rating and ranking the city in terms of tourism. In this way we can realize the comparative comparison and tourist attractive and the performance of tourist atmosphere. Besides the spatial pattern of tourism infrastructure provided for balanced development.
In this paper, according to urban infrastructure and services used by tourists in the host society paid attention to rating and ranking of cities of Semnan province on one hand to tourism. On the other hand its way presented a model to strengthen the centers and areas which has low tourist attractions.
We found that residential infrastructure such as hotels, motels and other residential units and catering, travel agencies, the number of bus companies, cultural and artistic exhibitions, public parks and recreational areas have an important role in tourism development.
First identifying tourism infrastructure for each city and then prioritization was based on VIKOR models. In fact in the first stage only with regard to the role of infrastructure in attracting the attention of tourists, ranking these three places respectively; Shahrod, Semnan and Damghan. Then with regard to all standard and the comparison of paired criteria ranking the cities of Semnan province is as follows. Finally based on Kapland methos Shahrood was place first and then Semnan, Damghan , Garmsar and Mahdishare as placed in next order respectively.

In this study, we want to analysis the Urban network and the spatial distribution of the population in the urban centers of the province during the years 1335 to 1390. Analytic - descriptive method is applied as the chief method in this practical study. The data were collected from the Statistical Yearbooks of Khuzestan. The collected data were analyzed by using software program EXCEL,along with rank-size rule methods ,logarithm distribution ,limit of class diffrennce, Entropy Coefficient, Elasticity Coefficient, we take to surveying about the condition of Urban network,city hierarchy and spatial distribution of the population in the khouzestan province. durig this years, two period have been identified.the first period, includes the years of 1335 to 1355.of the characteristic in this period,we can point to the lack of primate city, relative equilibrium in the distribution of population in Urban classes, the number of big cities and centralization of the most part of population in them, the lack of existence of the excellence of ahvaz to big cities of the province and a very few number of small cities. The second period includes the years 1355 to 1390. With the attack of Iraq to Iran in the year 1359, a turning point a ccurs in the Urban system of khouzestan province. This war led to the evacuation of population in two big cities, namely Abadan and khorramshahr and also to many changes of population in the Urban system of the khouzestan province.during this period, the Urban network of khouzestan province has been out of equilibrium. The primate city is on the rise.Ahvaz separates itself from other cities and To become a metropolis of millions. the number of small cities strongly increased.

Temperature is one of the important elements of weather, resulting in part from solar energy absorbed by the effects of the Earth's surface and is converted to thermal energy. Maximum temperatures in the hot period of the year, especially in the hours after the city, should be given more attention. Analyzing the maximum temperature can also be normal evaluation mechanism to evaluate changes and track climate change. This study aimed to identify the spatio-temporal patterns and determine the maximum monthly patches of country, so the main focus of the maximum temperature will be identified.
Research The common statistics and homogeneous 125 synoptic stations with a common statistic period of 30 years (2010-1980) is used, then the station data using kriging interpolation software in the area of ​​data with ArcGIS 10.2.2 of cells to dimensions 15 × 15 km was extended. In this study for investigation of the spatial structure of cells, maximum temperature coefficient of dispersion country is evaluated. As well as for investigation the pattern of the maximum temperature of Iran, the new methods of spatial statistics, spatial autocorrelation (Moran World) and cluster analysis Clusters and Outlier, shot spots to study the temporal and spatial patterns and changes in the maximum temperature is used.
The results showed that the highest maximum temperature of spatial anomalies in January, February and March has happened. The result of Moran World trend proves it that changes within a year of maximum temperatures of Iran followed the cluster model and on the bases of output of statistics follows the pattern of clustering of Iran with the maximum temperatures happened in March with the amount of 0/973876. Reviews of the structure’s temperature using clusters and outlier showed that in the cold months decrease maximum temperature uniformity and homogeneity in the hot summer months the maximum temperature will increase. In the meantime, based on hot spots, the maximum temperature in the coastal shores of the Caspian Sea, parts of the West and North West and North East of the country has negative spatial autocorrelation (clusters of low value) and part of the central region as well as parts the South East and central regions has positive spatial autocorrelation (clusters with high-value, respectively).
Based on the analysis of spatial autocorrelation, spatial autocorrelation negative areas every 12 months relates on parts of the North West, North East and the Zagros bar. Areas with positive spatial autocorrelation often located on South coast of Persian Gulf and Oman respectively. Every 12 months, the upper area of ​​the country has no significant pattern of spatial autocorrelation. Spatial analysis showed that the maximum temperature patterns of the two spots for the maximum temperature of in the form of an island faced the South East, South, South-West and Central Iran. Low cluster areas mostly based on Zagras bar area, North West, North East and the North Coast. These areas formed the core of certain areas of the country's hot and cold. The results showed that latitude and altitude of the country is evident in the distribution of the maximum temperature. Results of this study with some of the previous findings in which the country's maximum temperatures were examined (Alijani, 2008: 50-64; Masoudian and kavyani, 2008: 53-66; Mojarad and Bastami, 2014: 129-152) have conformity.

The human need for energy is continually increasing and the limited sources of fossil energy are reducing. The indiscriminate use of fossil fuels pollute the environment and threaten life on the earth. Besides, because of difficult terrain, unfavourable topographical conditions and inaccessibility of some mountainous roads to national electricity network or high costs of these systems’s implementation, the solar energy as a renewable and free energy is considered the most important replacement for fossil fuels. The aim of this research is study of GIS and remote sensing techniques to calculation of net solar radiation reached to the earth’s surface (Rn) and zoning radiation in the studied area and determine the rate and intensity of the affecting factors, including the height, slope and slope aspect.
The studied area included area of 220km of Zanjan-Tabriz Highway with geographic coordinates is beginning of 36º 39′ N latitudes and 48º 26′ E longitudes to 46º 50′ N latitudes and 37º 36′ E longitudes.
In this study, satellite Landsat 8's data for six months (May to October 2013), DEM images for this area with a spatial resolution of 30 meters and also ENVI5.1, ERDAS IMAGINE2011 and ArcGIS10.1 softwares, for preparation of images, calculations, spatial and temporal analysises and geting output of results have been used.
In this investigation, the SEBAL algorithm was used to calculate the net solar radiation reaching to the earth’s surface. This algorithm formed of 25 models which calculate the evapotranspiration (ET) and other necessary factors of the energy balance equation. In the SEBAL algorithm the data of satellite images of visible, near infrared and thermal wavelengths is used for estimation of net radiation energy, soil heat flux, sensible heat flux and the latent heat flux for every pixel in images.
Results of this investigation can be summarized as follows:- The topography of studied area has variable height; it is beginning of 1103 meters up to 2083 meters. Due to this variety of topography, the area has variable net surface radiation.
- In this method, the distribution of radiation is almost the same for all months and with create a 200 meter buffer around the road the distribution of radiation changes from 111 to 714 w/m2.
- The results show that in SEBAL algorithm, the correlation of radiation is 0.0916% with slope, 0.2794%with slope aspect, and 0.0137% with height. the used SEBAL algorithm in this study is flat model and is not mountain model. In SEBAL flat model the slope and slope aspect factors are important for calculation of net solar radiation reached to the earth's surface, but height factor is not effective so the least amount of correlation is related to height.
-The slope aspect is the most important factor in determination of the amount of received radiation energy. So that the South slope and slopes face sun in all study range received the most radiation and in northern and behind of sun slopes is reverse.
The studied area has different surface net radiation because of various topography. The distribution of radiation is almost the same for six months (May to October). The SEBAL algorithm has the highest correlation with slope aspect and the lowest correlation with height. The South slope and slopes face sun in all studied range received the most radiation. The amount of obtained radiation for the whole months is in the range of 111 to 714 W/m2 and also Photovoltaic cells are sensitive to solar radiation and receive it from radiation threshold to 1000 w/m2. So it can be concluded that the solar radiation in this area in the six months of study has the potential for performance of solar photovoltaic projects.