نشریه کاوش های جغرافیایی مناطق بیابانی
سال یکم شماره 1 (بهار و تابستان 1392)

Given that a substantial proportion of water allocated to agriculture, Evapotranspiration can be calculated for the development of programs such as planting, water regulation, hydrological studies and etc. Also the issue evapotranspiration can be useful in the study of drought.
In this research using images from Landsat 5 TM (41 pictures), meteorological data related to Yazd synoptic stations and SEBS, evapotranspiration was calculated for the period 1990 to 2011 of the central region of Yazd, The results were compared with the results of pan evaporation and FAO Penman-Monteith equation to estimate the accuracy of this model in arid region of Yazd. Emission files required by SEBS model using GRASS software in Linux script was produced. Other data were calculated in ILWIS with the help of Yazd meteorological station data.
Results showed that, the evapotranspiration obtained in SEBS whit the FAO Penman-Monteith evapotranspiration methods had statistically significant correlation, but the correlation was not high. This could be due to a lack of continuity from one body of water ,intended to facilitate the comparison of model results with reality.

Sinkholes are holes in limestone ground or other soluble rocks. These holes are formed in almost cylindrical or cone shapes, and their average size is around three meters. Various natural and human factors have played an important role in the formation of this phenomenon Occuring gradually, sinkholes may not have the same costly and destructive effects and consequences as floods or earthguakes. The city of Abarkuh, located in the South West of Yazd province, includes areas that are faced with the problem of sinkholes. In recent years, the occurrence of sinkholes in the two villages of Faizabad and Horok around this city has caused significant damages to farming land as well as equipment. This study aims to find out about the areas prone to sinkhole occurance in the future and provide suggestions as to lessen damages. To evaluate the factors influencing the occurrence of sinkholes and to predict the risk of this occurrence in these areas, GIS and fuzzy logic were used respectively. For modeling, nine criteria were chosen as the main influetial ones. Then, each layer got fuzzy using fuzzy membership functions available in geographic information system (Gis10). The results of this model generally regard about 32 percent of an area of about 17 sq km that faces a high risk of sinkholes. The area is mainly located in the center of the county. Also, 13 percent of this area, 7 square kilometers, is less potential for sinkholes.

The First step in performing de-desertification and preventing desertification must be based on the recognition of phenomena that cause desertification. Desertification is a phenomenon affected by many factors such as natural, social, economic ones and reciprocally affecting these factors. This research was conducted to investigate the human factors (social, economic) that affect desertification in Mortazeye desert located in Taft Township, Yazd Province. The population consisted of all the inhabitants of the villages that benefit from this region (Kahdoeye, Disran, Sharif Abad and Erdan; N=1217). A sample of 100 was selected based on Cronbach's alpha through a proportionate stratified sampling technique. The questionnaire consisted of 22 questions developed to collect data. The data were analyzed by SPSS. 22 factors summarized to seven main factors by applying Factor Analysis Technique. These seven factors (natural resource management, agricultural slump, fuel provision, urban development, irrigation methods, level of farmer's technical knowledge and skill) totally accounted for 76.3 percent of variations of human factors that have an effect on desertification in Mortazeye desert.

Identifying the effective factors in the development of gully erosion and its zonation is one of the basic and important tools for the management and controlling of this phenomenon. Also, choosing the most suitable and operative method helps to diminish the effects of this phenomenon. Hence, the aim of this research is to identify the factors influencing the development and spreading of the gully erosion and zonation of sensitive lands in Kahoor plain basin by the AHP method. According to this, at the beginning, factors with the most effects on the gully erosion development in the area were identified as slope percentage, slope orientation, lithology, lands use, and vegetation. These items were digitized in the geographic information system (GIS). Then, using aerial photos, the gullies were mapped. Next, using the AHP method, the effective factors were compared two by two, and the weight of each factor which indicated its impact rate was calculated with regard to the quantity values. Then, the weighted maps of each factor were prepared and, finally, gully erosion zonation was created by using the weighted layers and weighted relevant coefficients. The results show that, among the above-mentioned factors, lithology with a coefficient of 0/4667 is the first and the land use with a coefficient of 0/2483 is the second important factor in creating gully regions.

One of the common and destructive phenomena in dry and arid regions of the world and Iran is dust storm which may have harmful effects on human life and environment. Iran is also exposed to this phenomenon because of its geographical location in arid and semiarid areas. Fars province, especially its southern and central regions, due to being located in low latitudes and its geographical position, takes less advantage of humidity routes, and its proximity to the major sources of dust within the deserts of Arabia and Iraq always exposes it to this phenomenon. Therefore, understanding how such dust is produced can be of benefit in reducing its destructive effects in the region. This research examines the hourly data of wind direction and speed and the current weather condition of synoptic stations in southern and central Fars (Shiraz, Lar, Lamerd, Darab and Fasa). After extracting the codes related to dust phenomenon (codes 6-9 and 30-35) and a statistical analysis of the aerology data related to this phenomenon using an SPSS software, the annual and monthly Wind Roses and Dust Roses of the synoptic stations in southern and central Fars were drawn using WDconvert and WRplot software during the common statistical period of 1992-2008. The results of this investigation show that the dust occurs in the stations of southern and central Fars province on most days in spring and summer. Also, the highest monthly frequency of this phenomenon may be assigned to the central stations of this province (Shiraz and Fasa), In the southern stations (Lar, Lamerd and Darab), the highest monthly frequency is related to July. In addition, the average days with dust in Lar, Lamerd, Darab, Fasa and Shiraz stations are 88.1, 39, 54, 30.3 and 56.1 a year respectively. Among the selective stations, Lar station has the highest annual average in terms of dusty days. The results of the research also suggest that the most days with dust occur in spring and summer.The highest frequency of this phenomenon in central and southern stations is May and July respectively. Studying the monthly and annual Wind Roses and Dust Roses of station, it is clear that the wind direction of dusts is equal to the direction of the dominant wind, and the maximum occurrence of this phenomenon is in afternoon hours. Since the average annual wind speed of dusts in this region is almost 1m/s, dust phenomenon in Fars province doesn’t have a local source (code 07); rather, the major origin of 98% is outdoors (code 06).

Construction of second homes is not a new phenomenon. In recent years, Iranian citizen and metropolitan residents have selected mountainous areas around cities and coastal areas for leisure and villa construction. Yazd province, due to its geographical location, suffers from a limitation of natural tourist attractions, but the slopes and villages of Shirkooh are in a good position to attract tourists and to provide second homes for city folks. Second homes in these areas, particularly after the widespread use of private cars, have increased to the peak from the 80s onwards. The most important factors in attracting tourists to these areas are the temperature difference between them and the surrounding towns and cities as well as relatively close distances to drive. Construction and expansion of second homes have had various economic, social, cultural, and physical environment effects. The purpose of this paper is to investigate the physical consequences of constructing second homes in rural areas of Shirkooh using a descriptive- analytical method, library work, and survey studies (questionnaires). The results show that second homes have caused the improvement of road quality and the physical development of villages; however, they have led to the destruction and loss of agricultural lands and orchards.

The time series is to try it with the last of the series, a possible model for generating data to identify and comment on this model series is about the future behavior. Possible models for time series of the same patterns are random processes. General trend in the time series is quite variable and not predictable, is uncertain. Random by random changes in the level and slope processes that occur in the series are identified. Generally, quantitative methods for time series forecasting methods can be divided into variable and multivariate methods. Data used in this study using a quantitative variable is checked. Variable in a method of analyzing past data to identify an appropriate model and assuming changed model; it predicts the future behavior of the series are. Quantitative methods with a variable in a series of four methods that can be fitted model for the series include: extrapolation of the curve, smooth exponential, the Holth- winterz and Box -Jenkins. In the present series as an experimental station of the four methods were analyzed And the diffraction data set at the top station of the curve is the best way to analysis extrapolation model was selected. Note that in addition to the monthly data showed a seasonal behavior for a series of linear trend and seasonal factors,Decomposition procedures were used. Decomposition procedures for the analysis of the series using the least squares regression line fitted to the data found. Multiplicative model in the next step in the process of sharing data, trend data are lacking. Then central moving average (with a length equal to the length of season), no trend data were mooted In each period, the median seasonal values of raw seasonal adjustment were calculated and then finally, the seasonal index for the data to the data was seasonally adjusted. Final results of time-series model to estimate changes in the scale of seasonal dust extraction for the stations studied, with graphs and charts to predict the final residual normal probability model was outlined. The remainder of the normal probability plots of the model cannot be assumed to be normal for the remaining stations of the on the occasion of his reason, and this model is fitted to time series data.

CDS, as a process in which the long-term prospects for a short-term plan are prepared, may be the best option in order to achieve sustainable development. It is implemented with a focus on strengthening economic competitiveness, poverty reduction, and environmental aspects of urban structures, urban space, infrastructure, social and cultural aspects. It (CDS) makes the present and future problems easier to understand and can modify the urban management through revising a city's economic structure. The present study has been conducted on the purpose of assessing the sustainability of Zabol against the Urban Development Strategy (CDS). The method of the study is a quantitative analytic one through library work and field visits. The findings reveal that owing to the lack of a comprehensive plan and the existing defects, such as the failing diversification of land application in Zabol provided by the comprehensive plan of the city, CDS strategy seems necessary for for the development of the city.

Periodicity of climate change during the Quaternary period has been the origin of many land forms and the formation of human civilizations. In this study, we seek to utilize this relationship and geomorphological evidence to delineate the climatic conditions of Jajrood basin in the final Quaternary.To do this, the glacial evidence remaining high in the area was traced up using Jajrood topographic maps, satellite images, and field visits. The evidence was found in the northern highlands across 440 cirques with a minimum and a maximum altitude of 2500 meters and 4300 meters respectively. Using the Wright method and the altitudinal position of the cirques, a snow line of 3000 meters was found for the basin. Also, temperature and precipitation maps of the basin were provided in the current situation and the late Quaternary by synoptic stations statistics, regression between temperature, precipitation and altitude, and by taking into account the height of the snow line. The results indicate an increase of 4.4 degrees in the temperature and 151.5 mm in the precipitation as compared to the past.

Organization of urban areas is a complex decision to make and an essential measure to take from the geographical point of view. Using the Analytical Hierarchy Process in Urban organization is of importance since it serves as a decision to increase reliability. This study aims at providing a new approach in organizing urban areas in the city of Semnan and helping decision makers prioritize areas to organize. The study take into account the environmental factors that influence the organization of urban areas surveyed through a hierarchical analysis (AHP) and the ARC/GIS environment software to prioritize urban areas. The research process includes data collection, calculations and statistical analysis, data entry into GIS, clustering and valuation standards. Also, the information obtained from corresponding experts has been incorporated. The research results show that of the environmental factors, climate can have the greatest impact on the organization of the city. Attention to the climatic conditions in the design of buildings and other accommodations and relying on technology cause harmony with the natural conditions of their environment and the identity of the city.