ARID REGIONS GEOGRAPHIC STUDIES
Year:2018 | Volume:9 | Issue:33|Papers Count:6

Lefebvre's theory of space production has been very much considered. In particular, it is important to integrate it systematically into the categories of city and space as a comprehensive and comprehensible social theory. Lefebvre's theory of space production has been remarkable in recent years and has responded well to the many questions posed in the early 1970s. Lefebvre in his trialectic in the first step contributes to content against the form, and then to the material reality against the idea. The pure thought emerged from the material existence as well as the being lived or experienced, and the mere experience without the thought that it makes and expresses is not real and social. The core of the theory of space production identifies three moments of production: first, material production; second, knowledge production; and, thirdly, the production of meaning. Space is understood in an operational sense and as an interconnected network of relationships that are continuously produced and reproduced. The results of the study show that what constitutes the representation of space in the current study is abstract and reasonable and plans depend on it. Because politicians in their political decisions and urban planners inevitably need to study the representation of urban spaces in order to present urban plans and projects. Mental images, on the other hand, are the result of interactions between humans and the environment and include the individual's mental awareness of the environment. Therefore, the study of mental images is the starting point for any analysis in the field of human-environment interaction. It can be stated that in the formation of the mental image, first, the environment of the city is perceived and then conceived, and the third aspect of this is the production of meaning and symbol, and in this regard it can be said that the mental image is always produced and reproduced.

Introduction: Sand ramp is a kind of sand dune located on or in the foot of some mountains slopes of arid and semi-arid regions. Although these landforms does not differ from other types of sand dunes in these areas apparently, but, there are significant differences between them from the point of view of slope, sediment grain size, Morphology, sediment homogeneous, stratigraphy, lamination, mineralogy, evolution trend, Paleoenvironment, and formation processes. Unlike desert sand dunes, which are created only by the wind process, fluvial and colluvial processes also play a large role in the formation and evolution of sand ramps. Because these landforms have a much smaller dispersion than the desert sand dunes in the world, they has less studied and known. In addition, they are buried under clastic sediments in some region and not visible. In Iran, sand ramps has been created in the in the center of the country in Yazd and Kerman Provinces. The main goal of the research is the study of how to provide high volume of sediments of sand ramps located around the Ernan Plain in the eastern slopes of Shirkouh Mountain in the south of Yazd. Therefore, two factors includes rock and its weathering were studied in specific climatic conditions. The sand ramps have been created in the past climate and they are stable and inactive at now. Materials and Method: For doing the research, we have used topographic (1: 50000), geologic (1: 100000) and DEM (with 5 meter resolution) maps and field observations as well. In field observations, several samples of one of a sand ram and also a sample from granite stone were taken. In laboratory, using XRD method, minerals of sediments and of the granite stone were determined. Also, to see better the granite and sediments samples, we provided thin sections of them. These section was magnified 60 times with the electron microscope and using the camera placed on them, different images were taken from their different angles. Thus, the minerals of sand ramps sediments and also granite stone and their properties were defined and analyzed. After clearing that the minerals of sand ramp sediments and granite stone (Monzogranite) are relatively the same, weathering of granite stones, as main stone of sand ramp genesis, were analyzed. Therefore, climate condition of the region, especially temperature and precipitation, were analyzed. In according to, the isotherm and isohyet maps for present time were drawn. Because, sand ramps has been created in the past cold period, in quaternary, past temperature were reconstructed and its map were drawn. Results and Discussion: The study area has located in the central Iran's desert region with altitude variations from 1700 to 3800 meters. According to, it has a very specific climate with high temperature and humidity fluctuations. These fluctuations have been the main factor of stone weathering and consequently, the formation of specific landforms during quaternary. The current temperature data show that the study area has two separate warm and cold seasons. So that temperature during cold season has drop severe and in about 3 months, includes December, January and February, the average temperature is around 2 to 3 degrees Celsius. However, the temperature at altitudes above 3000 meters for a cold period reaches to below zero degree. Because of high altitudes, precipitation is more than 200 mm per year. Therefore, the preglacier morphoclimatic conditions is dominant on the region weakly at now and frost and melting ice happens, especially during the cold season. Reconstruction of the past temperature in the region showed that the area has been 13 ° cooler in the Pleistocene cold period. Besides, the findings of the sand ramp sediment showed that Plagioclases, Alkali Feldspars, Quartzes, Biotite, Muscovite, Apatite and Amphibole are the major minerals orderly according to the volume and the abundance. These minerals create the monzogranite rocks of eastern slopes of Shirkouh Mountain. Conclusion: Results showed that sand ramp sediments had been provided by monzogranite rocks weathering of the eastern slopes of the Shirkouh Mountain. The study of developing sand ramp showed that it is forming on the foot of slope of altitudes above 2400 meters. Where granite stones had been outcropped and the preglacier climate is dominant. In fact, the preglacier morphoclimatic condition had caused to weather granite stones. Results, also showed that the temperature in the past period had been 13 ° C cooler than present. In this condition, the slopes above 2500 m. had have glacial morphoclimatic and below them had been influenced by preglacial morphoclimatic conditions. These climates have been favorite for degradation and weathering of granites. The presence of moisture destroys biotite and feldspars minerals and causes to separate other minerals, such as quartz, from each other. Temperature also affects granite weathering. Because its constituent minerals have different temperature expansion points. For example, the expansion of the quartz temperature is three times that of feldspar. Therefore, temperature changes create pressures inside and between mineral grains that cause them to be separated. However, lower temperatures with minimal moisture (that is preglacier conditions) are one of the most important factors affecting the weathering of granite. Thus, with the destruction of granites, a large amount of fine-grained sediment materials is provided and carried by the water or ice tongue to the downstream. Theses sediments have been ascended on the mountain slopes by winds and created sand ramps.

The present study, with a futuristic approach, identifies the most important factors affecting the future status of sustainable tourism in Yazd province and examines the extent and manner of these factors on each other. This research was applied in terms of its purpose and in terms of a combination of documentary and survey methods, and in terms of its nature, based on new methods of futuristic, analytical and exploratory science, which has been carried out using a combination of quantitative and qualitative models. . The statistical population of the study was 18 tourism experts of Yazd province. First, 29 components were composed of overwritten documents and theoretical sources, selection and matrix of cross-effects of components, and the analysis was done through the Mick-Mac software. Based on the results of the model, tourism in Yazd province is an un sustainable system and "the balanced distribution of facilities and amenities, and the social capacity of the local community in attracting tourists to act as an indispensable factor. " None of the components of tourism development in Yazd province can be defined as a target factor. This indicates that the issue of tourism development in Yazd province is multilateral in terms of management and tourism elites of Yazd province. "Security" and "level of development and economic situation of the local community" are very close to the risk. "Drought", "Inflation" and "Participation and Strengthening of Nongovernmental Organizations" were the most influential ones. In total, 10 factors were selected as the key factors of tourism development in Yazd province. The level of development and the economic situation of the local community, targeting the allocation of tourism development credits, inflation, transportation infrastructure, services, intelligence and intelligence, droughts, and the quantitative and qualitative reduction of water resources, security, comprehensمive plans, NGOs and the improvement and development of inter-organizational relations were the key factors influencing tourism development in Yazd province.

One of the key elements of rural management in the country is decentralization, which examines and evaluates perennial performance and awareness of its strengths and weaknesses by the rural community is an indispensable step for optimizing the future of the activities of the organizations. The purpose of this study was to optimize the performance of the land managers by emphasizing the suitability model. The statistical population consists of 31 villages with a central department of Izeh city with more than 5 years of history and has 17624 inhabitants. The sample size was estimated at 380 people based on the Cochran formula, which was distributed according to the population of each village. The number of samples at the village level was randomized systematically. The designed indicators were designed in order to determine the merit of the managers in four dimensions in a 47-item format. The formal validity of the questionnaire was confirmed by a panel of experts. Its reliability was estimated to be 0. 84 based on Cronbach's alpha. For analysis, the use of spss and lisrel software was used. The results indicated that among managers 'merit dimensions, farmers' performance in environmental aspect with factor load of 0. 74 had the highest competency and economic performance with 0. 65 had the least amount of merit. The results of Friedman test for rating competency indicate that socio-cultural competence has the highest rank.

Prioritization of watershed basins includes classification of sub-basins on the basis of the existing conditions and erosion intensity, which ultimately leads to protective operations and watershed management in more significant and susceptible sub-basins. In this research, in order to prioritize Ghezel Owzan-Sefidrud sub-basins against sensitivity to erosion, linear and form-based morphometric parameters are applied as physiographic factors involved in erosion of basins, and on the other side, erosion and vegetation factors are used as external and protective dynamic factors. In order to estimate the morphometric parameters, SRTM digital elevation model with a 30-m land resolution was utilized; furthermore, to prepare the vegetation map, a MODIS image frame of the maximum vegetation time, together with the NDVI index was used. In order to approximate the erosion rate of the basins spatially, the rainfall data of TRMM satellite along with the Fornier index were utilized; also, the CP method of ranking was applied for prioritization. The prioritization results on the basis of morphometric parameters indicated that the sub-basins are categorized into two classes including the high-priority type with 45. 46% and medium-priority type with 54. 54% of the basin area. The prioritization based on the erosion rate and vegetation demonstrated that the studied sub-basins are more diverse than morphometric-based one; accordingly, 9. 1% of the land belongs to very high susceptibility class, 63. 63% to high susceptibility class, 18. 17% to medium susceptibility class, and 9. 1% to low susceptibility class. The integrative prioritization on the basis of all three factors showed that 45. 45% of the sub-basins are in high susceptibility class as the following order: Goltappeh, Taleghan, Mahneshan, Ghorveh and Divandarreh basins; they need protective activities. As well, the rest 54. 55% of them belongs to the middle class.

Kaloutaks are a geomorphological forms of arid and semi-arid regions around the world. These features are extensive and varied in Iran, resulting from the erosion of fluvial and lake sediments of the Quaternary. Kaloutaks are mostly extended over the Eastern and Southeastern Iran and have unique features. Meanwhile, the kaloutaks in the playa of Sistan Hamun are considerably extended. The studied area includes part of the kaloutaks in this region. The main objective of this study was to examine and find the origin of sediments deposited in the old delta of Hirmand River, the main area for the extension of kaloutaks. To this end, five sediment samples were specifically taken from the area and examined using XRD and XRF laboratory analysis methods. Results showed that sediments such as quartz, aluminum, calcium, and other evaporates have the highest percentage in kaloutaks. Moreover, based on the elements obtained from the tests and examining the geographical maps of Iran and Afghanistan, it can be concluded that these sediments have both an internal and external origin. Eroded and sedimented formations of flysch in the Eastern Iran confirm the internal origin of sediments, and the presence of quartz, aluminum, calcite, dolomite, muscovite, albite, and other minerals indicate the external origin of these sediments, transferred by Hirmand River and sedimented in the playa of the Hamun. Based on results, the sediments of the old delta of Hirmand River have provided the best condition for the erosion and formation of kaloutaks in this region due to pedological features and climatic factors.