فصلنامه مطالعات جغرافیایی مناطق خشک
پیاپی 26 (زمستان 1395)

One of the critical issues related to sustainable urban twenty-first century urban growth pattern, and today most researchers believe a significant relationship between physical development of the city (urban form) and urban sustainability. So far as the organizing body of the cities under the framework of sustainable development is necessary. The aim of this study is to understand the physical-spatial development pattern of Kashan and its compatibility with sustainable development model . Type of study is applied and descriptive-analytic methods do And the attempt is made taking into account criteria of population, area, density, per capita, in terms of quantitative models such as the balanced distribution of (model Shannon entropy, Gini coefficient), the degree of aggregation (including Moran coefficient) and the model Holdren answer the question.1-Whether physical growth of the city of Kashan in three and a half decades (years 1355 to 1390) has complied model of sustainable development? The results of the physical model survey of the city of Kashan by urban form evaluation models show the urban form Meanwhile, unequal and unbalanced distribution of population in the city and lack of coordination with the physical development over recent decades, the pattern of Spatial and physical growth model Kashan has follow urban sprawl, Followed by negative consequences for the city of Kashan has created sprawl and smart growth strategies are, therefore, needs to use.

The natural environment has performed as determinative factor for vitality of the human habitations since the dawn of era, like habitations’ places and other human foundations which have been absolutely influenced by natural factors particularly geomorphological and geological factors. Geomorphological studies will evaluate environmental conditions of the chronological settlement of the habitations and their dispersal situations by determining processes which predominate over the region and by considering landforms’ changes. Thus, the importance of geomorphological studies at dwelling human habitations will be revealed. The present research deals with studying the function of geomorphological factors over the dispersal of the life societies at northern slopes of the Karkas altitudes analytically and by relying on field studies and library resources. Therefore, initially, the thematic geomorphological map of the region is provided on scale of 1:25000 by form analysis method and process of geomorphic perspectives, then, habitations having the population more than 100 people (including 74 towns and villages having the population of 435373 people) have been analyzed. The research results demonstrate that Glaciations and Glacier Canyon landform are the most important factors in the spatial distribution of the habitations. All regional habitations are located at the lower altitude to the perennial snow border line. (2500 meter) Forty-five habitation points are located at mountain zone including 5 towns and 27 villages. Thus, the most important territorial zone is mountain. (the convex surface) Surveying the employment status of the villages demonstrated that economical status of the rural habitations base on Playa unit is more desirable than other units.

Marl is one of the most important sedimentary units are in Iran because of the physicochemical characteristics and high rate of erodibility. These properties caused large civil damages and environmental impacts and so, the study of erosion and erodibility of the marl units is necessary. One of the most important points about marls is elements in them and grain size nature and their effects on amount of erosion. The chemical and physical proprieties of soil are very important in the development of badlands. This study deals with the physicochemical characteristics of the marl units and their effect on various forms of erosion in Pishva-Varamin region. Badlands are a typical landform of greatly dissected fine-grained materials in arid or semi-arid environments like Varamin, although they are also found in different climatic conditions. Badlands typically have steep, high drainage densities; high erosion rates, unvegetated slopes, and a tendency to form dried cracks in regolith profile, making the surface puffy. Geology and climate are several factors determining the tendency to badland formation. Marl, loose formations, runoff and rain splash, together with massive wasting processes such as creep, flow and sliding, become the dominant factors determining landform genesis, resulting in the formation of badlands in silty- clay slopes.
In this research, firstly, rain simulated (using field simulator) in five marl units in area with different forms of erosion, in addition to sampling the soil and sediments and then runoff and produced sediment amounts in each point were measured in laboratory. Also, parameters such as of sodium, potassium, calcium, magnesium, gypsum, electrical conductivity, content sedimentary particles agglomerate and SAR percent (SAR) were measured. In analyzing the data, analysis of variance and comparison of means method were used in SPSS software.
Result and Grain-size composition, mineralogical, and geochemistry of soil and runoff chemistry parameters was characterized on both eroded (south-facing) and non-eroded (north-facing). Only a few grain-size parameters and silt and clay mineralogy discriminate eroded from non-eroded slope substrates. Erosion occurs where the fine fraction is abundant, mostly silt grains. This may be due to reduced permeability in the eroded soil, whereas the non-eroded one is more stable with respect to weathering, as it is more permeable. The abundance of clay minerals is affected by pedogenetic processes in the non-eroded slope, which increases in mixed layers and indirectly reduces the amounts of other minerals, making clay mineralogy a discriminating parameter in the two different types. Chemical data enable discrimination between eroded and non-eroded slopes. Parameters such as pH, SAR (sodium adsorption ratio), TDS (total dissolved salts) and PS (percentage of sodium) are distinctive parameters for both eroded and non-eroded slopes. TDS values increases in depth in the non-eroded slope, whereas the maximum TDS is just below the crust in the eroded one. Averagely, eroded substrates are higher in pH, SAR and PS than non-eroded ones. The ESP amount (exchangeable sodium percentage) of the eroded slope has a higher value than the non-eroded one. Crusts are less dispersive than eroded substrates, and non-eroded substrates behave as crusts. This suggests that the portion of the slope most severely exposed to weathering tends to stabilize, due to strong decreases in SAR, PS and ESP. Several diagrams reported in the literature show similarly anomalous crust samples on eroded slopes, compared with other samples coming from greater depths on eroded slopes. In the present case study, the exchangeable form of Na characterizes crusts more than the soluble form. The meaning of maximum SAR and TDS (and covariant parameters) is interpreted as the effect of decreased permeability, as suggested by a local increase in the fine-grained fraction, which coincides with maximum TDS. Variations in SAR values are of primary importance for soil erosion, because many authors have used solution chemistry (i.e., SAR, PS, TDS, EC) as a descriptor of dispersivity.
Based on results of analysis of variance in various forms of erosion in Pishva area are significantly different in the sodium ion, sodium absorption ratio and the percentage of silt and clay. Percentage of silt size grains is one of the most important factors in soil erosion in this area. The average amount of sodium ion and sodium absorption ratio in marl samples of region, increase from sheet to gully erosion forms while average clay percentage decreases in this trend. Finally, three variables of sodium ions, sodium absorption ratio and clay percentage of marl samples can be significant factors in erosion and related forms in this region. This study describes the erosional mechanism, which involves morphological and geographic exposure and climatic elements, as well as grain size, mineralogy, chemistry and exchangeable processes of soils.

The quality of the urban environment as part of quality of life, the most important topics in the field of urban studies that rapid urban growth, the concentration of population and activities have been changed. Since the quality of the urban environment has two dimensions of objective and subjective. It is also objectively assessing both the environment and on people's perception of the urban environment is done. In this context, the aim of this paper is to evaluate the quality of urban environment Sabzevar housing is taking measures to diagnose and evaluate the factors impacting the quality of the urban environment. In this study, the method used is descriptive-analytic and in terms of purpose from the application-development method is used. In the first step, the method of data collection, library and documentary has been. In the second step after designing the questionnaires and calculated the statistical population (housing residents Sabzevar) through Cochran Formula 340 is predicted questionnaire. The questionnaires were completed through the field survey randomly. The research method of analysis, based on one sample T-test and multivariate regression and hierarchical has been analyzed. The results of the study show that the residents from the residential properties are satisfied. However, not satisfied the features of the urban environment. Quality of the urban environment, achieved from characterize of residential environment and urban environment, That the average 2.62 less than the theoretical mean (3) that shows the quality of the urban environment is low and people are not satisfied. Also, among the three indices of the urban environment, physical-spatial features is with beta coefficient of 0.735 importance from the social features with beta coefficient (0.732) and content features with beta coefficient (0.603). The final level analysis model of the urban environment with beta coefficient (1.014) more important relative to residential environment with beta coefficient (0.513) in the study area is the quality of the urban environment.

Public space is the realm of the concrete and substantial presence of the different social groups with different behavior patterns. The concept of space in this sense is an entity that, by the people and through individual and collective action and social relations are formed. The presence of people in the space-in a way that is free from domination, could Strength the urban life. this paper, by considering the concept of space as a problem, trying analyze the concepts of knowledge, exclusion and inclusion, strength and power to the people in space and through space, And finally, formulated each in relation to the space. In fact common denominator of these concepts,is the Concept of Space and each of them understood in relation with the Space. In other words, article, seeks to show how space can help realize the potential of the individual and Objectivity each of these concepts? What ways can Space provided or mutually limit the individual agency , collective resistance and the formation of power, exclusion and inclusion and the formation of spatial awareness? In response to this questions- that are the a major concern of text, article first as Introduction and Objectives, discussion about public space and space and articulates the subjective questions and concerns of text. Then, under the Theoretical View to the Presence of People in Space, the categories of production and reproduction of urban space and how to interact with power relations in urban space, time and experience and consciousness space, presence and strength of objects in space, the agency and social activities are detailed and discussed. In this context and in accordance with the Theoretical View of text, This article trying to-with maintain his independence of thought and logic relying on the presence of various groups, formulating the Agency in a conceptual framework that mentioned and In this Theoretical Framwork analyze the concept of Space, Without the trap of theoretical dogmatism.

Precipitation as one of the important elements of each region is that it has a considerable impact water sources. The meantime snowfall in the water supply area, particularly in mountainous areas and areas without rainfall in summer is very effective. West Azerbaijan as one of mountainous provinces and lacked the summer rains are that an important part of their precipitation in the form of snow received that in recent years with the drought and the drying up of Lake Urmia has faced. In this research uses data SCDATA related to 7 synoptic stations with different time periods between 1951 to 2012 and with provincial distribution, the first snow and rain data separate and then based on the of computational and sequential Mann-Kendall(MK) and Sen.’s estimator index and the cumulative sum test were analyzed. The results show upward trend snowfall percent in the southern regions of the province and the general trend of decreasing precipitation in northern stations have occurred since 2000. While in majority of the stations, Snowfall has started downtrend from1994. In between stations, Khoy the highest qualitative and quantitative changes and Piranshahr has been no significant change. However, major changes are sudden rainfall in the Khoy and Urmia stations.

Climate change, especially on account of greenhouse effect, has created disastrous problems in recent years directly or indirectly affecting different sectors in Iran. One of the most important misfortunes is the increase of climate and environmental crises such as flood, drought, tropical cycles, sea level rise and the dust storm, the commonest of which in Iran are flood and drought. In this study, by using GCM model (two models of ECHAM4 and hadCM3) and down scaling the output by the help of statistical models of LARS_WG, raining data for the next period and also for the next 20-year period (from 2011 to 2030) were calculated. Afterwards, by the use of drought criteria (ZSI,PN,SPI) , the drought condition in Gorganrood-Gharehsou Basin were studied.. Moreover, droughts in a basic 20-year period from 1989 to 2008 were analyzed and the frequency and strength of the droughts compared to the next period were studied. The results, while proving the criteria for the study of drought, showed that in the following years drought will be increased compared to the basic period. This proves the climate change in the region. Moreover, rain patterns in winter will change and thereof there will be drought problems in next periods.