نشریه جغرافیا و برنامه ریزی محیطی
سال سی‌ام شماره 4 (پیاپی 76، زمستان 1398)

Cities are complex spatial systems that are directly related to economics, politics, and power. Urban land-use changes are an economic-spatial category. Changes in urban land use and the tendencies of the society to intervene in space reflect the structure of the spatial economy in cities. In this research, an attempt was made to study the patterns and trends of intervention in urban land. Many studies have been conducted on land use and land prices, but the study of land-use change trends and its relationship with land price changes has been less considered. To this end, the approvals of the Commission Article Five of Tehran have been analyzed. This research was applied from the perspective of the type of research. The documentary method of data collection and secondary data have been used. The statistical population of the study was the total approvals of the Commission Article Five in Tehran from 2006 to 2018 (1385-1397 AH) with 194 decrees and 1322 clauses. The sampling method was purposive (733 clauses). Cluster analysis and pattern analysis were performed using the Moran I algorithm and the Gettys-Ard-G statistic in Arc Gis software. The results showed that the spatial economy in Tehran was based on the development of high-quality urban land in the rich areas of the city. Districts 1, 2, 3, and 6 were identified as hot spots, and Districts 10, 13, 14, 17, and 19 were identified as cold spots in the structure of the spatial economy in Tehran. The dominant tendency of land-use change was toward residential, commercial, administrative, and tourism. Greenspace, residential, and development reserve lands were identified as the dominant factors for land-use change. The spatial pattern of these changes was clustered. The continuation of this trend will lead to the influx of capital into the northern regions of the city, the classification of the society, and the escalation of land price disparities in the northern regions with other areas of Tehran. The solution to this problem is to change the country’s economic structure, strengthen local government, reduce its dependence on unsustainable resources, and impose tolls on building permits.

Various morphotectonic landforms have been created by the activity of the Dehshir Fault and the 2nd and 3rd degree Riddle faults in Plio-Pleistocene. The most important of these can be the structural depressions of Abarghoo and Taghestan along the faults derived from the Dehshir Fault in the west and smaller and numerous other depression such as Rashkouieh, Ernan, Chah Shir and Chah Torsh along the eastern faults of the Dehshir Fault. The purpose of this study was to investigate the western depressions of the Dehshir Fault in the south and southeast of Shirkouh Mountain in the south of Yazd city. The results showed that these depressions, like many other closed depressions in central Iran including Gavkhuni, have been formed due to the transtension of a stretched-separated basin. The study area was located in a cutting zone between the two active dextral faults of Dehshir-Baft and Rafsanjan-Ernan. The counterclockwise rotation of the fault block between the mentioned two faults has created local extensional zones and reduced the crustal thickness. This has uplifted the geothermal curves and partial melting and created local post-Pliocene local volcanism. Following this phenomenon, several dacitic domes have formed along the fault strike and intersection in the south and southeast of the Shirkouh Mountains and the folding of Miocene sediments. The activity of the faults, along with the rise of the domes, has led to the fragmentation of the previous smooth surface, and has caused the subsidence of some parts of the area and created several structural depressions

The present study was conducted in order to formulate livability scenarios of rural areas based on the principles of futures studies of villages in Eslamabad-e-Gharb County. This study was applied-theoretical and descriptive-analytical in terms of the purpose and the nature based on the approach of futures studies. The scope of this research was rural villages of Eslamabad-e-Gharb and the statistical population included 30 experts in the field of the livability issue who were selected purposefully. The Delphi method, the Micmac software, and the Scenario Wizard software have been used for data analysis. The results of the research showed that 30 items were effective in the livability of villages in Eslamabad-e-Gharb. Because all values obtained from the T test in different dimensions were significantly lower than the error level of 5%, a collective agreement was reached among the experts on the proposed items with a 95% confidence level. The results of the Micmac software showed that 11 factors played a key role in the livability. Subsequently, using the scenario analysis, 42 probable scenarios were designed for 14 key factors. After analyzing possible situations using the Scenario Wizard software, 3 strong scenarios, 2,818 poor scenarios, and 25 believable scenarios have been obtained. Among these three scenario groups, 25 believable scenarios have been selected as desirable scenarios for the livability planning of villages in Eslamabad-e-Gharb. This scenario has been analyzed using the inductive method and was divided into three scenarios: golden, believable, and catastrophic.

Forecasting maximum discharge of the basin requires accurate information on the amount, severity and distribution of precipitation. For prediction of maximum runoff of a basin using relationship of Q = 0.278 CiA, the rainfall intensity in the whole basin is considered constant. The amount of precipitation in different parts of a basin is obtained through interpolation methods. This method is known as duration-area. Because rainfall is a very variable parameter, probability of an unpredictable estimate of precipitation is high. In this study, using the radar data, the amount and severity of rainfall over the basin were obtained. (intensity-duration-area method). Basin concentration time lines were prepared in G.I.S. Software. Coordinates of environment and area of the curves were defined for radar and its implementation program was written in radar software. Then amount and severity of precipitation were estimated by the radar. Because volume was directly used, the relationship changed. The maximum runoff was simulated and compared with observation runoff. Maximum runoff was high in severe rainfall. If soils of basin were already wet, maximum runoff was high. Conditions were different in low rainfall. If the severity of the rainfall was low and then increased, the amount of runoff was more than expected. If the intensity was high and then decreased, the amount of runoff was lower. This was the result of the spatial and temporal dispersion of precipitation in maximum runoff. Time delay between maximum runoff and simulation in severe rainfall was short. And time lag in ordinary and low rainfall was long. Using a constant runoff coefficient does not estimate maximum runoff value accurately. Due to the characteristics of rainfall (intensity, amount, duration, spatial and temporal distribution) and soil moisture characteristics of the soil, various coefficients should be used.

Rivers have different patterns along their path, and understanding these patterns could help researchers understand and predict the responses of human activities and natural factors of the river. In addition, in the morphological analysis, the flow power is one of the most important parameters. Therefore, the purpose of this study was to analyze the channel form and to evaluate the river power in different return periods as well as to estimate the shear stress in the Givi Chay River using Landsat 8 images, topographic maps, geology, hydrological, and field data. Morphological and hydrological indices, as well as methods for analyzing the total river power, river specific power, and shear stress, were used to achieve the purpose of the study. The calculation of the bending coefficient showed that the river pattern was sinusoidal in the first and third intervals and was meandering in the second interval. According to the central angle characteristics, the first and the second intervals were in the highly-developed meandering form and the third interval was in the developed meandering form. Also, according to the results of the study, the highest amount of the total river power was in the first interval at the 4th, 5th, and 6th sections. The specific strength of the river was high in the third intervals and the 2nd, 1st, 5th, and 6th sections. At present, due to the low strength of the lithological formations in these sections, the erosion of the riverbed is observed in these sections. The lowest specific power was due to the high river width and low bed slope at sections 12 and 13. The highest amount of shear stress was in the first interval in sections 5, 6, 2, and the lowest shear stress was in sections 12 and 13. In general, channel formation and channel dynamics in the Givi Chay River were influenced by discharge, lithological resistance of the riverbed, and human interference (encroachment on the riverbed, construction of bridges, and dumping of construction waste and debris).

Increasing temperature, decreasing rainfall, soil salinity, a severe decline in groundwater aquifers, prolonged droughts, revising the crop cultivation pattern, and replacing products that are compatible with the current conditions have become inevitable. Accordingly, the present study was conducted to locate areas susceptible to cultivating saffron and taking into account the ecological needs of this product. In this regard, based on the Analytical Hierarchy Process (AHP) analysis method in the ARC/GIS10.3 software environment, modeling was performed and then the information was spatially analyzed. The parameters and data used included earth and soil data and climatic data with the duration of a 30-year common statistical period (1985-1015) were collected from synoptic and climatological stations in different regions of Hamedan province. Then, based on the importance of each parameter, using the AHP model, the weight of the criteria was measured at the study area level. For spatial analysis, the information was entered into the Expert Choice Software, and clustering, criterion evaluation, and data integration were performed and finally, the final layer was produced.The results showed that 56.56% of the land in Hamedan Province was used for saffron cultivation in perfectly suitable and suitable classes, 27.7% was in relatively suitable conditions, and 15.69% was in unsuitable classes. Plains suitable for planting saffron included Kaboudar Ahang, Hamedan, and part of Razan. And Asadabad, Tuyserkan, and parts of Malayer and Nahavand were in inappropriate classes. According to the final map, as we move from the south, southwest, and southeast to the north of the province, the potential of the regions for saffron cultivation will increase and this situation will continue until the cultivation of this crop is more justifiable due to ecological factors

Trees can record the long-term effects of climate variables. With the help of dendroclimatology knowledge, these variables can be reconstructed, especially for areas with short-term climatic data. For this purpose, in this study, six forestry plans were selected by using the thickness of Iranian oak tree rings in Golestan province. Then, using a multivariate surface response regression analysis in the STATISTICA software environment, different temperature components (including monthly, maximum average, and minimum average) of 15 meteorological stations for the growing period from April to September were reconstructed. The research findings showed that the temperature variations in the growing season over the past 170 years in Golestan province have been characterized by six major oscillatory cycles. Also, according to the results of the present study, it was found that the recent 40-year period (1971 to 2011) has had significant changes in the mean and median temperature compared to the former three 40-year periods.

Today, climate changes are the most serious challenges facing humans. The climate change refers to any change in the climate over time which is primarily due to natural changes or human activities. Drought is one of the most dangerous climate changes affecting a wide range of climates and ecosystems and the affected geographical areas have increased sharply in the last four decades. In this regard, the outlook for the drought situation in Iran over the next 30 years shows that drought in the country will increase and during 2025, 2032, 2035, and 2039 most parts of the country will face a severe drought. Meanwhile, the drought situation in 2039 will be much more critical. This is because most of our country is in the realm of arid and semi-arid climates of the world. Iran alone has more severe arid, arid, and semi-arid areas than most of the Europe. During the last 40 years, 27 different drought phenomena have occurred in the country. Therefore, some experts believe that drought is a climatic reality in Iran. The location of more than 50% of Iran's area in arid and low water regions causes drought periods and its effects to overcome wet periods. Areas that are climatically arid and semi-arid are prone to the effects of drought. In this regard, the most vulnerable class of the society, which are farmers, are more severely affected by this natural disaster, because farmers' reliance on dry farming can increase vulnerability and affect the lives of farmers. Therefore, in case of drought, it is necessary to review the living conditions of rural households and identify factors affecting them. Rural households in Hindijan County, like other rural areas in Khuzestan province, have faced many challenges in recent years due to drought and increasing dust, and their living standards have dramatically decreased. In this regard, the present study was conducted with the general aim of explaining the cognitive factors affecting farmers’ tendency towards livability in drought conditions. The statistical population of the study consisted of all rural households in Hendijan County located in Khuzestan province, the total number of which was 1906 households. By using Krejcie and Morgan Table, 230 of them were selected by the stratified sampling method with a proportional assignment. The data collection tool was a standard questionnaire whose validity was confirmed by a panel of experts. Its construct validity and reliability were confirmed by Cronbach's alpha and combined reliability. In this study, the Theory of Planned Behavior (TPB) was used as the basis. The results showed that attitude, moral norms, adaptation knowledge, self-efficacy, and sense of belonging had a positive and significant effect on the tendency of rural households to live in drought conditions. While individual identity and perceived behavioral variables did not have a significant effect on the intention of rural households towards livability. It should be noted that the independent variables accounted for 84.5% of the variance of the dependent variable (intention of rural households to livability). In this regard, according to the results of the research, it is suggested that by improving the knowledge of adaptability and self-efficacy of rural households, they can improve their livability in drought conditions.