Researches in Earth Sciences
Year:2018 | Volume:9 | Issue:35 |Papers Count:13

Polycentric city-regions are the result of the increasing processes of growth in different spatial configurations. Such phenomena areparticular type of spatial system that have their unique and distinctive characteristics. Misunderstanding the nature of Polycentric city-regions and their specific guidance and control mechanisms especially in developing countries, would prevent them of experiencing sustainable spatial development. Traditional planning procedures and approaches are unable to face challenges presented by such city-regions, while insisting on their continuation would lead to inextricable problems. This is despite the fact that the strategic spatial planning might address the challenge properly. The purpose of this article is to discuss the eligibility of spatial strategic planning as a responsive and applicable procedure to face the challenging nature of Polycentric city-regions within a system approach. This article is based on explanatory research methodology, which is followed by an analytical description of events in order to explain their relationship within the framework of systems approach. The output of this article is the analysis of major characteristics of polycentric city-regions and a theoretical model would be introduced in order to explain how the guidance and control mechanism of such city-regions can be assumed to be within a spatial strategic planning approach.

In order to study the effect of urbanization growth on temperature and precipitation in Babolsar Station in the period 1968-2008 and show differences, two types of urban and non-urban stations were selected. According to the criterion of distance up to 500 meters from the city border, Babolsar Station was selected as the urban station, and based on the criterion of at least 2 km away from the nearest town, Nowzarabad stations were selected as non-rural ones. Urban development index and Shannon entropy were used to measure urban development and Mann-Kendall was used to study changes in climatic parameters. The results of the physical condition of Babolsar Station indicate a dramatic fragmented physical development. Analysis of the trend of temperature showed that total the average temperature, and the average minimum daily temperature follow a significant trend and gradient of their changes in the urban station of Babolsar is more specific and steep than non-urban stations. Tau Kendall of the temperature changes show that climatic data of Babolsar Station are influenced by the urban microclimate and the environment around the station. Since Babolsar Stations was formerly located outside the urban area and then became an urban station and urban development of Babolsar caused changes in temperature of this station.

Today's metropolitan areas are exposed to natural hazards in many parts of the world for a variety of reasons due to the high density of population and facilities. This poses a kind of challenge to urban planners. The District 1ofTehran metropolis is exposed to different altitudes, faults and rivers in northern Tehran, and a susceptible and exacerbated urban risk factor that has various geomorphologic hazards and constraints that need to be addressed in order to reduce those basic measures. In this study, we tried to apply data from modeling of environmental criteria and layers using Analytical Hierarchy Process (AHP) method and classification by fuzzy method and using GIS spatial analysis, the environmental vulnerability of the area should be considered and zoned. According to the results of the calculations, the vulnerability of the Tehran metropolitan area with the AHP-Fuzzy combination model was determined based on the calculated weights. Areas 8, 3 and 4 are the most vulnerable parts of the city against natural hazards; while areas 1 and 2 are the least vulnerable to environmental hazards. The vulnerability map shows that 28. 22% of the whole area is vulnerable to high vulnerability, with the largest area of this category being located in area 3. And the neighborhoods of Golabdareh, Darband and Tajrish, while a Tehran metropolitan area is affected by the lack of basic urban construction, regardless of the natural drainage network, with increasing impenetrable and impenetrable levels of penetration. Water is the result of rainfall and runoff increase.

Extreme cold and frost are considered to increasing damage to agricultural and installations. Synoptic analysis of these glaciers helps predict their occurrence. In this study, in order to study the coincidence of cold waves of the west of the country, the minimum daily temperature data of four Hamedan, Khorramabad, Sanandaj and Kermanshah stations during the statistical period of 1961-2010 for cold months of the year were prepared from the Meteorological Organization. Then, the numerical threshold of cold waves was obtained using mean and standard deviation of the minimum daily temperature, and as a result 56 days with cold waves were determined. The SLP data and HGT for 56 dayswere used to extract and analyze the patterns of surface pressure and the geopotential height, respectively using hierarchical cluster analysis based on Ward’ s method. The results showed that a cross-sectional pattern was identified as the main cause of cold weather in the studied cases. In this pattern on the surface of the sea, the central core has a central pressure of more than 1032 hp on the north-western and western of the country, which, due to the circling around the region, causes a high loss of high latitudes. Atthe level of 500hPa, deeptroughislocatedin the western partof the regionwhichIt causes the vertical flow of the western winds and the northern flow of streams and currents, as a result fall with in the northern cold air down through the long, important role in the occurrence of cold temperatures, resulting in the occurrence of cold waves in the area.

Over the past decades, global warming has undergone significant changes in weather and climate cycles, such as increased water vapor in the atmosphere, increased Precipitation and reduced Precipitation. This research was designed with the aim of modeling Precipitation in the region of West Asia under the influence of climate change. For this purpose, the Precipitation data of the West Asia region for the period 1961-2015 and 2016-2045 was downloaded under the A1B scenario of the HADCM3 model from the Canadian Climate Change Center (CCCSN). In the next step, using the R2 and RMSE statistics, the accuracy of the model was evaluated and the modeling results were of great accuracy. The slope of precipitation, using the sen'smethod, showed that in January, February, July and August, precipitation would increase and decrease in other months of the year. The Precipitation season with the Man-Kendall method also shows that the prevailing trend is decreasing throughout the year, and the incremental precipitation will only be related to precipitation and 24-hour Precipitation. Also, the results of this study showed that Precipitation in the Mediterranean and Sudanese systems is increasing, and this increase will not have a good prospect for the aquatic environment of the region, as 1-areas with increasing trend during the warm year will evaporate the Precipitation received from the surface and An increase in precipitation in the cold season also causes flooding of the rainforest.

The Boroujerd Boroujerd igneous metamorphic complex is part of the Sanandaj-Sirjan structural zone. This igneous complex emplaced in the Upper Jurassic (167 ± 20 million years). This complex intruded into older metamorphic schist and formed the metamorphic halo in the Hornblende hornfels and pyroxene hornfels metamorphic facies. A Migmatites observed in parts of the aureole that is evidence of local increased geothermal gradient in the Boroujerd aureole contact metamorphism. Quartz, feldspar and with mica are main minerals in leucosome migmatites part, and orthopyroxene +garnet+sillimanite+cordierite +corundum are present in the melanosome part. In the high P-T location indicated temperature and pressure above the pyroxene hornfels facies and equal to lower boundary of the granulate facies. Associated garnet-biotite cation exchange, maximum temperature is 635-720° C. The maximum pressure is 3-4 Kbar. This temperature and pressure are higher than normal contact metamorphism and this P-T condition can crystallize special minerals, such as corundum.

The amount of the Total Organic Carbon (TOC) is one of the most important parameters in geochemical evaluation of hydrocarbon source rocksand subsequent petroleum system modeling. We proposed a three-step approach in predicting and modeling TOC content from well log data. Initially, TOC is determined in 92 core and cutting samples using Rock-Eval pyrolysis method. In the next step, the TOC values were predicted from well log data using intelligent neural network applying back propagation algorithm. Correlation coefficients between the network output and target data in the training, validation and testing steps for the optimized model are 0. 9, 0. 88 and 0. 91, respectively confirming the reliability of the approach exerted in predicting TOC. Finally, geostatistical methods were used to build a 3D model of this parameter in the field scale. The proposed methodology is illustrated using a case study from the world's largest non-associated gas reservoir, the South Pars Gas Field, in the Persian Gulf basin.

Khak-Sorkh iron deposit lies about 42 km west of the Yazd city. The area is located in the central part of the Urumieh-Dokhtar magmatic belt and is covered by upper Triassic-lower Jurassic sedimentary units and Oligo-Miocene intrusions. Intrusion of Oligo-Miocene granitoids into Cretaceous limestones resulted in iron skarn mineralization. Magnetite is the main iron ore mineral; minor copper mineralization also occurs locally as malachite staining at surface. Two main structural trends can be distinguished: NW-SE which follows the main trend of the Urumieh-Dokhtar belt, and NE-SW trend that transects the former one and dissects magnetite bodies in some places. In this study Euler deconvolution and analytical signal methods have been used for interpretation of geophysical data. Depth of magnetic anomalies determined by Euler deconvolution clarified that magnetic bodies are located at shallow depths in the NW of the area. The trends of the detected anomalies correlate very well with the general trend of the Urumieh-Dokhtar belt. This can be used as an exploration tool for magnetic anomalies in the area and likely in other parts of the Central Urumieh-Dokhtar belt. Based on magnetic anomalies 15 diamond bore holes were drilled at the NW part of the region which cut the ore bodies at predicted levels with average ore assay of 39 percent total iron. Depth and extension of predicted magnetic bodies have been confirmed by drilled bore holes and 39% FeOt average grade has been yielded.

Theriver water – groundwater interaction between the Aghmiunriver and Sarab aquifer has been evaluated along the Sahzab to Aghmiun villages sector of the river using mini-piezometers. Eight station were considered along the Aghmiun river channel in the study segment during the October 2016_July 2017 period. With defining the hydraulic gradient between the river and aquifer. For assessment hydraulic conductivity, the hydraulic conductivity of the sediments is obtained by sampling from the river basement in laboratory. In order rate of water exchange has estimated with Darcy equation. Based on this research, it can be concluded that there is a hydraulic interaction between the Aghmiun River and Sarab aquifer. In those seasons that the precipitation rate is lower than the annual mean rate (summer and fall), the water penetration rate from river to aquifer is higher than Winter and Spring in which the precipitation rate is more than annual mean. Further, in some parts of the river the Sarab aquifer is charging the river. Generally, the Aghmiun River is charging the Sarab aquifer by a 5. 182 MCM rate per year.

The Gurpi Formation at Anaran Anticline in SE of Lurestan Province consists of 269. 5 meters of marl with limey marl intercalations; additionally, two formal members’ viz. Seymareh limestone and Emam-Hasan argillaceous limestone are also exposed. Studies reveal the presence of 70 species of calcareous nannofossils belonging to 38 genera, based on which 8 standard global biozones were differentiated. Consequently, the Gurpi Formation was attributed to middle Campanian through Paleocene. There is a distinct hiatus at Cretaceous-Paleogene boundary based on paleontological evidence, as deduced from the absence of nannofossilbiozones NP1-NP4. It seems that the reactivation of Anaranlinement as paleohigh resulted in change of facies and a hiatus in the succession of Gurpi Formation at SE of Lurestan Province.