Researches in Earth Sciences
Year:2012 | Volume:2 | Issue:8 |Papers Count:9

Considering this fact that Iran lies on earthquake-prone belt of the Alp – Himalaya, how often, we observe destructive and devastating earthquakes in this country, therefore avaluation of active tectonics and threat assessment, damages and occurrence of these activities in urban area is very important. Study area (1117 Km2) is located in north of Neyshabour city and southern highlands of Binaloud. A detailed study have been conducted by using seven quantitative morphometric indexes such as ratio of the basin shape (BS), the height integral (Hi), the asymmetric basin (AF), mountain forehead sinuosity index (Smf), valley floor width to height ratio (Vf), river sinuosity index (S), and the index gradient along the river (SL). The results of these studies were combined with each other in different layers. Then, according to evaluation of seven morphometric indexes, also using the ArcGIS, SPSS and Minitab software, the active tectonic zoning map of the area were drawn quantitatively and were separated in four categories (very active, active, semi active and inactive). Based on mentioned map, the southern part of the study area, with an area of 538/441 square kilometers equivalent to 36/32% of the area of study area, have very active tectonic. The drawn zoning map shows increasing in tectonic activity from north to the south-south west in southern domain of Binaloud. Adjusting this areas to compressional faults of north of Neyshabour, Neyshabour and numerous historical and instrumental seismic activity of this active faults is an important point which proofs the correctness of this research. We hope that these kinds of basic research studies conducted in different areas and authorities use them in heavy construction and urban planning.

Mijan area is located in northeast of Jiroft in Kerman Province, and it is a part of Jebal-e Barez batholith. The lithologic composition of the intrusive bodies in Mijan area within Jebale_Barez complex varies and consists of alkali granite, alkali syenite, granodiorite and quartz syenite. The magmatic nature of these rocks is sub-alkaline and calc-alkaline, and belongs to potassic calc-alkaline and high potassium series. Study of geochemical data indicates that these rocks have been formed in tectono-magmatic environment within active continental margin. The origin of most of intrusive rocks in Mijan area is continental arc, and these rocks are of pre-collision and syn-collision types. The spider diagrams of regional rocks indicate that they feature magmatic arc characteristics. These rocks have been formed due to oceanic crust subduction, dehydration and mantle wedge melting. Mijan intrusive rocks have undergone three magmatic phases as the most extended rocks in the area are related to the final phase and the least extended ones belong to the early phase.

Fractal dimension of seismic process in wedge-shaped shear zone of Dehshir fault was calculated by square method which its result was 1. 0003 that is twice the area‘ s (0. 522). It means that the amount is less than the fractal dimension of the fault zone network (1. 65). In the 20th century, energy release in the northern part of wedge-shaped shear zone of Dehshir fault has been along Aghda-Rhmat Abad and Taft fault. Although the hidden activities of thrusts in the southern part can be proved by geological investigations, the appearance of Ernan and Dheshir faults indicates that the energy in the southern part has been used through non-creep strain. Fractal dimension is reduced from the northern parts towards the central and southern part of the shear zone that shows increase in spatial faulted in brittle crust of the above-mentioned zone. It means that most of the energy is spent in deforming and breaking of the Earth's crust in that area. Generally, instability is reduced in apical region of the wedge-shaped shear zone towards the middle and end of it. Quaternary energy in this area has been spent in the growth and displacement of the previous fractures and any new growth has not been made, that is, forces in the area has not changed during successive years and energy release along the faults and previous fractures has been in a steady trend.

Climate change impacts in recent years have resulted in significant changes in the availability of freshwater all over the world due to changes in precipitation and temperature. In this paper, the effect of climate change on the groundwater resources in Ramhormoz plain was studied. The water supply in agriculture, industrial and domestic sectors in this region is highly depend on groundwater, Therefore it is important to project future changes in groundwater level particularly for water resources management. In order to assess the climate change effects on the groundwater level, the output of one of the General Circulation Models (GCM) was used. Due to low resolution of GCM outputs, the LARS-WG model was utilized for downscaling daily temperature and rainfall data. The downscaled data were used to determine future recharge and discharge of the aquifer and to simulate variations in groundwater levels. Then dynaimc model was developed using neural network in MATLAB. The results of climate change impacts on groundwater assessment in the study region showed a decreasing trend of water level of the aquifer. The management strategies should be examined in order to mitigate the climate change impacts on groundwater resources in this region. The resultes of study also indicated that then will be mone decrease under the A2 Scenario.

Desertification could be consequence of ecosystem collapse in the areas with nonequilibrium states caused by environmental perturbations. These fragile ecosystem have high vulnerable to desertification process. Many areas of Iran located in fragile environments, and more than 75% area occupied by arid and semi-arid ecosystems. The purpose of this research is vulnerability mapping and strategic development for combating desertification in Khorasan-Razavi province. In the first step, the desertification vulnerability map was provided based on the land use map of 2012 year and PROMETHEE algorithm. In the second step, six strategies have been determined under expert‘ s opinions and were ranked by PROMETHEE algorithm. The results indicated that 91. 7 % of province areas are in high vulnerability class. Also about 2. 36 % and 5. 85 % of areas shows moderate and low classes. The grazing control program is main strategy to combat desertification and irrigation improvement, erosion control, water resources management and soil reclamation are other main strategies.

Land use is the basic tools for land value and the physical development of the city(Braimoh etal, 2007, p4). The final goal of is to create a land planning ecological balance in, and social justice in development and construction the city. Kelardasht according to economic growth and development, and due to immigration and high growth rates has had the rapid physical changes in the past two decades. Changes in land use, government agencies such as the Natural Resources Municipal, Agricultural Jihad that can have a significant role. The aim of this study was to investigate the role of state of goverment in the changing pattern of urban land use in Kelardasht. The hypothesis of this study was to investigate the regulation of land use (municipal, natural resources, agricultural) that deals with the change of indiscriminate use of urban space. The research methodology is descriptive and applied. The population consisted of 150 experts and officials are concerned about the use changes in the relevant institutions and to analyze the data collected we used SPSS software and statistical methods such as quantitative relationship between Pearson, Chi2, Friedman and Choproph Coefficient. According to the results of research, violations, weakness, financial, legal demands and pressures upon the influence of political pressure, lack of performance monitoring tools to monitor changes and organizations are the most important factor of land use change in public institutions (municipalities, Jihad of Agricultural Natural resources). And administrative corruption, government coordination and harmony, the house of representatives also have a role in influencing the land use. Also municipality has an important role in the change of land use. Jihad of Agriculture and Natural resources are in the second and third priority.

Urbanization, land surface temperatures and pollution cause to make major change in urban environment which such implications are evolution geomorphic systems. Weathering is the most important process in geomorphic systems that altere in metropolis. Tehran is the largest and the most important city in Iran, due to enlargement, high population and high level of airpollution density, the geomorphic system has been changed. The meteorological data (1990-2009) of stations in Tehran and Pollution data (2009-2011) including SO2 and NO2 of 15 stations and high gain thermal infrared image of Landsat ETM+ in 11 April 2001 were used. Physical weathering was studied in thermal expansion and Freeze-thaw classes. Zonation of the weathering of the primary elements was performed by kriging based on semivariogram in order to Tehran was evaluated in a wider zone. Interpolation pollutants, calculate land surface temperature and definition and rusty texture were investgated to detect the Tehran geomorphic system. The results indicated to dominate physical processes in Tehran. But the involvement of pollutants, land surface temperature and comparison of field observations in the rusty and good texture shows a system of chemical weathering in the south and center of Tehran, which is also seen scattered in the margins. Thus change of geomorphic system exists in central and southern Tehran which is spreading around by increasing urban density and pollution.