Showing 681 results for Type of Study: Research
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Volume 16, Issue 42 (9-2016)
Abstract
In Iran the issue of occurring natural disasters, particularly mesoscale convective systems. They are important on one hand, because of their increasing intimidations and causing damages and on the other hand, because of their increasing abundance, time of duration, and happening. Therefore life cycle, constituton condition and mesoscale convective systems features in west of Iran using satellite and extention area index and thresholds of brightness temperature 221 and 243 K have been studied. After their statistic analysis, based on mesoscale convective system importance, life and daily cycle, behavior parameters, and synoptic conditions of this system life cycle were analysed. Most of the systems have been formed in southeastern Iraq and in western Zagros hillsides. Wile puberty stages (the maturity) and their expandings were increased with the height increase; in turn, declining of the systems began by passing Zagros chain mountains. The system extention area at the system life cycle starting increases with a smooth process; whereas the reduction process of the system extention area at the declining stage was severe and sudden.
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Volume 16, Issue 42 (9-2016)
Abstract
There are numerous methods to estimate missing values of which some are used depending on the data type and regional climatic characteristics. In this research, part of the monthly precipitation data in Sarab synoptic station, east Azerbaijan province, Iran was randomly considered missing values. In order to study the effectiveness of various methods to estimate missing data, by seven classic statistical methods and M5 model tree as one of efficient data mining methods, hypothetical missing values were estimated using precipitation data from neighbor station. The results showed that multiple imputation, Delta Learning Rule, and Multivariable Linear Regression (MLR) yield relatively more accurate results with fewer errors. The results also indicate the fact that, developing if-then rules, M5 tree model, as one of modern data mining methods, has been able to give the most accurate results among the mentioned methods with four simple linear relationship and statistical values including correlation coefficient (0.974), Nash-Sutcliffe model efficiency coefficient (0.948), RMSE (5.11), and MAE (4.189). Therefore, taking simple modeling process, functionality, comprehensibility, and high accuracy of this method into account, this method is proposed to estimate monthly precipitation missing values.
Aghil Madadi, Elnaz Piroozi,
Volume 16, Issue 42 (9-2016)
Abstract
The purpose of this study is erosion and sediment is estimated in whole of Lay watershed, located in the North Wast of Iran.In this study, the model of WEPP, was provided for simulation and forecast of erosion and sedimentation in the study watershed. The data required for WEPP model are entered in six files, including soil file, management, climate, slope, channel and pounds files. In this study, after determining of work units, the information for developing file were collected. In this region there are, 3 types of soil, 2 managements and 5 channel types. After making the files, WEPP model was run via Geowepp software. It is notable that in this software water erosion and sediment amount was estimated by three methodes of hillslope, watershed and fow path. In these methods sediments estimated were 0.308, 0.215, 0.491 tha-1 y-1, respectively. According to estimated results, the hillslpe with 0.308 tha-1 y-1 was in good agreement with actual amount 0.319 and is suitable for the erosion and sediment of Lay watershed.
Mohammad Hassan Yazdani, Ali Soltani, Hossein Nazmfar, Mohammad Amin Attar,
Volume 16, Issue 42 (9-2016)
Abstract
Urban segregation has been a problem of many cities of the world. Many researchers have interested in the urban segregation issues. Urban segregation has strongly concentrated poverty and created underclass. Different types of urban segregation exist, including income and racial or ethnical segregation, and depending on the contextual mechanisms within a city. To understand and plan a better community, urban planners needs to know how to measure the segregation and interpret the results. There have been many developments of segregation measures. Some evolved and some remained unchanged. This paper is studied the most used multigroup measures of residential segregation (8 indicators) in Shiraz city and between different socio-economic groups of it by using of the Segregation Analyzer Software. In general, the results show the occurrence of segregation in the medium amount to the high amount and by the calculated values of 0/7177, 0/5785, 0/5474 – 1, 0/5407, 0/3969, 0/3759, 0/3613, 0/3375 in the city of Shiraz. On the other hand, the use of Hot spots Analysis in the study area shows that the greatest concentrations of the socio-economic high group are in almost near the center of Shiraz city and the northwest of city, and for the socio-economic medium group exists in the west of city. Also there is the greatest concentration of the socio-economic low group in the southwest of Shiraz city.
Ahmad Reza Ghasemi,
Volume 16, Issue 43 (12-2016)
Abstract
Air temperature is one of the most frequently used parameters in the assessment of climate change at global and regional scale. So researchers have tried to modeling and predicting it with different models. This study also aims to model and predict the country's monthly minimum and maximum temperature. Investigates of temporal temperature changes is done by Sen’s estimator and Pettit method and predicting made by Holt-Winters model. The results indicated that the minimum temperature during 1961 to 2010 increased by 2.9º C . This rate is more in stations located in the warm and dry regions (3.1°C) than any other stations (1.8°C). While the maximum temperature gradient changes are lower and is about 2.1°C. The results also confirmed the performance of Holt-Winter's forecasting model. Beside a few exceptions, the minimum and maximum temperature will be increased until 2020. The highest increase of temperature will occur in Khoy, so that the minimum and maximum temperature will be increased about 0.6°C and 0.28°C, respectively.
Mohsen Hamidianpour, Abass Mofidi, Mohammad Saligheh, Bohloul Alijani,
Volume 16, Issue 43 (12-2016)
Abstract
In this study, the interaction between atmosphere and earth surface and its effect on the simulation of Sistan wind structure in the East of Iranian plateau is investigated. For this purpose, four experiments have been carried out with RegCM4, with horizontal resolution of 20 km. In non-topography experiments, the model was implemented in three different conditions. The results indicated that the Sistan wind is a multi-scale climate phenomenon which will be affected by topography both in wind intensity and in wind direction in the lower troposphere. In the synoptic scale, the pressure gradient which dominates between Pakistan heat low and the Turkmenistan anticyclone (Caspian Sea high pressure) can create a large scale background northerly flow in the lower troposphere which will be passing through the whole area in the east of Iranian Plateau. Furthermore, in meso to regional scales, the topography of the area would be responsible for creation and maintenance of a Low Level Jet (LLJ) through a mechanical and thermal forcing. the mechanical forcing of mountains are responsible for appearance of two LLJ cores across eastern borders of Iran which their preference locations would be around Atishan Desert in the north and upstream of Hamon Lake in the south. As a general result, by eliminating the topography in all non-topography experiments, the LLJ core will disappear on upstream of Hamon Lake as the most important mechanical forcing of the mountains. However, eliminating only the southern Khorasan Mountains will accelerate the north LLJ core in the Atishan Desert, while the LLJ core on the upstream of Hamon Lake will disappear over the Iran Borders at the same time. To evaluate the influence of thermal forcing of the mountains on Sistan wind structure, the total heating, as a residual term of thermodynamic equation, is calculated. The results indicate that mountains have a significant role to building a local low level circulation in the east of Iranian Plateau.
Ahmad Reza Arabameri, Mohammad Hossein Ramesht,
Volume 16, Issue 43 (12-2016)
Abstract
Municipal solid waste (MSW) is the natural result of human activities. If an appropriate management system do not use to this problem, it may lead to environmental pollution and jeopardize the human health. Landfill site selection in urban areas is a critical issue due to its huge impact on the economy, ecology, and the environmental health. Therefore, numerous criteria must be considered and the selection process is a complicated since it has to integrate social, environmental and technical parameters. In this study, the most suitable candidate sites for locating landfill in Shahrood-Bastam watershed, as a case study area are determined by using an integration of the Geographical Information System (GIS) and Multi Criteria Decision Making (MCDM) methods. For this purpose, 12 data layers including Elevation, Stream density, Fault density, Habituate density, distance to road, plan curvature, lithology, slope, Temperature, soil, land use and distance to protected area extracted with Arc GIS 10.1 are prepared and one of MCDM methods which is Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is implemented. For determination of criteria weight, analytic hierarchy process was used. Lithology, land use and slope criteria with the highest score (0.24, 0.18, and 0.14) had the greatest impact on landfilling. The results showed that, zone 2 for the reason of low fault and drainage density, suitable distance of Urban areas, appropriate slope, topography and lithology has obtained the lowest Euclidean distance from ideal positive (0.026), the highest Euclidean distance from ideal negative (0.228), and the lowest relative distance from the ideal solution (0.894), as a result, The greatest weight and highest priority is allocated for landfill. The results of this research will be fruitful in systemic management approach of urban regions
Aliakbar Anabestani, Hamdollah Sojasi Qeidari, Fahime Jafari,
Volume 16, Issue 43 (12-2016)
Abstract
The rural guide plan is the most important tool in the management of rural development in Iran. The final purpose of the plan, improvement of life quality and providing a safe and attractive environment to live in rural areas. The aim of this study is to emphasize the characteristics rural guide plans, which include: Improve the quality of housing, street network, land use and access to services, environmental rural its effects on the objective quality of life of the villagers tested. The research method in present study was functional in terms of purpose, and analytical-descriptive and solidarity methodologically. The study population was selected from 22 villages in which guide plan had been implemented, among them 8 villages with a population of 3835 households was selected by using sampling method. From the selected villages by using sampling method (Cochran), 249 randomly selected rural households were interviewed. Data collected from the questionnaires, were analyzed using the statistical analysis methods in SPSS, and Fitness model search EQS software. According to the results of Pearson's correlation tests, the findings of present study showed a significant and strong correlation between implementation of rural guide plan and the mental facet of life quality by a 0.75 correlation coefficient, so that rural guide plan explained 57% of the variation of dependent variable, and among guide plan dimensions the changing environmental rural affected the objective improvement of life quality of villagers by 29 percent. There is a direct and complete correlation in spatial distribution of relationship between the implementation of guide plan and the objective quality of life in 8 study villages.
Behrooz Mohammadi Yeganeh, Mehdi Cheraghi, Fovad Samadi,
Volume 16, Issue 43 (12-2016)
Abstract
Research goall is survey in the situation of quality of housing and rural vitality and survey of relationship of housing quality and vitality of rural settlements. The population of research is Khawmirabad county (Kurdestan Province, Mariwan Township) with 2737 households. Research method is analytical –description based on questionnaire and it is applicable research . In order to gathering the data we used documentary and field method and interviews and questionnaire based on Likert scale(five – range opinion)has been used. In order to sampling we used random sampling and by using of Cochran formula that sample size is equal to 290 households. In order to analysis of data’s from questionnaire, we used both of Descriptive (mean and deviation) and Inferential(One sample T, Linear regression, Chi- square) Statistics. The results of this study indicate a low level of economic dimensions (2.34) and political (2.97), vitality and quality of housing than the average (2.74). This difference is statistically significant at the alpha level 0.01 numerical difference utility as evaluation and assessment is negative. The results also show that the greatest impact of the quality of housing is on the social dimension with a beta coefficient of 0/570 and the lowest on the economic dimension with 0/077 beta coefficient.
Saeed Balyani,
Volume 16, Issue 43 (12-2016)
Abstract
Knowing of precipitation values in different regions is always of main and strategic issues of human which has important role in short- term and long-term decisions. In order to determine of precipitation model and forecasting it, there are different models, but given that the precipitation data have a spatial autocorrelation, the spatial statistic is a powerful tool to recognition of spatial behaviors. In this research, for determine of precipitation model and predicting of it with geographical factors e.g. altitude, slope and view shade and latitude- longitude by using spatial regressions analysis such as ordinary least squares (OLS) and geographical weighted regressions(GWR), 13 synoptic stations of Khuzestan province from establishment to 2010 were used. Results showed a powerful correlation between precipitations with geographical factors. Also results of modeling through OLS and GWR representative that forecasting of GWR is close to reality, so that in GWR, the sum of errors of residuals is less, the is more and there aren't any spatial autocorrelation in residuals and the residuals are normal. The of OLS can only justify 75 percent of precipitation variations with spatial factors while in GWR this quantity is 82- 97 percent. Accordingly, it was found that, in east, northeast and north of province the altitudes, in east and northeast and Zagros Mountains the view shade and slope are the most important spatial factors, respectively.
Gholam Hassan Jafari, Asghar Rostamkhani,
Volume 16, Issue 43 (12-2016)
Abstract
One of the unique properties of northern landforms of zanjanrood catchment is having smooth surfaces that have been interrupted by deep valleys. Rivers that don’t have a wide catchment upper their front mount are running in parallel deep valleys that the topographical situations don’t let them to receive around surface runoffs. This situation has made them to move in parallel form and not to join with each other. In some parts of sub basins, the water dividing line had been incorporated with the beach of main river valley (Sohrein River). The extent of catchments upper the mount front is not in a situation that let to dig valleys that sometimes exceeded to hundreds meters deep. These valleys had kept their primary height differences than it’s around. According to these properties, the style of formation and their evolution was considered as a geomorphological point. To get the answer, topographic and geologic maps and satellite images was made, and traced the geomorphologic effects of faults and corrected in different field works. Evaluation of tectonic activity in area, have been estimated by using Morphtectonics indicators of asymmetric factor (Af), integral hypsometric curve (Hi), valley floor width-to-height ratio (Vf) and transverse topographic (T). Relative Active Tectonics Index (LAT) showed the whole basin high activity (class2). Based on the Af index uplift have been attributed to the right bank in Sohrin and Sarmsaqlv basins and in Qracharian sub-basin to the left bank. Which states that the center of Neotectonic power center located in the place between the three sub-basins?
Khadijeh Javan,
Volume 16, Issue 43 (12-2016)
Abstract
In this study, the Frequency and the spell of rainy days was analyzed in Lake Uremia Basin using Markov chain model. For this purpose, the daily precipitation data of 7 synoptic stations in Lake Uremia basin were used for the period 1995- 2014. The daily precipitation data at each station were classified into the wet and dry state and the fitness of first order Markov chain on data series was examined using Chi-square test at a significance level of 0.01 and was approved. After computing transition probability matrix, the persistent probability, average spell of dry days and rainy days and weather cycle was calculated. By calculating the frequency of 1-10 rainy, the spell of this periods and 2-5-days return period were calculated. The results show that in this study period the average of rainy days is 25% and the probability of Pdd is more than other states (Pww ، Pdw و Pwd). The average spell of rainy days in the study area was estimated at about two days. Generally, in all stations the persistent probability of wet state is more than rainy state. Estimation of frequency and spell of rainy days and 2-5-days return period show that with increasing duration, the frequency of rainy days decreases. Also with increasing duration of rainy days, their spell is reduces and return period increases.
Kamal Omidvar, Reza Ebrahimi, Mohammad Kykhsrvy Kayani, Ghasem Lkzashkoor,
Volume 16, Issue 43 (12-2016)
Abstract
The aim of this study was to investigate the effects of global warming on where the slope changes when the monthly temperature in Iranian territory over the coming decades (2050-2015). The simulated temperature dynamic model EH5OM subset Hybrid Models atmospheric circulations (GCM) selection and data model of the Center for Theoretical Physics Salam (Italy) were derived from emission scenarios A1B scenario was chosen given the scenario of 2100 -2001 found that from 2050 to 2015 were used in this study data is then output the data in the fourth edition of the regional climate model (RegCM4) Linux environment was fine scale output data Downscaling model with dimensions of 27/0 * 27 / Degrees latitude is where the dimensions of 30 x 30 km area of approximately cover the average temperature of the matrix deals 13140 2140 * was extracted. Finally, the slope of the average monthly temperature during the period under study by Mann-Kendall slope age and matrix computation in MATLAB software 13140 * 12 respectively. Results show rising temperatures in March and April to June, more than 90% of the country, that it will be spring's warmer. Increasing the temperature in the winter months and spring mountainous parts of the western half of the country is warming the cold regions of Iran. Temperature negative trend in October and November in the northern part of the eastern half of the region's countries could be indicative of colder temperatures in the northern West.
Mohammad Saligheh, Mohammad Hossein Nasserzadeh, Thmineh Chehreara Ziabari,
Volume 16, Issue 43 (12-2016)
Abstract
In this research, the relationship between NCPI and CACO indices with autumn precipitation of Southern Coast of Caspian Sea (SCCS) was investigated. In this regard, two sets of data were used (Aphrodite and Station). And the days with more rainfall than long-term average rainfall station and on condition that the rainfall is more than 70% of the region rainfall, were chosen as a day of widespread rainfall. The sea level pressure data was extracted and by cluster analysis and coalition method was clustered. Then, a representative of the widespread precipitation days from station dataset was selected, investigated and analyzed accordingly. The results state that within all patterns there exists a high pressure on the upper side of the Caspian Sea, or a margin of high pressure is extended on to the sea itself. These high pressure regions have relatively cold nature that can cause currents in the northern direction while intersecting with the relatively warm water during the summer. These currents can absorb moisture during their motion towards south which can lead to their instability. In addition, one should not forget the fact that in each three investigated patterns, dynamic factors at high levels have intensified the abovementioned phenomenon and enhanced the instability, which as a result brought about widespread precipitation. Continuously, the abovementioned Remote bond indices were extracted on a daily basis and their relation to north coast widespread rainfalls was studied, which came to a meaningful relationship between these index sets and fall index sets. The relationship is direct with NCPI or surveyed stations, and it’s an inverse relationship with CACO. On the other hand, the study of indexes anomalies on the days without rainfall and with rainfall was done by One Way ANOVA and Tukey test. The result was a meaningful index anomaly on the days with and without rainfall.
Jalil Mohammadi, Alireza Mohammadi,
Volume 17, Issue 44 (3-2017)
Abstract
Social capital including values such as trust and cooperation and solidarity in a residential zone is a concept that has been very important and critical in the process of urban renewal in recent decades. The aim of the present study was to measure the degree of social capital and to investigate the relationship between social capital and physical interference pattern and continued motivation of residence. And it also tries to identify the type and extent of the relationship between social capital with the increased participation and the rate of the implementation of urban renewal projects, on the other hand. The present study is a survey –based research. It is descriptive - analytical. The conceptual questionnaire was used as an instrument in this study. Formulation of theoretical foundation was based on library resources. The population of the present study consisted of all the inhabitants living in Zanjan old texture (family heads) that was 46150. Using multi-stage random sampling was used and 330 samples were selected using Cochran formula. The results showed that the Zanjan old texture residents have the social capital above average; nearly it was true in all of its components. Also significance relationship does not exist between social capital and the renewal of old urban texture. Due to various factors including lack of trust in the body of urban management, lack of reinforcing the planning of required effective variables, residents are uncertain and in doubt on the issue of renewal and improvement of urban old texture. So, it emphasizes on the importance of planning in this area.
Mohamad Reza Mobasheri:, Samira Ranjbar,
Volume 17, Issue 44 (3-2017)
Abstract
The goal of this study is to identify farms which are affected by wheat rust disease. For this, the sensor data of Landsat 7 satellites in growing season of 2013 and 2014 along with some laboratorial data containing reflectance spectrum of leaf and leaf health degree in different levels of disease are used. The reflectance values of leaf are collected by an ASD spectroradiometer in the range of red and near infrared spectrum. The spectral are simulated for Landsat sensor bands using their spectral response functions. Then with the index of DVI and data obtained for leaf health, the Wheat Health Index was introduced. The correlation coefficient obtained is 0.82 and the relevant RMSE is 0.089 which is really good result for diagnosing highly advanced disease. The results show that, this index has a good performance in wheat high growing season when the greenness is high. It can diagnose regions that are healthy from those whom are blighted. Because the WHI index is a spectral index and is sensitive to leaf color, if the acquired images are close to the harvesting time, its performance will be weakened. The selected region in this survey is located in Fars, province, Saadatshahr city.
Firouz Mojarrad, Amanollah Fathnia, Saeed Rajaee Najafabadi ,
Volume 17, Issue 44 (3-2017)
Abstract
The aim of this study was to provide a reliable estimate of the amount of solar radiation in Kermanshah province by using “Liu and Jordan” model in order to develop solar sites. The amount of atmospheric elimination in each month was calculated using an index called clearness index () and the results were applied on different slopes, aspects and heights. Then, according to the obtained results, amounts of direct, diffuse and total radiation were calculated in different slopes of the region and the relevant maps were consequently drawn. The results showed that the minimum amount of atmospheric elimination and thus the maximum amount of received radiation in the province occurs in late spring and summer due to the increase of clearness index () with a maximum of 1360 cal/cm2/day in May. the least amount of received radiation occurs in Janury equal to 386.3 cal/cm2/day. Radiation variations at the provincial level are high between lowlands and highlands in Janury and December, according to the angle of radiation and significant elevation changes in the region. However, in summer, distribution of surface radiation is almost identical because of high solar radiation, and thus standard deviation amount of received radiation is reduced. The highest amount of radiation is received in Javanrood city as much as 528.1 cal/ cm2/day due to greater heights, and the lowest amount is received in Qasr-e Shirin city as much as 443.6 cal/ cm2/day due to lower heights.
Siamak Baharvand, Salman Soori,
Volume 17, Issue 44 (3-2017)
Abstract
Landslide mapping is one of the approaches (which can be) used to define the slope stable critical areas and the maps prepared based on this demarcating are used in desining sustainable development. The purpose of this study is to compare the landslide susceptibility mapping models based on Fuzzy logic, Information value and area Density applied in the Chamsangar watershed. According to the tectonic and Iran old basins divisions, this basin is a part of folded Zagros. To study the stability of slopes in the Chamsang field, in first step the sliding point and subsequent distribution maps of landslide were prepared using satellite images and field visits (recording the sliding points by GPS). in this study, Landslide-related factors such slope, aspect, altitude, lithology, rainfall, landuse and distance from the road and drainage used in the landslide susceptibility analyses. To assess and classify was there models outputs the Sum of Quality (QS) index used. Results show that area Density model with QS=1.85 is the more suitable than Information value model with QS=1.60 and Fuzzy logic with QS=0.554 based on the out put of the area Density model, the 36.31, 44.78, 16.62, 1.65, and 0.63 percent of the area is located in very low, low, medium, high and very high risk classes, respectively.
Somayeh Soltani Gerdfaramarzi, Aref Saberi, Morteza Gheisouri ,
Volume 17, Issue 44 (3-2017)
Abstract
Rainfall is one of the most important components of the water cycle and plays a very important role in the measurement of climate characteristic in any area. Limitations such as lack of sufficient information about the amount of rainfall in time and space scale and complexity of the relationship between meteorological elements related to rainfall, causes the calculation of these parameters using the conventional method not to be implemented. One method of evaluating and forecasting of rainfall in each region is time series models. In this research, to predict the average annual rainfall synoptic station at Mahabad, Uromiya and Mako in West Azarbayejan provience during 1984-2013, linear time series ARIMA was used. To investigate model static, Auto Correlation Function (ACF) and Partial Auto Correlation Function (PACF) was applied and with differencing method, the non-static data transformed to static data. In next step, stochastic models to estimate the annual rainfall average were used. With regard to the evaluation criterion such as T, P-VALUE < 0.05 and Bayesian Information Creterion (BIC), ARIMA (1,0,0), ARIMA (0,1,1) and ARIMA (0,1,1) models was determined as a suitable model for predicting annual rainfall in the three selected stations at Uromiya, Makoo and Mahabad. In the following, the annual rainfall for 3 (2013-2016) years is forecasted which based on rainfall data in that time, the adjusted model was acceptable.
Esmaeil Nasiri, Ali Ahmadi, Reza Rahmani ,
Volume 17, Issue 44 (3-2017)
Abstract
Migration is among important issues that less developed and developing countries have confirmed during the recent five decades. This issues in Iran has attraced a lot of researcher and planner views. Irregular and increasing migrations have created a lot of consequences for cities and the target settlements, social effects of migration on the cities is among such consequence these, in this project, ethnocentrism, linguistic diversity and conformance quality are considered among the city's residents. This issue has been studied in Takestan Qazvin. For illustrating the issue, theories of Michael Todaro, Edward Sapir, Benjamin Whorf and William Samner have been used. The research has been done according to library methods (documents) and field methods (special for questionnaires and measurement).In addition to confirming the questionnaire by the experienced faculties, its reliability has been obtained in accordance with Cornbrash’s Alpha coefficient by 82,2 percent and the SPSS software is used for analyzing and processing. The result obtained by analyzing questionnaire filled in by 400 people that the number has been chosen according to Morgan's Table, and the people have been chosen randomly, shows that there is a meaning full relation ship between ethnocentrism and linguistic diversity with development of the city.