Showing 177 results for Mohammad
Dr Mohammad Mahdi Hoseinzadeh, Dr , Mis Sepide Imeni,
Volume 18, Issue 51 (6-2018)
Abstract
The process of precipitation – runoff of each basin, is influenced by hydrologic, geomorphology conditions, geological formation and vegetation. There are different methods in drainage basins. One way to estimate the runoff height is Curve Number (CN) method. That reperesents the hydrological behavior of basin. data were collected for statistics of climate and then topographic map of 1: 25000 and geological map of 1: 100000 by GSI was used. Smada software for calculate the short – term rainfall at different return periods. As well as Arc GIS software for mapping Curve Number by combining maps of land use, soil hydrological groups and moisture of soil with using the table of America Soil Conservation Service (SCS). And then modeling related in the GIS mappings of runoff height of Hesarak catchment was prepared. The aim of this study, was to determine Curve Number and estimate runoff coefficient and maximum discharge runoff with SCS method in various units catchment is. The results showed, hydrologic condition and soil hydrological groups are the most important parameters to determine the CN and affect on runoff. The most potential for runoff is in downstream of basin that specified with urban land use. Also average weight of Curve Numbers those obtained for each sub catchments, Chapdareh sub catchment (S2) with 88 Cure Number and mean of runoff 28.15 mm had the highest volume of runoff, Dochenaran sub catchment (S3) with 89.3 Curve Number and mean of runoff 24.54 mm and sub catchment of the twin branches (S1) with 90.1 Curve Number and mean of runoff 17.36 mm had The lowest amount of runoff probability and spill potential. But in general potential runoff in this basin is relatively high. The maximum amount of runoff Curve Number in condition of high humidity is 99 and 78 is the lowest.
Doctor Maryam Ilanloo, Sir Hosein Bicgarian, Sir Mohsen Yahya Soltani, Sir Mohammad Mehdi Bahramian,
Volume 19, Issue 52 (3-2019)
Abstract
Solid waste is an integral part of human life, generation of various quantities and qualities of which is one of the greatest environmental problems of the current era. Application of modern tools and technology to find the right place for recycling, where the volume of recyclable materials can be reduced, seems vital for reusing the recoverable materials contained in normal waste and their recycling and reusing in the cycle of industry. The study aimed to find a location for recycling and its converting industries in Kelardasht, Iran. This was a descriptive and analytical research with a survey approach. At first, experts of the field were recognized and a scientific panel was formed to identify the relevant criteria through Delphi method. In this respect, five criteria of the distance from residential and commercial areas, the distance from urban streets, the distance from the river, the distance from the hospital and education centers, and the distance from hotels, banks, and offices were selected. After that, the permitted distances for these criteria were determined by Delphi technique, followed by the application of the centroid method to determine the exact distances. Moreover, the analytical hierarchy process (AHP) and geographic information system (GIS) were exploited to determine the and use weights in raster maps and generation of the zoning map. Furthermore, the best locations for recycling were selected in Kelardasht using field survey method and based on the zoning map. According to the results, four sites were selected for recycling of recoverable solid waste in this region
Mr Sirous Hashemi Darebadami, Dr Ali Darvishi Boloorani, Dr Seyed Kazem Alavipanah, Mr Mohammad Maleki, Mr Reza Bayat,
Volume 19, Issue 52 (3-2019)
Abstract
The term urban heat island (UHI), described the phenomenon of climate change in urban areas compared with surrounding rural areas. UHI effects include: increasing in energy and water consumption, air pollution expansion and interfering in thermal comfort. Surface urban heat island (SUHI) contains patterns of land surface temperature (LST) in urban areas that has interaction with UHI in urban canopy layer and urban boundary layer and investigate with thermal remote sensing. SUHI has diurnal and seasonal variations so requires multi-temporal data to analysis SUHI. In this study, the multi-temporal MODIS (Aqua and Terra) data product were used to analyze the SUHI in day and night in Tehran metropolitan. Physical and biophysical surface properties such as: land cover/land use (LULC), elevation, albedo, vegetation index (NDVI) and impervious surfaces index (NDBI) were used to interpretation of the LST and SUHI changes. The results showed that SUHI in Tehran, has spatial-temporal diurnal and seasonal variation. So that during warm days the surface urban cool island (SUCL) is formed in Tehran. At night times, SUHI index values was different between 2 and 5 ° C (maximum in the spring). The results also showed that different of land cover thermal properties, albedo and elevation was the most important factors is the diurnal changes of SUHI while phonological changes of vegetation and albedo, was the most important factors in seasonal changes of SUHI.
Mr Ali Mohammadpourzeidi, Professor Bohloul Alijani, Associate Professor of Climatology Mohammad Saligheh, Mr Mohammadsaleh Gerami,
Volume 19, Issue 52 (3-2019)
Abstract
owledge of spatial rainfall behavior in environmental, land planning is effective. These changes in the later place in the form of time later and in the climate of the area. The Target of this study was to reveal the presence or absence of precipitation trend in the ratio of the height of local precipitation behavior and identify province mazandarn. Therefore, the purpose of the rainfall data station 32 (Meteorological Agency and Department of energy), the statistical period 1988-2010. To get the regression analysis of precipitation process was used to identify the local behavior of precipitation, the method of spatial statistics were used. The results obtained from the behavior of precipitation, the existence of the process within the scope of the study and the emphasis is most consistent with the Be modified regression model at adjustment indicate. According to the regional behavior of precipitation, using local spatial statistics, spatial Moran well hot spots check this behavior. The results showed that precipitation in the province of Mazandaran has the pattern of clusters with high value. According to the local hot spots and methods Moran, West Coast up to a height of 700 m has positive z score and clusters with high value, 99% confidence level. This range includes 15% of the total of the province. The range of the Southern Highlands as well as the negative z score and clusters with low value with a confidence level shows 99%. This range is also about 20 per cent of the province's total. About 65 percent of the total area of the province as well as the lack of a significant trend show.
Dr. Mohammad Javad Vahidi, Dr. Rasoul Mirabbasi,
Volume 19, Issue 53 (6-2019)
Abstract
In order to protect soil and water resources should be identified erodible areas of watersheds, to be able to prevent land degradation and to control erosion in the form of soil conservation planning or watershed management. Therefore, the present study aimed to classification and delineation of susceptible areas to water erosion in the Hervi watershed using Hjulstrom curve, has been conducted. Increasing of accuracy, speed and facility of spatial achievement, using GIS technology, are advantages of the present study. In this study, were separated 10 sub-watersheds based on the feeding levels of streams. Spatial variability of soil properties in sub-watersheds, such as texture and the mean diameter size of the particles using hydrometer method were measured; also the maximum potential velocity of outlet in sub-watersheds based on the characteristics of each sub-watershed were calculated. Then, status of erosion and sediment in watersheds and sub-watersheds was studied using Hjulstrom curve (based on the mean diameter size of sediment particles and the maximum potential velocity of outlet), and was comparatively classified in term of erodibility. Finally, delineation map of susceptible regions to water erosion in the study area were obtained. The results revealed that the upstream and side areas of the watershed including: Sub-watershed No.4 (8.94% of the land), has very high erodibility, and Sub-watersheds No.1 and No.9 (36.94% of the land) have high erodibility. These areas are steep and often devoid of vegetation or have poor vegetation (such as poor pastures and rain-fed farming); so, it is necessary a proper strategy to prevent further erosion.
Mohammadreza Goodarzi, Atiyeh Fatehifar,
Volume 19, Issue 53 (6-2019)
Abstract
In the present time, with the increase of industrial activities and the neglected environmental issues, the effects of climate change have become more evident and poses this phenomenon as a global difficult. Increasing the probability of occurrence of extreme climatic events such as flood and increasing the frequency and intensity of the effects of climate change. The northwest of the country is one of the most vulnerable areas of the country due to its semi-arid and mountainous climates and high rainfall variability. Therefore, zoning due to climate change is essential. Therefore, in this study, in order to investigate the risk of flood in the Azarshahr basin, due to climate change, using the CanESM2 general circulation model under RCP8.5 scenarios negativity according to the assessment report fifth IPCC, rainfall and temperature variables were down scaling by Statistical down scaling model (SDSM). Then,with hydrological model SWAT the daily runoff, the basin map and the lines of the canals are achieved. The results of the evaluation of the SDSM model with a coefficient of determination and Nash-Sutcliff 0.95 on average represent the good performance of the model in the down scaling of large scale data. The results show an increase of 0.23 ° C and 4.53% rainfall and maximum discharge. The basin is zoned with the combination of the maximum mean discharge map, the coefficient and distance from the river with the AHP approach. Due to the zoning they are 41.55% of the area of the basin, at very low and low risk, 27.23% at average risk and 31.2% at high and very high risk. Also, with the final map, it became clear that the mid-basin had a high risk due to its prerequisite conditions and that it needed to carry out managerial actions.
Elham Yarahmadi, Mostafa Karampoor, Hooshang Ghaemi, Mohammad Moradi, Behrouz Nasiri,
Volume 19, Issue 53 (6-2019)
Abstract
Investigating of rainfall behavior in the spatial-temporal dimension and determining the tolerance thresholds of different geographical areas with respect to vegetation, animal life and human activities, is essential for any decision in the environment. Therefore, precipitation data of 27 stations were received from the Meteorological Organization during the 60-year period and After the data were evaluated qualitatively, The distribution of temporal and spatial mean, coefficient of variation, skewness and probability distribution of 20% maximum and minimum monthly and seasonal autumn and winter, for a period of 60 years (1951-2010), two 30-year periods (1980-1951), (1981- 2010) and two 10-year periods (2010-2001), (1951-1960) were calculated and were zoned using GIS. Studies show, except on the shores of the Caspian Sea, there is little change between autumn and winter patterns. The average rainfall of the southern shores of the Caspian Sea has decreased to the west and east. in other areas of the country, the spatial and temporal variations of rainfall in the autumn are very highand from the north to the south, the mean decreases and the coefficient of variation and skewness increase. In winter, maintaining the pattern of autumn, the average precipitation increases and the coefficient of variation decreases. The average precipitation of 30 years and 10 years of the second winter season, compared to the first 30 years and 10 years, and also the 60 year period, has decreased in most stations, which is consistent with the results of the Mannkundal test. Analysis and review of the 20% minimum and maximum seasonal rainfall show that the intensity and range of performance of winter precipitation systems in the second 30 years have decreased. Also, the frequency and severity of drought in the autumn season have increased in the second 30 years and in the last 10 years. The highest decline occurred in the western and eastern parts of the Caspian coast and in the northwest, which requires special attention to managers in light of the areas of activity and concentration of the population.
Nafiseh Varkianipor, Doctor Seyed Mohammadreza Hosseini, Doctor Roohalla Samiee, Doctor Majid Shrafi,
Volume 19, Issue 54 (9-2019)
Abstract
Abstract in the late 20th century, it has been a tremendous change in all spheres of business, such as globalization of enhancing competitiveness of information technology development competition attention to the quality of customer and such as these are the administration in the public sector with these serious challenges one of the most important approaches to address these challenges is to address the entrepreneurial debate in society as well as women play an important role in promoting employement and improving the economic situation of the community and it is an important factor in shaping social affairs. First, the analysis of sustainable rural development and sustainable development of women identified by using alpha cronbachs alpha test and sustainable development of rural sustainable development have been used to prioritize the relationship between women's entrepreneurial development and sustainable development of rural sustainable development. Women's activities led to poverty reduction and sustainable rural development.
Miss Leila Montaseri, Dr Abolghasem Amir Ahmadi, Dr Mohammad Ali Zangeneh Asadi,
Volume 19, Issue 55 (12-2019)
Abstract
Abstract
In this research, to review the role of geomorphological phenomena has been discussed in the change of chemical quality of water in the part of geography the north east of the country. Geomorphological phenomenon discussed in this research is marly hills that is result of volcanic-sedimentary activities of geological tertiary and is discussed the role of chemical effects this hills in mudding water one of the rivers current in its area (Kalateh-Sadat river in west Sabzevar) to irrigate agricultural lands around this river, that slang term to it "water-coloring" they say. In this study, methods of field observation, interview with local farmers, sampling and analysis of water and physicochemical experiments have been used. The results of tests and comparative the chemical quality of clear water and muddy water showed that the rate of deposition percent (turbidity), total hardness (concentration of calcium and magnesium) and water salinity (Electrical Conductivity) is higher in muddy water; but statistical analysis and diagramming Schuler & Wilcox and classification of SSP and SAR determined that this increase is not as critical and dangerous and the quality of potable and agricultural water of Kalateh Sadat river and even its total hardness is in favorable condition and well. In other words, marly hills and water mudding does not cause of significant changes in water chemical quality of river; Therefore, can be used of muddy water for irrigating agricultural land.
Miss Rahimeh Rostami, Dr. Ali Mohammad Khorshiddust, Dr. Mohammadreza Nikjoo, Dr. Hassan Mahmudzadeh,
Volume 19, Issue 55 (12-2019)
Abstract
The drying of Lake Urmia has had many environmental impacts on the surrounding areas of the lake. In this research, efforts have been made to identify vegetation coverings that are compatible with the study area and then it use of multiplicative decision-making models for identify areas susceptible to cultivation of these products. In the present study, following the study of species in the region of rapeseed, was selected as a suitable halophytes plant. Initially, using Landsat 5 and 8 images, the changes in the land use type and vegetation cover type of the region were investigated from 2000 to 2016, and after calculating the changes, the potential planting of the halophytes plant was sought. The ANP Fuzzy method was used to estimate the ability to cultivate rapeseed. Main criteria used in this research are topography, soil and meteorology. The topographic sub criteria are included: height, slope and tilt direction, soil criteria including soil texture, soil salinity, and soil pH and soil organic matter. Finally, the criteria for meteorological data are total annual precipitation, Relative humidity, average annual temperature, maximum annual temperature and annual minimum temperature. These layers first be changed to fuzzy and then, applying the weight of each of the following criteria, a map of the main criteria of soil, topography and meteorology was prepared and finally, by combining these three main parameters, the potential mapping was obtained. The results indicate a 25.43 percent reduction in water content and an increase of 21.03 percent in saline areas between 2000 and 2016, and the results of identifying areas susceptible to cultivation of halophytes plants have identified 14.28 percent of the study area suitable for rapeseed cultivation.
Msc. Graduated Student Najmeh Daneshvar-Marvast, Dr Somayeh Soltani-Gerdefaramarzi, Dr Samaneh Poormohammadi,
Volume 19, Issue 55 (12-2019)
Abstract
The phenomenon of evapotranspiration causes water and moisture losses from water, soil and vegetation levels. Due to the small amount of atmospheric precipitation and water resource constraints in Iran, it is important to calculate it through a suitable method. The present research attempts to evaluate the evapotranspiration reference crop (ETo) and present it in the form of zoning map as a basic tool for water management. In this study, the long-term average of seven meteorological stations and evaporation pan data were used to determine the appropriate ETo estimation method. Evapotranspiration of reference crop was calculated to 14 methods the based on climatic information in each station. Computational methods including combinational methods Penman-based, radiation-temperature method, temperature method and radiation method. The most appropriate computational method was selected based on the R2 and Nash -Sutcliffe statistics. The zoning of evapotranspiration of reference crop was carried out based on the geographic information of the meteorological stations and the GIS software. The results of the research indicate that the best method for this region as the cold and moderate climate are FAO radiation and Blaney-Criddle. Also, the zoning result shows that west of the catchment has less evapotranspiration rather than its east. Sunshine hours, maximum temperature and wind speed were the most effective factors for evapotranspiration in this area by sensitivity analysis.
Hosseinali Roohbakhsh Sigaroodi, Mostafa Karampoor, Hooshang Ghaemi, Mohammad Moradi, Majid Azadi,
Volume 19, Issue 55 (12-2019)
Abstract
Investigating the variability of the spatial-temporal pattern of rainfall, which can lead to climate change, due to its strong impact, is of interest to various scientists. For this purpose, after receiving the daily precipitation data of 27 stations for the period of 60 years (2010-1951), its quality and the total monthly precipitation and statistics necessary for the continuation of the research process such as mean, coefficient of variation, skewness, probability estimate of 20% The upper limit of the maximum and minimum rainfall average were calculated experimentally for a period of 60 years and two 30-year periods (1951-1980 and 1981-2010) and two periods of 10 years (1951-1960 and 2010-2001) for each of the spring and summer seasons Was calculated. The studies show relatively modest variations in spring and summer precipitation patterns on the Caspian coast, Northwest-West, 30 and 10 years old, compared to the 60-year, 30-year, and 10-year periods. In general, the mean of precipitation decreases from north and northwest to south and south east and increases the amount of coefficient of change and skidding. Except for the Caspian Basin, in the remaining stations, the average spring precipitation is higher than the average summer rainfall. There is a clear difference in the long-term characteristics of precipitation and its changes. It is worth mentioning that the increase in the coefficient of variation of the 30-year and 10-year periods is comparable to the corresponding periods at all stations, which indicates a decrease in the monthly and seasonal mean of spring and summer precipitation, which confirms the results of the decade and the first decade of the second decade. The greatest decrease occurred in the northern and western parts. In the second 30 years, the incidence of dry sunshine and drought-affected stations has increased. Therefore, it confirms the climate change for the Caspian and the Southwest coast.
Mohammad Motamedi, Seyedhassan Rasouli, Mohammad Nasiri,
Volume 19, Issue 55 (12-2019)
Abstract
In public organizations such as municipalities, the design and deployment of a performance and control assessment system can lead to the proper management of urban managers on the road to achieving goals, tasks, strategies and development plans and urban development, in accordance with the quality, cost and time desired. Therefore, this article attempts to study the satisfaction of urban performance in urban services by using the views of citizens of the city of Farouj. For this assessment, using theoretical studies, 21 types of urban services were selected in three sections: Technical, Public and Cultural Services. At the next stage, the questionnaire was designed based on these services. Then, 400 questionnaires were distributed among the citizens of the case study city. In the next step, 380 questionnaires were completely and correctly collected and entered into SPSS software. Finally, the results of the study were analyzed by statistical tests. The results of the research indicate that the average satisfaction rate of public services in the city of Farouj is 3.53, which can be said that the level of citizens' compliance with this service is in the middle level. The average satisfaction rate of technical services in the city of Farouj has been calculated to be 3.31, and the average satisfaction rate of cultural services in city of Farouj has been calculated to be equal to 3.5. The results of statistical analysis indicate that the level of significance is more than 0.05 in relation to four of the urban services. This means that in terms of the services of sports spaces, the collection and disposal of surface water, the quality of leisure travelers and the respect of the clients, the level of satisfaction of citizens is equal to the average. In relation to two indicators of pedestrian quality and public participation, the mean difference with the statistical test was calculated to be 0.16 and -0.19 respectively, which indicates that the satisfaction of these services is lower than the limit on average. In other indicators, citizens' satisfaction is above average
Dr Saadi Mohammadi, Dr Askandar Moradi, Sharmin Hosaini,
Volume 20, Issue 56 (3-2020)
Abstract
The horizontal and urban growth of the past few generations, due to the dominance of the centralized planning system in the country, has led, in accordance with the principle of village-to-city interconversions, that many villages located around cities have undergone numerous changes and changes in the indicator status Of development. These changes, in addition to having positive aspects in most cases, have had a negative impact on the sustainable development of rural areas located in the vicinity of these cities. In the current applied research, a quantitative and qualitative approach with a spatial and descriptive-analytic approach has been carried out. The main objective of this research is to identify the consequences of the Marivan Creep phenomenon on the changes in the development status of the surrounding villages, Over the last few decades, physical development has been speeding up. Data gathering in the theoretical part of the documentary and in the field was conducted by a survey method based on an interview with the local people and the locals to identify the outcomes, and then the classical distribution of the questionnaire among the studied villages and simple random among 203 households supervised by The Cochran formula was determined by volume, 30 from local development experts and observers of the status quo, in order to generalize the findings from the interviews. The results of analyzing the data with the fundamental theory of the technique in the qualitative section and the single-sample t-test in the quantitative section showed that the urban creep phenomenon, in addition to limited positive consequences in improving the physical condition, caused social deficiencies, failure Economic problems, inadequate visual quality, natural environment degradation and institutional management failures in the development of villages studied.
Dr. Mohammad Eskandari Sani,
Volume 20, Issue 56 (3-2020)
Abstract
One of the UN Millennium Development Goals is women's participation in urban management. This article develops a theoretical framework for analyzing the relationship between community- based planning and women participation in cities. In this regard, collective action, social capital, and neighborhood as location for community planning are used. The framework identifies a series of variables that are theorized to affect a community's capacity to women participation. Method of study is analytical descriptive. The statistical population is women over 18 years old in Nematabad neighborhood. 29 questionnaires are distributed randomly. According to the findings it is recommended that, the strategy for development of community-based planning can be very effective in urban planning system in Iran as this strategy for host communities could bring about social welfare, justice, and socio- economic suitability. Also Social Network, marriage, education level, employment are the most important elements that affect women's participation in the development of community-driven development programs.
Dr Mohammad Ebrahim Afifi,
Volume 20, Issue 56 (3-2020)
Abstract
Land use maps are considered as the most important sources of information in natural resource management. The purpose of this research is to review, model, and predict landslide changes in the 30-year period by LCM model in Shiraz. In this research, TM Landsat 4, 5 and OLI Landsat 8 images were used for 1985, 2000 and 2015 respectively, as well as topographic maps and area coverage. Subsequent validation and detection of changes were made using the prediction model of variation The use of LCM markov and the model of user change approach. The images were classified into four classes of Bayer, garden, urban lands, and arable land for each of the three periods. According to the results, aquaculture is the most dynamic user in the area, which has led to an upward trend during 1985-2015, so that the amount (4337 ha, 12.7%) has been added to this area. The Bayer user change trend was also a downward trend during 1985 to 2015, reducing the 99.1995 hectares of this class. The results of the change in the 1985 changes with a kappa coefficient of 0.88, in the 2000 period with a CAAP of 0.77, and in the period 2015 with a Kappa coefficient of 0.92. The results of the change detection in 2030 are such that if the current trend continues in the region, 20.33% will be added to the crop category, so that in 2030, agricultural cropping will be 95.60% of the area of the area Gets In the Bayer and Garden uses 21.22% and 0.21% of the total area of each user has been reduced and has been added to the urban area. The prediction map derived from the Markov chain model is very important for providing a general view for better management of natural resources.
Mrs Sara Behvandi, Dr Mohammad Reza Zandmoghadam, Dr Abbas Arghan, Dr Zeinab Kekehabadi,
Volume 20, Issue 56 (3-2020)
Abstract
Today, the huge economic damage of natural hazards, especially of the micro-organisms, to human societies has led the concept of economic sustainability to mitigate the effects of crises to become an important area in crisis management. The purpose of this study was to investigate the role of environmental hazards (effluents) on Ahwaz economy. This research can be considered as a type of applied-development research, and is a descriptive-analytical study in a correlation manner. The population of the study consisted of all residents of Ahwaz, in 1395, there were no more than 1302000 people. The sample size was 384, based on the Cochran formula, and randomly available. To investigate the data, the structural equation path analysis was used in Amos18 software. The results indicated that the microprocesses had an effect on the economy of Ahwaz with a coefficient of 0.31 and a significant level of 0.002. Also, the effect of fiery gradients was 0.73, and the significance level of 0.000 on the tax, the microguns, with the coefficient of influence 0.45 and the significance of 0.000 per facility, the effects of the micrographs with the coefficient of 0.55, and the significance of 0.000 on the housing, With a coefficient of influence of 0.17 and a significant amount of 0.008 on transportation. Accordingly, microblogging has the most impact on finance with a coefficient of 0.73, and transportation with a coefficient of influence of 0.17 has had the least effect.
Mohammad Motamedi, Mohammad Gharavi,
Volume 20, Issue 56 (3-2020)
Abstract
Cities are dramatically turning into complex social, economic, and environmental systems. Each urban system is vulnerable when it can not adapt to its changing conditions and critical situations. Therefore, in recent decades, natural disaster response approaches have introduced a new concept of urban resilience to prepare for disaster as much as possible. Is. Despite the recent attention and the abundant use of the concept of resilience in different areas of theoretical and practical limitations of this concept, this study aims to explain the causal pattern of resilience of cities. The present research is based on the descriptive-causal methodology. The statistical sample of the study was compiled by 35 experts and specialists in urban planning. Fuzzy Dumbled Fan was used to achieve the research goal. The findings of this study showed that based on the values of D-R, among the four metrics of urban resilience, the physical criterion with the value (0.943) was the most effective measure of resilience in the city. Also, based on the D + R values, the physical criterion with the value of (896/2) was identified as the most important resiliency criterion in the city.
Ms Mahboobeh Pouratashi, Dr Mohammad Moradi, Dr Ebrahim Fattahi,
Volume 20, Issue 57 (6-2020)
Abstract
This research aims to study the impact of temperature and wind in the southern low-pressure system and its associated precipitation in the southern regions of Iran. As The southern low pressure system moves eastward, it crosses the southern regions of Iran, causing medium and heavy rainfall in these areas. In this study, two southern low-pressure systems that caused heavy rainfall on March 11, 2015 and January 17, 2000 in southern Iran were selected, analyzed and simulated using the numerical Weather Research and Forecasting (WRF) model. Since the wind and temperature fields play a significant role in the southern low-pressure systems, four experiments were performed for investigating the effects of temperature and wind on the intensification and weakening of the southern system. The simulation results showed that the simulation for the increased (decreased) temperature caused the weakened (intensified) the southern low pressure in the studied area. This result showed that the vertical structure of the southern low-pressure and its physical characteristics are similar to the mid-latitudes cyclones, and these systems were different from the thermal low pressures. The results of wind speed changes showed that the increased (decreased) wind speed simulation caused an increase (decrease) in relative vorticity, thus the southern low pressure was intensified (weakened). In both cases, the rainfall was decreased by the increased temperature simulation, and decreased temperature caused an increase in rainfall. It was also seen that the increase in wind speed caused the special humidity advection to be increased and then the rainfall increased. Also the amount of rainfall decreased when conditions did not provide for the advection of specific humidity or the wind speed reduced.
Mohammad Hossein Nasserzadeh, Zahra Hejazizadeh, Zahra Gholampour, Bohloul Alijani,
Volume 20, Issue 57 (6-2020)
Abstract
The plant community in an area is the most sensitive indicator of climate. A visual comparison of climate and vegetation on a global scale immediately reveals a strong correlation between climatic and vegetation zones and this relationship, of course, are not co-incidental. The main object of this study is to reveal the spatiotemporal association between climatic factors andvegetation Cover (NDVI) incorporate MODIS and TRMM product in Kohkiloyeh O Boirahmad province of Iran. So that the in this paer we use MOD13Q1 of MODIS product as NDVI layer for study area. MOD11A2 as landsurface temperature and 3B43 TRMM as meanmonthly accumulative rainfall for study area during 2002 to 2012 in 0.25° spatial resolution also were used as climatic factors. We use the correlation and cross-correlation analysis in 0.95 confident level(P_value =0.05) to detection the spatial and temporal association between the NDVI and 2 climatic Factor(LST and rainfall). The results indicated that during winter (December to March) the spatial distribution of NDVI is highly correlated with LST spatial distribution. In these months the pixels which have the high value of NDVI are spatiallyassociated with the pixels which have highest value of LST (6 to 14C°).As can be seen in table 1. Season the spatial correlation among NDVI and LST is so high which is statistical significant in 0.99 confident level in winter. In transient months such as May, October and November,(temperate months in study region ) the spatial correlation among NDVI and LST is falling to 0.30 to 0.35 which is not statistical significant in 0.95 confident level. Finally in summer season or warm months including Jun to September, we found the minimum spatial association among the NDVI and LST.. In temporal aspect we found that the maximum correlation between NDVI and LST simultaneously appears and not whit lag time. The spatial correlation of NDVI and TRMM monthly accumulative rainfall was statistical significant in spring season (April to Jun) by 1 month lag time in remain months we don’t find any significant correlation between NDVI and rainfall.
