Mohammad Fallah Zazuli; Alireza Vafaeinezhad; Mir Masoud Kheirkhah Zarkesh; Fariborz Ahmadi Dehka
Abstract
Dusthazephenomenon in the recent decadeis one of the most important environmental challenges in Iran, West and Southwest Asia.This phenomenon is one of the processes of desertification occurring in arid and semi-arid regions of the world. Remote sensing is thescience and technique for the acquisition ...
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Dusthazephenomenon in the recent decadeis one of the most important environmental challenges in Iran, West and Southwest Asia.This phenomenon is one of the processes of desertification occurring in arid and semi-arid regions of the world. Remote sensing is thescience and technique for the acquisition of information from geographic phenomena without any contact with them.Todetectthephenomenonofdusthaze,large-scaleimagesare needed withwidecoverageandhighfrequency. Therefore,theimagesrelatedtoMODISsensoraresuitablefor thestudies on thephenomenon of dusthazeduetothe presence of highspectralbands. Detection of the generating origin or the source of dust haze particles and its quick monitoring with accuracy and low cost is of great importance. The main objectives of this research are to identify the generating source of dust haze entering the West and Southwest regions of Iran and to monitor the movement of dust haze as well. In this research, the occurrence origin of dust haze phenomenon is related to June 18, 2012 which occurred in the Western and Southwestern parts of the country, and was identified with the help of satellite images and by using visible and thermal bands of MODIS sensor and usingthe Ackerman index.It was found out that, its main origin was the point where Tigris and Euphrates rivers meet, which is within the northern and northeastern parts of Iraq and western Syria, and It was further found that the images of the MODIS sensor are suitable for dust haze monitoring due to its availability, low cost, and its repeatability in 2 periods of time within 24 hours. Also, its synoptic analysis to detect the movement of dust haze from the source into Iran was investigated using 500 hectopascal level synoptic data of geopotential height, sea level pressure and the wind current direction maps of 500 and 1000 hectopascals. The results of the synoptic analysis have optimized the origin detection and the way of dust haze transmission, and makes it more appropriate to predict the path of the dust haze motion. Finally, its movement demonstration from the source into Iran was trackedby the use of GIS and Spatial Analysis Tools. Dusthazephenomenon in the recent decadeis one of the most important environmental challenges in Iran, West and Southwest Asia.This phenomenon is one of the processes of desertification occurring in arid and semi-arid regions of the world. Remote sensing is thescience and technique for the acquisition of information from geographic phenomena without any contact with them.Todetectthephenomenonofdusthaze,large-scaleimagesare needed withwidecoverageandhighfrequency. Therefore,theimagesrelatedtoMODISsensoraresuitablefor thestudies on thephenomenon of dusthazeduetothe presence of highspectralbands. Detection of the generating origin or the source of dust haze particles and its quick monitoring with accuracy and low cost is of great importance. The main objectives of this research are to identify the generating source of dust haze entering the West and Southwest regions of Iran and to monitor the movement of dust haze as well. In this research, the occurrence origin of dust haze phenomenon is related to June 18, 2012 which occurred in the Western and Southwestern parts of the country, and was identified with the help of satellite images and by using visible and thermal bands of MODIS sensor and usingthe Ackerman index.It was found out that, its main origin was the point where Tigris and Euphrates rivers meet, which is within the northern and northeastern parts of Iraq and western Syria, and It was further found that the images of the MODIS sensor are suitable for dust haze monitoring due to its availability, low cost, and its repeatability in 2 periods of time within 24 hours. Also, its synoptic analysis to detect the movement of dust haze from the source into Iran was investigated using 500 hectopascal level synoptic data of geopotential height, sea level pressure and the wind current direction maps of 500 and 1000 hectopascals. The results of the synoptic analysis have optimized the origin detection and the way of dust haze transmission, and makes it more appropriate to predict the path of the dust haze motion. Finally, its movement demonstration from the source into Iran was trackedby the use of GIS and Spatial Analysis Tools.
Marzieh Khanahmadi; Mahdi Arabi; Alireza Vafaienejad; Hani Rezaiean
Volume 23, Issue 89 , May 2014, , Pages 88-98
Abstract
Constructing new urban facilities needs a precise investigation on the right method of establishing such facilities in different areas of the city. Selecting an optimal place based on different and sometimes controversial characteristics is the first fundamental issue in correct allocation of urban facilities. ...
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Constructing new urban facilities needs a precise investigation on the right method of establishing such facilities in different areas of the city. Selecting an optimal place based on different and sometimes controversial characteristics is the first fundamental issue in correct allocation of urban facilities. This is especially important if crucial issues like human life are also considered. Thus due to the importance of endangered human lives, optimal selection of fire stations is considered to be crucial. Considering the uncertainty about information sufficiency and comprehensiveness of inferences drawn by tools like spatial information system, fuzzy model is used in combination with analytic hierarchy process. In the beginning step of the study, influential factors in locating fire stations were determined and standard maps were produced and prepared. During the study, a survey performed on the experts opinions indicated that these criteria do not have the same influence in locating stations. Thus, these criteria should be assigned different weights based on their importance and influence. Analytic hierarchy process (AHP) and Export choice software were used to weight these criteria. After collecting expert opinions and in order to avoid possible non-expert opinions, adaptability of the judgments were calculated. After verifying CR values, these weights were used in subsequent steps. In the next step, fuzzy logic was used to rate these layers. Prepared layers were transformed into fuzzy logics using different membership functions which were selected according to experts’ opinion. Finally, AHP and weighted linear combination (WLC) were used to integrate fuzzy criteria with fuzzy membership functions and calculated weights, and in this way appropriate zones for building fire stations were identified and determined. Simply relying on the map results cannot have the necessary efficiency in locating an optimal place for the fire stations. Therefore, standard functional radius of available stations were determined using network analysis in GIS environment. Then, places with a high score for building stations and those covering whole area in a standard time were selected. This research seeks to display the efficiency of applying integrative logic for ranking layers using AHP in GIS environment. The integrated model benefits from high capabilities and it can be applied for different goals (selecting the optimal place for a site) and in different spatial situations.
