Document Type : Research Paper
Professor, Management and programing of Environment, Faculty of Environment, University of Tehran,Tehran, Iran
Engineering Geology M.D Student, Tehran OLOM TAHGHIGHAT University
Geographic College Professor, Tehran University
The process of urbanism in countries that are developing, like Islamic Republic of Iran with increasing of the number and the size of cities and the fast accepting of population have been caused the forming of problems like an in-official economics and in-official settlement and was become creating high population in main and old places of city and increasing of air pollution and the kinds atmospheric pollutants in cities. (Pazhouhian and Morad Hasel, 1386). The most atmospheric pollution of big cities of Iran have direct relating between kind and the rate of the pollutants with density blocks of population in crowded places and full of population in term of the period of time and a place have geographic aspects. Every phenomenon of air pollution is in term of density and kind of the coordination pollutant have specific place and time.
In this study has been used density classification method for studying relation between population and quantity & kind of atmospheric pollution in the big city of Kermanshah base on estimating number of population and calculating pollution in statistical block that are include 62 statistical point sample with determining rate of quantity of populations and geographic coordination studied place by using universal finding coordinate system (GPS). Statistical populations of ready research are include quantity of populations and quantity & kind of pollution that time period is 7 day in the suburb of Kermanshah big city.
Using geographical information system (GIS) has high usage as a main tool for geographic analyze to recognize existence law on relation between human and environment. Using by geographical information system (GIS) in studying and analyzing space-place distribution of pollutant area with quantity and kind of air pollutions, started in 1970. There will be possible to provide the place data station, order, space show of pollution data, assimilate data and space analyze by using of the facilities and technique of this system. Preparing place data station about parameters as a kind of pollutants and determining geographical coordinate workshop and factories and busy population place and quantity of air pollution and usable managing possibility for interring, saving, updating and taking data with speed and high quality are main ability of geographical information system technology. GIS central of Tehran municipality, 1384.
Using geographical information system (GIS) with the decision support system (MCDM) can be used effectively in scanning and managing of atmospheric pollutions data for studying place distribution of differential pollutants and evaluations trend rate of pollutant quantity as an environmental decision support system (EDSS) in controlling and intelligent managing of critical pollution in the big city specially Kermanshah city.
Cheraghi in research with “studying an comparing of air quality in Tehran and Isfahan cites offer ways to improve” topic of working in 1387. He concluded that the most pollutions are in Khordad, Sharivar, Aban, Bahman months in Tehran and also is Khordad in Isfahan. Also, in this study showed that 60 percent of days have been above standard index. Ardakani & Cheraghi in research with “sanitary quality evaluation of Tehran air with air quality index to measured station of air pollution separately” topic showed air quality of Tehran city has been increased above standard limit that determined by EPA for 261 days in 1385. Mousavi, in a study entitle, A Comparative study of air quality in Tehran since 1376 to 1377 concluded in 1376 that air quality in 32 percent of the days have been were insanitary description and 5 percent of days have been were very insanitary. While in this cases have been increased 34 and 6 percent.
United States Environmental Protection Agency EPA, selected 6 main pollutions as criteria and divided to 2 primary and secondary categories. Primary pollutions are substances that inter directly from sources into the ambient air and included five pollutants that are carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter with diameter less than 10 microns (PM-10) and lead (pb). Secondary pollutants refer to material that produced by interactions in the air surrounding ground and in this category can be named by ozone (O3).
The air pollution index
One of the widest of used index for reporting and comparing the air pollutant is PSI index (Pollutant Standard Index) that has been developed by the Environmental Protection Agency of America (ESI). The index is calculated based on measuring concentrations of five major air pollutants (CO, PM10, O3, SO2, NO2) and it is possible to convert PSI index.
Materials and tools have been used in the research include:
Maps of (a population density map with scale 1: 25000, highways and streets maps, prevailing wind direction maps, preparing DEM), determining geographical coordinate of studied urban place (statistical samples) with GIS
The software used includes: Office/ Excel, Arcview, Gis and lateral Software as Crime Analysis and Case
Statistical data and population data
Process of in this study involves the following steps are:
First stage: the studying of the library for previous researches, characteristics of pollutants, the evaluating of layers by GIS.
Second stage: collecting and entering data and statistical data and coordination and elevation points, extra separately in Excel software (Excel) with dbf format that have been stored in separated columns.
Third stage: calling data and statistical tables on the Case and Crime Analysis software
Forth stage: determining place coordinate of air pollution measured stations, recognizing major pollutant point of city, direction and kind of pollutants distribution are in the city surface base on kind of pollutant scene of height and density of pollutant, determining air pollutant index as kind and quality of air in emergencies and crises time to (digital layers) format in the Arc GIS software.
Step five: preparing of digital maps and graded class of the effected parameters in the production and distribution of pollutants.
Materials and methods of research
Research base has been used density classification method on bill of population amount and pollutants measuring on the statistical blocks that included 62 statistical point samples with geographical coordination by universal finding coordinate system (GPS) for studying about relation between population to amount and kind of pollutants in the big city of Kermanshah. Statistical population prepared research are collection of population amount and pollution quality and kind of pollution that are collected for 7 days period in the big city of Kermanshah. The basic tests that used are median center tests, distance from standard deviation and ellipse of standard deviation. And near neighbor index has been used for identifying polluted the quantity of air pollution is between clustering tests. By using geographical information system (GIS) and universal finding coordinate system and pollutant measuring tools and Case & Crime Analysis software can be recognize the place of pollutants amount of pollutants in the big city of Kermanshah.
Statistical methods of basic graphic
The first group of analysis method of place is basic graphic statistical methods that by quality attention to center and space distribution of pollutants recognize in the geographical suburb of the big city of Kermanshah. Standard deviation Ellipse and median center point are comprehensive statistical test. Median center point can be used as an approximate index for comparing of space distribution of pollutants place or study about kind of specific pollutant periods of time.
In other word, the median center has been determined central location to basic average of all of forms contaminated sites. Standard deviation Ellipse has been showed dispersion levels of the places air pollution.
Median center and standard deviation ellipses
The median center of the polluted sites (air pollution) is based on five major air pollutants (CO, PM10, O3, SO2, NO2) of Kermanshah city that are located on Azadi Square, across the Shahid Beheshti boulevard from the 22 Bahman tree ways to Sepah square, Modaress Crossroad to Aiatollah Kashani square, Shahid Ashke Talkh street to end of Jalili street, the suburb of Azadegan square. Ellipse standard deviation shows pollutants distributional area of Kermanshah that has a stretch from north to south.
Kernel density estimates test
Kernel density estimate test is one of suitable methods for drawing statistical data and analytical-definitions as the smooth surface in the geographic areas. Kernel density estimates test make smooth surface of data density changes as amount and kind of pollutants in the site. This calculation was done in geographic information system by Arc GIS software based on mentioned methods and for recognizing centers of air pollutant in Kermanshah city.
Analytical method for Kernel test is other way for space analyzing of air pollutant of places in cities. In this method, relation between quantity and kinds of pollutants to density of population is measured in geographic unit with specified dimensions.
Results show, the emission of 5 atmospheric pollutants follow clustered patterns in Kermanshah. Geographical distribution average center of air pollutant point are coordinate toward city center (Nawab three ways to Kashani Square). Also, ellipse standard deviation of the pollution has been stretched in the North West, South East. Closer look at the standard ellipse of distribution is showing more stretch directed toward South East. The nearest neighbor index of statistical test has been used to determine the random distribution or clustering of Atmospheric pollutants emission in prepared research. Quantity of the nearest neighbor index in the distribution of pollutant points are equal too.
Table 1. The amount and kind of atmospheric pollution in the city of Kermanshah
Kind of air pollutant
Quantity of air pollutant
Source: the authors
The distribution quantity of atmospheric pollution with 5 pollutants (CO, PM10, O3, SO2, NO2), of insufficient fuels of petrochemical industries have clustery distribution of the statistical form because when the result of the nearest neighbor index test was smaller than one that’s show measured information’s has cluster pattern in polluted place of city.
Also, Kernel density method that’s more suitable method to draw geographical statistical data specially on time and location coordinating continued data was used for determining and analyzing characterizes of 5 pollutants (CO, PM10, O3, SO2, NO2) as amount and direction of distribution in the Kermanshah. It was determined base on this method that major concentrated atmospheric pollutants of place (center) result of industrial cars of fuel are being according to Azadi Square, across the Shahid Beheshti boulevard from the 22 Bahman three ways to Sepah square, Modarres crossroad to Aiatollah Kashani square, Shahid Ashke Talkh street to end of Jalili street, suburb of Azadegan square, determined by this method. Too, main centers of 2 inferior center is located in Moalem and Elahieh the small towns in Kermanshah.