Development of a new method for recognition of Iran deserts based on climatological criteria
Mohamad khosroshahi :Research institute of forest and rangelands. Tehran. Iran. P.O.box:13185-116, Email: khosro@rifr-ac.ir http://khosromk.blogfa.com
Majid hosseini: research center of natural resources, Tehran, Iran. Mjhosseini@hotmail.com
Aziz karami: research center of natural resources, Tehran, Iran.
Abstract:
Desert and desertification is one of the climate change causes. Usually;desert areas are increasing yearly duo to climate change and human activities. Currently the extent of desert areas has not been recognition based on a proper and scientific criteria .
In this paper we conducted to identify desert regions from nonedesert based on some suitable climatological parameters in Tehran province. In order to carry out this project, we selected 34 meteorological stations in Tehran province and their spatial distribution were determined using GIS technology. The climatological indices used to segregate desert from nonedesert were;precipitation rate, coefficient of variation, daily mean intensity & irregularity factor of precipitation and mean temperature & evaporation. For each climatological index we prepared an isomap using mentioned criteria. Interface between mountainous and plain was selected as base line index in separate desert from nonedesert area. The 6 different layers were overlaid and compared with natural physiography of land. The final map make it possible to identify a strip boundary located in that interface, between plain and mountain. It is concluded that, regions based on this strip, three zones were formed, which called desert(inside zone), semidesert(middle zone) and nonedesert(outside zone). In semidesert area climatological characteristics were common both with two others regions located both side of boundary strip.
Key word:desert, desertification, climatology, climate change, GIS, Tehran province.
Majid hosseini: research center of natural resources, Tehran, Iran. Mjhosseini@hotmail.com
Aziz karami: research center of natural resources, Tehran, Iran.
Abstract:
Desert and desertification is one of the climate change causes. Usually;desert areas are increasing yearly duo to climate change and human activities. Currently the extent of desert areas has not been recognition based on a proper and scientific criteria .
In this paper we conducted to identify desert regions from nonedesert based on some suitable climatological parameters in Tehran province. In order to carry out this project, we selected 34 meteorological stations in Tehran province and their spatial distribution were determined using GIS technology. The climatological indices used to segregate desert from nonedesert were;precipitation rate, coefficient of variation, daily mean intensity & irregularity factor of precipitation and mean temperature & evaporation. For each climatological index we prepared an isomap using mentioned criteria. Interface between mountainous and plain was selected as base line index in separate desert from nonedesert area. The 6 different layers were overlaid and compared with natural physiography of land. The final map make it possible to identify a strip boundary located in that interface, between plain and mountain. It is concluded that, regions based on this strip, three zones were formed, which called desert(inside zone), semidesert(middle zone) and nonedesert(outside zone). In semidesert area climatological characteristics were common both with two others regions located both side of boundary strip.
Key word:desert, desertification, climatology, climate change, GIS, Tehran province.
posted by khosroshahi | 3:54 AM
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