ارزيابي بيابانزايي در شرق اصفهان با استفاده از مدل مدالوس

چكيده انگليسي :

Desertification Evaluation with MEDALUS Models in East of Isfahan Ali Khanamani khanamani@gmail com Department of Natural Resources Isfahan University of Technology IsfahanDegree M Sc Language FarsiSupervisor R Jafari Reza jafari@cc iut ac ir H R Karimzadeh H Karimzadeh@cc iut ac ir AbstractDesertification is one of the most important challenges of this century This problem can be seennot only in arid and semi arid areas but in some areas of dry semi humid At presentdesertification as a problem is involved many countries including developing countries Desertification process is related to natural factors and incorrect human performances Thepurpose of this study is to assess the current status of desertification in south and east vast plainsof Segzi in Isfahan province Study area covers 112167 ha and south boundary of region islimited to Zayanderud River In present study Medalus model is used for assessment of thedesertification process For this purpose the six major criteria including status of vegetation climate soil ground water erosion water and wind and the management and policies are used Each criterion involves numerous indices so that the plant covers Criterion is including fourindexes percentage of plant cover range condition trend conservation against erosion andresistance against drought The climate Criterion is including three indexes precipitation potential of evapotranspiration and aridity index the soil Criterion is including eleven indexes soil pH electrical conductivity EC percentage of organic matter percentage of soil gypsum percentage of soil chloral content of soil sodium soil texture content of soil HCO3 sodiumabsorption ratio SAR content of calcium and Mg and percentage of soil saturation moisture ground water Criterion is including seven indexes content of chloral content of calcium contentof HCO3 ground water pH ground water electrical conductivity EC sodium absorption ratio SAR and TDS and erosion Criterion is including two indexes PSIAC class and IRIFR class Inorder to investigate of management criterion lands are firstly divided into three parts of range mine and agricultural lands and the management situation is evaluated in each part For eachindex an information layer is firstly produced Then with geometric mean of these layers eachcriterion layer is obtained In continue after calculation of the geometric mean of criteria layers final map including current situation of desertification is produced The results indicate that 81299ha of the area are placed at sever class and 30868 ha at very sever desertification class Most ofthese areas are related to the north and central part of the region including bare lands withinappropriate management The study area is located in the sever class of desertification fromclimate criterion and also in three classes of medium severe and very severe class ofdesertification form soil and vegetation point of view Form ground water and erosions water andwind criteria the study area is located in two classes of severe and very severs class ofdesertification and management criterion is also located in the severe class of desertification Theresults also reveal that in study area climate and vegetation criteria have the most effects andgroundwater and erosion criteria the least effect on desertification The most important criteria inpresent study include Climate vegetation management and policy soil groundwater and erosioncriteria respectively Key Words Desertification MEDALUS model Criteria Index Isfahan Segzi plain

خناماني، علي

ارزيابي بيابانزايي در شرق اصفهان با استفاده از مدل مدالوس

معيار , شاخص , دشت سگزي اصفهان