8250

7648

كارشناسي ارشد

بيابان زدايي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده منابع طبيعي

1392

پانزده،184ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

حميدرضا كريم زاده، رضا جعفري

حميدرضا پاكزاد

19/9/92

سعيد سلطاني، حسين بشري

مهندسي منابع طبيعي

ID7648

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Impact of Gavkhouni international wetland drying on desertification process Abstract Wetlands are important ecosystems which have mostly been dried due to inappropriate management In drying process wetlands are converted into desert like conditions in long term This research has studied the effect of Gavkhouni international wetland drying on desertification processing the east of Isfahan province Land use cover maps of the study area including water surface bare land salty land and vegetation over were produced using MSS 1976 ETM 2006 and TM 2011 Landsat images and maximum likelihood supervised classification technique In this study also MEDALUS method was used to map spatial distribution of desertification based on six indices of soil indicator surface gravel electrical conductivity organic material soil texture sodium absorption ratio and soil depth and three indices of climate indicator rainfall evaporation and aridity index The threshold speed of wind erosion and the shear strength of soil were also determined with Wilcanov method and pneunometer in the region Results of image classification showed that the area of four land use cover has changed from 468 01 km2 to 0 39 km2 from 5168 54 km2 to 5478 45 km2 from 205 05 km2 to 368 42 km2 and from 84 16 to 78 5 km2 respectively in 36 years According to the classification maps most of the wetland has been dried therefore nine soil profiles from mountain to playa units and climate indicator were used and analyzed for determining desertification condition in the northeast part of the wetland Results indicated that the profile 1 classified as low desertification class profile 2 as moderate class profile 3 as severe class and profiles 4 8 as very sever class The threshold speed of wind erosion and shear strength of soil also showed a decreasing trend along the transectfrom mountain to playa which indicates that with drying up the Gavkhouni international wetland it can be an important dust source at provincial and national levels Keywords Gavkhouni wetland soil properties soil shear strength wind threshold speed MEDALUS model satellite data PDF created with pdfFactory trial version www pdffactory com

حميدرضا كريم زاده، رضا جعفري

حميدرضا پاكزاد

سعيد سلطاني، حسين بشري