5797

5412

كارشناسي ارشد

مرتعداري

اصفهان: دانشگاه صنعتي اصفهان، دانشكده منابع طبيعي

1389

چهارده،110ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

سيد جمال الدين خواجه الدين

سعيد سلطاني، رضا جعفري

31/1/90

عليرضا سفيانيان، مرتضي خداقلي

1396/07/05

كتابنامه

مهندسي منابع طبيعي

ID5412

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Monitoring Drought Using Satellite Data With Emphasis on Vegetation Cover in Semirom Isfahan Region Somayyeh Jabbari s jabbari 62@yahoo com Date of Submission Mar 14 2011 Department of Natural Resource Isfahan university of technology Isfahan 8415683111 Iran Degree M Sc Language Farsi Supervisor Sayed jamaledin Khajedin Khajedin@cc iut ac ir Abstract Drought is natural and complex phenomenon which happens everywhere Its occurrences have always followed by huge damage Considering its damage figures and statistics the drought d studying and monitoring is necessities confirmed During recent years our country Iran was faced by many drought events which have damaged the natural resources which cannot be compensated therefore studying drought is essential for researches and managers The purpose of this study is Monitoring drought using satellite data with emphasis on vegetation cover in Semirom region TM WiFS and AWiFS satellite images of 1996 2004 and 2009 were used respectively In order to perform the studying purpose the field data were collected during the may 2009 simultaneously with AWiFS data acquisition data Then considering the environmental factors such as altitude slope direction climatic factors and vegetation indices derived from above satellite data multiple regression equations were prepared using step wise regression analysis The intended regression model for each year were used to produce percentage vegetation cover of the study area For a suitable pasture vegetation map interpretation to split the vegetation cover classes the density slicing method were applied and suitable thresholds were confirmed to determine rangeland vegetation cover classes including 0 20 20 30 and 30 40 percent canopy cover The classes changes were linked to each other while decreasing a class caused the other classes increasing Studying the three year classified maps stated that the 30 40 and 20 30 classes have change the most respectively Whereas decreasing these two classes areas caused the 0 20 vegetation cover class increasing Studying the produce maps information along with altitude and slope confirmed that the pasture with vegetation cover classes 20 30 and 30 40 are located on higher altitude with gentle slopes With a comprehensive regression model such as the obtained model in the percent study calculating the dependent variable such as vegetation cover percentage changes according to rainfall is possible through independent variable The dependent variable in this study is pasture vegetation cover and first of all the rain amount in the most effective variable on vegetation cover annually changes so if we consider that management factor is constant even if it is a mismanaged system then one can monitor the drought vegetation cover changes using satellite data In order to a better and more precisely vegetation mapping and introducing suitable classification for drought monitoring a longer period of precipitation data is needed and which at least two dry periods and two wet years should be included in the data set Keyword Drought monitoring Satellite data Semirom The sensors TM WiFS and AWiFS

سيد جمال الدين خواجه الدين

سعيد سلطاني، رضا جعفري

عليرضا سفيانيان، مرتضي خداقلي