4390

4138

كارشناسي ارشد

آبياري و زهكشي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1387

نه، 87، [II]ص.: مصور، جدول، نمودار

ص.ع. به: فارسي و انگليسي

سعيد اسلاميان، جهانگير عابدي كوپايي

صفيه محمودي، اسماعيل لندي

24/12/87

فرهاد موسوي، پرويز احسان زاده

مهندسي كشاورزي

ID4138

به فارسي و انگليسي: قابل رؤيت در نسخه ديجيتال

Abstract Considering the increasing impacts of human on the enhancement of greenhouse gases and hence global warming much attention has been paid to the studies on climate change in the developed countriesduring recent decades Atmospheric carbon dioxide levels have been recorded continual increases sincethe 1950s a phenomenon that may significantly alter the global and local climate characteristics such astemperature and available water resources Increases in carbon dioxide and other greenhouse gases in theatmosphere have caused global temperatures to rise by an average of 1 F over the past century Thisglobal warming has resulted mainly from human activities such as the combustion of fossil fuels anddeforestation Global temperatures are expected to rise more this century as emissions of heat trappinggases continue to mount While the impacts of climate change will vary from region to region it s clearthat almost every place on the planet will be affected For assessing and detecting climatic changes assessment of sensitive parameters in evapotranspiration calculating can be suitable selection which affectclimate condition and climate change In Iran as an arid and semi arid country around 93 5 of the totalwater resources has been used for agriculture purposes therefore changes in climatic regimes may affectthe agricultural water demands because evapotranspiration may be affected by the changes inmeteorological variables e g temperature solar radiation wind speed and relative humidity In thisstudy were used fifty four year monthly records of temperature relative humidity sunshine duration wind speed and precipitation depth from 1951 to 2005 in five climatologically different regions of Iran The regions include Tehran Esfahan Shiraz Tabriz and Mashhad The monthly evapotranspiration werecalculated by Penman Monteith formula in these regions and were comprised with lysimeter data forestimating of Penman Monteith precision and found it as a good result A sensitivity analysis ofmeteorological variables was carried out using Penman Monteith formula Temperature wind speed andrelative humidity were achieved as sensitive parameters Then trend and persistence analyses of sensitiveparameters and precipitation depth were performed using the Mann Kendall test the CumulativeDeviation test Linear Regression and the Autocorrelation Coefficient The results indicated relativehumidity in Esfahan Shiraz Tabriz and Mashhad and also wind speed in Tehran Esfahan and Shirazhave the significant and stable trends such that they decrease In Mashhad temperature increases and inTabriz precipitation depth decreases with the significant trends also By the way homogeneity normality and randomness tests were performed by Mann Whitney test Kolmogorov Smirnov test and Run test The aim of analyzing time series is determination of long term behavior of observation data findingchanges model to use for engineering designs and other projects Key WordsPenman Monteith evapotranspiration Mann Kendall test Cumulative Deviation test Autocorrelation Coefficient Climate Change

سعيد اسلاميان، جهانگير عابدي كوپايي

صفيه محمودي، اسماعيل لندي

فرهاد موسوي، پرويز احسان زاده