Climatology
Jaber Soltani; masoud ahmadi nik; Ahmad Ahmadinik
Volume 23, Issue 69 , December 2019, , Pages 127-147
Abstract
Reference evapotranspiration is one of the necessary parameters to determine crop water requirements and irrigation planning. Having accurate estimates of this parameter is essential for planning and managing of water resources. Several experimental models have been proposed to estimate evapotranspiration. ...
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Reference evapotranspiration is one of the necessary parameters to determine crop water requirements and irrigation planning. Having accurate estimates of this parameter is essential for planning and managing of water resources. Several experimental models have been proposed to estimate evapotranspiration. According to the spatial variability of climatic parameters, using remote sensing method that considers these changes is very favorable. Among the most widely used models that accurately estimate evapotranspiration using remote sensing, can be mentioned wavelet model. In this regard, the purpose of present study is to evaluate the accuracy of wavelet models to estimate the reference evapotranspiration using parameters derived from satellite images contains the Earth's surface temperature and amount of water vapor in the atmosphere. In this study, used atmospheric and satellite images data of four station contains Anar, Kerman, Rafsanjan and Shahrebabak to develop and evaluate wavelet models. In the first scenario, temperature, in the second scenario, atmosphere water vapor parameter and in third scenario, both parameters simultaneously was used as the model input. Results of this study showed that despite the high accuracy of models in different scenarios, the wavelet model use two-parameters, temperature and steam simultaneously (third scenario), with a coefficient of 90% compared to other models had the more accurate.
Climatology
Batool Zeinali; Sayyad Asghari
Volume 22, Issue 65 , November 2018, , Pages 205-222
Abstract
Purposes of this research are introduction acceptable index for detection of dust storms and also identifying sources and pathways affected by this phenomenon in the East of Iran by studying a the dust storm using MODIS satellite images. For this purpose were used dust storm hourly data, satellite images ...
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Purposes of this research are introduction acceptable index for detection of dust storms and also identifying sources and pathways affected by this phenomenon in the East of Iran by studying a the dust storm using MODIS satellite images. For this purpose were used dust storm hourly data, satellite images of Modis and also digital and visual indexes including NDDI, BTDI, BTD, LRDI and false color composing for identifying dust storms. Finally, the studied dust storms were monitored using satellite images. Results indicated that LRDI index and false color composing have the higher resolution than the other indexes for detection of dust storms. Results monitoring dust storm event in the eastern Iran in summer indicated that storms sources of east area are dry beds of Hamoon lakes, Rigistan, Margo and Khas deserts at the convergence of the borders of Iran, Afghanistan and Pakistan and central Iran. The results of this research can be used in identifying of dust sources and pathways affected from this phenomenon by organizations and institutions to national and international planning.
