علوم و مهندسی آبیاری (Apr 2018)
An Algorithm for Selecting the Effective Distance of the Wind Shelter to Verify the Wind Shelter Status at the Lake Level of Dams (Case Study: Lake of Dez Reservoir Dam)
Abstract
To calculate the wind shelter index (Sx) for points in a region, the wind shelter index values are calculated for each set of points in different lengths and directions. Among these lengths, the length of the Sx corresponding to it has the highest wind shelter and is known as an effective length. Winstral et al. (2002), Winstral and Marks (2002), Erickson et al. (2005), Molotch et al. (2005), Molotch and Bales (2006), Sharifi et al. (2007), Litaor et al. (2008), Tabari et al. (2009) and Maroufi el al. (2010) in order to determine the effective length in snowy areas inevitably used the correlation of Sx values for each desired length and depth of snow. Winstral et al. (2009) in study of wind speed distribution methods determined the effective length by establishing the relationship between the difference in the values of the Sx and the difference in the velocity of the wind. Farokhzadeh et al. (2014) also succeeded in determining the effective length by examining the correlation between a parameter named average wind shelter slope and Sx, provided that the selected points were in wind conditions. Therefore, due to the limitation in the method proposed by Farokhzadeh et al. (2014) for calculating the Sx in non-snow areas such as lake levels, the use of a specific type of algorithm for determining the effective wind shelter length seems necessary (Shahi, 2017). Therefore, in this study, according to the existing conditions, a method was proposed for selecting the effective length of the shelter.
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