Evaluation and improvement of uncertainties in Ahvaz radar data with emphasis on Z-R relationship calibration

Authors

1 Faculty of Water Sciences Engineering, Shahid Chamran University of Ahvaz

2 PhD student of Faculty of Water Sciences Engineering, Shahid Chamran University of Ahvaz

3 Faculty of Engineering, Jondishapour University of Dezful

Abstract

Weather radar can potentially provide suitable high-resolution spatial and temporal rainfall estimation. Radars do not measure rainfall intensity directly and the reflectivity must be converted to rainfall intensity using some form of transfer function. This transfer function is commonly referred to as the Z-R relationship and it is assumed to be a power law written in the form Z = aRb. In this study, different optimization approaches were used to find suitable climatological Z-R relationships and minimum radar antenna elevation angle for Ahvaz radar station. The radar data between 2007 and 2012, together with the storm, daily and mean daily rainfall depths at Twenty five rainfall stations during the same periods and topographical data in GIS system were used. Based on the statistical result of different calibration approaches, climatological Z-R relationships in the forms Z = 166R 2 (for storm), Z = 165R 17 (for mean daily rainfall) and Z = 166R 2 (for daily rainfall) have acceptable statistical indicators for radar rainfall prediction. In addition, the angle 0.446 is suitable radar antenna elevation angle to remove Ground clutter and beam blocking for Ahvaz radar.
 

Keywords


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