Improvement of Accuracy of Runoff Estimation by using XRAIN(X-band polarimetric multi parameter Radar Information Network)

Abstract

X-band Multi Parameter radars (XMP) have been installed quickly in Japan in purpose of heavy rain disaster prevention around metropolitan area. XMP have an advantage in observational accuracy over conventional C-band radars. So they are expected to provide accurate rain fall information which improves the accuracy of runoff model about flood prevention around mountainous areas. In this study we examined to apply rain amount observed by XMP to a distributed rainfall-runoff model to analysis typhoon runoff. XMP showed good accuracy in comparison of ground rain gauge especially the area near radar sites but the results of runoff analysis was underestimated by attenuation. The method to correct low accuracy areas due to attenuation in XMP by C-band radars are proposed.