International Journal of Computing Science and Applied Mathematics
Vol 5, No 2 (2019)

Error Modeling Radar Rainfall Estimation Through Incorporating Rain Gauge Data Over Upper Blue Nile Basin, Ethiopia

Megbar Wondie Birhan (Washera Geospace and Radar Science Laboratory, Department of Physics, Science College, Bahir Dar University, Bahir Dar, Ethiopia)
U. Jaya Prakash Raju (Washera Geospace and Radar Science Laboratory, Department of Physics, Science College, Bahir Dar University, Bahir Dar, Ethiopia)
Samuel T. Kenea (Climate Research Division, National Institute of Meteorological Sciences (NIMS), Jeju-do, Republic of Korea)



Article Info

Publish Date
17 Aug 2019

Abstract

Accurate and precise measurements of rainfall from weather radar reflectivity data is essential to supplement the limited characterization of spatial and temporal measurements provided by insufficient network and density of rain gauges. While weather radar has high spatial and temporal resolution, it contaminated with various sources of errors due to the conversion of reflectivity to rain rate and the projectile rainfall motion. Error modeling improvement with the application of projectile rainfall motion correction is essential to improve the radar data. However, stile is not well documented for over the world as well as Ethiopia. Therefore, the aim of this study was to generate an error model for weather radar rainfall estimation by incorporating gauge rainfall data over upper Blue Nile basin, Ethiopia. Projectile rainfall motion correction is considered on the data of reflectivity and rain rate to determine empirical error model parameter values. The model parameter values are found, multiplicative factor (a) was 55, the exponent factor (b) was 1.12, standard deviation of proportional error was 0.08 and standard deviation of random error was 0.07. The value of the total error varied from -0.45 to 1.16 mm and the domain of proportional error was greater than random error. After applying the projectile rainfall motion correction, the total error is reduced by 12%. In general, the assumption of projectile method is quite useful for improving the radar data over upper Blue Nile basin in Ethiopia as well as over the world. Hence, we wish to extend this method for other regions.

Copyrights © 2019






Journal Info

Abbrev

ijcsam

Publisher

Subject

Computer Science & IT Education Mathematics

Description

(IJCSAM) International Journal of Computing Science and Applied Mathematics is an open access journal publishing advanced results in the fields of computations, science and applied mathematics, as mentioned explicitly in the scope of the journal. The journal is geared towards dissemination of ...