A regional hourly maximum rainfall extraction method for part of Upper Blue Nile Basin, Ethiopia
Book Chapter
Alem, AM, Tilahun, SA, Moges, MA et al. (2019). A regional hourly maximum rainfall extraction method for part of Upper Blue Nile Basin, Ethiopia
. 93-102. 10.1016/B978-0-12-815998-9.00009-9
Alem, AM, Tilahun, SA, Moges, MA et al. (2019). A regional hourly maximum rainfall extraction method for part of Upper Blue Nile Basin, Ethiopia
. 93-102. 10.1016/B978-0-12-815998-9.00009-9
This chapter discusses an extraction method of hourly maximum rainfall from daily maximum rainfall data in part of Upper Blue Nile basin. A regional growth curve with site-specific quantiles of hourly maximum rainfall is also developed. The extracting method was developed using four hourly and 162 daily recording stations in the basin. Regionalization was carried out by clustering analysis with an input of latitude, longitude, elevation, and mean annual rainfall. The grouped stations were evaluated with discordant measure. Regional homogeneity of the stations was tested by heterogeneity measures using daily maximum rainfall of 62 stations. The dimensionless ratio of hourly maximum rainfall to daily maximum rainfall (r max) that was modeled with a specific probability distribution was used as an approach to extract hourly maximum rainfall. The Upper Blue Nile basin was grouped in two clusters and it was found that Pearson type III and Generalized Extreme Value distributions are best representatives for the dimensionless ratio r max of each region with a heterogeneity measure (H1) of 0.88 and 0.77, respectively. The extracted hourly maximum rainfall was also fitted with Pearson type III and Generalized Logistic distributions and quintiles were finally estimated for each region.
