TITLE:
Flood Generation Mechanisms and Potential Drivers of Flood in Wabi-Shebele River Basin, Ethiopia
AUTHORS:
Fraol Abebe Wudineh, Semu Ayalew Moges, Belete Berhanu Kidanewold
KEYWORDS:
Flood Drivers, Climate Factors, Watershed Characteristics, Human Drivers, Principal Correlation Analysis (PCA), Multiple Regression Model
JOURNAL NAME:
Natural Resources,
Vol.13 No.1,
January
29,
2022
ABSTRACT: Flood is a natural process generated by the
interaction of various driving factors.
Flood peak flows, flood frequency at different return periods, and potential driving
forces are analyzed in this study. The peak flow of six gauging stations, with
a catchment area ranging from 169 - 124,108
km2 and sufficient observed streamflow data, was selected to develop
threshold (3rd quartile) magnitude and frequency (POTF) that
occurred over ten years of records. Sixteen Potential climatic, watershed and
human driving factors of floods in the study area were identified and analyzed
with GIS, Pearson’s correlation, and Principal Correlation Analysis (PCA) to
select the most influential factors. Eight of them (MAR, DA, BE, VS, sand,
forest AGR, PD) are identified as the most significant variables in the flood
formation of the basin. Moreover, mean annual rainfall (MAR), drainage area (DA),
and lack of forest cover are explored as the principal driving factors for
flood peak discharge in Wabi-Shebele River Basin. Finally,
the study resulted in regression equations that helped plan and design
different infrastructure works in the basin as ungauged catchment empirical equations to compute QMPF, Q5,
Q10, Q50, and Q100 using influential climate,
watershed, and human driving factors. The results of these empirical equations
are also statistically accepted with a high significance correlation (R2 > 0.9).