Content area
Abstract
Evaluating the flood and drought hazards provides vital information for sustainable water resources management, particularly in semi-arid, water-deficit environments. Most prior studies were limited in exploring the flood and drought hazards, which are important for early warning systems and preparedness. This study characterized the hydrological extreme hazards on the Gereb-Geba reservoir, namely the Suluh, Genfel, and Agula rivers. Flood frequency analysis was performed using the fitted flood frequency distribution in MATLAB. The 2D hydrodynamic model HEC-RAS was implemented to produce a flood-inundation map. Meteorological, agricultural, and hydrological droughts were analyzed using the Standardized Precipitation Index (SPI), Vegetation Condition Index (VCI), and Streamflow Drought Index (SDI), respectively. Using the Generalized Extreme Value (GEV), the estimated flood magnitude showed an increasing tendency in all the rivers across all the return periods (2-, 5-, 10-, 20-, 50-, and 100-years). The reservoir inundated an area of 12.8 km2 at an elevation of 1830 m.a.s.l. with a water depth of 80 m at the outlet. Suluh experienced more severe to extreme hydrological drought episodes than the Agula and Genfel rivers. Severe to extreme meteorological droughts were also observed in the respective catchments. Moreover, severe agricultural drought prevalence was also detected across all the river catchments. This study provides vital and comprehensive flood and drought information for water resources planning, management, and development.
Details
Water shortages;
Early warning systems;
Flood frequency;
Drought;
Water supply;
Rivers;
Water resources planning;
Water depth;
Stream flow;
Agricultural drought;
Standardized precipitation index;
Extreme values;
Vegetation;
Water resources management;
Frequency analysis;
Flood frequency analysis;
Drought and floods;
Floods;
Drought index;
River discharge;
Water resources;
Catchments;
Flood management;
Hazards;
Outlets;
Flood magnitude;
Weather hazards;
Two dimensional analysis;
Hydrology;
Frequency distribution;
Flooding;
Hydrologic studies;
Hydrologic drought;
River catchments;
Reservoirs;
Stream discharge;
Aridity;
Hydrodynamic models;
Semiarid zones;
Watersheds
; Amanuel Zenebe 2
; Yazew, Eyasu 3
; Yisak, Biniyam 4
; Atkilt Girma 2
; Araya, Muez 5 ; Gebreyohannes Zenebe 4 ; Giannini, Alessandra 6
1 Institute of Water and Environment, Mekelle University, Mekelle, Ethiopia; Institute of Climate and Society, Mekelle University, Mekelle, Ethiopia
2 Institute of Climate and Society, Mekelle University, Mekelle, Ethiopia; Department of Land Resources Management and Environmental Protection, Mekelle University, Mekelle, Ethiopia
3 Institute of Water and Environment, Mekelle University, Mekelle, Ethiopia; Department of Land Resources Management and Environmental Protection, Mekelle University, Mekelle, Ethiopia
4 Institute of Climate and Society, Mekelle University, Mekelle, Ethiopia
5 Department of Dam and Infrastructure Construction, Tigray Water Works Construction Enterprise, Mekelle, Ethiopia
6 Laboratoire de Météorologie Dynamique/IPSL, Ecole Normale Supérieure, PSL Research University, Sorbonne Université, Ecole Polytechnique, IP Paris, CNRS, Paris, France; International Research Institute for Climate and Society (IRI), Columbia University, Palisades, NY, USA