Decision making
; Forecasting
; Rain
; Soil moisture
; Weather forecasting
; Awareness systems
; Central Africa
; Decision makers
; Eastern Africa
; Forecast information
; Rainfall patterns
; Seasonal rainfall
; Sub-saharan africa
; Floods
; arid region
; decision making
; disaster management
; flood
; flood control
; flooding
; precipitation intensity
; rainfall
; soil moisture
; Africa
; Madagascar
; Sub-Saharan Africa
英文摘要:
In light of strong encouragement for disaster managers to use climate services for flood preparation, we question whether seasonal rainfall forecasts should indeed be used as indicators of the likelihood of flooding. Here, we investigate the primary indicators of flooding at the seasonal timescale across sub-Saharan Africa. Given the sparsity of hydrological observations, we input bias-corrected reanalysis rainfall into the Global Flood Awareness System to identify seasonal indicators of floodiness. Results demonstrate that in some regions of western, central, and eastern Africa with typically wet climates, even a perfect tercile forecast of seasonal total rainfall would provide little to no indication of the seasonal likelihood of flooding. The number of extreme events within a season shows the highest correlations with floodiness consistently across regions. Otherwise, results vary across climate regimes: Floodiness in arid regions in southern and eastern Africa shows the strongest correlations with seasonal average soil moisture and seasonal total rainfall. Floodiness in wetter climates of western and central Africa and Madagascar shows the strongest relationship with measures of the intensity of seasonal rainfall. Measures of rainfall patterns, such as the length of dry spells, are least related to seasonal floodiness across the continent. Ultimately, identifying the drivers of seasonal flooding can be used to improve forecast information for flood preparedness and to avoid misleading decision-makers.
Red Cross Red Crescent Climate Centre, The Hague, Netherlands; School of Archaeology, Geography and Environmental Science, University of Reading, Reading, United Kingdom; Institute for Environmental Studies, VU University Amsterdam, Amsterdam, Netherlands; International Research Institute for Climate and Society, Columbia University, New York, United States; Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands; European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom
Recommended Citation:
De Perez E,C,, Stephens E,et al. Should seasonal rainfall forecasts be used for flood preparedness?[J]. Hydrology and Earth System Sciences,2017-01-01,21(9)