Heavy daily rainfall characterization and flooding repeating: contribution of three (3) days sliding total to the purposefulness of threshold amount rainfall inducing flooding (Abidjan district, South-est of Ivory Coast)

Daily rainfalls as they reach a certain threshold, induce severe flooding in some township of Abidjan district during the largest rainy season. This paper focuses on defining and identifying of heavy daily rainfall threshold linked in flooding over the Abidjan district. The heavy rainfall maximum and critical occurrence period ascertainment has been possible thanks to the likelihood occurrence (from 0 to 100%). Identifying heavy rainfall threshold related to flooding-causing started with classification and definition of precipitation recorded from 2012 to 2014 over all stations of Abidjan district with the percentile. Then, using the rainfall total sliding window technic helped finding a threshold amount inducing severe flooding. The critical period rainfall and flooding occurrence (likelihood occurrence of 75%) start from May 27th to June 22th. Rainfall total sliding and past flooding analysis revealed a threshold amount precipitation around 100 mm. Henceforth, this threshold could helped forecaster offices by issuing advisories and warnings for flooding when precipitation expected, at any location of Abidjan district, is near or exceeds the amount of 100 mm.