Chief's Island is the largest island in the Okavango Delta.The flooding patterns of the Delta arise from the two sources: the major source is a late autumn to early winter flood arising from rainfall in the catchment areas of the Quito and Cubango River systems of south-eastern Angola. A possible late summer flood may occur when local rainfall over the Delta is high. Vegetation types are distributed in a mosaic as a function of water availability, water table level, soil type and frequency and duration of flooding.