The diversity of inundated areas in semiarid floodplain ecosystems

Contemporary methods for managing flood plain ecosystems are biased towards temporal patterns of flow. Such approaches disregard the inherent spatial complexity associated with the flooding and drying of flood plain ecosystems and the influence this has on their productivity and biodiversity. This study investigates how the character of inundated patches changes through two flood events in the Narran Lakes ecosystem, Australia. A series of Landsat thematic mapper (TM) images were used to elicit patterns in inundated-patch character over time. Characteristics including patch number, size, shape and proximity to other patches were calculated for each image and subjected to multivariate statistical analyses. Strong positive relationships were observed between patch number; richness of patch area, shape and. proximity and total surface area inundated. Hysteresis was also observed for the latter three relationships. This work highlights the importance of incorporating both spatial and temporal aspects of flood plain inundation in detennining environmental water allocations for flood plain maintenance.