Spatial and temporal variations of suspended sediment responses from the sub-tropical Richmond River catchment, NSW, Australia

Suspended sediment exports from the Richmond River catchment were examined during 2 hydrological years (1994–96). On a yearly basis, the Richmond River catchment produced 93% of the suspended sediment load, while sediment exports from the Bungawalbin Creek subcatchment always remained low due to its flat topography and extensive forest coverage. Suspended sediment hysteresis patterns exhibited a clockwise response for 2 steep and less forested subcatchments and an anti-clockwise response for relatively low gradient and more forested subcatchment during all flood events. Land use changes in the Richmond River subcatchments indicate a possible increase of suspended sediment load of about 6-fold from their pristine condition.