Impacts of improved grazing land management on sediment yields. Part 2: Catchment response.

Summary In many agricultural regions investments are made into improved land management and catchment restoration with the aim of reducing sediment and nutrient delivery to downstream water bodies. This paper presents the results of an 8 year field study that evaluated the impact of improved grazing land management (GLM) on a 14 km 2 sub-catchment of the Burdekin River in northern Australia. Land condition recovery and changes to runoff and sediment yield were measured on hillslopes (using three flumes) and at the end of the catchment (using automatic water sampling). Ground cover was monitored at the beginning of the wet season at hillslope and catchment scales using direct measurement and Quickbird satellite imagery. At the catchment scale, improved GLM resulted in an increase in mean ground cover between 2003 and 2007, relative to a control grazing property. However, the total suspended sediment yield from hillslopes did not decline due to the disproportionately high yields from low (