title: Assessing the potential underestimation of sediment and nutrient loads to the Great Barrier Reef lagoon during floods.
abstract: Much of the sediment and nutrient load to the Great Barrier Reef (GBR) lagoon happens during over bank floods, when discharge can be significantly underestimated by standard river gauges. This paper assesses the potential need for a flood load correction for 28 coastal rivers that discharge into the GBR lagoon. For each river, daily discharge was divided into flows above and below a 'flood' threshold to calculate the mean annual percentage flow above this threshold. Most GBR rivers potentially need a flood load correction as over 15% of their mean annual flow occurs above the minor flood level; only seven rivers need little/no correction as their flood flows were less than 5% of the mean annual flow. Improved assessment of the true load of materials to the GBR lagoon would be an important contribution to the monitoring and reporting of progress towards Reef Plan and associated marine load targets.
authors.affiliation: CSIRO Land and Water, Australian Tropical Science and Innovation Precinct, 145 James Cook Drive, Townsville 4811, Australia. jim.wallace@csiro.au
authors.forename: Jim
authors.initials: J
authors.lastname: Wallace
authors.forename: Fazlul
authors.initials: F
authors.lastname: Karim
authors.forename: Scott
authors.initials: S
authors.lastname: Wilkinson
mesh_terms: D000383:Agriculture / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D055868:Floods / Q000706:statistics & numerical data*; D019015:Geologic Sediments / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen