Informing particulate nitrogen export estimates using the MERGE-D model for gully erosion.

Speaker: Melanie Roberts
Affiliation: Griffith University

Abstract

Gullies are hot spots of erosion – responsible for as much as 40% of the sediment that ultimately reaches the Great Barrier Reef.  This sediment, and the nutrients transported with it, contribute to poor water quality outcomes, which is the greatest threat to the reef after climate change.  Understanding the contribution of gully erosion to the bio-available nutrient pool in addition to fine sediment loads is essential to determining the cost-benefit of different landscape rehabilitation and management options to meet water quality targets and protect the reef.

The MERGE gully erosion model was developed in partnership with Queensland Government and the Queensland Water Modelling Network to provide a process-based model to inform gully rehabilitation actions at specific sites.  In this talk, I introduce the MERGE model and an in-development extension of the model MERGE-D.  MERGE-D provides an essential extension to MERGE to enable the accurate prediction of particulate nutrient export, and therefore the contributions of gully erosion to the bio-available nutrient pool in coastal and marine environments.