Assessment of the significance of extreme events in the Alligator Rivers Region: impact of Cyclone Monica on riparian vegetation (Allosyncarpia ternata rainforest), in-channel large wood loadings, channel erosion and treethrow in the Ngarradj Creek catchment

During the 2005–2006 wet season Cyclone Monica impacted greatly on the Ngarradj catchment, resulting in a large amount of tree fall through out the catchment and along the stream channel boundaries, resulting in some places in the complete removal the riparian monsoon rainforest. The existence of the large woody loadings within the creek along the two reaches prior to Cyclone Monica as well as an extensive pre Cyclone Monica data set on channel parameters such cross sections, particle size etc provided a unique opportunity to study the impacts before and after this extreme event. A project was initiated following the cyclone to remeasure the large wood loadings, re survey channel cross sections, collect bed material samples so that before and after comparisons could be made. Erosion pins were also re-installed along each of the reaches. The project was run in collaboration with Newcastle University with Professor Wayne Erskine taking the lead role and eriss providing field and logistical support.