Bathymetric modelling of shallow freshwater bodies with short-wave, small-footprint aerial lidar

Downstream flythrough of 1 m cross-sections extracted from a bathymetric lidar survey of the Lower Wairau River, Marlborough, NZ. Captured April 2022.

MBIE NZ, Smart Ideas
2021-2023

Team

Prof James Brasington, Dr Justin Stout, Dr Michael Pingram (also WRC). 

The Problem 

Mapping the underwater topography, or bathymetry, of shallow waterbodies continues to present a technological challenge. Currently, this can only be achieved through costly and time-consuming surveys of cross-sections and depths by soundings from boats or by wading where possible.  The 3D bathymetric (underwater topography) models that can be produced using this new sensor have the potential to significantly advance the mapping of what lies beneath the surface of rivers, lakes and coastal waters, creating opportunity to enhance our understanding of flood risk, sedimentation and erosion, as well as river habitat and ecological condition.

Research Goals 

We aim to quantify the confounding effects of water clarity, bed substrate, vegetation, and flow state on the quality of the observed data retrievals from a shortwave, small footprint green lidar sensor capable of penetrating the water’s surface. This will enable us to evaluate and optimize survey and sensor acquisition settings in order to mitigate these effects and support future operational deployments.

Project Partners:

Land Information New Zealand: Stuart Caie

Department of Conservation: Sue Clearwater, Dave West

Waikato Regional Council: Bryan Clements

Otago Regional Council: Tim van Woerden

Environment Canterbury: Shaun McCracken

Vadis Geomatics: Will Marson

Outputs

Stout, J. and Brasington, J. 2022.  Probabilistic Modelling of Bathymetric Retrievals with a New Class of Small Format Shortwave lidar.  AGU Fall Conference, Chicago, Dec 2022.