Since the Environment Agency’s (EA) decision to make all LiDAR (Light Detection And Ranging) point clouds publicly available, they have become a commonly used data source allowing better informed decisions to be made at lower cost. Here we explain how we make use of them.
Since the Environment Agency’s (EA) decision to make all LiDAR (Light Detection And Ranging) point clouds publicly available, they have become a commonly used data source allowing better informed decisions to be made at lower cost.
LiDAR, in a nutshell, is a surveying technology that scans the landscape by firing lasers and collecting millions of reflected pulses. Differences in the returns and wavelengths are processed to provide information on things such as the elevation and intensity of the reflected surface. These returns form a point cloud and can be automatically classified using pre-defined algorithms.
At ABPmer we use LiDAR datasets in a number of ways to provide an understanding of coastal environments.
When clients request site condition assessments for potential developments, LiDAR sourced data is one of the primary pieces of information used for understanding the basic characteristics of the land. This is because of its versatility; transects can be used to understand the land gradients, the point cloud returns and classifications can show the extent of differing types of vegetation or man-made structures and elevations can be used to calculate dredge volumes. These were used when developing the technical design of a potential managed realignment site at the RSPB Skinflats reserve.
As the EA has been collecting LiDAR data since 1998 historic analysis of the conditions of structures, change in coastlines or habitat extents can all be quantitatively assessed with consistent accuracy. This is crucial for monitoring change over time, pinpointing specific events that may have had an effect or predicting the future condition of assets if a rate of change continues. Such historic LiDAR data was useful for understanding the evolution of the spit at Pagham Harbour when we were considering options for its future management.
Our hydrodynamic modelling specialists depend on high quality data inputs to support model development. High resolution LiDAR data is frequently an important piece of the digital terrain jigsaw, thanks to the sheer magnitude of returns that are collected. This, in combination with other survey data, ensures we have the best elevation coverage for our models at the most suitable resolution. We used LiDAR data of Morecambe Bay’s intertidal areas to support the hydrodynamic model we developed for the North West Coastal Connection Route Corridor project.
Prepared by Dan Williamson, ABPmer GIS Specialist
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