The scope in the scanning

The long-term impact of global warming on our economy and health can not be over-estimated. Government legislation and public consciousness are forcing environmental issues and climate change to the top of the agenda for local, regional and central government. At the top of the list of information requirements to facilitate accurate and relevant local planning for climate change, is geographical information. If you don’t have a precise understanding of where problems are occurring, you can not possibly plan to address them. Typically this information might be sourced from a combination of existing datasets and bespoke data capture. Identifying a single source for the required data alleviates difficulties of data access and integration.

Remote sensing
Whilst high quality measurements may be taken of specific areas using ground based techniques, these do not always provide the overview required for environmental management purposes. Remote sensing offers the opportunity of delivering a tool box approach to monitoring, targeting the required level of detail using an array of different sensor types.
    
Put simply, remote sensing is the capture of data of an environment without direct contact. Remote sensing techniques vary from the very simple, for example, aerial photography, to the very complex, like laser scanning for terrain height mapping. Instruments also range in distance from space borne sensors all the way down to tripod based instrumentation. Typically, when planning for climate change and addressing environmental issues such as those faced by government bodies, a combination of tools and techniques from aerial and ground based measurements, result in the best solution.  

Environmental planning
In addition to holding an extensive archive of spatial data, Geomatics Group, a specialist business unit within the Environment Agency, offers the capability to capture a wide range of data types from airborne, terrestrial and marine platforms. These data are integrated at source, to produce a series of products which are GIS ready and may be readily used by the client in planning for climate change.

  • Urban planning and design
  • Flood risk mapping and management
  • Habitat surveys
  • Heat loss surveys
  • Land use surveys
  • Environmental management

Laser scanning LIDAR instruments produce high resolution digital elevation models (DEMs). Removal of surface objects from this digital surface model can result in a highly accurate bare earth digital terrain model (DTM). Analysis of this terrain model, enables the effects of factors such as slope and aspect on the erosion potential of sites to be investigated. This knowledge can then be used for flood protection, planning and protection of sensitive habitats.
    
LIDAR derived digital terrain models are also used extensively when investigating flood risk, by integration with numerical models. During a flood event, data can be gathered on a range of variables including, flood extent and flood depth. These data are used to generate flood models, providing an invaluable tool to local authority planning departments for flood risk assessment, emergency planning and flood defence policy.
    
When more detailed assessment of the urban environment is required, vehicle and tripod LIDAR systems are used. Our vehicle-based system collects extremely detailed and accurate point cloud data, which when processed, produces realistic 3D visualisations of the survey site. This cost effective and rapid technique can be used to generate detailed models of urban environments, for surface flood modelling, in the detection of coastal erosion and for surveying architecture and street furniture for urban planning.
    
For land cover classification, biomass studies and mapping coastal habitat, the CASI (Compact Airborne Spectrographic Imager) can be used. This system measures reflected light from the visible and near infra-red portion of the spectrum, which is used to map areas of differing vegetation types.
    
Aerial surveys of heat loss from buildings, offers a powerful management tool to target grant investment in residential properties and advise commercial properties of their energy efficiency. Using a Thermal Airborne Imager™, entire towns or cities can be surveyed in a single flight and the resulting data seamlessly matched up to individual buildings on OS Mastermap™, to create a map showing the indicative heat loss rating from every building.
    
Whilst each of these datasets may be obtained from a variety of sources, the use of one supplier to collect and integrate the data ensures that the data are of the highest quality and are ready for immediate use in a GIS environment.
    
Geospatial data has become a vital tool for environmental and climate change planning. Local and regional government have an essential role to play and can use these datasets to assist them in making key policy decisions.

For more information
To find out more about the Geomatics Group, call 01225 487631 or go to www.geomatics-group.co.uk.

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