The latest aerial photography and detailed earth surface models from Bluesky are being used for demonstration in a state of the art software package developed to assess the risk and impact of flooding. The ISIS by Halcrow suite is one of the leading software packages for river modelling, used extensively across the world for flood forecasting, flood risk mapping and flood alleviation scheme design by government organisations, environmental regulators and engineering consultants. To support the launch of ISIS 2D Halcrow has included some GeoPerspectives aerial photography and Digital Terrain Models (DTMs) from Bluesky, to enable users to evaluate the improved modelling functionality.

ISIS 2D is the latest addition to the ISIS by Halcrow suite of products. A fully hydrodynamic computational engine, it is designed to work either as a stand-alone tool or within the ISIS suite of products enabling dynamic integration between ISIS Professional and ISIS 2D. At the core of the software are two advanced algorithms that have been specifically designed to replicate different types of hydraulic conditions within rivers, estuaries and floodplains. ISIS 2D is available for free and can be downloaded from www.halcrow.com/isis, and has all of the same features as the full version but is limited to 2,500 2D cells.

“The data sets supplied by Bluesky are being used in ISIS to allow users to evaluate the new 2D modelling components. The DTM is used to generate trial models of flooding from rivers, the sea and dam failures, while the aerial photography is used to enhance the visualisation by providing a real world background,” commented Dr Matt Horritt, specialist modeller in the Water and Engineering Management division of Halcrow.

Bluesky has supplied Halcrow with GeoPerspectives aerial photography for test sites including river, coastal and dam break flooding. The photogrammetrically derived Digital Terrain Model supplied by Bluesky is also part of the GeoPerspectives range, offering a resolution of 5 metres the data is accurate to 1 metre and is available off the shelf for the whole of England and Wales. Both products can be viewed and purchased online at www.bluesky-world.com.        

“We chose the data from Bluesky as they were of sufficiently high resolution and accuracy for broad scale modelling,” continued Dr Horritt. “The DTM is particularly effective for modelling in complex urban or vegetated environments as it is essential to represent ground level rather than the tops of trees or buildings.”

GeoPerspectives is a joint venture between Bluesky and Infoterra providing national coverage of orthorectified aerial photography, digital terrain and surface models (DTM/DSM) for 3D modelling, and colour infrared imagery (CIR) for vegetation analysis.

Website: www.bluesky-world.com

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Notes for editors

ISIS is one of the leading software packages for river modelling, used throughout the world on flood forecasting, flood alleviation scheme designs, flood risk mapping, flood risk assessments and catchment management planning projects. It provides engineers and managers with a set of flexible and cost effective tools so that they can make decisions to proactively manage our environment.

For more information on ISIS, please visit our websites at www.halcrow.com/isis and www.isisuser.com or contact Vijay Jain, ISIS sales and marketing manager on +44 (0)1634 248729.

Halcrow Group Ltd, “Halcrow”, specialises in the provision of planning, design and management services for infrastructure development worldwide. Founded in 1868, the company has developed into a leading consultancy in all of its core sectors – water, transportation, maritime and property. The company’s 8,000 employees operate from a network of over 80 offices worldwide.

Halcrow is owned and managed by its employees and staff shareholders, making it one of the largest independent firms of its kind. The company provides consultancy services to government departments, public sector authorities and utilities, industrial and commercial companies, international funding agencies and financial institutions.

Bluesky is a UK-based specialist in aerial imaging and remote sensing data collection and processing.  An internationally recognised leader with projects extending around the globe, Bluesky is proud to work with prestigious organisations such as Google, the BBC and Government Agencies.

Bluesky has unrivalled expertise in the creation of seamless, digital aerial photography, 3D landscape/cityscape visualisations and prints and also runs a national mapping centre, providing digital mapping, satellite imagery and aerial photography including ultra-high resolution imagery of cities and towns.

The highly accurate 3D digital maps, captured from aircraft mounted lasers, are being used to assess the flood risk at critical utility sites across the UK. The project, undertaken by Ambiental on behalf of one of the UK’s largest water companies, used LiDAR (Light Detection and Ranging) data supplied by aerial survey specialist Bluesky to help scrutinize the likelihood, extent and depth of potential flooding as part of a review of flood defence measures at each of the five sites.

The Bluesky data is part of a 3D terrain map, available online at www.bluesky-world.com, that covers most of England and Wales including all major urban centres, coastal areas and flood plains.

Ambiental, a specialist environmental risk mapping and modelling consultancy, used a combination of existing datasets, models and gauged data in combination with their proprietary modelling and mapping techniques to assess and quantify each flood source in turn. Potential sources of flooding considered during the analysis included fluvial (river), tidal, surface water, sewer and groundwater. The high resolution LiDAR data, supplied by Bluesky, was used to map each risk in 3D to ascertain the spatial distribution of different flood depths. The results of these assessments were used for business planning, specifically within cost-benefit analysis for flood defence measures at each site.

“The use of high-resolution, high-accuracy remotely-sensed data, such as the LiDAR data supplied by Bluesky, was critical to timely and cost effective completion of this project,” commented David Martin, Technical Manager at Ambiental Technical Solutions. “By utilising off-the-shelf data we were able to achieve considerable savings in terms of time and money over conventional ground-based surveying techniques for a project where time was very limited.”

In order to capture the highly accurate LiDAR (Light Detection and Ranging) data a survey aircraft equipped with a system of lasers is used. Lasers are beamed to the surface and the time taken for the beam to bounce back to aircraft-mounted receivers is recorded. Using the known position of the aircraft (derived from on-board satellite positioning equipment), the time taken for the return of the laser beam and the known value of the speed of light, results in the distance between the aircraft and ground being calculated. Additional readings can also be taken to determine the height of buildings, vegetation and other surface structures.

Website: www.bluesky-world.com

Editorial enquiries, contact Robert Peel on tel. +44 (0)1666 823306

Colour separation requests – please fax only to +44 (0)1666 824 668

All reader enquiries to Bluesky sales on +44 (0)1530 518 518

Editor’s Notes:

Bluesky is a UK-based specialist in aerial imaging and remote sensing data collection and processing.  An internationally recognised leader with projects extending around the globe, Bluesky is proud to work with prestigious organisations such as Google, the BBC and Government Agencies. Bluesky has unrivalled expertise in the creation of seamless, digital aerial photography, 3D landscape/cityscape visualisations and prints and also runs a national mapping centre, providing digital mapping, satellite imagery and aerial photography including ultra-high resolution imagery of cities and towns.

www.bluesky-world.com

Ambiental is a specialist environmental risk mapping and modelling consultancy founded in 1997 as a partnership of researchers at Cambridge University. The company has grown rapidly and now includes experts in the fields of flood modelling, risk management, insurance, rainfall simulation, climate change, geomorphology, computer programming, civil engineering, Geographical Information Systems (GIS) and applied mathematics. Ambiental offers a complete flood risk assessment service for property developers, architects, energy providers and loss adjustors and has completed projects in the UK, USA, mainland Europe and Asia.

www.ambiental.co.uk

A special map which helps to reveal the types of crop and other vegetation from the air is being made available online by aerial mapping company Bluesky. By using infrared sensors fitted to aerial survey aircraft, England and Wales are currently being mapped to reveal land use in more detail than ever before. The multicoloured map contains a wealth of information essential to support major environmental projects including crop monitoring, coastal management and forestry studies.  It complements aerial photomaps and land height maps already available online at www.bluesky-world.com, where visitors can view their local area by entering a place name or postcode.

Using the very latest digital imaging technology Bluesky has captured the CIR information, invisible to the human eye. Specially developed sensors mounted on a survey aircraft are used to record measurements from a specific part of the electromagnetic spectrum, the scientific term for the collective types of energy and light emitted from the sun, which includes both visible (the normal rainbow of colours we see everyday), and invisible (such as near infrared) parts.

Providing a unique view of the earth’s surface CIR images provide a valuable tool for studies in landform, vegetation, pollution and other effects of human activity on our environment and the the earth. For example, leaves of healthy, growing vegetation reflect a high level of near-infrared wavelengths and appear red on colour-infrared film while unhealthy or dormant vegetation may appear light red or a light shade of blue-green. These obvious colour distinctions make colour-infrared photographs useful in assessing the health and coverage of plants on our land.

Water, on the other hand, absorbs near-infrared wavelengths and appears almost black in the image, although water with varying amounts of suspended particles appears as shades of blue. In addition, near-infrared wavelengths penetrate atmospheric haze and result in clear, crisp images even when traditional aerial photography cannot be captured.

“CIR data is simultaneously acquired during the GeoPerspectives data capture programme,” commented Rachel Tidmarsh, Managing Director of Bluesky, “making it the perfect complement to the other layers of detailed geographical information that are already available online at www.bluesky-world.com, including the most up-to-date aerial photography and detailed height models”.

Website: www.bluesky-world.com