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The challenge

The impact of urbanisation on the natural environment and environmental services

Key considerations for planners and policy makers today are the impact of urbanisation on the natural environment. Environmental factors such as air and water quality management, economic viability, urban heat islands and population density are also examined.

Urban land covers, heights and surface properties from Jan/Feb 2020. In this display, vegetated areas are coloured green, and building roofs are coloured orange. Other surfaces are depicted in grey scale. Heights and reflectance properties are also recorded. Region includes the suburb of Nedlands and Dalkeith Perth. Zoomed area displays Nedlands Golf Club and Melvista Park.

Quantitative information on the changing natural and built composition of cities is crucial for planning for service provision, resource allocation and regulatory compliance. It also assists with modelling of the future impact of planning scenarios as well as assessing the success of past programs.

Urban Monitor™ developed by CSIRO's Data61 Remote Sensing and Image Integration team, is a software that addresses the absence of cost effective and detailed landcover information by establishing monitoring baselines and detailed time-series' of landcover information. High-performance computing solutions are applied to collections of information from commonly acquired, and globally active, aerial and space-borne sensors.

Our response

Combining land cover statistics with spatial data

Urban and peri-urban areas contain various land surfaces such as roofs, roads, irrigated and non-irrigated trees, bushes and lawns. Each surface has an impact on the hydrological and energy cycle. These impacts vary in complex ways as the surfaces change over time.

Urban land covers, heights and surface properties from Jan/Feb 2020. This image features the Nedlands Golf Club

Using routinely collected aerial photography and other data, Urban Monitor™ can monitor variations in these surfaces at high precision (e.g 0.1 to 0.3m), recording their presence, area, status, volume and height above the ground or sea level Digital aerial photography is routinely collected by governments to produce images. Urban Monitor™ can then fully utilise the data's quantitative potential to provide monitoring information..

Urban Monitor™ highly automated computer algorithms geometrically and radiometrically calibrate and analyse the data. The algorithms then create quantitative assessments and comparisons of city features using relevant time and space statistics.

For instance, land cover statistics of a local government area may be compared with previous years, and these are meaningfully compared with those of other councils. This information combined with other spatial data, forms the basis of Urban Monitor™.

The results

Urban Monitor working with governments to develop and enhance the urban canopy

Urban Monitor™ has been applied to a variety of problems some of which include, urban greenspace and heat island assessment, direct and indirect ground water recharge estimation, and off-site monitoring of land cover and elevation change resulting from oil and gas operations. Baselines have been established for the greater metropolitan areas of Perth, Melbourne and Sydney.

One of the key uses of Urban Monitor™ has been to support state and local government authorities to develop their urban forest strategies. This standardised and high-quality Urban Monitor™ derived resource has been used by numerous local government authorities to develop their urban forest strategies.

Local governments utilise the information to identify where they are losing trees, where they need to re-plant, and offers robust, evidence-based information, suburb by suburb. This enables local governments to tailor their policies and strategies to protect and enhance their individual urban canopy.