Built-Up Extent

Earth Observation (EO)-based data can be used to identify and classify settlements, outlining the extent and key characteristics of urban areas. EO data makes it possible to determine when and where land transitions from non-urban to urban (or vice versa), analyse settlement characteristics, and gain better insights into development patterns (e.g. leap-frogging or ribbon development) and quantifiable growth rates over time.

These metrics provide valuable information about the types of settlements and their changes, supporting urban planning, land and natural resource management, and disaster preparedness efforts. Comparing actual urban growth with statutory development plans or designated protected areas, for instance, can indicate weaknesses in enforcing development controls.

While built-up extent can be produced solely using optical EO imagery, radar data (e.g. from Sentinel-1) can serve a complementary role since active radar emitters are unaffected by cloud cover and can operate at night. The final information product should always be validated using Very High Resolution (VHR) imagery and/or reference building outlines.

EO Capability on GDA App

Access ready-to use instances of this EO Capability on the GDA Analytics & Processing Platform (APP). The two Capabilities linked below can be used by any registered user. You can register to the GDA APP here.

Built-up areas delineation – Generates a complete map of built-up infrastructure both in densely and sparsely urbanised areas, suing Sentinel-2 L1C.

Built-up areas change detection – Compares two single-band classified Sentinel-1 L1C images to identify appearing, disappearing, and changing objects over time.