NSW Govt launches new Gravity Model to track terrestrial hazards

Gravity Model

The NSW Government has unveiled a new ‘Gravity Model’ for the state, providing vital spatial data on terrain, water flow, and potential flood and other natural disaster risks across NSW.

The project – part of the Government’s overall smart cities framework – will offer an improved dataset to help manage earth resources and infrastructure projects, as well as provide engineers with crucial insights to identify major natural hazards across the state.

The Government will initiate airborne gravity surveys, capturing data from aeroplanes equipped with gravity sensors; data captured from these sensors can help to increase the accuracy, at “real-world heights”, of Global Positioning Systems (GPSs) to just a few centimetres.

The new data collection method is hoped to deliver more accurate height determination from Global Navigation Satellite Systems (GNSS) positioning (including GPS systems) across the entirety of NSW.

Current datasets, some of which are sourced from systems predating GNSS positioning (pre-1992), are said to provide low spatial accuracy.

Acting NSW Surveyor-General Thomas Grinter noted that existing geophysical and geodetic data, which looks at the Earth’s shape, orientation and gravity field, are considered ”out-of-date, incomplete and inconsistent”, with a substantial portion of this data formed from a combination of land-based, satellite and airborne gravity data collected across several decades.

According to the Government, the launch of the Live NSW Gravity Model spatial service would offer benefits for the exploration and management of groundwater stores, earthquake hazard detection, bushfires and natural disaster recovery efforts, as well as major infrastructure and construction planning across the entirety of NSW – an area covering more than 800,000 km2.

Data from the Gravity Model will be used to help improve and make decisions on land use, large infrastructure projects, flood mapping as well as property, construction and agriculture, potentially generating resource investment opportunities and aiding regional jobs growth.

The project is expected to be captured in five stages from May 2022 and will be completed by December 2023, beginning with the regional west of NSW and moving towards the coast.

The Government assured citizens that privacy will be protected throughout the process, with the focus directed solely at capturing data from gravity measurement instruments, and would not emit any signals, or impact people, animals or infrastructure.

Raw gravity datasets captured through the Live NSW Gravity Model will flow through to Geoscience Australia’s (GA) online portal and Geological Survey of NSW’s (GSNSW) online mineral viewer.

Gravity model data will also be made freely available through the NSW Government’s open data platforms and licensed for public use.