Spatial technologies in planning: WACE Year 12 Geography
“Explain how GIS, remote sensing and GPS are used in planning and apply them to spatial analysis”
Spatial technologies, geographic information systems, remote sensing and satellite imagery, and global positioning systems, are tools that capture, store, analyse and display geographic data; in planning they let analysts layer information such as land use, population and hazards, run overlay analysis to find suitable or at-risk sites, monitor change over time, and present evidence that supports sustainable, well-targeted decisions.
What this dot point is asking
SCSA wants you to know what each spatial technology does, how it supports planning, and how to interpret spatial data in stimulus questions. This is a skills dot point that appears directly in the external examination.
The main spatial technologies
A geographic information system (GIS) is a computer system that captures, stores, analyses and displays spatially referenced data as layers. By overlaying layers such as land use, transport, population and environment, a GIS lets planners analyse relationships and answer location questions that a single map cannot.
- GIS. Layers and analyses spatial data, the core planning tool.
- Remote sensing and satellite imagery. Captures information about the surface from aircraft and satellites, used to map land cover and monitor change.
- GPS. Provides precise location, used to collect field data and georeference observations.
How spatial technologies support planning
Planning is fundamentally about location, and these tools turn data into decisions.
- Mapping the present. Layering current land use, infrastructure, population and environment to understand a place.
- Overlay and suitability analysis. Combining layers to find sites that meet criteria, for example land that is flat, near transport, outside flood zones and not high-value habitat.
- Monitoring change. Comparing satellite images over time to track urban sprawl, vegetation loss or coastal change.
- Modelling and scenarios. Projecting growth and testing where infrastructure or housing should go.
- Communicating decisions. Producing clear maps for the public and stakeholders.
To decide where to locate a new sustainable suburb, a planner loads GIS layers for slope, flood risk, existing transport, vegetation and land ownership. The GIS overlays them to highlight land that is gently sloping, served by transport, outside flood and habitat areas, and available. Satellite imagery confirms current land cover, and GPS is used to verify conditions in the field. The technologies together turn many separate datasets into a single, defensible siting decision that balances the dimensions of sustainability.
Interpreting spatial data in the exam
Stimulus questions often present GIS layers, satellite images or thematic maps and ask you to analyse them.
When interpreting GIS or satellite material, identify the data layers shown, describe the spatial pattern, explain it using geographic concepts, and evaluate the source: its date, resolution, and what it omits. Strong answers state how the technology supports a planning decision rather than just describing the image.
Strengths and limitations
Spatial technologies are powerful: they integrate huge datasets, reveal patterns the eye would miss, and make decisions transparent and repeatable. But they have limits. Outputs depend entirely on data quality, currency and resolution. They can give a false impression of precision, omit social context that does not map easily, and concentrate power with those who control the data. A strong answer treats the technology as essential decision support, not an automatic answer.
A balanced response shows how GIS, remote sensing and GPS work together to inform sustainable planning, while interpreting their outputs critically.
How the technologies work together
The three technologies are most powerful in combination rather than alone, and examiners reward students who show this integration. Remote sensing and satellite imagery supply up-to-date surface data over large areas, for example mapping vegetation loss or the spread of urban land cover. GIS then stores that imagery alongside other layers such as population, transport and hazard data and analyses the relationships between them. GPS links the desk-based analysis back to the real world by recording the exact location of field observations, so that ground truthing can confirm what the imagery suggests. A planning workflow might therefore use satellite imagery to detect change, GIS to analyse and model where growth should go, and GPS to verify conditions on site, with the final maps communicating the decision to the public and stakeholders. Showing this end-to-end chain, rather than describing each tool in isolation, demonstrates the applied understanding the course requires.
- Confusing GIS with a map
- GIS analyses layered data; a map is one possible output.
- Describing imagery without analysis
- Explain the pattern and its planning meaning, not just what is visible.
- Ignoring data quality
- Always evaluate date, resolution and source.
- Overstating objectivity
- Spatial technologies reflect the data and choices behind them; they are not neutral truth.
Exam-style questions
Questions in the style of SCSA exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
WACE 2022-style10 marksExplain how GIS, remote sensing and GPS are used in planning, and evaluate the limitations of relying on spatial technologies.Show worked answer →
A 10 mark response needs the role of each technology and a genuine evaluation.
Roles. GIS layers and analyses spatial data to map the present and run overlay or suitability analysis; remote sensing and satellite imagery capture surface information and monitor change over time; GPS provides precise location for field data and georeferencing. Together they support siting, monitoring and communicating decisions.
Evaluation. Outputs depend entirely on data quality, currency and resolution; technologies can give a false impression of precision; they omit social context that does not map easily; and they concentrate power with those who control the data.
Conclude that spatial technologies are essential decision support but not automatic or neutral answers. Markers reward the distinct role of each technology and a real evaluation of limitations.
WACE 2023-style6 marksExplain how overlay analysis in a GIS can help select a suitable site for new development.Show worked answer →
A 6 mark response needs the overlay mechanism and a worked criterion set.
Mechanism. A GIS stores data as layers, such as slope, flood risk, transport, vegetation and land ownership. Overlay analysis combines these layers so that only locations meeting all chosen criteria are highlighted.
Worked example. To site a sustainable suburb, a planner overlays layers to find land that is gently sloping, near transport, outside flood and habitat areas, and available, turning many separate datasets into a single defensible decision.
Conclude that overlay analysis lets planners weigh multiple spatial criteria at once, which a single map cannot do. Markers reward the layer-combination mechanism and a clear suitability criterion set.