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Defining a real-world problem and designing a comprehensive GIS workflow to address it.
Can you prove exactly where a new community garden would have the highest impact on urban heat islands? With GIS, you don't just guess; you calculate the solution.
Every great GIS project begins with a Spatial Question. Unlike a general research question, a spatial question specifically investigates how location, proximity, or distribution influences a phenomenon. To be effective for a capstone, your question must be researchable—meaning you can answer it using available data and GIS tools. A weak question might be: 'Is there pollution in the city?' A strong spatial question is: 'What is the correlation between industrial zoning proximity and air quality index (AQI) readings within a radius of residential neighborhoods?' This defines the where (residential neighborhoods), the what (AQI and industrial zones), and the how (correlation within a specific buffer).
Quick Check
What is the primary difference between a general research question and a spatial question?
Answer
A spatial question specifically focuses on how location, proximity, or geographic distribution affects the subject of study.
1. Start with a topic: Renewable Energy. 2. Add a location: Cape Town, South Africa. 3. Add a spatial constraint: 'Which rooftops in the central business district have the highest solar potential based on aspect and shading?' 4. Final Question: 'How many megawatts of solar energy can be generated if of north-facing roofs in the CBD are utilized?'
Once your question is set, you must identify your Data Inventory. GIS data generally falls into two categories. Vector data represents discrete features using points (wells), lines (roads), or polygons (city boundaries). Raster data represents continuous surfaces using a grid of cells, or pixels, where each cell contains a value (e.g., elevation or temperature). For a sustainable development project, you might combine vector layers (like 'Bus Stop Locations') with raster layers (like 'Population Density Grids'). You must also document Metadata—the data about the data—which includes the source, the date of collection, and the coordinate system used.
Quick Check
If you are analyzing the average temperature across a province, would you use vector or raster data?
Answer
Raster data, because temperature is a continuous surface rather than a discrete point or line.
Scenario: Planning a new wildlife corridor. 1. Vector Layer: Protected forest boundaries (Polygons). 2. Vector Layer: Known animal sighting locations (Points). 3. Raster Layer: Digital Elevation Model (DEM) to calculate slope (Grid). 4. Raster Layer: Land Cover classification (Grid).
Which of the following is a properly formatted spatial question?
You are calculating the NDVI to check vegetation health. If and , what is the NDVI value?
In a weighted overlay analysis, the sum of all weights () should typically equal 1.0 (or 100%).
Review Tomorrow
In 24 hours, try to explain the difference between a Buffer and an Intersection to a peer, and write down the NDVI formula from memory.
Practice Activity
Open a GIS software (like QGIS or ArcGIS) and try to find the metadata for a local open-data layer. Identify its coordinate system and last update date.