Heat Maps as a Layer Styling Tool in GIS

What are Heat Maps?

Heat maps are graphical representations where data values are displayed through a color gradient. The higher the value, the more intense (or brighter) the color shade.

Why Use Heat Maps?

Heat maps make it easy to visualize the density of specific phenomena or data within an area, highlighting the most and least intense regions. They can represent various metrics like temperature, population density, pollution levels and more.

Additionally heat maps aid in data analysis and interpretation, supporting forecasts and informed decision-making based on visually presented information.

Where to Apply Heat Maps?

• Climatology and Meteorology

  Used to display temperature anomalies, precipitation levels, wind speed, and other weather data. Heat maps help researchers and meteorologists analyze climate trends and make weather predictions.
  
  

• Geography and Geology

  Applied to represent natural phenomena such as earthquakes, volcanic activity, hydrological processes, and more. Geologists use them to understand geomorphological features and Earth surface processes.
  
  

• Ecology and Environmental Protection

  Applied for tracking the distribution of living organisms, pollutants, air and water pollution levels, and other ecosystem-impacting parameters. They assist in planning environmental conservation and restoration efforts.
  
  

• Transportation and Urban Planning

  Used to analyze traffic flows, infrastructure load, population distribution, and other factors influencing urban and regional development. Heat maps facilitate optimized planning of transport routes and urban spaces.
  
  

• Marketing

  Used to analyze customer distribution, purchase patterns, demand, and other data, helping companies identify trends and improve sales and marketing strategies.

Key Benefits of Using Heat Maps

• Ease of Understanding Information

  The use of a color gradient in heat maps makes complex data more accessible and intuitive for users, simplifying the process of interpreting information at a glance.
  
  

• Revealing Patterns and Trends

  Heat maps are powerful in uncovering hidden patterns, correlations, and trends within data. These insights can be instrumental in guiding data-driven decisions and identifying areas for further investigation.
  
  

• Efficient Visualization of Large Data Sets

  Heat maps offer an effective way to represent large volumes of data within a compact area. By displaying extensive information without overwhelming the viewer, they ensure clarity while preserving detail.
  
  

• Spotting High-Density Areas or "Hot Spots"

  One of the main strengths of heat maps is their ability to highlight areas with the highest or lowest density of a given phenomenon, helping users focus on critical points of interest.
  
  

• Enhanced Communication and Presentation

  Heat maps serve as an excellent visual tool for presenting research results or complex reports, providing a clear, straightforward format that appeals to a broad audience and facilitates understanding.

How to Use Heat Maps in GISCARTA

Heat maps can be created using specialized software and online services like QGIS, ArcGIS, Tableau, Google Maps, and others. GISCARTA also provides a heat map styling feature for layers. Here’s how to set it up:

Step 1: Access Layer Display Settings

To adjust the display style of a layer, go to the layer settings by clicking the three dots on the right side of the layer’s name.

In the pop-up window select Properties.

Step 2: Configure Layer Styling

In the Layer Settings menu, select Styling.

From the available styling options, choose Heat Map as the tool for layer visualization.

Step 3: Set Up the Heat Map

In the Attribute section, select a numeric field from the data attribute table to determine the color intensity of each point. If no attribute is chosen, all points are assigned the same intensity, and the heat map is based on point density. When an attribute is selected, each point will be weighted according to its attribute value.

Next, select a Color scheme to display the heat map.

The Radius slider lets you adjust the size of the circle representing each point on the map.

Another characteristic, Blur, controls the softness of the circle’s boundaries.

How is the Heat Map Scale Built?

If an attribute is selected, each point is weighted based on the attribute's value. The weight of a point can vary from 0 to 1. If the value exceeds 1, it defaults to 1, and if it’s below 0, it defaults to 0. To achieve accurate results, it’s best to use an attribute with values scaled between 0 and 1.

In the Alias column, you can set a label for the layer legend. The legend will display in the project as a color gradient.

The final map styled as a Heat Map may look like this:

Our findings show that heat maps are an effective way to interpret the spatial distribution of various phenomena. You can now confidently use this tool in your new projects!