Visual analysis plays a key role in geographic information systems (GIS), especially when working with multi-temporal and heterogeneous spatial data. Many practical tasks require not just displaying multiple layers, but also visually comparing them to identify differences, trends, and changes. The traditional method of turning layers on and off one by one often proves inconvenient and incomplete.

How the Layers Comparison Widget Works

The widget is designed to visually compare two map layers by splitting the displayed map. The user can interactively change the layer display boundary, observing differences in real time.

The most common mode is the Swipe mode: the map is divided by a vertical or horizontal line, which the user drags, revealing one layers on top of the other.

The widget can be applied to both raster data (satellite images, digital elevation models, soil property maps) and vector layers (plot contours, soil polygons, administrative boundaries).

Unlike analytical tools that generate quantitative indicators, this widget is primarily focused on visual interpretation. Its main advantage is the quick and clear identification of spatial differences without complex computational procedures.

Application

The layers comparison widget is widely used in various fields of spatial analysis.

One of the most common applications is monitoring land use and land cover changes, where satellite images from different periods are compared to identify urbanization, deforestation, or the transformation of agricultural lands.

In soil and environmental studies, the tool allows for the comparison of soil property models, assessment of differences between datasets, and visual verification of digital soil mapping results.

For "before-after" tasks, the widget is used to assess the impact of natural disasters, implement infrastructure projects, and perform land reclamation or restoration activities.

In urban development and territorial planning, it is used to analyze historical and modern maps, assess spatial development, and assess changes in functional zoning.

Furthermore, the interactive nature of the tool makes it an effective presentation and communication tool, especially in web GIS and public mapping services.

The GISCARTA platform also implements a layer comparison widget, which will be described below.

Working with the widget on the GISCARTA platform

Step 1. To start working with the widget, you need to enable its availability on the toolbar.

Step 2. Now you need to configure the widget in its working window.

You must select the layers that will be compared with the original project.

You can also customize the comparison display:

– left/right, bottom/top.

– vertically/horizontally/through a magnifying glass

FAQ

What is the Layers Comparison widget used for?
It is designed for simultaneous visual comparison of two map layers to identify changes and differences.

What data types are supported?
The widget works with both raster layers (images, models, thematic maps) and vector layers (polygons, boundaries, contours).

What comparison modes are available in GISCARTA?
You can customize the direction (left/right, top/bottom) and display format (vertical, horizontal, or through a magnifying glass).

Key Takeaways

The Layers Comparison widget provides a visual and quick way to identify spatial differences between layers.

This tool is widely used in monitoring territorial changes, environmental analysis, and urban planning.

Flexible display settings in GISCARTA allow you to tailor the comparison mode to specific analytical tasks.