What is the primary purpose of using sun altitude and sun azimuth in GIS?

The primary purpose of using sun altitude and sun azimuth in GIS is to enhance terrain visualization and modeling. Sun altitude refers to the angle of the sun above the horizon, while sun azimuth is the compass direction from which the sunlight is coming at a specific point in time. These two measurements are crucial in digital terrain modeling and visualization because they help in creating realistic representations of landscapes, especially when simulating how sunlight interacts with topography.

When analyzing terrain, the way light casts shadows and highlights different features can significantly affect the perception of the landscape. By adjusting the sun altitude and sun azimuth in GIS, users can produce shaded relief maps that illustrate the three-dimensional aspects of the terrain. This adds depth to the visualization, making it easier to interpret elevation changes, slopes, and other geographic features.

In contrast, the other options do not primarily involve the interaction of sunlight with terrain. Weather patterns are not directly analyzed through sun position; land use changes focus on human activities over time, and wildlife migration patterns are more concerned with animal behaviors rather than light conditions. Thus, using sun elevation and azimuth primarily serves to improve the representation and understanding of physical landscapes in GIS.