HillshadeModelle

HillshadeModelle, often translated as hillshade models, are digital representations of terrain topography used to simulate how sunlight would illuminate a landscape. They are created by processing a digital elevation model (DEM) to calculate the illumination intensity for each point on the surface based on a defined light source direction and angle. This process typically involves determining the slope and aspect of the terrain at each pixel and then applying a mathematical function to estimate the degree of illumination.

The primary purpose of hillshade models is to enhance the visual perception of terrain relief in maps and digital displays. By adding shading, subtle topographic features that might be lost in a flat representation become more apparent. This makes them invaluable tools for cartography, geographic information systems (GIS), and environmental analysis. They can help visualize mountain ranges, valleys, ridges, and other landforms, providing a more intuitive understanding of the landscape's structure.

The parameters used in generating a hillshade model, specifically the azimuth (horizontal direction of the light source) and altitude (vertical angle of the light source), significantly influence the final appearance. Common defaults often place the light source in the northeast or southeast, mimicking the sun's typical position. While useful for visualization, hillshade models do not represent actual illumination levels but rather a symbolic interpretation of light and shadow to emphasize topography. They are often used in conjunction with other map layers, such as contour lines or color-coded elevation data, to create rich and informative visualizations.