GEOG 286 Lecture Notes - Lecture 14: Digital Elevation Model, Viewshed, Azimuth
Document Summary
Note: look at turkey thing for test three, will be stuff on datums and coordinate systems. Terrain analysis: analyzes characteristics of terrain using a digital elevation model (dem) Widely used in physical geography, geology, hydrology, planning, archaeology, engineering, ecology. Slope: the flatness or steepness of the terrain, expressed in degrees, percent grade, based on focal and local operations. Rise: change in elevation, difference between two cells. Run: change in 2d distance, distance between two cells. Contour: contour lines connect locations with the same elevation, useful for understanding election, slope, drainage, etc. Hillshade: illumination of terrain by artificial light source, values from. Helps reveal terrain features (cliffs, water bodies), direction that landscape features fadce. Main settings: altitude (angle of light sources above horizon), azimuth (direction of light source shines from) Aspect: direction the terrain faces, outputs value from -1 to 359 with 0 = n, 90 = E, 180 = s, 270 = w, -1 = flat.
