Properties of Contour Lines
Compiled by Mark Francek (more info) at Carleton College (more info) (SERC) and Central Michigan University (more info)
Find animations helping students interpret hachured lines, contour spacing, and valley/ridge placement. There is even an animation that gives students practice drawing contour lines.
Contour Lines and Elevation, Exploring Earth and Steve Reynolds (more info) This animation features a static image of a contour surface on the left and an oblique 3-D view of the same area. Upon starting the animation, by clicking adjacent arrows, a surface of water begins to rise. By examining the views in both windows, a simulated flood shows how contour lines trace out equal elevations and how concave/convex undulations in the contour lines would be represented in 3-D. The animation can be paused and rewound to stress important points.
Interpreting Topographic Maps, San Diego State University (more info) This Flash animation delves into magnetic declination, the angle between magnetic north and true north. To see declination values, enter your locale declination in the input box (positive for east declination, negative for west declination). The true north on the frame will then reset to take into account inputted values, with true north shifting to the east for positive values and to the west for negative values.
Contour Lines and Valleys, Exploring Earth and Steve Reynolds ( This site may be offline. ) This animation features a static contour map to the left and a digital elevation model on the right that can be manipulated for different perspectives with arrow buttons. Focus on the main valley, indicated by concave-downward trending contours, that cuts through the center of both images. The valley is most prominent between two and six thousand feet. The animation can be paused and rewound to stress important points.
Hachures, Exploring Earth and Steve Reynolds ( This site may be offline. ) This animation includes a static contour map to the left and a digital elevation model on the right that can be manipulated for different perspectives with arrow buttons. This Flash animation focuses on the properties of hachured lines associated within a volcanic cone. Hachured lines are used to show closed depressions. The animation can be paused and rewound to stress important points.
Spacing and Contours Source, Exploring Earth and Steve Reynolds ( This site may be offline. ) This animation shows a static contour map to the left and a digital elevation model on the right that can be manipulated from different perspectives with arrow buttons. This Flash animation focuses on the spacing of contour lines. Widely spaced lines indicate gentle slopes while closely spaced contours indicate steep slopes. The animation can be paused and rewound to stress important points.
Draw Contours, Visual Entities (more info) This Flash animation allows students to create and edit contours. The "Draw" mode allows the user to point and click on the map placing control points that are connected by a contour line automatically. The delete or backspace removes control points. Clicking on the "Edit" mode button will place the correct configuration of individual contours at 10 foot intervals from a range of 610 ft. to 690 ft. At any one time, a student can only see the correct contour configuration for one interval. Note that the 630 and 640 closed contours located in northwest corner of the map should be marked as depressions and therefore hachured lines, although there is no indication that this is the case. This is a fairly challenging exercise for a beginning student but mastery of this exercise would indicate a good working knowledge of contour line properties.
