Explanation: The elevation gradient between each contour line is the contour interval, which is usually indicated on the map. It represents the difference in elevation between adjacent contour lines. It's important that each contour line represents the same amount of gain or loss in elevation because it allows us to accurately determine the elevation of any point on the map. If the contour interval is not consistent, it can be difficult to accurately determine the elevation of a point, which can be critical in certain situations, such as hiking or mountaineering.