{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture14 - Contours on maps What CI Geography 12 Maps and...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Geography 12: Maps and Spatial Reasoning Lecture 14: Representing heights on maps Professor Keith Clarke Contours on maps. What CI? What is a contour line? Imaginary line joining points of equal elevation above or below a datum Contour lines have a specific contour interval Interval is the vertical distance between contours CI is a function of scale and units Relief is the highest elevation shown minus the lowest Contour lines
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 Features of contours Contour interval Index contours Intermediate contours Supplementary contours • Depressions Uncertain contours Bathymetry: isobaths Contour interpretation Interpolation 100 x CI=20m Y Z X > 140 and < 160 Y > 120 and < 140 Z > 100 and < 120 Slope Slope = Rise vs. Run Four expressions: Slope ratio (e.g. 1:10) Slope fraction (e.g. 1/10) Percent slope (rise per 100 units of run) 10% Degrees from horizontal (tan S = rise / run)
Image of page 2