What is Topography? • Topography – the study of shapes and features on Earth’s surface • Differences in Elevation – height above sea level • Sea Level = 0 feet/meters (base)
How to Read a Topography Map • Basic Unit = Sea Level • Benchmark – a point that has been accurately measured for its position/elevation\ • Contour Lines – “circles” that mark different levels of elevation (same interval)
Steepness and Slope • Contour line interval - the difference in elevation between neighboring contour lines • Contour lines CLOSE together = VERY steep • Contour lines FAR away = VERY gradual
Quick Quiz #3The contour interval is 50 meters • If the first contour line is at sea level, what is the highest elevation (A)? • How high is Point 3? • Which side, east or west, is steeper? How do you know?
Accuracy vs. Precision. Write your own definitions… Accurate. Precise.
Accuracy and Precision • Accuracy – how close you are to the desired outcome/measurement • CAN BE DONE IN 1 TRIAL • Precision – how close your measurements are to one another • MUST BE DONE IN MULTIPLE TRIALS
Accurate or Precise? Precise!