Mapping the world Field- Any region of space that has some measurable value. Field value- The thing that is being measured in the field (represented on a map).

Examples: elevationtemperature air pressuresnow depth pollution concentration These are all shown as isolines

Isoline- A line that connects points of EQUAL field values. Examples: Type of linefield value Contour lineelevation Isothermstemperature Isobarsair pressure

Interval Equal change in value from one isoline to the adjacent isoline (what the lines go by). Must remain the same for the whole Field Map.

Index Contours Numbered contour lines Darker or different color. Normally have even values.

Valleys Lower elevations between hilltops or peaks. Relief: –The difference between highest and lowest point on a map (Top of hill to bottom of valley). –*Note Rivers flow through lowest areas.

Rivers/Streams Water must flow downhill. When crossing a stream, contour lines must bend (point) upstream! (Like an arrow head pointing up hill)!

Steep location or Flat? Steep area (Fast change)-Contour lines are close together. Flat area (Slow change)-Contour lines are farther apart.

Gradient Calculation Use the equation on the front of your ESRT Substitute the data into the equation Solve with proper units!!

STOP HERE AND CALCULATE

Rules for drawing Isolines Connect points of the same value with one line. Always keep higher values on one side and lower values on the other side. Lines should be curved smoothly (no sharp angles).

Lines should close in a loop or run off the field. Interval between lines must be the same (contour interval) Adjacent lines should form similar shapes.

Lines must never touch or cross one another. *When crossing a stream, contour lines must bend (point) upstream.