Mapping Earth Midterm Review Topics u Isolines u

Mapping Earth Midterm Review Topics: u. Isolines u. Drawing isolines u. Topography maps) (Reading Contour –Finding Interval –Hills –Steep/gradual slopes –Gradient –River Direction –Maximum/minimum elevation –Depressions (hachured marks) u. Profiles

Isolines u Connect points of equal value – Isotherm: temperature – Isobars: barometric (air pressure) – Contour lines: elevation

Drawing Isolines u Connect the points with the same value u Estimate between which other values the line should be drawn u Lines should be curved, not angular u Extend lines to edge of map u Never cross isolines

Topography (Contour maps) u 1 -dimensional representation of a 3 D landscape u Shows the shape of the land

Finding Interval u Difference between one contour line and the next u May be given on map u Labeled lines are Index Contours

u Subtract the value of two consecutive Index Contour Lines u Then count how many contour lines there are from one Index Contour to the next (only count one of the Index Contours) u Divide the difference by the # of lines 300 -200=100 m 5 lines 100/5= 20 m

Hills u Hills or mountains are shown by contour lines that form closed loops

Steep/gradual slopes u Steep Slope: contour lines are close together u Gradual apart Slope: contour lines are far

Gradient Difference in Elevation Distance between two points u Label with given units!

River Direction u Contour lines bend upstream

Ocean is Sea Level = 0 elevation

Depressions (hachured marks) u The first hachured line is the same value as the last contour line. u Each hachured line decreases by the contour interval

0 u Interval = 10 u 1 st Hachured line = 20 u Elevation at point A= 10 u Ocean=

Inferring Maximum/minimum elevation u Max: Value just below what the next contour line would equal Z= 99 ft u Min: Value just above what the next contour line would equal Y= 21 ft • Z • Y

Maximum Elevation u Represented by Triangle symbol

Profiles u Cross section (side view) of the contour map u Use mark and slide method u Keep a STEADY hand u No numbers on x-axis u Use contour interval on Y-axis

What the max atflowing? point E? What is direction is elevation Mud Creek What is the 139 SE contour interval? 20