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Published byCandace Sutton Modified over 9 years ago
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October 9 th, 2011
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Let's look at our first topic under Mapping Skills - Contour Lines.
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A contour line on a map is a line that joins points of equal elevation.
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The contour line represented by the shoreline separates areas that have elevations above sea level from those that have elevations below sea level
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Lets review the basics of Latitude and Longitude
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(shown as a horizontal line) is the angular distance, in degrees, minutes, and seconds of a point north or south of the Equator. Lines of latitude are often referred to as parallels.
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Degrees latitude are numbered from 0° to 90° north and south Each degree of latitude is about 69 miles (111 km) apart
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(shown as a vertical line) is the angular distance, in degrees, minutes, and seconds, of a point east or west of the Prime (Greenwich) Meridian. Lines of longitude are often referred to as meridians
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The degrees continue 180° east and 180° west where they meet and form the International Date Line in the Pacific Ocea
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To precisely locate points on the earth's surface, degrees longitude and latitude have been divided into minutes (') and seconds
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Scale A map represents some portion of the earth or sky on a two dimensional surface. The size of the individual features need not be indicated if a map scale is given
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two dimensional feature of the earth’s surface. eg road map, city plan, drainage network map, map showing political boundaries
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shows three dimensional features of the earth’s surface, that is, the relief or topography of the land surface or ocean floor through the use of contour lines
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Map scale expresses the relationship(ratio) between distance on the map and the true distance on the ground (In reality) Every Map should have its scale clearly indicated Ex: 1:90000
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Lesson 2: October 22, 2010
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According my source in BC there would be no reason to use a calculator on the Geography Provincial exam Review Homework Scale Gradient Military Grid and Map Symbols Topographic map Interpretation Air Photo Interpretation
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Let's look at how to calculate gradient which is a measurement of the steepness of the land or simply slope
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A method to locate points on a map. With this method, a system of numbered lines is superimposed on a map and position is stated by quoting the numbers of the lines that intersect at the point in question.
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Let's look at some basic guidelines to assist you in interpreting an air photograph
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Shape Cultural features: - some features such as airport runways have a distinctive shape which make them easy to identify Natural features-- quite easy to tell the difference, for example, between an orchard (rows of trees with regular spacing) and a forest area with irregular tree growth
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formed by the repetition of a feature eg farm fields, rows of trees in an orchard, oil storage tanks at a refinery
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- high objects such as towers, chimneys, bridges, or high buildings cast shadows which help you to identify the object
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Cultural Features - roads and tracks will usually have a light grey tone as they are fairly reflective of light - railways: medium grey - bridges: vary according to construction material
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Natural Features Water - generally appears dark grey or black since it absorbs much of the light
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Vegetation - most will vary from shades of grey to black
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Soil - bare ground usually has a light colour but the wetter it is, the darker the tone
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Crops - cultivated fields and fallow fields are almost white in tone
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General Guide Spring: sharp, distinct field patterns due to differences in tillage and crop development Summer: dark tones for maturing crops and heavily leafed trees Fall: distinct field patterns because of the various stages of crop development and harvesting Winter: when there is little or no snow cover, tones are generally drab and dull
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See Notes for Interpretation http://www.sd36.bc.ca/sites/semiah/mleziva/uni t2/U02L09.htm http://www.sd36.bc.ca/sites/semiah/mleziva/uni t2/U02L09.htm Homework
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