1. Environmental GIS Nicholas A. Procopio, Ph.D, GISP nick@drexel.edu

2. Map Review A map is defined as a representation, normally to scale and on a flat medium, of a selection of material or abstract features on, or in relation to, the surface of the Earth. A map is defined as a representation, normally to scale and on a flat medium, of a selection of material or abstract features on, or in relation to, the surface of the Earth.

3. Map Characteristics Usually out of date Usually out of date Show only a static situation – one slice of time Show only a static situation – one slice of time Often elegant/artistic (much more so in distant past, more functional in recent times) Often elegant/artistic (much more so in distant past, more functional in recent times)

4. History of Maps Earliest direct evidence of mapping comes from the middle east. Earliest direct evidence of mapping comes from the middle east. Thought to be Babylonian clay tablets that depict the earth as a flat circular disk Thought to be Babylonian clay tablets that depict the earth as a flat circular disk Most date it as 2,300- 2,500 B.C. Most date it as 2,300- 2,500 B.C.

5. Early Views of the Earth Thales (625-547 BC) proposes a disc on an ocean Thales (625-547 BC) proposes a disc on an ocean Anaximander (611 – 554 BC) proposes a cylinder with the land curving on its surface Anaximander (611 – 554 BC) proposes a cylinder with the land curving on its surface Pythagoras (6 th century) – proposes a sphere due to geometrical perfection. Pythagoras (6 th century) – proposes a sphere due to geometrical perfection.

6. Early View of the Earth Cartography became considerably advanced in ancient Greece. Cartography became considerably advanced in ancient Greece. The concept of a spherical Earth was well known among Greek philosophers by the time of Aristotle (ca. 350 B.C.) and has been accepted by geographers since. The concept of a spherical Earth was well known among Greek philosophers by the time of Aristotle (ca. 350 B.C.) and has been accepted by geographers since.

7. Conceptualizing the Earth Eratosthenes (276 – 195 BC) first calculated the circumference of the earth. Eratosthenes (276 – 195 BC) first calculated the circumference of the earth. Value was determined to be 24,663 - 27,967 miles Value was determined to be 24,663 - 27,967 miles Actual value is 24,902 miles Actual value is 24,902 miles

8. Conceptualizing the Earth Ptolomey Ptolomey Defined the elements and form of scientific cartographyDefined the elements and form of scientific cartography Created first projection in 150 ADCreated first projection in 150 AD

9. Ptolemy’s Projection

10. Ptolemy’s View of the World Ptolemy promulgated a value for the circumference of the earth much less than the actual number Ptolemy promulgated a value for the circumference of the earth much less than the actual number This would have a significant impact on human history This would have a significant impact on human history By observing Ptolemy’s work, it appeared to Columbus that Asia was much closer to Europe By observing Ptolemy’s work, it appeared to Columbus that Asia was much closer to Europe

11. Early Map Forms As Europe entered the Dark Ages, the ideas about the shape of the earth were gradually lost. As Europe entered the Dark Ages, the ideas about the shape of the earth were gradually lost. In Europe, the view of the earth is based primarily on theologic premises. The map became a religious statement as opposed to a geographic tool. In Europe, the view of the earth is based primarily on theologic premises. The map became a religious statement as opposed to a geographic tool. Many outlying areas are decorated with religious symbols and mythical figures. Many outlying areas are decorated with religious symbols and mythical figures.

12. Early Arabic Maps Al-Idrisi was the leading mapmaker of the Middle Ages Al-Idrisi was the leading mapmaker of the Middle Ages His world map (shown with south oriented at the top) was world renown His world map (shown with south oriented at the top) was world renown

13. Early Maps Early European explorers often drew maps of newly discovered coastlines. Early European explorers often drew maps of newly discovered coastlines.

14. Mercator In the 16 th Century, Mercator created the Mercator projection In the 16 th Century, Mercator created the Mercator projection Allows mariners to sail to their destinations by following a rhumb line Allows mariners to sail to their destinations by following a rhumb line

15. A rhumb line is a line or direction on the surface of the earth that follows a single compass bearing and makes the same angle with all meridians, resulting in a curved spiraling toward the poles

16. Early Maps Waldseemüller's world map, 1507 Waldseemüller's world map, 1507 The first map to incorporate New World discoveries. The first map to incorporate New World discoveries.

17. Advancements in Cartography In the late 17 th Century, Newton proposes that the earth is not a true sphere but an oblate spheroid In the late 17 th Century, Newton proposes that the earth is not a true sphere but an oblate spheroid Proposal submitted as a corollary to his theory of gravitation Proposal submitted as a corollary to his theory of gravitation

18. Advancements in Cartography In the late 17 th Century and early 18 th century, measurements of degrees of latitude support Newton’s proposal that the earth is an oblate spheroid In the late 17 th Century and early 18 th century, measurements of degrees of latitude support Newton’s proposal that the earth is an oblate spheroid The length of a degree of latitude decreases northward, suggesting the earth flattens toward the top The length of a degree of latitude decreases northward, suggesting the earth flattens toward the top Soon after the establishment of degrees of latitude, degrees of longitude are established Soon after the establishment of degrees of latitude, degrees of longitude are established

19. Greenwich Prime Meridian The Prime Meridian, the first line of longitude, was established in 1884 The Prime Meridian, the first line of longitude, was established in 1884 The prime meridian was established as a means of developing a navigational and timekeeping standard, as the pace of development and travel accelerated in the 19th century The prime meridian was established as a means of developing a navigational and timekeeping standard, as the pace of development and travel accelerated in the 19th century

20. Greenwich Prime Meridian In 1884, 25 countries reached agreement at a conference in Washington, USA, that the Greenwich Meridian would be adopted as the `Prime Meridian' (zero degrees) from which time could be set and from which other points of longitude could be calculated In 1884, 25 countries reached agreement at a conference in Washington, USA, that the Greenwich Meridian would be adopted as the `Prime Meridian' (zero degrees) from which time could be set and from which other points of longitude could be calculated

21. Greenwich Prime Meridian Before the establishment of the prime meridian in 1884, almost every town in the world kept its own local time! Before the establishment of the prime meridian in 1884, almost every town in the world kept its own local time!

22. Advancements in Cartography In the 18 th Century, there is a rapid expansion of thematic mapping In the 18 th Century, there is a rapid expansion of thematic mapping Various layers of spatial data on a series of similar base maps Various layers of spatial data on a series of similar base maps 18 th Century maps of the Battle of Yorktown, drawn by French cartographer Louis- Alexandre Berthier contained hinged overlays to show troop movement.18 th Century maps of the Battle of Yorktown, drawn by French cartographer Louis- Alexandre Berthier contained hinged overlays to show troop movement.

23. Types of Maps Reference map Reference map Shows the simplest properties of the map dataShows the simplest properties of the map data Often display political boundaries, streams, roads, and townsOften display political boundaries, streams, roads, and towns Thematic map Thematic map Show colored, grouped, or coded information on a particular themeShow colored, grouped, or coded information on a particular theme

24. Types of Maps Topographic - a reference tool, showing the outlines of selected natural and man-made features of the Earth Topographic - a reference tool, showing the outlines of selected natural and man-made features of the Earth

25. Types of Maps Thematic map - a tool to communicate geographical concepts such as the distribution of population densities, climate, movement of goods, land use etc. Thematic map - a tool to communicate geographical concepts such as the distribution of population densities, climate, movement of goods, land use etc.

26. Chloropleth Maps Choropleth map - uses reporting zones such as counties or census tracts to show data such as average incomes, percent female, or rates of mortality Choropleth map - uses reporting zones such as counties or census tracts to show data such as average incomes, percent female, or rates of mortality

27. Isopleth Maps Isopleth map - shows an imaginary surface by means of lines joining points of equal value, "isolines" Isopleth map - shows an imaginary surface by means of lines joining points of equal value, "isolines"

28. Area Class Maps Area class map - shows zones of constant attributes, such as vegetation, soil type, or forest species Area class map - shows zones of constant attributes, such as vegetation, soil type, or forest species

29. Other Types of Maps Graduated symbol map Graduated symbol map Symbols locate features and the size of the symbol correlates to the value of the featureSymbols locate features and the size of the symbol correlates to the value of the feature

30. Other Types of Maps Dot map Dot map Dots depict locations of featuresDots depict locations of features

31. Map Features Title Title Symbols Symbols Legend Legend North Arrow North Arrow Place-names Place-names Credits Credits Inset Inset Scale Scale

32. Symbols Map symbols are the representations of the real-world features. The mapmaker can assign a certain symbol to represent a feature but most maps follow a specific guideline for representing features. Map symbols are the representations of the real-world features. The mapmaker can assign a certain symbol to represent a feature but most maps follow a specific guideline for representing features.

33. Map Representations

34. Legend The legend lists the symbols used on a map and what they depict The legend lists the symbols used on a map and what they depict The symbols should appear on the legend exactly as they do on the map The symbols should appear on the legend exactly as they do on the map

35. North Arrow The question of “what is north” can be an issue on some maps The question of “what is north” can be an issue on some maps The earth has a “true” north and a “magnetic” north The earth has a “true” north and a “magnetic” north Most maps reference true north Most maps reference true north

36. Inset Occasionally, data and observations may be densely cluttered in small sections of a map. Occasionally, data and observations may be densely cluttered in small sections of a map. The mapmaker provides insets to zoom in to these cluttered locations The mapmaker provides insets to zoom in to these cluttered locations

37. Scale The amount of reduction that occurs when taking the real world and expressing it as a map The amount of reduction that occurs when taking the real world and expressing it as a map In most maps, scale is extremely important In most maps, scale is extremely important Scale can be indicated by Scale can be indicated by Verbal (1 inch equals 2000 feet)Verbal (1 inch equals 2000 feet) Numeric (1:24,000)Numeric (1:24,000) GraphicGraphic

38. Scale Large scale map features are relatively large. Small scale map features are relatively small. Large scale map features are relatively large. Small scale map features are relatively small. Large Scale 1:1000 Large Scale 1:1000 Small Scale 1:250000 Small Scale 1:250000

39. Scale Large Scale Small Scale More Detail <-------------------> Less Detail 1:24,0001:100,0001:500,0001:1,000,000