The
Science
of
Geography


Essen/als of Geography GEOGRAPHY 101 • • • • • The Science of Geography Earth Systems Concepts Loca/on and Time on Earth Maps, Scales, and Projec/ons Remote Sensing and GIS The Science of Geography GEOGRAPHY IS: • Geography – from geo “Earth” and graphein “to write” • Geographers use spa/al analysis • Geographers use Earth systems science THE STUDY OF THE SPATIAL RELATIONSHIP BETWEEN HUMANS AND THEIR ENVIRONMENT ON THE SURFACE OF THE EARTH 1 Geography is SPATIAL: • The science that studies the rela/onships among – natural systems, – geographic areas, – society, – cultural ac/vi/es, – and the interdependence of all of these over space. NATURE AND CHARACTER OF PHYSICAL SPACE ITS MEASUREMENT, INTERRELATIONSHIPS AND THE DISTRIBUTION OF THINGS WITHIN IT Physical Geography is • The spa/al analysis of all the physical elements and processes that make up the environment. Earth Systems Concepts • • • • • Systems Theory Open systems Closed systems System feedback System equilibrium 2 ATMOSPHERE HYDROSPHERE THE ENERGY - ATMOSPHERE SYSTEM THE WATER, WEATHER, AND CLIMATE SYSTEM THE THIN VEIL OF GASES SURROUNDING EARTH THE OPEN SYSTEM CONTAINING ALL OF THE EARTH’S WATER FORMS A PROTECTIVE BOUNDARY BETWEEN OUTER SPACE AND THE BIOSPHERE CONSISTS OF THREE STATES : EXTENDS OUT ABOUT 300 MILES FROM THE EARTH’S SURFACE LIQUID, SOLID, AND GASEOUS WATER HAS IMPORTANT HEAT STORAGE PROPERTIES FORMED BY GASES ESCAPING THE EARTH’S CRUST AND INTERIOR . . . WATER IS AN EXTRAORDINARY SOLVENT AND FROM ALL THE EXHALATIONS OF ALL LIFE OVER TIME LITHOSPHERE THE EARTH - ATMOSPHERE INTERFACE EARTH’S CRUST . . . AND THE PORTION OF THE UPPERMOST MANTLE DIRECTLY BELOW THE CRUST Loca/on and Time on Earth • • • • La/tude Longitude Great circles Prime Meridian and standard /me EXTENDS DOWN ABOUT 45 MILES CONTAINS THE EARTH’S SOILS 3 LATITUDE ANGULAR DISTANCE MEASURED NORTH OR SOUTH OF THE EQUATOR FROM A POINT AT THE CENTER OF THE EARTH LONGITUDE THE ANGULAR DISTANCE EAST OR WEST OF A PRIME MERIDIAN FROM A POINT AT THE CENTER OF THE EARTH A LINE CONNECTING ALL POINTS OF THE SAME LATITUDINAL ANGLE IS A PARALLEL THE EQUATOR IS AT 0* A LINE CONNECTING ALL POINTS OF THE SAME LONGITUDE IS A MERIDIAN THE POLES ARE AT 90* NORTH AND SOUTH LONGITUDE THE PRIME MERIDIAN . . . PARALLELS: CONNECT POINTS OF EQUAL LATITUDE IS AN ARBITRARY MERIDIAN DESIGNATED AS 0* LONGITUDE IT IS THE POINT FROM WHICH . . . LONGITUDES ARE MEASURED EAST OR WEST GREENWICH, ENGLAND WAS SELECTED BY INTERNATIONAL AGREEMENT IN 1884 MERIDIANS: CONNECT POINTS OF EQUAL LONGITUDE 4 Maps, Scales, and Projec/ons EARTH REVOLVES 360* EVERY 24 HOURS 15* OF LONGITUDE EVERY HOUR SO EACH TIMEZONE COVERS APPROX. 15* OF LONGITUDE MAPS A MAP IS A GENERALIZED VIEW OF AN AREA . . . • Map – a generalized view of an area, as seen from above and reduced in size • Scale – ra/o of map units to ground units • Projec/on – process of transforming spherical Earth to flat map SCALE IS THE RATIO OF THE DISTANCE ON A MAP TO THAT IN THE REAL WORLD USUALLY SOME PORTION OF EARTH’S SURFACE . . . AS SEEN FROM ABOVE . . . IN TWO DIMENSIONS . . . AT A GREATLY REDUCED SCALE SCALE IS EXPRESSED AS A: REPRESENTATIVE FRACTION GRAPHIC SCALE WRITTEN SCALE 5 SCALE A 1:1 SCALE WOULD MEAN . . . THAT AN INCH ON THE MAP REPRESENTS AN INCH ON THE GROUND THIS SCALE IS IMPRACTICAL . . . BECAUSE THE MAP WOULD BE AS LARGE AS THE AREA BEING MAPPED A MORE APPROPRIATE SCALE FOR A LOCAL MAP IS 1 : 24,000 MAP PROJECTIONS A SCALE OF 1 : 24,000 IS A LARGE SCALE . . . OBJECTS APPEAR LARGER SO THE MAP IS LESS ABSTRACT A GLOBE IS THE ONLY TRUE REPRESENTATION OF: DISTANCE DIRECTION AREA A SCALE OF 1 : 50,000,000 IS A SMALL SCALE . . . OBJECTS APPEAR SMALLER SO THE MAP IS MORE ABSTRACT SHAPE PROXIMITY A FLAT MAP . . . DISTORTS THESE PROPERTIES 6 MAP PROJECTIONS A MAP PROJECTION . . . IS THE REDUCTION OF A SPHERICAL GLOBE ONTO A FLAT SURFACE . . . Remote Sensing • Ac/ve remote sensing • Passive remote sensing IN SOME ORDERLY AND SYSTEMATIC REALIGNMENT OF THE LATITUDE AND LONGITUDE GRID Geographic Informa/on Systems (GIS) • GIS systems combine spa/al and aTribute data • Maps can contain mul/ple data layers: – Physical features – Cultural features • Layers can be added to create composite overlay 7