Monday 27 August 2012


Geographical Space Components


 

Geographical Space Characteristics

Geography studies the” humanized space” ( Where a human society is in interaction with the environment).

Geographical Space is the perceived space and continuously transformed by the relationship between its natural, social, economic, politic and cultural characteristics.  The geographical space has changed through time because of natural processes as well as human intervention.

 
Geographical Space Characteristics´ Components


Each characteristic is formed by a group of components, for example the ones sown on the chart below:

 


Natural
Social
Cultural
Economic
Politic
 
* soil
 
* water
 
* climate (weather)
 
* relief
 
* flora
 
* fauna
 
*population dynamics
 
- growth
- migration
 
* ethnics
 
- languages
- religions
 
 
 
* artistic demonstrations
 
* cultural globalization
 
* people´s cultural heritage
 
* economic activities
 
* trade flows
 
* communication channels and means
 
* political organization
 
* international conflict
 
* international organizations
 

 
Geographical Space Categories

 
Diversity means variety and is the result of the combination of natural, social, cultural, economic and politic aspects to  local, national or worldwide levels. Climate, relief, natural resources, how population uses  them, etc., produce a great diversity of the geographical space and that is why there are  different regions, landscape, views and territories with environmental, cultural and economic  characteristics that make them unique.
 
Analysing these components and characteristics we will know if the space we are  talking about is urban, rural, semi- rural, etc.
 
 
Spatial Analysis Categories

Geography studies the”humanized space” ( Where a human society is in interaction with the environment).

Geographical Space is the perceived space and continuously transformed by the relationship between its natural, social, economic, politic and cultural characteristics. The geographical space has changed through time because of natural processes as well as human intervention.
  
Analysis of the geographical space will lead you to understand that you belong to a time and a space and that we are related with the natural and social changes that surround us. There are 5 main categories for spatial analysis and they are:

Place or Site: Is the smallest unit of analysis, is any place where a human can carry out his/her daily activities, it can be a neighborhood, a park a city. It is a place which creates a feeling of belonging and identity with a community. (room, house, school, neighborhood, club, park, etc.).

 
Environment: is the surrounding area of where we live. When we refer to the physic or biologic characteristics of a place we are talking about the natural environment, for example the jungle around the Amazon River. The social or human environment is which contains cultural or economic demonstrations like Chichen Itzá or te petroleum zone of Minatitlán.  You can also talk about a rural or urban environment.

 
Landscape:  Is the group of components perceived by the eyes and that has specific characteristics like vegetation, climate, relief, etc. It can be natural (woods, desert, jungle, etc.) or social or modified (rural, urban, semi urban, etc.)

 
Region: Is a geographical space characterized by some natural, cultural or economic  elements that differentiates it from others. For example close areas that share the same climate may form a climate region (cold, warm, tropical, etc.). We can also talk about agricultural regions, language regions or cultural regions.
 

Territory: Is the space that shares the same government. It is limited by artificial or natural frontiers (state, country, municipality, etc.). It´s study belongs to national or local scale.

 

Relationship of Geographical Space Components in a Place, Environment, Landscape, Region and Territory.
 

The interaction between the components results in all the elements (natural, social, cultural, economic and politic) being related. For example the different climates influence the variety of natural regions, in the economical activities of each place and the social and politic organization of its inhabitants.
 

There is an enormous diversity in our country and world. This diversity is so big because the combinations of the components vary and the people who inhabit them gives each special characteristics. ( Broadway Street in New York, Garibaldi´s Square in Mexico City, etc. where the  demonstration of artistic folklore gives each a characteristic  aspect that distinguishes them from other places.

 

The main division form of recognizing an environment is urban or rural, but urban or rural zones can be very different according to the country , region territory, etc.
 


Utility of Graph and Number Scales on maps

 


 

Geographic Space can be analyzed to different scales: worldwide, national or local.

 

A map can show continents, countries, states, and cities or show the roads and landmarks of a town. It can show routes of a transportation system, such as bus or subway lines, different landforms and elevations, different kinds of natural resources, or varying temperatures in a specific area. A map can also show historical data, such as changes in population, housing development, or crime. A globe is a map on a round model that shows places on Earth.

A map key or map legend is a chart that explains what symbols mean on a map. On many navigational maps, a black dot stands for a city, a star stands for a state’s capital, and a star inside a circle stands for a country’s capital. Airplanes stand for airports and black or yellow lines stand for highways, roads, or streets. Different maps have different symbols, though many share the same basic symbols.



Many maps have a compass rose, which is a tool that displays directions. The cardinal directions are north, east, south, and west. The intermediate directions are the points in between the cardinal directions: northeast, northwest, southeast, and southwest.

 
 
 

 

Many maps also have a scale, which is a tool that compares distance on a map to distance on Earth. The scale helps the user figure out real-life distances by looking at a map. For example, suppose there is a map where 1 inch represents 1 mile. Two landmarks that are 3 inches apart on the map are 3 miles apart on Earth. Different maps have different scales so you should always refer to the map key or legend to look for the scale.

 
 

 

Remember that a map is a visual representation of a much larger area of land. In order to be useful, a map must by necessity be small enough to be handled by an individual.

 

Because the Earth is round and maps are flat, it is impossible to create a map with a perfect scale. Some parts of the map will be too large, while others will be too small. The larger a territory represented by a map, the greater that the distortions in scale will be.

 

It is important that we recognize how to read, understand, and utilize scale as we examine the various maps that we encounter. There are three common methods used by map makers to depict scale. These methods are referred to as the graphic method, the verbal method, and the fractional method.

 

The Graphic Method

 

A Graphic Scale depicts scale using a line, with separations marked by smaller intersecting lines, similar to a ruler. One side of the scale represents the distance on the map, while the other side represents the true distances of objects in real life. By measuring the distance between two objects on a map and then referring to the graphic scale, it is easy to calculate the actual distance between those same items.

 


 

There are many benefits to using a graphic scale. First and foremost, it is a straight forward, easy way to determine scale. Secondly, if a map’s size is enlarged or decreased, the scale is also enlarged or reduced, meaning that it is still accurate.

 

The Verbal Method

The verbal method of depicting scale simply uses words to describe the ratio between the map's scale and the real world. For example, a map might say something like, “one inch equals one hundred and fifty miles.” Calculating scale on a map using the verbal method is easy. Simply measure the distance on the map and then follow the verbal directions to calculate the actual distance.





 








 

The Fractional Method

The fractional method for portraying the scale of a map uses a representative fraction to describe the ratio between the map and the real world. This can be shown as 1:50,000 or 1/50,000. In this example, 1 unit of distance on the map represents 50,000 of the same units of distance in the real world. This means that 1 inch on the map represents 50,000 inches in the real world, 1 foot on the map represents 50,000 feet on the map.

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Large Scale Map Versus Small Scale Map

 

A map which depicts a small territory is referred to as a large scale map. This is because the area of land being represented by the map has been scaled down less, or in other words, the scale is larger. A large scale map only shows a small area, but it shows it in great detail. A map depicting a large area, such as an entire country, is considered a small scale map. In order to show the entire country, the map must be scaled down until it is much smaller. A small scale map shows more territory, but it is less detailed.

 

Map Reading – Measuring Distances

 

1. Scale:

Objects on the map are drawn to scale: this means the length is changed by the same proportion as the width.

Example:

 

The most used are usually 1:50000 (most common) or 1:25000 scale maps.

 

For a 1:50000 map: 1 cm on the map equals 50000 cm on the ground (which is the same as saying 1 cm = 500 m or 2 cm = 1000 m).

 

For a 1:25000 map: 1 cm on the map equals 25000 cm on the ground (which is the same as saying 1 cm = 250 m or 4 cm = 1000 m).

 

In map reading we usually measure distances in kilometres (km) instead of metres (m). 1 km = 1000 m.

 

Key Ideas:

 

A grid square is 1 km by 1 km on the ground. This means a grid square measures 2 cm across on a 1:50000 map or 4 cm across on a 1:25000 map.

 

A 1:25000 map has twice as much detail as a 1:50000 map, because the grid squares are twice as large.

 

 

 

2. Estimating Distances:

 

As said above, a grid square measures 1 km by 1 km. The diagonal distance(from bottom left to top right say) on a grid square is approximately 1.5 km. A quick method of measuring a straight line on the map is to count grid squares:

 

Examples:

 

• If a straight road covers 4 grid squares on the map, it will measure approximately 4 km on the ground.

• If the straight edge of a forest covers 3.2 grid squares on the map, it will measure approximately 3.2 km on the ground.

• If a road runs diagonally across two grid squares it will measure about 3 km on the ground.

 

Please note this is a rough method only. It is not suitable for accurate measurements.

 

3. Accurate Measurement of Distances

Height = 3 cm

Length = 6 cm

 

Reduced by 50%:

 

Height = 1.5 cm

Length = 3 cm

 

Part A: To measure a straight line between two points:

 

• Use a ruler and convert the ruler measurement to the distance on the ground.

• Alternatively, lay the straight edge of a piece of paper between the points and mark the paper where they are. Transfer the paper edge to the scale bar at the bottom of the map and read off the distance on the ground.

 

Part B: To measure a winding route:

• Use a piece of paper with a straight edge and ‘work’ it along the route on the map.
 


 

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Remember which mark on your paper strip is the start of the route.

Don’t take the paper strip off the map – just mark it and rotate it when you get to a bend on your route.

When you’ve put the last mark on your paper strip (eg. the end of your route) lay the strip over the scale bar at the bottom of the map.

Read off the distance between the start and end marks on your paper strip.

You can also use string to measure distances on the map. Knot or mark your string at the start of the route and work it round in the same way you would the paper strip. Proper map measurers can also be purchased from outdoor shops.

 

Practice this method to get good at it. Measuring distances is a very important

 

 
 
Geographic Coordinates and Time Zones

Latitude and Longitude


Latitude and longitude lines are use to locate coordinates on the earth or on a map.

In classical Greece and China, attempts were made to create logical grid systems of the world to answer this question. The ancient Greek geographer Ptolemy created a grid system and listed the coordinates for places throughout the known world in his book Geography. But it wasn't until the middle ages that the latitude and longitude system was developed and implemented. This system is written in degrees, using the symbol °.

Latitude


When looking at a map, latitude lines run horizontally. Latitude lines are also known as parallels since they are parallel and are an equal distance from each other. Each degree of latitude is approximately 69 miles (111 km) apart; there is a variation due to the fact that the earth is not a perfect sphere but an oblate ellipsoid (slightly egg-shaped). To remember latitude, imagine them as the horizontal rungs of a ladder ("ladder-tude"). Degrees latitude are numbered from 0° to 90° north and south. Zero degrees is the equator, the imaginary line which divides our planet into the northern and southern hemispheres. 90° north is the North Pole and 90° south is the South Pole.

Longitude


The vertical longitude lines are also known as meridians. They converge at the poles and are widest at the equator (about 69 miles or 111 km apart). Zero degrees longitude is located at Greenwich, England (0°). The degrees continue 180° east and 180° west where they meet and form the International Date Line in the Pacific Ocean. Greenwich, the site of the British Royal Greenwich Observatory, was established as the site of the prime meridian by an international conference in 1884.

How Latitude and Longitude Work Together


To precisely locate points on the earth's surface, degrees longitude and latitude have been divided into minutes (') and seconds ("). There are 60 minutes in each degree. Each minute is divided into 60 seconds. Seconds can be further divided into tenths, hundredths, or even thousandths. For example, the U.S. Capitol is located at 38°53'23"N , 77°00'27"W (38 degrees, 53 minutes, and 23 seconds north of the equator and 77 degrees, no minutes and 27 seconds west of the meridian passing through Greenwich, England).


Three of the most significant imaginary lines running across the surface of the Earth are the equator, the Tropic of Cancer, and the Tropic of Capricorn. While the equator is the longest line of latitude on the Earth (the line where the Earth is widest in an east-west direction), the tropics are based on the sun's position in relation to the Earth at two points of the year. All three lines of latitude are significant in their relationship between the Earth and the sun.

The Equator

The equator is located at zero degrees latitude. The equator runs through Indonesia, Ecuador, northern Brazil, the Democratic Republic of the Congo, and Kenya, among other countries The equator divides the planet into the Northern and Southern Hemispheres. On the equator, the length of day and night are equal every day of the year - day is always twelve hours long and night is always twelve hours long.

The Tropic of Cancer and The Tropic of Capricorn


The Tropic of Cancer and the Tropic of Capricorn each lie at 23.5 degrees latitude. The Tropic of Cancer is located at 23.5° North of the equator and runs through Mexico, the Bahamas, Egypt, Saudi Arabia, India, and southern China. The Tropic of Capricorn lies at 23.5° South of the equator and runs through Australia, Chile, southern Brazil (Brazil is the only country that passes through both the equator and a tropic), and northern South Africa.

The tropics are the two lines where the sun is directly overhead at noon on the two solstices - near June and December 21. The sun is directly overhead at noon on the Tropic of Cancer on June 21 (the beginning of summer in the Northern Hemisphere and the beginning of winter in the Southern Hemisphere) and the sun is directly overhead at noon on the Tropic of Capricorn on December 21 (the beginning of winter in the Northern Hemisphere and the beginning of summer in the Southern Hemisphere).

 
The reason for the location of the Tropic of Cancer and the Tropic of Capricorn at 23.5° north and south respectively is due to the axial tilt of the Earth. The Earth is titled 23.5 degrees from the plane of the Earth's revolution around the sun each year.

 
The area bounded by the Tropic of Cancer on the north and Tropic of Capricorn on the south is known as the "tropics." This area does not experience seasons because the sun is always high in the sky. Only higher latitudes, north of the Tropic of Cancer and south of the Tropic of Capricorn, experience significant seasonal variation in climate.

Prime Meridian


While the equator divides the Earth into Northern and Southern Hemispheres, it is the Prime Meridian at zero degrees longitude and the line of longitude opposite the Prime Meridian (near the International Date Line) at 180 degrees longitude that divides the Earth into the Eastern and Western Hemispheres. The Eastern Hemisphere consists of Europe, Africa, Asia, and Australia while the Western Hemisphere includes North and South America. Some geographers place the boundaries between the hemispheres at 20° West and 160° East so as to not run through Europe and Africa. The Prime Meridian and all lines of longitude are completely imaginary lines and have no significance with regard to the Earth or to its relationship with the sun.

Links for more information:


 

 

Time zones


Time zones are areas of the Earth that follow the same definition of time. Formerly, people were using apparent solar time, resulting in the time differing slightly from town to town. Time zones partially rectified the problem by setting the clocks of a region to the same mean solar time. Time zones are generally centered on meridians of a longitude that is a multiple of 15º; however as the map below shows, the shapes of time zones can be quite irregular because of boundaries of countries. All time zones are defined relative to Coordinated Universal Time (UTC), the time zone containing London. (Underlined words take you to links for further information )
 
 






Location of Places and Time Zones on Maps

 

To exactly locate a place in the world is done using the geographical coordinates given by its latitude, longitude and altitude.

To know the time of a place located at the east you need to add an hour for each 15° of longitude (to the west- to the left in a map) and to know the time of a place located to the west you need to subtract an hour for each degree (to the east – to the right on a map).

 

Definitions:

Croquis: simplified form of a small area map.

Plan: Small representation of portions of geographical space ( city, neighborhood).

Map: Earth´s surface representation.

Atlas: Collection of maps.

Globe: 3D Representation of Earth





MAP PROJECTIONS








Representation
Description
Advantages
Disadvantages
Illustration
 
Cylindrical (Robinson , Mercator and Peters projections are all cylindrial projections.)

 

A cylindrical projection map is the most common type of map.

Mathematically projected on a Cyllinder conceptually  tangent to the Equator.
Best Uses: To represent all earth.
 
Best Uses: To represent all earth.

Areas close to the equator have very little distortion. All areas on the map are proportional to the same areas on the Earth. Directions are reasonably accurate in limited regions. Distances are true on both standard parallels. The projection works well for mapping areas that extend equally from the center point, such as North America

The closer to the poles that one travels, the more distorted the map becomes.Greenland appears to be many times larger than it really is.Areas and shapes
of large areas are distorted. Distortion increases away from Equator and is extreme in polar regions. Map, however, is conformal in that angles and shapes within any small area (such as that shown by USGS topographic map) is essentially true.





 
 


Conic

A conic projection map is created by placing a cone shaped screen on a globe. The resulting projection is more accurate than the cylindrical projection map discussed above. However, the further we travel down the map, the more distorted and less accurate the map becomes. Mathematically projected on a cone secant at two standard parallels.
Parallels are semi-circles and meridians get all together at the poles.
 
 
 
Best Uses: To represent parts of the world, speially middle latitudes.
 
 

Any straight line on the map is a rhumb line (line of constant direction). Directions along a rhumb line are true between any two points on map.Good for navigation.

Distances are true only along Equator. Areas and shapes of large areas are distorted. Distortion increases away from Equator and is extreme in polar regions. Map, however, is conformal in that angles and shapes within any small area. The map is not perspective, equal area, or equidistant.
   A rhumb line is usually not the shortest distance between points.




 Azimuthal (Planar)

A plane projection is created by placing an imaginary screen directly above or below a globe. The image that would result is called a plane projection. This type of map projection is not commonly used.
 
Best Uses:
 
-Equatorial: To represent eastern and western hemispheres.
 
- Polar: For representing Artic and Antartic areas.
 

It has the useful properties that all points on the map are at proportionally correct distances from the center point, and that all points on the map are at the correct azimuth (direction) from the center point.

Distances and directions to all places are true only from the center point of projection. Distances are correct between points along straight lines through the center. All other distances are incorrect. Distortion of areas and shapes increases with distance from center point.

 
 
 Mercator´s Projection: Exagerates surfaces  over 80° latitude. Polar continental zones look bigger than they really are.
 
Robinson´s Projection: Pseudo-cylindrical projection in which continents appear longer but show more precise dimensions. Shows good shape of continents and oceans.
 
Peter´s Projection: Its advantage is to show a more realistic dimension of continents, with less distortion at middle latitudes, but deforms equatorial and polar zones.
 
There are two other common forms of representing the Earth:
 
Mollweide: Has and elliptical shape and areas look very deformed. Used to represent exactly zones close to Greenwich meridian.
 
Goode: Oceans are very deformed. Maintains good shape of continents but oceans anre very deformed.
 
 
 
 
Mercator

 Peters (Peterson)

Robison
 
Comment: Which is more accurate and what kind of projection each is? (cylindric, conic or planar)