Lap #1b: GIS on the Web

Stefanie Wieschalla
Geog 206


1a)

GIS Definition one from: http://www.webopedia.com/TERM/G/GIS.html

Short for Geographic Information Systems, tools used to gather, transform, manipulate, analyze, and produce information related to the surface of the Earth. This data may exist as maps, 3D virtual models, tables, and/or lists.

GISs can be as complex as whole systems that use dedicated databases and workstations hooked up to a network, or as simple as "off-the-shelf" desktop software.

GISs play an important role in many organizations. For instance, police and fire departments may use GISs to locate landmarks and hazards, plot destinations, and design emergency routes. GISs may also be used by governments, research institutes or any other body that can't possibly handle the task of manually processing large amounts of geographical data.



GIS Definition two from: http://gps.about.com/od/glossary/g/GIS.htm

A Geographic Information System, or GIS, integrates data, hardware, software and GPS to assist in the analysis and display of geographically referenced information.

GIS is a general term that refers to any scientific effort to integrate data to help researchers visualize, analyze, and explore geographically referenced information. For example, GIS is helping researchers measure the speed of glacier melting in Greenland and Antarctica. GIS can assist in the analysis of small-scale and localized data, as well, such as development trends, or watershed analysis.

The field of GIS has advanced rapidly in recent years, with the availability of rapidly increasing computer power, development of software, and proliferation of inexpensive GPS devices.

GIS is frequently used to create maps that illustrate hidden data. For examples, visit Geodata.gov.



GIS Definition three from: http://www.nwgis.com/gisdefn.htm

GIS (Geographic Information Systems) is a system of hardware and software used for storage, retrieval, mapping, and analysis of geographic data. Practitioners also regard the total GIS as including the operating personnel and the data that go into the system. Spatial features are stored in a coordinate system (latitude/longitude, state plane, UTM, etc.), which references a particular place on the earth. Descriptive attributes in tabular form are associated with spatial features. Spatial data and associated attributes in the same coordinate system can then be layered together for mapping and analysis. GIS can be used for scientific investigations, resource management, and development planning.

GIS differs from CAD and other graphical computer applications in that all spatial data is geographically referenced to a map projection in an earth coordinate system. For the most part, spatial data can be "re-projected" from one coordinate system into another, thus data from various sources can be brought together into a common database and integrated using GIS software. Boundaries of spatial features should "register" or align properly when re-projected into the same coordinate system. Another property of a GIS database is that it has "topology," which defines the spatial relationships between features. The fundamental components of spatial data in a GIS are points, lines (arcs), and polygons. When topological relationships exist, you can perform analyses, such as modeling the flow through connecting lines in a network, combining adjacent polygons that have similar characteristics, and overlaying geographic features.



1b)

All definitions discuss GIS somehow as a computer-based system to support the gathering, preservation, storage, retrieval, analysis, output, and distribution of spatial data and information.

1c)

The main difference lies in the amount of information’s provided. Where some definitions are right to the point, others are giving detailed information’s about GIS as an information system as well as an approach to science. However, some definitions contain further unique phrases and descriptions.

1d)

As a result, one can consider the field of GIS as one with many different aspects that can be used in many different areas of life.

2.)

Example one from: http://libraries.mit.edu/gis/examples/examples.html

City Space

Overall, the map demonstrates the Boston Metro Area. The color red illustrates industrial land; the pink coloring refers to “Other” that is currently used land and the grey area shows all other values. The map serves as verification that land that was used to be utilized by industrial development is in fact empty space today and hence can be used for redevelopment projects. Therefore, there is in fact space to live or build in the city of Boston, much of it is even close to business district and connected to transportation.


Example two from: http://libraries.mit.edu/gis/examples/examples.html

Pure Water Access

The map illustrates the northern land area of the country Ghana. Different colors represent different types of water sources used by household in the three regions of northern Ghana. The dominant coloring is yellow, which refers to “Dugout”. This map is one of a few others related to planning access to safe water in order to encourage the promotion and sale of household water, treatment and secure storage technologies.


Example three from: http://libraries.mit.edu/gis/examples/examples.html

Sea Surface Temperatures

The map generally indicates the locations of deep sea sediments cores in order to reconstruct sea surface temperatures over the last 10,000 years. The lighter blue coloring demonstrates high elevation (1838), where the darker blue color shows low elevation (- 7887). The red border lines show the north and south Gulf Stream boundaries given that the Gulf Stream is mainly in control of the temperatures in this region. Moreover, the green dotes indicate the sediment core locations.

3.)


Differences between maps (Cartography) and GIS:

• In general, output from GIS does not have to be a map.

• Text output may be more important than a map for analysis reporting.

• Many GIS are designed with poor map output capabilities.

• The main differences between a GIS and a mapping system are in their functional components.

A GIS contains these four components:  a. Input   b. Database    c. Analysis    d. Output
In contrast, a mapping system can be described in three components:  a. Input   b. Map design   c. Output


Similarities between maps (Cartography) and GIS:


• Much GIS output is in the form of hard copy maps or graphic displays.

• Design of graphic output is critical to effective use of GIS analysis.

• Maps are the main source of data for GIS and GIS has roots in the analysis of information on maps.

• Many standard GIS operations were conceived and executed where possible on analogue maps.

• Many people use GIS to make maps.

• Both cartography and GIS however use map/data layers.

Lab 1a: Setting Up Your Blob, ect.

Stefanie Wieschalla
Geog 206

“Generic Names for Soft Drinks”

I located the first map “Generic Names for Soft Drinks” on the website http://www.popvssoda.com/. This map of the United States has been created Matthew Campbell and Prof. Greg Plumb and illustrates the regional variations in the use of the term “Pop”, “Coke” and “Soda” to describe soft drinks in general. As one can notice from the map, the use of these different terms is somehow linked to where people are positioned throughout the country. Hence the greater parts of residents in California and around the state are referring to soft drinks as “Soda”, which is indicated by the yellow to green coloring, but from Texas to Florida people usually name them “Coke” as it is shown in red. Yet, the majority of Americans identify soft drinks as “Pop”, which becomes very clear when looking at the large amount of blue coloring. I found that very interesting given that I actually never heard the term “Pop” before, even though the overall majority of U.S. residents are calling soft drinks this way. Furthermore, I am surprised that only so few states are actually referring to “Soda” because I assumed that would be the most popular term. The results also reveal a certain amount about who these people are and this is something I find particularly interesting. 

“USA National Gas Price Heat Map”

The second map “USA National Gas Price Heat Map” that I located at http://www.gasbuddy.com/  indicates the price for gas by countries. The areas are color coded from red to yellow and then green according to their price for the average price for regular gasoline. It becomes clear that whole Pacific Cost is the most expensive area when looking at gas prices, here indicated in red, where the South East has overall the lowest prices, shown in green. I think it is very interesting to find out that not all major cities have really expensive prices of gas given that I originally assumed that in any given metropolitan city of the U.S., like Los Angeles and for example New York, the prices would be similar. But when looking at the map, one can observe that in all other areas, except from the Pacific Coast, gas is actually fairly cheaper. In general, the map is great because if can also help you find the cheapest gas prices in your city since one can zoom in and out. 

“Earthquake History of CA”

The last map on earthquake history of the complete state of California, which I retrieved from http://www.consrv.ca.gov/cgs/rghm/quakes/PublishingImages/statewide_view_gif.gif  reveals information on where, when and how strong earthquakes have been in CA. The first time span starts around 1769 and lasts till 1868, which is shown in the red coloring code. The second time period (in blue) persists till 1931 and the final one (in green) ends in 2000. Furthermore, the magnitudes of these various earthquakes are indicated in circles that vary in seize according to their strength. Interesting to note is the fact that quite a few strong earthquakes, with a magnitude of 7.0, have been recorded in the very northern part of California’s cost. Then of course areas as San Francisco, Los Angeles and San Diego have a very knowable history of seismic activity. However, the inland of the state has barely any earthquake activity recorded, only when looking down to the South one can notice some past activity. Also, the North East corner of CA is fairly untouched by past earthquakes. It also seems interesting that earthquakes have actually highly increased through time. Back in the first time span, there where clearly fewer quakes when compared to the last time period, which goes up to the year 2000.