Sunday, December 6, 2009

Lab - Weeks 9/10

This map shows that the counties with the highest percentage of Asians are generally located along the coasts, particularly the west coast. The classification method used was the Geometric Interval algorithm, which attempts to find a balance between having a similar number of elements per class and having consistently-sized class ranges. Since the lower bound of the highest-percentage class is a mere 7.8% we can infer that a majority of counties in the United States have a very small proportion of Asians.

This map indicates that Blacks are generally concentrated in the South - though there are also high percentages in urban areas throughout the rest of the country, such as in LA county. The distribution of Blacks across the United States appears much more polarized than the distribution of Asians - across the northern United States most counties have a population of less than 0.2% Blacks, while in the south, nearly every county has 27% or above. Once again, the Geometric Interval classification method was used. The generally higher class percentage values suggest that Blacks make up a greater proportion of the total US population than Asians.

This map shows the percentage of the population identifying themselves as "Some other race," using the Geometric Interval classification method. There appears to be a higher concentration of these individuals in the western United States than the east, with particularly high concentrations in the Southwest. Interestingly, nearly the entire state of New Mexico has over 7.6% of its population identifying itself as "some other race." There are also significant proportions in Florida, North Carolina, and much of New England.

The Geometric Interval classification generally created broad distribution of colors across the map, which was effective in portraying the differences between individual counties. However, it may have masked the relatively low overall population of Asians and those of "some other race." Thus, although this census data is available freely to the public, it can be mapped in a variety of different ways depending on the mapper's desired emphasis.

GIS is an extremely powerful tool which facilitates analysis of collections of raw data. With a bit of work, it can be used to transform this numeric data into visualizations which make geometric patterns immediately obvious to any viewer. While I appreciate the principles behind GIS and recognize its potential, I found the ArcGIS software we used to be quite unintuitive. It had an extremely steep learning curve and performing simple tasks was often unnecessarily complex. However, with the increasing popularity and accessibility of GIS, this is an issue which will likely resolved with time. I was surprised with the already-high availability of GIS data across the Internet, which continues to increase daily. Undoubtedly, GIS is an incredibly useful development; with applications to so many fields, soon it will be virtually ubiquitous.

Monday, November 16, 2009

Lab - Week 8


The Station Fire, the largest and most damaging of the 2009 California wildfires, began in Angeles National Forest, near Highway 2 north of La Canada Flintridge on September 26. The initial attack on the fire was unsuccessful due to two factors. First, rough terrain in the area of the outbreak made transportation of firefighting equipment by ground difficult. Second, dry and thick vegetation covered the surrounding area, creating an extremely volatile environment which posed significant risk to firefighters.

The fire mostly spread north through the vegetation of the Angeles National Forest, becoming the most devastating since the forest was officially named in 1892. By the morning of August 31 the fire was only 5% contained and had burned 85,000 acres, destroying 18 structures. It spread north through the forest, endangering structures in the city of Acton to the north, and to the south, endangering the northern areas of the cities of La Crescenta, La Canada Flintridge, and Altadena. Residents of these areas experienced forced evacuations to nearby high schools.


By September 1 the fire had burned nearly 122,000 acres and destroyed 53 structures, and remained 5% contained. Residents of northern Glendale and Tujunga were now forced to evacuate. Though the fire was 22% contained by September 2 the fire, it had burned 140,000 acres and destroyed 90 structures including 62 residences.

The map above shows that most of the fire's growth occurred between August 29 and September 2. Its rapid growth was attributed to strong winds as well as the volatile, dry nature of the vegetation in the Angeles National Forest. Assisted by increased humidity, firefighters were finally meeting some success in containing the fire, with 50% by September 6, when all forced evacuations had ceased. The fire was not fully contained, however, until October 16, 2009, with the assistance of rain. In total it had burned 160,577 acres and cost nearly $90 million. Restoration and rehabilitation of affected areas in the Angeles National Forest had begun.

One of the most significant effects of the Station Fire is the tremendous environmental damage it inflicted. 73% of the soil burn was classified as moderate to high. Since the Angeles National Forest has considerable tectonic activity, with multiple fault lines, its terrain is dramatic (as shown in the map below), with over half of the slopes in the burn area have a grade of 50% or more. These two factors along with the new lack of vegetation create a significant risk of erosion and sedimentation, which pose a threat to people and property in the Angeles National Forest and in the aforementioned communities. Devastating landslides and debris flow may occur in a storm.



Resources

"InciWeb the Incident Information System: Station Fire." inciweb.org. Web. 18 Nov. 2009. http://inciweb.org/incident/1856/

"Fire and Aviation Management: Station Fire Initial Attack Review." United States Department of Agriculture Forest Service , 13 Nov. 2009. 18 Nov. 2009. http://www.fs.fed.us/news/2009/releases/11/station-report-11-13-2009.pdf

"Burned Area Report - CA-ANF 3622." United States Department of Agriculture Forest Service , 23 Sept. 2009. 18 Nov. 2009. http://www.fs.fed.us/r5/angeles/station/BAER/2500-8%20BAER%20Assessment%20Report_Station%20BAER_Public%20Release_10.16.2009.pdf

"Station Fire Growth Slows, But New Areas At Risk" Neon Tommy, 28 Aug. 2009. 18 Nov. 2009. http://blogs.uscannenberg.org/neontommy/2009/08/in-the-news-california-wildfir.html

Millikin, Mary. "Los Angeles fire growth slows with more humidity." Reuters, 1 Sept. 2009. 18 Nov. 2009. http://www.reuters.com/article/latestCrisis/idUSN01488953

Monday, November 9, 2009

Lab - Week 7

These maps are of a rectangle in Fresno County, California, which spans from about 37.0428° N to 37.4367° N and from -118.9336° W to -118.4806° W, using the North American 1983 geographic coordinate system. The highly mountainous terrain in most of the map is the southern end of California's Sierra Nevada mountain range. At the northeast corner of the map is Owens Valley, one of the deepest in the United States, whose western border is the Sierra Nevada.

Hillshade:

Slope:

Aspect:
3D Rendering:

Monday, November 2, 2009

Lab - Week 6

Mercator (Conformal)
Distance measured between Washington DC and Kabul: 10,115 mi
Gall Stereographic (Conformal)
Distance measured between Washington DC and Kabul: 7,164 mi
Sinusoidal (Equidistant)
Distance measured between Washington DC and Kabul: 8,101 mi

Equidistant Conic (Equidistant)
Distance measured between Washington DC and Kabul: 6,971 mi

Bonne (Equal-area)
Distance measured between Washington DC and Kabul: 6,753 mi
Mollweide (Equal-area)
Distance measured between Washington DC and Kabul: 7,895 mi


Because a spherical object such as the Earth can not be flattened onto a plane, map projections are essential. Without map projections we would be limited to only spherical models of the Earth, which, while still useful, lack the flexibility and portability that 2D maps offer. 2D maps can be printed into books, displayed on computer screens, or hung on walls. 2D maps also can inherently display a greater amount of the Earth's surface simultaneously than globes, and consequently are useful for displaying a large amount of geographical data at once (for example, maps displaying worldwide GDP or quality of life.) Thus there is a desire to create accurate map projections.

However, map projections always include some element of distortion because the Earth is not a developable surface. As a result, a multitude of map projections exist, each designed to preserve a certain aspect of the Earth's geometry. Conformal map projections, such as the Mercator and Gall Stereographic projections above, preserve angles, and thus are useful for calculating bearings in navigation. However, conformal projections fail to preserve areas or distances, often with enormous size distortions. In the Mercator projection, for example, the size of areas far from the equator is greatly exaggerated: Greenland appears to be almost as large as the entire continent of Africa, and Antarctica dwarfs every other continent in size.

Equidistant map projections, as their name implies, preserve distances along certain lines or from certain points (since preserving distances from every point to every other point is impossible.) Equidistant map projections are obviously optimal for measuring distances or calculating travel times, but one must be aware of which points or lines conserve actually distance. Measuring the distance from Washington DC to Kabul, Afghanistan using the Sinusoidal projection gave a figure more than 1,000 miles greater than with the Equidistant Conic projection; clearly distance was not preserved along this path.

Equal-area map projections, such as the Bonne or Mollweide projections above, preserve areas. Area distortion is one of the most immediately obvious forms of distortion, and thus equal-area projections are often more visually pleasing than other types of map projections. These projections are useful in thematic maps, maps which associate certain attributes with geographic areas - such as maps of world religions or chloropleth maps like population density. Maintaining area is also useful in statistical analysis of the globe: observing geographic distributions of various phenomena.

Sunday, November 1, 2009

Lab - Weeks 4/5


(Click to enlarge)(Extent map for above)




The main advantage of GIS is consolidation of geographic data. When multiple layers of various types of data are combined, geographic patterns begin to emerge. Presenting this data using clear maps makes it easy to read and makes geographic trends immediately obvious. If data were simply displayed in graphs or tables of numbers, it would be much more obscure and citing it to make any arguments would require a good deal of explanation.

GIS software also standardizes geographic data presentation. Maps generated using the same software will tend to look more similar than maps created independently, without the assistance of proprietary software. This further increases readability for people familiar with the world of GIS.

GIS, however, is not without a few pitfalls. GIS software like ArcGIS is tremendously powerful and thus has quite a steep learning curve. Creating effective maps and using such software to its fullest potential requires sufficient training, and may not be intuitive to those trained in traditional methods. GIS software is also very expensive; combined with the learning curve, it may be off-putting to neogeographers who might otherwise be interested.

Effective use of GIS requires a tremendous amount of data, which would be time-consuming to collect. Furthermore, professional GIS-created maps are expected to have a high level of accuracy, so extra caution must be taking in ensuring data is accurate and properly measured.

Sunday, October 18, 2009

Lab - Week 3

World's 25 Tallest Skyscrapers

Please start by zooming out so that you can see the entire world - or better yet, click "View in larger map"


View World's Tallest Buildings in a larger map

Neogeography offers unprecedented scope and brand new perspectives to the subject of geography. Neogeographers may focus on "worldly" information - relevant to everyday life that may be dismissed as nonacademic or unscientific by professional geographers. The sheer amount of data and content offered by current user-driven projects such as Wikipedia or Youtube demonstrates the potential of a similar trend in geography. Neogeography also makes information much more accessible - before current developments in neogeography one would rarely think to utilize professional sources like USGS topographic maps as part of day-to-day activity. Now we use tools such as Google Maps daily to locate new places or to accustom ourselves with our surroundings.

Despite the practicality of neogeography there is still a place for traditional geographic information sources. Neogeography has few standards - and there is little to stop someone from releasing false information. Geographic information compiled professionally has guaranteed credibility and thus is more suitable for research projects. Neogeography is a malleable, dynamic field; there is importance in solidifying it as as a discipline of peer-reviewed science. While its very nature ensures that neogeography will grow quicker and have a larger scope, there is nothing preventing traditional geographic information from becoming just as accessible or ubiquitous in the future.

Monday, October 5, 2009

Lab - Week 2

  1. This quadrangle is named the Beverly Hills Quadrangle.
  2. The adjacent quadrangles are: Canoga Park, Van Nuys, Burbank, Topanga, Hollywood, Venice, and Inglewood.
  3. The quadrangle was first created in 1995.
  4. The map was created with NAD 27 and NAD 83.
  5. The scale of the map is 1:24,000.
  6. a. 5 cm on the map is equal to 1200 m on the ground.
    b. 5 inches on the map is about 1.89 miles on the ground.
    c. 1 mile on the ground is equal to 2.64 inches on the map.
    d. 3 km on the ground is equal to 12.5 cm on the map.
  7. The contour interval of the map is 20 ft.
  8. a. Public Affairs is centered at about 34.074° latitude, -118.439° longitude, or about 34° 4' 26.4" latitude, -118° 26' 20.3994" longitude.
    b. The tip of Santa Monica pier is about 34.007° latitude by -118.500° longitude, or about 34° 0' 25.2" latitude, -118° 30' 0" longitude.
    c. The Upper Franklin Canyon Reservoir is centered at about 34.120° latitude, -118.410° longitude, or about 34° 7' 11.2" latitude, -118° 24' 36.0" longitude.
  9. a. Greystone Mansion's elevation is about 581 ft, or about 177 m.
    b. Woodlawn Cemetery's elevation is about 141 ft, or about 43 m.
    c. Crestwood Hills Park's elevation is about 636 ft or about 194 m.
  10. The map's UTM zone is Zone 11.
  11. The UTM coordinates for the lower left corner of the map are about 3763000 m N, 361500 m E.
  12. There are 1,000,000 square meters per cell.
  13. The magnetic declination of the map is 14° or 249 miles.
  14. The intermittent stream between the 405 freeway and Stone Canyon Reservoir flows south.