Tuesday, June 1, 2010

Lab 8 Census 2000

The first map represents the Black population by county in the continental US. Black percent population is represented by the different shades of teal. As shown in the accompanying legend, the lightest shade of teal represents a population percentage of less than 3% and the darkest shade of teal represents a population percentage greater than 60%. From the shades of teal throughout the US, it can be observed that there is a relatively high Black percent population in the south/southeastern counties. (The counties with no color had data that were null).


This second map is a representation of the Asian population by county. The darkest shade of grey represents population percents of above 20 and the lightest shade represents population percents of below 0.5. Geographically, specific regions such as the Bay Area, Los Angeles and New York City observe relatively high percent population (around 10-20%) of Asians. In contrast, almost everywhere else in the US (between the East and West coasts) observes low percent populations (less than 5%). It can be seen that in comparison to the Black population, the Asian population spans fewer counties.

This third map is a percent population representation of “some other race alone” for the continental US. The lightest shade of green represents a population percentage of less than 1%, where the darkest shade of green represents a percentage of 22% and above. The term “some other race alone” points to races other than: White, Black, Asian, Native American and Pacific Islander. The main contributing race to this is most likely the Hispanics/Latinos. This assumption agrees with the observation that the counties along the US-Mexico border (Southern California, Arizona, Texas) show higher population percentages (10 – 22+ %) than everywhere else in the US (showing single digit percentages for the most part).


By comparing and contrasting the percent populations for each of the races, many pieces of information can be retrieved but many difficulties can also arise. Different races are concentrated in different parts of the country, and simultaneously give rise to various explanations as to why/how. The Black population is concentrated in the Southern states, most likely due to the historical presence of slavery in the south. A relatively high percentage of Asians are seen in the Bay Area, likely due to the Silicon Valley technology. The “some other race alone” percentage is high along the US/Mexico border, most likely due to the possibility that the race category mainly consists of Hispanics/Latinos from Mexico. One difficulty was defining interval definitions for the various races, when each race had different percentage distributions. Through this census lab, number/population data was combined with spatial data to visually provide an easy-to-understand distribution of the various races throughout the US.

GIS (Geographic Information Systems) aids and encourages spatial thinking, connecting data to space. Initially, ArcGIS was an intimidating software but eventually, I was able to experiment more and more with its limitless tools and ability to manipulate and represent data. GIS is also a communication tool, as the mapmaker must always keep in mind the target audience and its needs. As internet technology further enables people to be connected, the instant sharing of spatial information introduces more possibilities of GIS. GIS overall made me more comfortable with extracting information from maps and spatial data in general.




Sunday, May 23, 2010

Lab 7 Mapping the Station Fire


Wildfires play a significant role in Southern California life. The dry, warm climate characteristic of the area makes wildfires a concern. They affect multiple aspects of life from weather to vegetation to transportation. Here, we will attempt to observe and analyze the effects of the 2009 Los Angeles wildfire on the major roads and highways of the area. By using GIS and mapmaking to combine shape files of the geographic boundaries, fire area and major roads and highways, we can analyze the relation between the fire and its effect on the roads.

8/29

On the first day since the outbreak of the fire, we see that Highway 2 and Big Tujunga Canyon Road are already affected. There is no question that these two major roads/highways are closed off. In addition, Highway 210 is in proximity of the fire area and as a precaution, the roads in the southwest (with Hwy 210) are likely to be closed off also. Soledad Canyon Road or Highway 14 in the north of the map are likely detours/alternate routes to get to/from Los Angeles to the Southwest/Northeast.


8/30

On the second day of the fire, the fire spreads Northwards and Eastwards. This could be seen by not only comparing the fire shapefiles of 8/30 to 8/29, but also the two shapes of varying times on 8/30. In addition to the roads/highways mentioned in 8/29, Highway N3, Soledad Canyon Rd, and Highway 14 are likely to be closed off also due to the increased spread of the wildfire.



8/31

On the third day of the fire, we see that the fire has not spread Northwards but has spread in the Eastern direction. The fire has now consumed part of Sand Canyon Road, making it more and more difficult to move from/to Los Angeles in the Northeast/Southwest direction by car. From the relatively smaller number of major roads/highways, it can also be inferred that the wildfire area is less urban and more mountainous compared to the web of roads/highways seen in the Southern part of the map.



9/01


9/02

On the fourth and fifth days of the wildfire, by comparing the relative sizes of the wildfire polygons it can be seen that the fire is starting to get under control and contained. The size of the fire ceases to increase as rapidly as it did in the first few days of the wildfire. Through overlapping the various layers related to the wildfire of Los Angeles (county lines, roads, highways, wildfire, California) in GIS, the progress of the fire can be monitored, along with its effect on the roads. A reference map to give the reader background information on the subject and a thematic map to focus on the cause-effect of that subject can be created. Combined, the reference and thematic maps enable one to answer questions such as “which roads are closed when and where?”.






Works Cited

Mapshare California State (Generalized). GIS at UCLA. Web.<http://gis.ats.ucla.edu//Mapshare/Download.cfm?FilePath=/Data/ESRI/9.3/Data%20and%20Maps%20and%20StreetMap%20North%20America/California/census/states.zip&GISDataID=4910>.

Mapshare Los Angeles County (2008). GIS at UCLA. Web. <http://gis.ats.ucla.edu//Mapshare/Download.cfm?FilePath=/Data/ESRI/9.3/Data%20and%20Maps%20and%20StreetMap%20North%20America/LACounty/LACounty_dtl_cnty_Select.zip&GISDataID=5540>.

Mapshare Los Angeles County Highways (1.04mb ver). GIS at UCLA. Web. <http://gis.ats.ucla.edu//Mapshare/Download.cfm?FilePath=/Data/ESRI/9.3/Data%20and%20Maps%20and%20StreetMap%20North%20America/LACounty/LACounty_highways.zip&GISDataID=5544>.

Mapshare Major Cities. GIS at UCLA. Web. <http://gis.ats.ucla.edu//Mapshare/Download.cfm?FilePath=/Data/ESRI/9.3/Data%20and%20Maps%20and%20StreetMap%20North%20America/LACounty/LACounty_citiesmjr.zip&GISDataID=5538>.

Mapshare Major Roads. GIS at UCLA. Web. <http://gis.ats.ucla.edu//Mapshare/Download.cfm?FilePath=/Data/ESRI/9.3/Data%20and%20Maps%20and%20StreetMap%20North%20America/LACounty/LACounty_mroads.zip&GISDataID=5551>.