Lab 8

      According to the report, the station fire was a devastating wildfire that started on August 26th, 2009 in Angeles National Forest (“Station Fire”). Until August 30th, the station fire had claimed 18 homes and two firefighters (Garrison, Zavis, and Mozingo). The fire was fully under control at 7:00p.m on Friday, October 16, 2009. Firefighters were able to contain the fire in the San Gabriel wilderness area because of the moderate rainfall earlier that week (“Station Fire”). The giant fire lasted for about 50 days and caused huge loss. Rep. Judy Chu, D-Calif., said that “mistakes were made but there is a valuable opportunity to learn and improve” (Quoted in Blood).

      The first map is a reference map of the station fire and the second map is a thematic map. This reference map shows the vegetation, the station fire perimeters, major highways, water features, and elevation of the LA County. The vegetation information comes from the California Department of Forestry and Fire Protection. The water feature and major highway data come from UCLA Mapshare. The thematic map is about the relationship between station fire and populated areas in LA County. The station fire perimeters information in both maps comes from LA County Enterprise website and the populated areas data come from UCLA Mapshare.

      In the reference map, we can see that although most major highways were not involved in the station fire, the fire involved the Angeles Crest Highway and was quite close to the Interstate 210 Highway. According to the Los Angeles Times, the Angeles Crest Highway was a popular road for campers and motorcyclists. However, the Los Angeles Highway was closed because of the station fire and reopened three months later (Roe). As for the Interstate 210 Highway, because people were evacuated timely, the fire did not cause too much loss. We can also see that the water features were not involved in the reference map.

      As can be seen in the thematic map, the purple areas are the most populated and the pink areas are the least populated. Therefore, we can conclude that most populated areas are located south of the station fire perimeters. People who were close to the station fire areas were evacuated. Yet the station fire did not influence too many people because the most populated areas were not involved in the station fire. In addition, the LA elevation legend shows that the darker an area is, the higher the elevation is. Therefore, most populated areas are located at lower elevations. The Northern California Fire Behavior Assessment indicates that “in areas with steep elevation gradients, shifting diurnal winds cause fires to continually change directions” (ONC Support). As a result, the populated areas in LA County were relatively safe. However, because the Angeles National Forest in which station fire happened was located at higher elevation, the fire was hard to control.

      Overall, the two maps reflect demographic and topographic information of the station fire that happened in 2009. From these two maps, we can see the potential of GIS. Using GIS, people can easily access data, integrate different data, and do spatial analysis. For example, using GIS, people can find out the topographic and demographic condition of the station fire and therefore predict the difficulty in fighting against the fire and the loss that the fire would cause.

 

Works Cited

Blood, Michael R. “2009 Los Angeles Station Fire Report Reveals Foggy Policies In The Forest Service.” Huffpost Los Angeles. n.p., 16 Dec. 2011. Web. 12 Dec. 2012.

Garrison, Jessica, Alexandra Zavis, and Joe Mozingo. “Station fire claims 18 homes and two firefighters.” Los Angeles Times. Los Angeles Times, 31 Aug. 2009. Web. 12 Dec. 2012.

ONC Support. “Northern California Fire Behavior Assessment.” Battle Creek Watershed Conservancy. n.p., 7 July 2008. Web. 12 Dec. 2012.

Roe, Lorraine. “Angeles Crest Highway Reopens: A Bittersweet Trip Through The Barren San Gabriel Mountains.” Los Angeles Times. Los Angeles Times, 7 Dec. 2009. Web. 12 Dec. 2012.

“Station Fire.” InciWeb. Incident Information System, 10 Nov. 2009. Web. 12 Dec. 2012.

Lab 7

     

This map is about the percentage of Black people ranked by percent in America. The data is county-level. We can see from this map that Alabama, South Carolina, North Carolina, and Georgia have the highest percentage of Black people. If we zoom in, we can see small pieces of rectangles. The map is made up of these cells. Each cell has a value, which is shown by a specific color. Each cell represents a county, because the map is based on county-level data.

     This map is about the percentage of Asian people ranked by percent in America. The data is also county-level. We can also see small cells if we zoom in, and these cells represent the counties in the United States. Different from the “Black” map, states with high percentage of Asian people are mostly located in the west, such as California and Washington.

This map is about the percentage of some other races ranked by percent in America. Like the data of previous maps, the data of “Some Other Race Alone” is also county-level. According to the “Some Other Race Alone” map, states like California and New Mexico have the highest percentage of people of other races. States like Indiana have the lowest percentage.

 Overall discussion: 

Because all three maps use county-level data, we can directly compare these maps. There are some interesting points of the maps. Firstly, compared to the other races, Asian people are distributed more evenly. Secondly, California is a very diverse state. The percentage of Black people in California is higher than many other states. In addition, it has the highest Asian people percentage, and it has a high percentage of other races. Thirdly, the three maps have some features, namely title, legend, scale bar, and north arrow.

I was impressed by GIS during the mapping process. GIS mapping can provide users with a more direct sense of information. In addition, it is very convenient to do geographic analysis through GIS mapping. However, the amount of information should be controlled, because people will be confused if map makers put too much information on a single map. In the three maps that I made this time, I only used data that relates to the themes of the maps. Moreover, map makers need to follow certain conventions. For example, map makers need to choose similar colors in order to make the maps neat, and maps have to contain features like title and north arrow.

Lab 6

        Theses maps represent an area near Bitterroot National Forest, which is located in Idaho. The extent information of the maps is listed as following: top: 46.731111111, left: -123.416111112, right: -123.321944446, and bottom: 46.6899999999. The coordinate system is GCS_North_American_1983.

Lab 5

The significance of map projections is that the projections transform three dimensional Earth into two dimensional maps. People can represent geographic information on a planar map and do spatial analysis using the maps. Therefore, map projections facilitate people’s activities by providing people with a two dimensional reference of their environment.

However, because projection is a process of mathematical conversion, there are inevitable distortions in every map projection.  For example, I made six world maps with different map projections and measured the distance between Washington, D.C. and Kabul on each map. I got six different results. For instance, the distance is 10,099.785 miles on Mercator but is 10,109.671 miles on Plate Carrée. The difference between these two projections is relatively small, as the distance is 6,730.704 miles on Bonne, which is much shorter than that on Mercator and Plate Carrée. From the distance between Washington, D.C. and Kabul, we can see how different projections are on maps. Therefore, people need to be careful when they use maps for information, especially when they need very accurate information.

Another disadvantage of projections is that people need to choose one that most suitable from many projections. Each projection has its own advantages and disadvantages. For Mercator and Plate Carrée, they are conformal map projections, so they preserve local shapes and angles. Yet conformal map projections do not preserve areas and distances between either two points. Bonne and Caster Parabolic are projections that preserve areas. In other words, areas on these maps maintain the same proportional relationship to areas on the Earth that they represent. However, those equal area projections do not preserve distances or shapes. Two-point Equidistant and Azimuthal Equidistant projections preserve the distances from the center of the projection to any place on the map, but the areas and shapes are distorted. Therefore, when select a specific projection, people need to figure out which attribution they need to be accurate. No projection can satisfy all the requirements. For example, if people require a map to preserve the areas, they should pick Bonne or other equal area projections instead of Mercator.

Although each projection has its own disadvantage, there is huge potential of projections. Because projections are based on different datum, it is important to make datum more accurate. As the geographic technology is developing, datum will become more and more accurate, and thus projections can apply to real world more accurately.

Lab 4

 

Potential and pitfall of GIS

        GIS has great potential for three reasons. Firstly, GIS provides people with convenient access to data. For example, I can use data in the data base whenever I want as long as I have the necessary hardware and software. Moreover, I can put new data into the database. In this lab, I created new date frames and changed the names of the frames. Unlike traditional map, which allows users only to get restricted information, GIS allows users to add new data and to change the frame of the database. In addition, GIS has huge advantage in today’s geography because it allows people reuse the raw data for other analytical purpose. In this lab, I accidentally made a mistake. I asserted a wrong diagram, but I fixed the mistake immediately by deleting the diagram and asserting a new one.
        Secondly, GIS is developing at an incredible rate. It is only about 50 years since GIS was created, while map has existed for thousands of years. The technology of map making is mature and has little potential, but GIS has many drawbacks that need to be overcome. Thus people will continue work on GIS, and GIS will continue to improve. Moreover, GIS develops along with technology, especially Internet and electronic devices technologies. Most people agree that these two industries have huge potential and are improving every day. Therefore, GIS is a new geographic field with huge potential.
    Thirdly, geodatabase is better than traditional files. Geodatabase eliminates redundant data and organize data automatically. Because users do not need to organize data, data order will not change when user change. In the lab, I only need to analyze the data rather than organize data, so others can still access to the data without being confused by changed that I made.
    Although GIS has huge advantages over traditional maps, it is far from perfect. Firstly, people should be careful of data organization of GIS. Because GIS is geographic information systems, it can accommodate huge amount of data. Larger database means it is more difficult to manage data efficiently. In my lab experience, I found it hard to find useful data when all the data were presented. I had to block out some data and frequently classify the data into different data frames.
        Secondly, although there are several data models in GIS, none of them are suitable in every situation. In other words, every data model has its own advantage and disadvantage. For example, raster data model can represent continuous data, but it is difficult for people to do spatial analysis. Vector data model represents discrete data well, while it has complicated data structure, which is bad for data management. Therefore, when using GIS, people need to evaluate all the data models and choose the most suitable data model, because no data model is perfect.
        Thirdly, computer technology is double-edged. It provides users with more convenient access to geography, but it also makes it easier to lose data if people forget to save their work or the system crashes. Data is not completely safe because system has the risk of crashing, even if people save their work. In my lab work, I lost my data once when my computer was out of control and I had to restart my work.