Thursday, June 14, 2012

Station Fire and LA Water Systems

There is an extensive network of water systems within and surrounding the San Gabriel Mountains, the site of the LA Station Fire in 2009. The LA Department of Public Works manages a flood control system that includes 14 dams, 500 miles of channels, and 3000 miles of storm drains. In this particular incident, at least six different watersheds were swept by fire (Figure B), some of this land that hasn't experienced fire activity in over forty years. 

Figure A
These water sheds are not isolated ecosystems. Canyons affected by the fire drain into the Los Angeles and San Gabriel Rivers, and these major deranges connect related populations, called metapopulations.
This means that fire damage to one habitat or species can have repercussions across the region. Some of the consequences of this fire, for example, include reduced water quality, loss of hillside vegetation, and sediment delivery. The dissemination of ash and other hazardous materials can change the water chemistry of whole streams and rivers, which carry these materials downstream and into other habitats.

Figure B
Ash and sediment delivery especially was an issue. Aquatic organisms require specific amounts of sediment to survive, and when these amounts are altered via natural disaster and human activity it can be a barrier to reproduction and recolonization, putting these organisms at risk of local extinction. A common problem with fires, and this incident was no different, is ash and sediment can shred fish's gills and drive of the alkalinity of the ecosystem. If high amounts of precipitation follows, as was the case in 2009,  aggregation of sediment and debris can form into flowing masses with the consistency of wet concrete, destroying everything in their path and pouring into the regions creeks and major drainage systems.  Wild life specialists forecasted that the sediment increase would be high for the region covered by the fire for the first year following.

A look at Figure C shows that the watershed most ravaged by the Station Fire was the Big Tujunga Creek. The Upper Big Tunjunga is a critical biological zone, home to several species of fish federally labeled as endagered or or sensitive to changes in the environment. In a region already sensitive to the pollution and fragmentation from LA's urban development, unnatural fires posed daunting challenges. Two of the populations most affected were the Santa Ana Sucker and the Speckled Dace. These species are now both more at risk due to modifications in water quality, stream side vegetation, and instream barriers.

Figure C
But there were also implications for the people who lived near the region. Loss of vegetation caused mudslides, as groundwater that used to serve hillside plants began to surface as springs and destabilizes rock and soil in some of the most tectonically active mountains in California. These slides destroyed building materials containing toxic materials like asbestos, gas, oil, and other chemicals, some of it eventually making it's way back into streams and rivers and distributed throughout the watershed.

References:

Archibold, Randal C. "After a Devastating Fire, an Intense Study of Its Effects." The New York Times. The New York Times, 03 Oct. 2009. Web. 15 June 2012. <http://www.nytimes.com/2009/10/03/science/earth/03fire.html?pagewanted=all>.

Rust, Brad, and Joe Gonzales. Station Fire Burn Area Emergency Response Hazmat Assessment Report. Rep. US Forest Service, n.d. Web. <http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5167077.pdf>

Sahagun, Louis. "Displaced Santa Ana Sucker Fish Are a Problem for Wildlife Authorities." Los Angeles Times. Los Angeles Times, 18 Jan. 2010. Web. 15 June 2012. <http://articles.latimes.com/2010/jan/18/local/la-me-station-fire-fish18-2010jan18>.

Welch, Leslie, Dan Teater, and Robin Eliason. Wildlife and Fish Technical Specialist Report Burned Area Emergency Rehabilitation for the Station Fire. Rep. N.p.: n.p., 2009. Print.

Zavis, Alexandra, and Corina Knoll. "After the Station Fire, a New Danger: Mudslides."Los Angeles  Times. Los Angeles Times, 17 Sept. 2009. Web. 15 June 2012. <http://articles.latimes.com/2009/sep/17/local/me-sandbags17>



Tuesday, May 29, 2012

Lab #7: Cartography



This first map was the least surprising of the three: it shows the percent change in county population of "some other race"--in other words, people who didn't identify as Black, American Indian, Asian, or Pacific Islander--over the decade from 1990 to 2000. The states that have the highest percent changes are, the border states: California, New Mexico, Arizona, and Texas. The map shows -- unsurprisingly -- that most of our immigration is happening through the US-Mexico border. Maybe if the census had a table for people who identified as Latino/a for this data set, the map would not look the same. I do wonder about that little splotch of color in Washington: do Canadians just really love that county in Washington?



This second map I still have questions about. It shows the Asian Population Density per county in the year 2000. I expected there to be an obvious concentration in California, but what we instead see is areas of high density in California, but also several areas of high density across the South, Mid Atlantic, and North East. Maybe this is the consequence of spending all my time in the Bay Area and Los Angeles county, but I thought there were far fewer Asians in the South than California overall. If you look at the map, though, you'll see that the counties in the eastern US are much smaller than those of California. In order to calculate density, I divided Asian Population of each county by the area of each county, so perhaps county size is what's making the difference in this map.


Finally, this map shows Black Population per county in 2000. The counties with the highest populations seem to be Southern California and the North East, as well as the South and Mid Atlantic. Just like we saw in the map for Asian population density, very few Blacks live in Middle America. I'm not very familiar with the demographics of Southern California, so the high population of San Bernadino County, the large county east of Los Angeles was surprising. We have to remember  though that is a map of straight population numbers, and not population density, which could explain San Bernadino--one of the largest counties in the US.


It's amazing that the government provides so much raw data that anyone with mapping software can just play with. Data collection seems like the tricky part; once you have a nicely formatted table, you can do a lot to analyze it relatively easily. As far as the census goes, I was a little disappointed in the some the data they didn't have. "Black, White, Asian, American Indian, and Pacific Islander" is a pretty pathetic set of groupings for the United States population. What about Middle Eastern? What about Latino? Were these not included because they're classifying people by "race" instead of "ethnicity"? These are ambiguous theoretical questions, but they clearly make a difference when you're showing them on a map. I also wonder about break values: having a legend makes the maps above transparent, but the maps could be manipulated to look a totally different way if I changed the break values. The census tutorial hinted that there are standards for US Population values so I used those, but I wonder if many people ignore them to achieve their desired effect.

As always, I'm impressed with my overall GIS experience, but wish the focus of our tutorials was less on fine details ("this is how you change the specific colors) and more on concepts and broad skills ("this is how to calculate values in a table. try doing several of them.") It seems like the exercizes emphasize both about the same, and then I lose the important pieces amongst the fluffy fun stuff. I'd rather my conceptual understanding be solid.



Tuesday, May 22, 2012

Lab #6: DEMS in ArcGIS

The maps below visualize the Bay Area Peninsula, where I grew up. San Francisco is the sparkling, urban 7x7 mile area at the tip of peninsula. When people from the bay area say they live on "the peninsula," they typically mean one of the cities south of San Francisco. So as you will see in the maps below, the top of the peninsula is not included. Instead, the main thing you see is the hills of Golden Gate National Recreation Center (blue, in the first map below). The fog rolls over these hills from the west into the reservoir (brown), which is just east, nearly on the San Andreas Fault Line. East of the reservoir is Highway 280 (not shown), which runs north and south along the peninsula separating the beautiful landscape from the residential areas. Many of these areas are on much flatter ground, which is why the rightmost portion of the map directly below looks like there might be ocean where there is really flat land. Around all of this land, of course, is the San Francisco Bay (east) and the Pacific Ocean (west).

With the exception of the 3D model, which is tilted slightly to the right to give you a better view of the interesting landscape features, each map is oriented with north at the top. For reference, the geographic coordinate system for these maps is GCS North American 1983, and the extent information is as follows: Top: 37.71 degrees;  Bottom: 37.34 degrees; Left: -122.62 degrees; Right: -122.62 degrees.




Tuesday, May 15, 2012

Lab #5: Map Projections

Six map projections and their planar distances between Washington D.C and Kabul, Afghanistan.
My favorite example so far of the huge variation in map types and functions is the one Professor Sheng gave in lecture about BART. What are the important features on a BART map? Is it the distance between stations? The coordinates of each station? The shape of each station? It isn't any of those really. As a Bay Area native, I can say for certain that nobody on the Peninsula or the East Bay cares minutes and degrees when they're going into the city (save the degree of fog)--not even distance.

What is important is the relative location--the order. Which stop do I get off at? When the lovely Bay Area Transit designers were making the BART map, they probably didn't worry too much about whether the scale was spot on. There are plenty of instances, though, in which precision is much more important. Say you want to know the distance between New York and LA--or hey, Kabul and Washington D.C? How far apart are they? An equidistant map projection, like the two shown above, might give you a good number. Some other map projections distort the distance between locations in favor of preserving other qualities, like area (See Bonne and Eckhert IV) or shape and angles (See Hotine Oblique Mercator and Stereographic).

This has positives and negatives. On the one hand, we have a lot of map projections at our fingertips, increasing the likelihood that there is one out there that measures what we want it to measure. If you look at the Equidistant maps above, you'll see that they have two very different functions.The Azimuthal Equidistant map preserves distances from the poles outwards, while the Equidistant Cyllindrical projection preserves distances across meridians and equators. That is why the Azimuthal produces a distance of over 8,000 miles, while the Cyllindrical produces one closer to 5,000. It turns out that in the case of Kabul and Washington D.C., neither of these is perfect, although the Cyllindrical map comes closer, since Kabul and D.C are at similar latitudes.

The downside is that map projections can be misleading and manipulative. Distortion isn't always apolitical. During the Cold War, for example, the United States used Mercator projections because they distorted the size of the Soviet Union, making it monstrously larger than it really was. What the Mercator does is distort areas based on their distance from the equator. So Greenland, for example, is larger than Africa, even though Africa is at least 10 times as huge. Maps shape the way we think about the world. They can shape the way we feel. Africa is a good example. A lot of people don't realize that the United States can essentially fit inside the Sahara Desert alone. Maybe if we had fewer cheeseburgers and better map projections growing up, we wouldn't be such big-headed Americans.

Tuesday, May 8, 2012

Lab #4: Introducing ArcMap



My GIS Experience:

My overall experience working through the GIS tutorial was enjoyable. I like maps. I like data. I like I'm learning a skill that allows me to make data digestible and beautiful. Most of my frustrations with the tutorial came from the length and tedium.Instead of working through one long, complex mapping excersise, that covered everything we were meant to learn, it would have been nice to work with a smaller data set--maybe with a more familiar subject (what is a parcel? I still don't even know)--and learn how to use the tools one by one.

I also found myself wanting to understand the system deeper. Where does this data come from? What does it look like in its raw form? How do the different layers interact with each other? I can tell that if I understood some of the foundational technicalities better, I would have a better grasp of what I'm doing when I manipulate the visual representation of the data. But there's clearly a lot to learn. Maybe this is both a pitfall and a potential. GIS is tricky and hard to democratize, but once you learn the skill, you have a lot of power at your fingertips.

The other thing I wondered about was how users collaborate on maps. It seems like it would be so easy to mix files up or save a pathway wrong. If I were working on a serious project with a partner I would want some way to document our progress, as well as our sources. Where did the data set come from? Has information become so accessible that it's normal for GIS programmers to regularly give and receive data sets from other entities? That could be another issue in terms of trust and credibility.

I'm interested in what kind of software is available to do GIS on macs. Frankly, I'm not interested in honing a skill unless I can do it on my own laptop, and I'll probably take what I learn from this class to explore what the other options and technology there is out there.

Tuesday, April 24, 2012

Lab 3: Neogeography!

West Coast Student Food Coops



Map explanation: I'm the co-founder of the UCLA Student Food Collective, a group that's trying to bring better food to campus and train students to be member-owners of a sustainable community business. It's an exciting project because we are one in what seems to be a growing movement of students who are trying to provide themselves and their campuses with better food, and over the course of the last year I've learned about local student food initiatives all over the country, but especially on the west coast. Some of these, like the Kresge Coop in Santa Cruz, have been operating since the 1970s, but many are recent start-up projects. I thought it would be interesting to not only map these student groups, but the network of resources they reference-- other local coops, farms, eco-centers, etc. What kind of food systems are these groups operating in? What kind of opportunities and resources do they have access to? I included a few goodies (hint: Berkeley has a song for you).

On neogeography: I remember when the fanciest map I knew was the pink and turquoise map of the California coast that my mom would fumble with as we drove up highway five from our small student apartment in LA to my grandparents' home in the Bay Area--and that was because I liked the colors. Now I have high resolution commercial satellite imaging at my fingertips. There are some fair warnings about what digitializing and democratizing all that information could mean: we'll start turning on our GPS instead of remembering where to go (who needs memory when you have a pretty iPhone?), that there will be hundreds of useless, misleading maps! ... and obviously I don't want the federal government making some kind of sweeping policy judgement on information from any old teen geek neogeographer cutting class to map.

But in the context, most of those warnings seem pretty silly. The potential that democratizing information unlocks is always much greater. Take the map above as an example: in relatively little time I made a visual representation of the work I'm doing in the context of my community, my peers, and my region. This map will probably grow, I'll send it to my friends at other coops, and they can add all the resources I missed--and that was just for a weekly lab assignment. On the other hand, if I want to ride my bike over to Santa Monica, I don't have to call Tony, who is probably busy in Tahoe saving the world for Americorps, because there already dozens of maps made by LA bikers on the internet. And I'll still probably bug Tony, but the point is that it's so much easier visualize and place yourself within your community now than it used to be. I think it's far more likely that with every passing year people will have a better understanding of what the world they move through looks like.

View

Tuesday, April 17, 2012

Lab 2: Map Anatomy

1.What's the name of the quadrangle? 
Beverly Hills, CA

2. What are the names of the adjacent quadrangles?

Canoga Park, Van Nuys, Burbank, Topanga, Hollywood, Venice, Anglewood, Quadrangle six not listed.

3. When was the quadrangle first created?
1995

4. What datum was used to create your map?
The North American Datum of 1927, although the NAD 1983 is also shown by dashed corner ticks.

5. What is the scale of the map?
1 : 24,000

6. At the above scale, answer the following: 
    (a) 5 cm on the map is equivalent to how many meters on the ground? 
1200 m 
    (b) 5 inches on the map is equivalent to how many miles on the ground? 
1.89 mi 
    (c) one mile on the ground is equivalent to how many inches on the map? 
2.64 mi 
    (d) 3 kilometers on the ground is equivalent to how many centimeters on the map? 
12.5 cm

7. What is the contour interval on your map? 
20 feet

9. What is the aproximate elevation in both feet and meters of: 
    (a) greystone mansion (in greystone park), 
It lies in the range of 540-590 ft.
    (b) woodlawn cemetary
140 ft
    (c) crestwood hills park 
630 ft

10. What is th UTM zone of the map?
 zone 11

11. What are the utm coordinates for the lower left corner of your map?
3763000 m N and 362000 m E

12. How many square meters are contained within each cell (square) of the UTM gridlines? 
1000


13. Obtain elevation measurements, from west to east along the UTM northing 377100, where the eastings of the UTM grid intersect the northing. Create an elevation profile using these measruements in excel. Figure out how to label the elevation values to the two measurements on campus. Insert your elevation profile as the graphic in your blog.


*Note: UCLA data points are outlined in yellow.

14. What is the magnetic declination of the map? 
14 degrees east

15. In which direction does water flow in the intermittent stream between the 405 freeway and stone canyon reservoir?
It flows south! You can tell by looking at the elevations along the stream. In the northern areas, the stream is at a higher elevation, suggesting southbound flow.

16. Crop out UCLA and include as a graphic on your blog.