Monday, December 12, 2011

California Earthquakes

Although living in California is thought to be the epitome of the American dream, the Golden State is home to many hazards and puts a threat to the large population. One of the most threatening and unpredictable hazards to the state are earthquakes. According to the theory of Plate Tectonics, California sits on top of two moving plates, which float on top of flowing magma. These two plates, the continental North American Plate and the oceanic Pacific Plate, form a transforms fault boundary most known as the San Andreas Fault. The millions of years of the fault’s lateral strike slip motion are a direct result of California’s many geological features such as the Transverse Mountain Ranges. When these two plates slide against each other, they create friction and put stress on the earth’s crust causing it to move and shake. This is the cause of an earthquake. Because California sits on top of a plate boundary, there are many transform faults all along the state. With the help of Geographic Information Systems and Technologies, or GIS, we can map the fault boundaries to view which parts of the state are at threat to earthquakes. Also, along with analyzing the fault data, we can spatially analyze population, households, schools, hospitals, buildings, and major freeways that are close to or intersect the faults at a local level to assess the possible damage that could occur from an earthquake. Furthermore, a map of major historic earthquakes could be a helpful visual to help assess and predict when the next possible earthquake could be.
By creating a map of California using ArcMap, we can see where the major and minor faults in California are located. Although knowing where the faults in California may help in predicting earthquakes, many times the epicenter (point on the surface directly above the focus) of earthquakes do not happen directly above a fault. They usually happen around or near a fault boundary as you would notice in the map that locates the major historic earthquakes of California. However, by knowing where the fault boundaries are located in California, we can study the areas around those boundaries and assess the risk and vulnerability of a city. 


Furthermore, mapping the historic earthquakes in the State of California can be very educational. By geotagging the locations of past earthquakes and categorizing them by magnitude, deaths and dollars in loss, we can learn from those past events and try to better prepare for the future. We can use the data information and assess how and why there was so much property damage or loss of life due to an earthquake. For example, the 1906 San Francisco Earthquake was a magnitude 7.8 and caused many deaths, injuries, and property damage. There was so much, now we know how much damage can occur from an earthquake that strong. Also, there are laws like the Public Fields Act, stating that all buildings in California must be retrofitted and earthquake safe to minimize damage. By knowing the magnitude of past earthquakes and learning about how they affected a city or area, we can learn from the damages and be better prepared for the future. 

By locating the fault boundaries in California on a map, we can analyze the possible threats an area is at risk of. In the case of Los Angeles, there are multiple faults that run through the county, as you can see in the map. Therefore many structures are at risk of shaking of the earth. Despite the Public Fields Act stating that all building are to be retrofitted or earthquake safe, these buildings could still be at risk if they are close enough to a fault boundary or epicenter of an earthquake that is rated higher than 6 on the Richter scale. Therefore, it is important to map structures that are within a significant distance of fault boundaries because these structures are at most risk. 


Locating schools and major buildings within 0.25 miles of fault boundaries are at major risk to earthquake damage. From the data provided on the UCLA GIS data site, we can locate these features using the select by location feature and display it in the map. Also, mapping the hospitals a mile away from the faults we can try to determine the possible damage to those important hospitals. The area for hospitals is extended a mile away from the faults because the loss of an important hospital could be a serious problem in a natural disaster because this will reduce the amount of emergency aid and resources. Furthermore, freeways that intersect a fault are at risk of major damage. The resulting map shows that there are 237 schools, 62 buildings, 46 hospitals and 41 freeways at risk of damage in the event of a serious earthquake in Los Angeles area.

Because Los Angeles is one of the most populated areas in the United States, many people and homes are at risk of injury and loss of property. By creating a map with the breakdown of population by city, we can see the areas that are most populated and the areas with the most house units and can analyze what areas could possibly face the most in property damage. 


Of course depending on the magnitude and location of a future earthquake, people and their properties will be affected differently, but by creating this map, we can have a better understanding of the potential damage could be in different scenarios. The most populated area in Los Angeles County is Los Angeles City and it has the most housing units. Other populous cities with many housing units are: Santa Monica, Long Beach, Thousand Oaks, Simi Valley and could potentially face major life risk and property loss. 

In conclusion,  by using GIS, we can evaluate the potential risks that people have by living in Los Angeles. By viewing the past earthquakes and seeing the damage they have done, we have an idea of how to prepare for the next big earthquake. We can not only see what schools, buildings, hospitals and freeways are at risk of damage but also the potential population and house units in danger of being injured or killed or destroyed. By using GIS and technologies we can better understand the occurrence and threat of earthquakes in California and Los Angeles.


Final Map Layout


Precipitation

      

      I chose to create a map of precipitation using the IDW and spline method of interpolation. Using the data of off the Water Resources homepage for Los Angeles, I created an interpolation of this season’s precipitation and the normal season precipitation. As the results show, it looks as if Los Angeles has not reached the normal precipitation falls in a normal season. You can see that in both the IDW and spline method, there are more dark blues in the normal precipitation maps therefore indicating that the normal precipitation has more rainfall. But some areas have reached what the “normal” rainfall would be and match the colors in this season’s map.
      The results of the difference between this season’s precipitation and the normal season’s precipitation are shown in a different map. The negative numbers or the lighter blue colors show that the precipitation of this season has not met the precipitation of a normal season. The darker blue colors show that the precipitation of those areas are higher than the normal season precipitation and this means that those areas have gotten more rain than average.
      However, it is difficult for me to tell which method is the more accurate method to use. At first, I liked the IDW method because I liked how it looked, but I think that the better method is the spline method, because it shows a smoother distribution. From the lecture, I got the impression that the IDW method was more complex because of the calculations involved in finding the unknown values. I believe that the spline method is the method of choice for this assignment because it represents the data more accurately and clearly and is a better visual than the IDW method.

Station Fire Analysis



In the introduction class to GIS I took last quarter, we had an assignment to create a map showing an element of the Station Fire and to write an essay about it. After completing the tutorial and going through the steps with the Station fire data I downloaded from Seamless and FRAP websites, I had a better understanding of the Station fire than I did before. Last quarter I just had a digital elevation model with roads showing what roads were at threat. I had the elevation because I knew that fire spread faster uphill. However, I realized that the slope model is a better representation of where the high and low hazard areas are. By doing this tutorial and assignment I learned a lot and received a lot of help from my classmates.
                After completing the tutorial I began to download the data. I easily downloaded the DEM from the seamless website. However, the vegetation cover was a lot more difficult to find. The seamless data could never find anything and a lot of things were not free. Some data I downloaded did not have the right metadata that I was looking for. After asking around, I downloaded the vegetation cover from the FRAP website (Fire and Resource Assessment Program). I then created a slope by percent model from my DEM I downloaded from seamless. Like from the tutorial I reclassified the slope into 4 categories 1, 2, 3, 4. I later changed these categories to low, moderate, high, and very high. In these categories I classified the ranges of slope by percentage. A high slope percent would be “high” which means that this area of high slope is also ranked “high” in hazardous because fire spreads more quickly when the slope is steeper. Furthermore, I created the vegetation cover map; however I also had to reclassify, like the tutorial. I classified the different categories of land cover into none-very low, low, moderate, high, very high. In the high categories were the vegetation that are dried and burn more easily and the lower categories are the ones that don’t burn at all or are less likely to burn. Lastly, in order to complete the fire hazard map, I combined the slope ad vegetation map to ultimately show the places of high and low vulnerability to fires. I did this just like in the tutorial through the raster calculator. The result was the combination of the two maps showing many of the designated “high” hazard areas inside of where the Station Fire burned.
                In conclusion, the fire hazard map helped me better understand how to create an analysis of fire hazard areas in chaparral covered slopes. Although the tutorial was very descriptive of how to do the assignment, I never fully understood what exactly I was doing and why I was doing it. I did not know why we needed to “reclassify” because the tutorial never said why, I said just to do it. Getting help from my classmates and asking a lot of questions were really how I learned how to create a fire hazard map. I had a lot of difficulty finding the data and it took a lot of my time but it all came together in the end. Also, it was often quite frustrating when the reclassify would not work and I had to redo everything. But I never gave up and a definitely had a positive and productive experience.




                Last year, it was discovered that there was a higher than normal amount of birth defects in Kettleman City, California. Because of this factor, Barbara Boxer put a delay on the growth of a nearby landfill, until the investigations of the birth defects are completed. There is reason to believe that the landfill might have an impact of the high levels of arsenic in the drinking water of the city and therefore could be hazardous to the people’s health. The drinking water test showed that there were high levels of arsenic, “a naturally occurring element in California soils that also is used in pesticides, herbicides, insecticides and metal alloys,” according to Louis Sahagun in his article “Feinstein, Boxer call for delay on plans to expand Central Valley landfill,” in the Los Angeles Times on February 10, 2010. Although not known yet, this may be a cause to the birth defects of the area. By using GIS and we can make a map overlaying different layers of water runoff, landfill runoff, and also wind patterns to help investigate the reasons as to why there are so many birth defects in Kettleman City, CA.
                We can make a map of Kettleman City and its surrounding areas and overlay the contours of the land around agricultural sites and rivers to see if there are any problems with the runoff. By making this map, we will be able to see if any of this runoff is improperly going into the water systems of Kettleman City. If so, this could be a reason why the arsenic concentration in the drinking water is so high. Further investigation would be needed in order to determine the effects of arsenic on human life. Also, this map could help show that there are no problems with the runoff and will allow investigators to move onto the next investigation. It is important to note that the team should investigate the kinds of pesticides used in the nearby farms.
                We can also make a map show possible landfill runoff. Two years ago, according to the article, “the site took in 400,000 tons of hazardous waste, including cancer-causing PBCs.” Although the landfill “is among the most heavily regulated and monitored facilities of its kind in the nation,” many residents in surrounding cities have observed safety violations of the facility. Therefore, this could mean that a leak in the system. Besides investigating and finding a leak, when found a map should be made to assess where the leaks goes to. This will show if the leak heads to groundwater that the cities are getting their drinking water from or maybe a nearby river of stream. If it does, it can be brought up to investigators that the many PBCs in the landfill could be leaking into the water and getting into the drinking water from Kettleman City. This could be the problem as to why there are birth defects in the area.
                Furthermore, landfills are not only hazardous for the chemicals they hold, but also the particulate matter and chemicals that are released into the air. This could pose health threats to surrounding areas that are downwind from the landfill. If we overlay the Kettleman City area with a general wind pattern map, we will be able to see if the fumes from the landfill do indeed travels over the Kettleman City. We will then be able to see if the decades of exposure to smog and particulates have had an effect on the birth defects.
                Birth defects are a big problem in Kettleman City because people do not know what the direct cause is. We can only begin to assume that it could be because of the large landfill near the city. By using GIS maps properly, we can assess the situation to find the problem. We can find out if the cause is pesticide runoff into the drinking water or landfill leak into a ground water tap. Or maybe even the exposure to particulates in air from being downwind of the landfill is the leading problem. Whatever it may be, the GIS maps will help pin point the direct cause and thus begin the steps that need to be taken to prevent further defects.

Medical Marijuana Dispensaries in the City of Los Angeles



Although medical marijuana dispensaries are legal in the City of Los Angeles, they should not be located within a 1,000 foot buffer of places where children congregate. This includes places such as schools and parks. It is extremely important that these dispensaries are not located within this buffer because children should not be exposed to the distribution of marijuana.
In the map above, the medical marijuana dispensaries in the City of Los Angeles are located. Also, a buffer (in red) has been created around all schools and parks. As you can see, there are some dispensaries that are located in the “red zone” and should be considered to be ineligible in the city. In January of 2010, the City of Los Angeles passed an ordinance to discontinue all dispensaries within the buffer and are currently in the process of shutting those places down.
There are many benefits to shutting down the dispensaries with the “red zone.” Not only will children’s innocence be protected but also they will be protected from many drug related crimes that potentially take place in areas that sell marijuana. The children will be safe and the parents will be happy. However, there are costs to shutting down these dispensaries because this means there will be more business at other locations thus possibly adding to the crime around those areas not in the “red zone.” Also, many families might live in areas that are not within a 1,000 foot buffer of schools and parks and therefore may be located by and eligible marijuana dispensary. This could cause these families to be unsafe in where they life and may cost them to relocated their home. In all, I believe it is a good idea to not allow medical marijuana dispensaries with 1000 feet of schools and parks because children do not need to be around marijuana.

Data and information found at:

http://cityclerk.lacity.org/cps/pdf/preliminaryResults08-25-10.pdf

http://gis.ats.ucla.edu//Mapshare/Default.cfm

Water Project suitability Analysis