Week 8) Lab 7 - Station Fire of 2009 in Los Angeles County

The STATION FIRE of 2009 in Los Angeles County

INTRODUCTION

The Angeles National Forest (ANF) is a mountainous habitat that is situated in the San Gabriel Mountains north of Los Angeles County. In August 2009, Station Fires decimated over 160,577 acres (655 square kilometers) of this territory.
The Station Fire was one of the largest fires in the history of LA county. As shown in the first of the four maps (which shows LA County in the context of Southern California), we can see that the fire took up entirely into its boundaries. To have a comparison of the size, 1 County's square kilometer every 19 has been burned by fires (655 on 12,308 km2, according to Wikipedia).

BODY

The first map introduces the Area in the General Context of California. The second reference map helps viewers identify the location of the Station Fire as well as size of the fire with respect to the County.

The map below displays natural features, such as river, streams and the topography within the neighborhoods of the Fires, the boundaries of Los Angeles County and the most important Conservation Areas and National Park (green/light red)

The fires started downhill, in a point of the Fire's perimeter relatively close to populated areas and traffic axis (see third and fourth map) , and spread in N direction over the parkland.


As we can see in the fourth and fifth maps, one factor why the station fire spread so quickly and why it was so hard to stop is likely to have been the scarce sources of water and waterlines within the fire perimeter, as well as capillary roads' distribution within the area. This means that firefighters were not able to hook up their hoses and fight the fires frequently and directly, they had to set controlled fires to and shovel dirt in order to counter the fire, while certain areas where fire was growing were simply inaccessible to firemen.

Also, Rivers, Streams and Lakes act as barriers for fires, which in this case may have had no obstacles along its way, sprawling in every direction and making efforts for firemen harder.
In fact, as we can see from the perimeters, the fire sprawled everywhere in the forest following elevation. The only sources of water or other fire fighting techniques they could use to slow down the fire was to use helicopters which were in limited number. Overall, there are 137 kilometers of water lines within the station fire perimeter, much less than the average of the rest of LA County.
Fire, as shown in the Second and the following fifth map, went fast in the initial phase when was climbing hills of ANF, and only in a second moment burned the largest section homogeneously toward E-NE, supported by the global winds coming from the Ocean.


Fires often run uphill on these slopes and even animals find it difficult to outrun a fire that moves uphill 16 times faster than it moves on flat land. (Sahagun, 2009).
The distinctive topography of the Angeles National Forest is one of the main reasons for the destruction and speed of the Station Fire. Reports from the incident stated that Fire was so large and powerful that only moderate rainfalls and the onset of winter conditions assisted the firefighters in controlling the fire. The potential for mudslides also is another effect of this natural disaster (Topynka-Lyn 2009).

The burnt area varies in slope and aspect, but overall it goes from lower to higher elevations, and from South West to North East, partially following the winds or breezes coming from the ocean but mostly a slope uphill.
The above map (5th), is a bidimensional representation of elevation in the area (DEM). The Black Shadow visible in the Red Area (Mountainous Area), is the extension of the Station Fire.
It shows how the Station Fire, after starting just at the feet of those mountains, sprawled north following the steep hills.
GIS analysis can predict where these conditions are likely to occur again in future, and which populated areas could be more affected by debris, erosion and mudslides caused by the fires, by analysis of Topographic features and Digital Elevation Models.

CONCLUSIONS

Overall, GIS analysis allows better studying, treatment and prevention of fires, as they have a very strong spatial component. In particular, allow us understanding processes such as those described below, which have been crucial during the event of the Station Fire in Los Angeles:

- Fires are more likely to occur for human actions, in fact are very related with presence of population (Risling, 2009).
- Elevation and Topography of land play a primary role for SPEED, EXTENSION AREA, ORIENTATION of fire's Sprawl, as warmer air tends to run uphill in higher elevations and also winds that could support fire are stronger the higher the elevation.
- Presence of Natural Barriers such as Waterbodies, Walls, Artificial Cutting edges or Roads are extremely important as factors for the control of fire.
Also, Roads are useful as Transportation way for Firemen and for capillary actions in all needed points of intervention.

REFERENCES

- “2009 California Wildfires.” Wikipedia, the Free Encyclopedia. Visited 19th November 2010.

- Bloomekatz, Ari B. “Station fire is largest in L.A. County’s modern history.” LA Times. 2nd September 2009. Visited 22nd November 2010.

- “Los Angeles County Spatial Information Library.” Department of Public Works. http://gis.dpw.lacounty.gov/oia/index.cfm?agree=agree
Visited on 21st November 2010.

- Risling, Greg. (September 2, 2009). "Huge wildfire portends bad Calif. fire season". Washington Post. Associated Press. http://www.washingtonpost.com/wp-dyn/content/article/2009/09/01/AR2009090100224.html?hpid=moreheadlines. Retrieved September 3rd 2009, visited 23rd November 2010.

- Sahagun, Louis. “Angeles National Forest Fire Takes Toll on Wildlife.” 1 Sept. 2009.
http://latimesblogs.latimes.com/greenspace/2009/09/fire-environment.html
Visited 23rd November 2010.

- U.S. Department of Interior, and U.S. Geological Survey. “The National Map Seamless Server Viewer.” Seamless Data Warehouse.Visited 20th November 2010.

6) Week 7 - Lab 6 - The Digital Elevation Model (coolest exercise ever!)

THE GRAND CANYON - ELEVATION DIGITAL MODEL OF ITS TOPOGRAPHY

The Grand Canyon is a worldwide famous attraction. With ArcGis it is possible to create in few steps a model of its topography and extract important data such as slopes, orientation, exact geographical location, and project all these in Thematic Maps starting from Remote Sensing data. As shown below, Digital Elevation models offer a wide range of application, such as Geomorphology and Geological Studies. It is incredibly high the level of precision these models can reach, ranging from 90x90 meters resolution worldwide, 30x30 in the US and Sub metrical resolution for commercial files. This map shows a representation of slopes using a chromatic range, a very common and useful tool of ArcGis applied in several fields of Geography. At the same way surface images from Mars, Venus, the Moon and Mercury have been studied by scientists in order to understand physical processes of their surfaces.

SPECIFIC DATA ABOUT LOCATION

The Grand Canyon DEM's data used for this exercise have been the Elevation Raster Data of the area with this four angles: From 35.64 to 36.61 North and from 113.97 to 112.79 West.
This means that the areas covered occupies approximately 0.97 degrees of LATITUDE and 1.18 of LONGITUDE, having as a result a Rectangular Shape.
The Geographical Reference Systems used is the North American Datum 1983, upon which the elevation data of the DEM are based.



The ASPECT Tool is also very useful, allowing us for example to understand which could have been the role of solar and winds' exposition of rocks into the processes of formation of topographic features, or, in case of Urban Planning and Architectural Studies, studying strategies for augmenting light exposure.


A Map that joins the two characteristics:

The last ones are some 3D models of the area, creating by adding a Z dimension into a new projection. Several Other tools such as a flyby or virtual guided tours can be created to have different perspectives of surfaces or objects.

Digital Elevation Models are an important and basiliar tool of GIS, which may be combined with all other thematic databases in order to discover relationships between patterns and probably the most important feature of Earth's surface.

5) Week 6 - Lab 5 - The Projection Exercise

ANSWERS

1) Equator is extended for 360 degrees;
2) The other Arcs of Latitudes, Northern and Southern of the Equator Arc, measure all 360 degrees.
3) They all correspond to a one full arc of Latitude.

4) 6,935 Miles between WASHINGTON DC and KABUL
5) Areas and Countries located closer to Equator have normal size, those closer to Poles are bigger.


6) 6,865 Miles with the Mercator projection (CONFORMAL-1)


7) 6,800 Miles with the Lambert Conformal Conic (CONFORMAL-2)


8) 5,065 Miles with the Equidistant Cylindrical (Equidistant-1)


9) 6,970 Miles with Equidistant Conic (Equidistant-2)

10) 10,190 Miles with Cylindrical Equal Area (Equal Area-1)

11) 7,270 Miles with USA Contiguous Albers Equal Area Conic (Equal Area-2)

THE IMPORTANCE OF DIFFERENT PROJECTIONS IN CREATING MAPS AND GEOGRAPHY

the significance, perils and potential of map
projections based on this exercise. Be sure to clearly reference your six maps as
examples

Geographical Projections are used to reduce surfaces of spherical or other 3D shapes into a 2D models. Inevitably, some information is lost during this process, as it is not possible to represent a Sphere on a Plane. One important characteristic or projection process is that it can be adapted to different needs. In fact, there are basically infinite formulas we can use for making surfaces from Geometrical Shapes. It depends by the Intersecting point we use as a touching point from the hypothetical surface and the sphere (or ellipsoid), and which surface are we going to use to represent the plane. We can use for example a plane developed from a Cone or a Cylinder, or other shape with a curvature.
Personally, I think that one of the best projection is the Mercator secant in two points of the globe, because is able to also maintain areas better than a normal Mercator. This Projection uses a normal cylinder, but it has tangent 2 points at 30 degrees North and 30 Degrees South of the Equator with the Sphere. Areas North of 30 deg. North and South of 30 deg. South will be slightly bigger than the reality, while the arc between 30 North and 30 South will be reduced to fix into the plane.

THE SIX MAPS

1) The First Map projection Image shows instead a Normal MERCATOR, which is the most widely used Conformal Projection. As it is possible to see in the image, this map preserves the Angles very well, but areas are inevitably deformed as well as distances do. Using more secant points (see paragraph above), could help to reduce this effects but it will never be possible to adjust the 3 properties of the projection (Conformity, Equal-Area, Equal-Distance). It is good for showing the whole world on a rectangular surface just to have an idea of all the continents it contains. The most wide use is done in Large Scale Topographic Maps and Nautical Charts, because on smaller areas such as less than one decimal degree, deformations are minimal. Ie. USGS Topographic Maps.

2) LAMBERT CONFORMAL CONIC Projection is widely used in Aeronautical Charts, and is made by intersecting a Cone on one Emisphere of the Ellipsoid or Sphere. The results is a map with two secant points corresponding to two parallels, where there is no distortion along the standard parallels, but distortion increases further from the chosen parallels. For a country like the US, all located into one Hemisphere and for most of its area close or between central arcs of latitude, it is a very useful and not much deforming projection.

3)The EQUIDISTANT CYLINDRICAL Projection preserves distances very good, but loses correctness of Areas and Angles. It is used when we want to make pretty accurate measurements, but we will not use it as a navigation map or to find out the surface extent of nations or regions.

4) The EQUIDISTANT CONIC is instead created by projecting all the two Hemispheres surfaces into a single Cone which starts from a single point, generally one of the Poles (North Pole usually). Areas are dramatically deformed in order to preserve distances. It is not very useful unless we are projecting only areas within 15-30 degrees from the center of the projection, the Pole.

5) The CYLINDRICAL EQUAL AREA is a projection widely used to represent all the surface of the globe. It maintains Areas Perfectly and Bearings pretty well, but dramatically exaggerates and stretch Continents and Items located far away from The Equator so Distances are inevitably and highly longer than the reality as far as we move north or south from the Equator.
It remains in every case a good projection for representing Countries' extensions and their are compared with the rest of the world.

6) USA CONTIGUOS ALBERS EQUAL AREA CONIC
The Sixth map is not used commonly, and we can explain why. Although Areas are preserved extremely well around all the surface represented, this projection results horrible for the preservation of both directions and Distances, which are reasonable only very close to the secant points of the Cone. The result is that only countries located close to the secant parallels are represented fairly well such as the United States in this case, which are also the center of the projection in order to be represented as much precisely as possible. It is definitely a Map I would use and center on a local region of the world, and I won't use for the representation of the whole globe.

PROBLEMS AND PERILS OF PROJECTION SYSTEMS
The most important Peril of projections is the fact that there are several standard ones but also everyone can create their own projection. This results in a big multitude of representations and maps that contain information not easily and immediately comparable. ARCGIS has a tool for changing the projection system of representations, but it could not contain the specific projection used to project the map and in this case we can lose important information contained such as distances or areas of the items, or, even worst, not realizing that we are using a wrong projection which is slightly different from the one the maps was created in. and we are then going to have incorrect data.

ADVANTAGES
In general, the enormous variability of projections allows us to use the best and close-to-reality representation system when we want to create or modify maps. Moreover, very useful tools such as ArcGis allowed us to easily manage projections, as long as we are competent and have the knowledge to use the right and proper projection at everytime.

4) Week 4-5 - The ArcGis Tutorial 3rd November 2010

These Maps have been created for the Tutorial of ArcGis of week 4. ArcGis has a strong ability of showing data across space and organizing them into logical group layers and in form of correlations. The above images correspond to the intermediate steps of the Arc Gis 9 Tutorial.
Although it has been built with a pretty good programming architecture, the software still has some pitfalls or disadvantages in logical construction of maps and databases.

A first problem is the interaction with ArcCatalog and files memory. ArcCat is the ArcGis Database and data management dedicated software. In fact, Arc catalog is not designed for keeping links at the moment of moving files from and to different Hard drives or positions inside the same drive. A simple move made outside of the ArcCatalog frame can create chaos even if all the files are inside the same "last folder". The architecture can be fairly improved.

A general disadvantage and pitfall of GIS as they are organized, is the "dark face" of what could be considered also a point of power: Its organization in layers.
In fact, in reality discrete objects and group of data are usually given at the same level (except for vertical-based objects such as most of the soils, elevation, etc) and mixed simultaneously. Data frames and layers are unable to replicate this condition of simultaneous presence of different things in the same way, where the discrete objects are mixed up but still recognizable and not simply separated and independent from each other.

During my use of the software for the tutorial, I found very hard sometimes to manage all these multiple and different data frames and understanding how the software was managing them. When we have two or more data frames on the left bar, ArcGis was visualizing only the last of these frames into the visualization area. This may induce users to think that something went wrong whe creating data because the are not appearing.

Especially when dealing with raster, pixeled images, times of data calculation and elaboration could be very long. ArcGis requires a lot of memory and processing capacity also for one single project. Also, unless saving every step on a new file, it is very difficult to return back and undo the last steps when saved. An algorithm that saves automatically after every step but keeps the previous status of the project would be very useful for a better use and allow users saving a lot of time when making mistakes, which is very easy.

Exported Maps from Arc Gis are considerably heavier in size because they contain a lot of pixel information when given with a detailed resolution. There is as a result a high difference between information given in Vector data in GIS and the Raster/Pixel based outputs in other formats.

Moreover, in general ArcGis is a sofitware that requires considerable time spent of practice to memorize and develop proficiency with tools and understanding of the logic behind. This is something very different from the other technical questions, but still has a large impact on managing and using tools available because users to not understand the full potentials.