2000 Cesus

The Asian population percent of continental North America is shown on this map. From this map one can see that the highest percentage of Asians is located in California. And this is shown through the dark brown color on California. To be exact, the darkest shade of brown is in the bay area and in Los Angeles. From this information, people learn that Asians usually live in the North Bay or in Los Angeles. This information can be applied and be useful for many things such as advertising. For example, now that people know where most Asians are, companies that have a lot of Asian customers might want to put their companies or ads in California.

There is a lot of “some other race” living west of North America. The highest percent of “some other race” is located in California, Washington, and New Mexico. Again this information can be used in the same way as with the Asian percentage map. Overall, it shows how diverse different places in North America is. In this map, it seems that Central America does not have “some other race”. This can mean that Central America is not very diverse.

Black population seems to cluster in the east- south of North America. Also, since the color shade is pretty dark or concentrated in California, it means there is still a high percentage of blacks in California but just not as high as in the south east. This information can give us information about the progress of blacks moving from place to place. From history, Africans were slaves and most were brought to the south east and from this map, it seems that Africans have not disbursed much and that they remained from they were.

In conclusion about census data, it helps as a visual aid to prove several points. People can use this information to do many things such as locating stores, or anything that attract a particular race or ethnicity group. And it can be done with other things besides race such as level of education, marital status, age group etc. Because different things attract different types of people, using census to see where these types of people are can help determine where the best and most efficient location to place something is.   

My overall impression of GIS is that it can be very useful but it is difficult to use because there is so much to learn and so many functions to this program. You can do many things with it and because of so many options, it isn't user friendly. GIS makes maps that can inform people about a topic and it can serve as a visual aid which is very helpful. However, much practice needs to be put into this program if someone wanted to use it in a presentation or to prove a point which can be time consuming. 

Week 7 Lab DEMs in Arc GIS

This area is the North Bay of California. The top portion of the map is the cities Vallajo which is located on the upper right hand corner, and San Rafael which is on the upper left hand corner. The bottom right portion consists of Hercules, Pinole Valley, Richmond, Berkeley, Oakland and Alameda. The bottom left portion is where The Golden Gate National Park and Sand Francisco are located.  This area has many small hills. Near Berkeley which is the bottom right corner is where one of the tallest hills and highest elevation are. The famous San Andreas fault line lies here. Another very hilly place is the Mill Valley and Tamaipais- Homestead Valley which is north of the Golden Gate Park in San Francisco. The extent of this map is 2106 columns and 2018 rows of raster data. The resolution in x direction is 0.000277777777796473 degree and resolution in y direction is 0.000277777777796473 degree. Coordinate system is top edge native is 38.2366666660223 degree, bottom edge native is 37.676111110429 degree, left edge native is -122.680555555471 degree and right edge native is  -122.095555555431 degree. The file size is 18 MB.

Map Projections

Different projections of maps are used for different things so picking the right map projection to use really depends on what your map is intended for or intended to do or show. Every map projection has its potentials and limitations. Some ways to determine preciseness and factors that play into picking a good map are showing the correct distance between locations, showing directions, showing the correct shape of the earth or the place you are looking at compared to real life, area and proportions are accurate and seeing how little the map is distorted. But really, it depends on what the purpose of the map is for in order to pick the right projection that fits.

A type of projection is equal area projection. As the name suggests, it is a map that shows all the places in an equal ration area and places are proportional to each other. Because it is it is proportional, it lets us know how big or small a place is relative to another. The Hammer and Craster map preserve the real relationship of size between one place and another. The Craster map does not have any distortions at latitudes 36°46' N. and S. at the central meridian. Thus if someone wanted to focus on the central meridian or this latitude, they would pick the Craster map because it doesn’t distort. The Hammer and Craster map can be good for thematic maps because since areas are proportional, when giving information about a population, someone can compare the population to the size of the place.

The Azimuthal and Equidistant Conic map projections are considered equal distant projections. Equidistant map projections show correct scale between points on the map or along every meridian. For the Azimuthal map, distances are correct between points along straight lines. On the map it shows that the distance between Washington DC and Kabul, Afghanistan is 13,413,685 meters which is the actual distance because they are equidistant maps. Compared to equal area maps such as Hammer that said the distance was 13,398,532 meters and Craster that said 13,018,095 meters, the Conformal maps such as Stereographic with distance of 15,897,194 Meters and Polyconic with distance of 11,823,160 meters, the distances are different due to distortions. It shows the distance from the center of the projection. This map is commonly used for polar aspects and to find correct distances between two places. The conic projection has the same spacing between parallels or lines so the scale would look the same and constant. Because scales are not distorted, distance between places is accurate so if someone wanted to use a map to find the distance between two places for travelling, they can use equidistant maps.

In conformal maps, the meridians and parallels cross at right angles. Because the scale is kept only when this happens, this map is good for local mapping in a large scale and small area. Conformal maps are not equal area so it would not be good to use it for statistics in an area, area density or population size in a place. Conformal maps also preserve angles so if someone wanted to find angles where the meridians and parallels, then conformal is useful. It is also useful when viewing a local map because it is not distorted.