Lab 7

The first map shows the African American population ranked by percentage in different counties in US. We can see from the graph, The darker blue represent higher percentage of black population. The lighter blue, the lower percentage of population. From this map, we can see most African American population lives in the south east of US, such as Florida, Georgia, Alabama, Mississippi, Louisiana and South Carolina. Some of counties contains 53% to 86% population of African American. While in other states,especially around west and central American, African American population is very low. Some of places is even below 4%.

The second map show the Asian American population ranked by percentage in different counties in US. The darker pink represent higher percentage of Asian population. The lighter pink represent lower percentage of Asian population. Overall, compared to African American, Asian population is much smaller in US. The most abundant area is in South California, Bay area, New York area and a small area in Washington state. In other areas, especially in south and central area, Asian population is relatively small.

The third map show the other races population ranked by percentage in different counties in US. We can see from the graph, the darker red represent higher percentage of other races. The lighter red, the lower percentage of population of other races. Overall, ,most other races population lives in the south west of US. As we expect, there are many Latin American population in the south west states such as South California, Arizona, New Mexico and Texas. Besides, we can see there are also large population in south Florida and north west of US. In other areas especially central and East, the population of other races are small.

In this lab, we create three maps for  population percentage for different races in US. We use ArcMap and ArcCatalog to join the excel data sheet and the normal map. After joining, we can easily see the excel data from the map. From this map, I think GIS is really useful and convenient for people's life. Before using GIS, I think it is really hard and boring for me to read through the data from excel. However, by using GIS, we can illustrate the boring figures into vivid maps. From these maps, we can easily get the ideas of these data. Overall, GIS bring us a convenient and vivid life.

Lab 6

The map I choose for this lab is a small area above LA county. The place is between Santa Monica Mountain and the Pacific Ocean. The coordinate for this regions is from 34. 29° N to 34.62°N and 119.67°W to 119.01°W. The Geographic Coordinate System for this map is GCS North American 1983.There are four maps: Shaded relief model, Slope map, Aspect map and the 3D map. These maps shows the areas from different levels of views, giving people different aspects. The map I choose for this lab is a small area above LA county. The place is between Santa Monica Mountain and the Pacific Ocean. The coordinate for this regions is from

Lab 5

The first picture is the conformal projection: Mercator and Stereographic map. The stereographic projection is a mapping tat projects a sphere onto a plane. It is the conformal projection because it preserves the original angles. However, it doesn't preserve distance or areas of the original figures. This projects is extremely useful in mathematics fields such as complex analysis, geology and cartography. However, the limitation of this projection is the extreme distortion as seen in the picture. The shape, equator, latitude, longitude are distorted by the projection. Therefore, this map will be hard for people to use. The second projection is Mercator. In his projection, latitude and longitude are in right angle. It preserves the angles and shapes. However, as the map goes to the poles. The scale increases and becomes infinite. This map is commonly used in navigation and is used for areas near the equator.

The second picture is equal area projection: cylindrical equal area and Behrmann equal area cylindrical projection. These two projections are similar. They both map longitudes as vertical lines and latitude as horizontal lines. They preserve the area of original figures. However, it distort the direction and distance especially near the poles. These projections is hard for use in research areas. However, they give people a clear view of world map.  The difference between the two projection is: Berhamn projection is narrower than the cylindrical equal area projection.

The third picture is equidistant projection: two point equidistant and azimuthal projection. Both projections preserve distance of the original maps. For the two point equidistant projection, distances from any point on the map to two control points scale to the geodesic distances of the same points on the sphere. This However, it distort the areas and directions. This projection is commonly used for use in measuring distance between two points accurately such as air routes. For azimuthal projection, it also preserve the distance, but not as well as the two point equidistant map. It shows distance and directions accurately from the center point, but distort shapes and size elsewhere.

In this lab, we measure the distance between Washington DC and kabul for each projection. For the conformal projection: The distance between two cities is 10164 miles for Mercator and 9960 miles for Stereographic projections. For equal area projection, the distance between two cities for the Berhamn projection is 8781 miles, which is a little less than the cylindrical projection: 10108 miles. For equidistant projection, the distance is 6648 miles for two point equidistant projection and 8341 miles for azimuthal projection. The true distance between two cities is around 6934 miles. Therefore, from the measurement above, we can see that the conformal projection and equal area projection both distort the distance between the two cities. Equidistant projections preserve the distant well: two point equidistant projection is nearly the same as the geodesic distant while azimuthal is a little bigger than 6934 miles. Therefore, form this lab, we can get the idea that each projection has their own purpose in use. If we want to measure the distant accurately, we would better choose the equidistant projections, especially the two point equidistant projection.

Lab 4

ArcGIS is a geographic information system (GIS) for working with maps and geographic information. It can be used by any people to use ,create compile, analyze, manage and share the geographic data.In this lab, we learn how to use ArcGIS by reading the software tutorial. By using the maps and data the professor provides, we create school and noise contour map, Land use within noise contour map, population density map, as well as a bar chart of land use in noise contour in ArcGIS. We learn about examining maps, creating legends, deriving data from the maps, adding roads on the maps etc.


Although I don't have any experiences in using geographic software, when I begin to learn how to use ArcGIS,  I discovered that it is not as hard as I thought. This program is pretty easy and clear to understand even for fresh people. The tools are clear without much explanation. Because the clear setting and the "undo" button, I can even do many creative options without worrying too much. Besides, the maps we tends to create is reality based. We may see such maps elsewhere before. Therefore, creating these maps will not be abstract so that we can get the idea without confusion.


Without much experiences in using ArcGIS, It won't be much for me to write about the difficulties I encounter. However, I do remember a difficulty I encountered while using ArcGIS. When we use the data view, we click the zoom in and zoom out button on the tools bar. When we switch to the layout view, there are more buttons relating to the map size. Sometimes,  click on the wrong button will mess up all the maps.


Overall, ArcGIS is a really powerful program. People can create the maps in detail and compile it with changes. Besides, this software can also create map with a special theme, such as the population density map we make. We can easily make the maps to illustrate the idea we want by gathering data in this software. Furthermore, ArcGIS also provides opportunities for everyone to create maps, encouraging people's interest in Geography. However, this widespread opportunities may bring pitfalls in ArcGIS. As we add the Airport Dr, which is not there at first on the map, people can edit maps based on their own knowledge and understandings in ArcGIS. Therefore, errors may be appeared in maps made by ArcGIS. Generally, ArcGIS is still a excellent software, providing benefits to people's life.