Chapter 1
The first chapter was able to give me a better understanding of what GIS is. It is a process looking at Geographic patterns in data and relationships between features. It was able to tell me the process I will go through when performing an analysis; the steps are as follows frame the question, understand your data, choose a method, process the data, and look at the results. It is important to look at your data and figure out how it can be analyzed before beginning in order to make the process easier. There are three geographic features they are discrete, continuous phenomena, or summarized by area .Each feature is used differently to find answers to a question. These geographic features can be represented in two different ways vector and raster. The vector method shows features of discrete locations and can even be used to pinpoint that spot of a crime. The raster model looks much different, features are represented as a matrix of cells in a continuous space. Depending on the size of cell for a raster layer it will affect the results of the analysis. I found it interesting that in each model certain features are better represented. Next the chapter talked about map projections and coordinate systems. It discussed that map projections can distort shapes of the features being displayed but generally when making maps of small areas that error is negligible. I found it interesting that the type of analysis you preform depends on the geographic attributes. The attribute values are categories, ranks, counts, amounts, and ratios. Finally, the chapter ends by talking about an important part of GIS analysis this is the data tables that contain attribute values and summary statistics.
Chapter 2
Chapter 2 begins by talking about why map where things are. Personally I would like to work in conservation so this next part stuck out to me. It discussed how mapping can show you places where you need to take action and when applied to conservation that could be destroyed Wetlands or protected habitats. What really helped me understand each of these chapters better was the real life examples they used. Deciding what to map actually was an easy concept for me to understand. For example how a police department may use GIS in order to figure out where the highest concentration of crimes are in an area. Each section was very detailed and helped me understand how to properly use GIS maps in the most efficient way. Additionally this chapter thoroughly listed out each step before and after making a map which helped me better understand the process. An important note was about how even basic maps that show where features are can reveal important patterns. The GIS uses the coordinates that you put in to draw the features, individual locations, linear features, and areas all will display something different depending on what you want to see .Although this chapter makes GIS seem easy to understand I’m sure there will be difficulties when using it in the future. I am excited to start the next step of applying my knowledge to the ARGIS program.
Chapter 3
In chapter 3 it’s really interesting to see what goes into mapping and how it is used to scale out the variety of businesses shown as examples on the first few pages. There are an endless amount of items you can map out, from the book we can see examples such as discrete features, continuous phenomena, or data summarized. From the text, most maps that show data summarized are expressed through shading each area that is also based upon its value or using charts to show the amount of each category in each area. It is surprising to me that business maps should not be grouped by employees because block groups vary so much in size. While on the other hand larger block groups should have more workers but can be more spread out. They would need to map workers by the square miles so that you can see some distribution. There is a way to use ratios in a mapping situation, it’s fun to hear the use of ratios can even out a difference in larger and smaller areas, or also areas with many different features even with the ones with a few. Some of the more common ratios that are used in a mapping setting seem to be averages, proportions, and even some densities. When classes are being represented there are features with some similar values by assigning them the same symbol. Having these makes you see some less features while also seeing features with similar values. Classes should be made manually if you are looking for a feature that has a specific criteria or a comparing feature in a specific meaningful value. The maps that are shown on page 69 and explained on 68 were really interesting to see because the similarities in visual representation in the natural breaks (Jenks) and quantile were so fun to look at because it seems as if they are representing the same thing. Also keeping the data simple while explaining and showing expressive topics seems very hard but with the GIS system it has to be done to help successfully make a map.