Chapter 4:
Mapping density is important for identifying patterns such as how much crime has occurred in a specific area. Before mapping, identify the features and the information that the map needs, this information will be useful for the viewer. There are two ways to map density: mapping features, which can be mapping businesses, or feature values, which can be the number of employees in a business. The information presented can be important depending on the views intention with the information. One way the chapter identifies mapping density is by using a dot map. The dot maps benefit the viewer because it can show the amount of features in an area with a given value for each dot so that the map is easier to read. Another way the chapter show density is by density surface. This confused me a bit because I’m not sure what the raster layer is and how that influences the density. The chapter also shows how lines can be interpreted for the length on the map. I thought it was interesting how the chapter gave examples of when density maps can be beneficial, such as population densities for census mapping, or employment mapping for bus routes. In the section about what GIS does, I was a little confused on how the chapter used neighborhood. I am uncertain if it is used in the way of urban living, people close together, or in other type of understanding. And with that however, it made sense about how to calculate the density base on the amount of features recorded to the area mapped. I thought that calculating the cell size was an interesting part of the chapter because it used words like “smoother” and “courser” to describe the patterns. I also thought the math equation was helpful.
Chapter 5
This chapter begins by stating the importance of analyzing if you’re using a single area or more than one to map your data. There are many different kinds of single areas but they are just a set area. However in multiple areas, you are able to compare more. I thought the examples were useful for this section. A key word was a continuous which means that the values continue overtime and examples are temperate, elevation, and precipitation. The chapter also goes into the different kinds of data plotting such as using lists, counts, or a summary. I also found the visuals to be helpful in this section as well. I thought it was interesting how the chapter showed layering GIS to show levels of importance. When selecting the features for inside an area, you need the have the dataset with features and the areas, as well as anything else that needs to be summarized. Whereas, overlaying GIS combines area and features to compare the layers and calculate a summary. This also includes having the features with area and the database, as well as anything that needs to be summarized. I thought the chart did a good job of explaining the pros and cons of each method and gave a list on the features needed. The chapter goes into a step by step process on drawling the lines and features. This includes a key method of being able to easily identify the features that are inside the area. It goes on the state that the features can be used by a single symbol, or be symbolized by category or quantity. Then draw a thick-black lines around the area the distinguish the area. You can use the GIS to make a report about different features. Later in the chapter, some key words such as count and frequency were used. Count meaning the total number of features inside an area. And frequency is the number of features in a given value.
Chapter 6
Mapping nearby can be important for city planning and notifying residents of certain structures. This can also help traveling range which is beneficial to define area served by faculty. Defining the distance around your features can be helpful in determining with method to use. Nearness can be measured by distance and cost. Cost includes time, effort, and money. The maps helped me in determining the difference between these key words. The chapter also points out the importance of measuring a flat plane, or taking the Earth’s curvature into consideration if it is over a long stretch of land. Another key detail to put into consideration is to analyze if there needs to be a list, count, or summary. I understood the chapters use of counts, however, I was a little confused about the lists and summaries. A key term from the chapter was inclusive rings which are used to find out the total amount increased as the distance increasing. Another key term is distinct bands which are used to compare distance to other characteristics. The chapter also laid out the three ways in which you can locate what’s nearby. One way is the straight-line distance which is reliant on the specificity of the source features and the distance and then the GIS finds out the features surrounding with the distance. Distant or cost over the network is when the source locations are laid out along with distance or travel cost. And lastly the cost over a surface is when you specify the location of source features and travel cost. I like the way that the chapter points out what is needed for each kind and lays out its pros.