Brokaw Week 2

Chapter 1: Introducing GIS Analysis

Some comments, notes, and questions I had while reading this chapter were plentiful. It was interesting to find out that spatial analysis is working to bring attention to real-world problems and issues people face. GIS is growing rapidly and we are finding more and more uses for its capabilities. GIS analysis is using models of the real world and looking at the geographical patterns. There are 3 types of geographical features: discrete, continuous phenomena, or summarized by area. Discrete locations and lines are actual spots found and can be easily read line buildings or bodies of water. Continuous phenomena are going to span the whole map you make because it shows weather patterns like rainfall or temperature. Interpolation is when GIS gives values to points irregularly or regularly spaced on a map. Geographical features summarized by area could be the number of households in each county, or business zip code. Reading about the two types of GIS models vector and raster I am a little confused. A vector model is a map that shows a point and is labeled using x and y coordinates mainly used to show small details. The raster model is for larger spaces that need to be analyzed and is not good if looking for precise measurements. I thought it was interesting to find out that map projects get distorted because of the curvature of the earth. So when looking at a large section of Earth it will relatively not be 100% accurate. After reading about ranks and counts and amounts for features that are mapped it gives me an idea why different levels are color-coded and categorized for their particular purpose. How will summarizing the values of a large population help us to find an average? Will data tables help to sort out ranks for a map that needs to be created? 

Chapter 2: Mapping Where Things Are

Why map where things are? To see patterns that may need another perspective besides being in a table or literature. What is the difference between distribution features and individual features? Distribution features are patterns and many professionals use GIS to target areas they are in need of their assistance. Deciding what to map? Is a process since you want a map to be easily read and understood and to correctly convey information to readers. Learning how to create features to be layered over other features to display different years or a pattern of change. Being detailed on either category or doing a broad overview to minimize distractions for the intended audience. Preparing data needs to be organized before starting a map and to have all features with a location. How will geographic coordinates be assigned to the GIS database? Will we be learning how to code features or will the software we use already be coded? It was neat to find out that we just told the GIS what features and symbols we wanted to be shown. Mapping a single type may or may not be able to show patterns but for a single type, all the same symbols will be used. What is the main idea behind GIS? It has many capabilities for setting coordinate pairs and storing the locations, symbols, and streets. Using a subset of features to layer data was neat to show the relationship between two completely different categories. 

Chapter 3: Mapping the most and least

To find a place to map you should look for areas with equal quantities of an abundance of species and, or a place with a decline or decrease in species. It’s all about finding information that will be helpful to us in the future. What we need to map is finding patterns with similar values with quantities that should be studied. The features we will be focusing on mapping will be centered around discrete and linear features. The continuous phenomena are areas that cover. When looking at a map or creating one the dark areas will be greater in value from lighter shades. All ranks will be coded in this way so that the more pigmented areas will be darker or have more than light colors. A map that shows the longest salmon runs were categorized and coded on a map and from the pattern it was determined that the counties will longer runs have watersheds. The difference between presenting or doing research with a map will be set up in two separate ways. If presenting a map it will need to be simple to show a pattern and a more generalized view. If doing research on a map it can be detailed and have lots of different features.  Business can be mapped by the number of employees and the size of circles will be used to show employment numbers. For a larger area say the whole state of Ohio using counts and amounts would be the most beneficial and it will be rounded numbers. Block groups vary in size so a rough guess would be sufficient.  Using ratios to show the distribution of features with averages, proportions, and densities.