Chapter 1:
The first thing mentioned in this chapter is that GIS has grown significantly more abundant in the past 2 decades, which doesn’t surprise me at all due to the ever increasing spread of information due to technology advancements and the internet. People have realized that GIS can be used for more than mapping. They can use it to address many worldwide problems and can be used in many different areas. Learning GIS is a very useful skill because you can find out how things are, why there are and where. Many people are learning how this system works because its uses across many fields are ever increasing and that is a big reason why I wanted to take this class even if I wasn’t an environmental science major. One thing I didn’t quite understand that was mentioned under the types of attribute values is ranks. I think it’s interesting how it is used when direct measurements are not easily quantified but it seems very subjective and I wonder how accurate the information could be if they are relative. When the book talks about the process of forming an analysis it reminded me a lot of the steps in the scientific method. Those steps are framing the question, understanding the data, choosing a method, processing the data and looking at the results. Geographical features are a big part in GIS and there are 2 types, discrete and continuous phenomena. A big thing that I took away from the beginning of the chapter was that maps are essentially areas of our globe translated to a flat plane and it made me think about how our world map kind of distorts how we see the countries as far as size and distance. This made me wonder if for larger areas a more 3d approach would be more accurate.
Chapter 2:
The first question that chapter 2 goes over is, why should we map where things are? Not only does mapping allow us to see where or what a feature is but also by looking at the distribution of multiple features it will help you notice patterns and in turn help you understand the area better. This ultimately is how you will find what areas meet your criteria and where action needs to be taken. When looking for geographic patterns, you first map the features in layers using different symbols in a way that is based on the information you need. The maps that you make are meant to display the appropriate information for the topic being addressed. It’s best to avoid unnecessary information that will just confuse what the actual purpose is and to cater the essential information to your audience. To prepare for actual mapping it is important that each geographical location has a coordinate location unless it is already in the GIS database. Since the information and goal you’re trying to achieve affects how you will make your map, it makes sense that when you have multiple features you make a key to show what each individual one is. I think it is very cool how GIS is able to take the input you give it and output a map and is a major advancement in how we show data. I wonder if how GIS works is kind of like a calculator in that you must put the information in a very specific way to get the information you need, and mistakes are mainly from human error? The type of symbols that will be assigned to features will vary depending on what other information, if you’re looking for patterns and how it will look if printed out. Overall this chapter gave me good insight into what all goes into making a map and what the role of GIS is.
Chapter 3:
The big idea that this chapter goes over is why would somebody map the most and the least of something and what I found was that the big reason is to find relationships and where resources need to be distributed the most. This strategy of adding quantity to the features you map adds an extra level of information that can be very useful. As mentioned in the previous chapter it is important to keep the intended purpose of the final product, whether it’s for exploring data or presenting it in a professional way. Your intentions should affect how the final map looks. Often what happens is you start out exploring and see what patterns pop up and then use that to generalize the map to reveal those patterns. When understanding what quantities are being represented, things like counts, amounts, ratios, and ranks all influence what you’re seeing. Once you understand the quantity that will be used for the map you can use symbols (as mentioned earlier) or something called classes. This looks colored or shaded in shapes with values assigned to the different colors, which makes data more obvious at first glance than if multiple symbols were bunched together. What I find really cool is how GIS can display information in so many ways including 3d. Graduated symbols, graduated colors, charts, contours and 3d perspective are the kinds of ways to display information and there are advantages and disadvantages to all of them. The patterns that can show up in maps can give you so much extra information that isn’t as obvious, such as high and low values, transitional changes, and relationships between features.