Geography 291: Geospatial Analysis with Desktop GIS

Chapter 4: Mapping Density

Chapter 4 focuses on mapping density and how it is done and the reason why it is needed.  Mapping density allows you to see where the highest concentration of features is.  Density is more useful when it comes to looking at patterns than individual features.  Mapping density is also useful when trying to map areas.  This chapter then talks about how you can use GIS to map the density of points or lines.  There are two different ways of mapping density; those being mapping density by defined area and mapping density by density surface.  When mapping density by defined area you can use a dot map or calculate each density value for each specific area.  By using a dot map to represent the density of individual locations, each dot would represent a specific number of features.  The closer the dots are on this map the higher the density is.  Then on the map each area is shaded based on these density values which allows for the viewer to see which areas have a higher density.  Mapping density by density surface is usually done in the GIS through a raster layer.  To create density surface various information related to specific features and location would be needed.  This method is more time consuming but is the more accurate method.   Each method is useful for its own reason.  For example mapping by defined area would be more effective if you already have the data summarized but mapping by density surface is more effective when you want to see a specific points concentration.  Creating a dot density map allows for the viewer to have a summarized and easy to understand way of seeing the density of a specific area.  Density surfaces are created in GIS as raster layers.  There is a specific density value for each cell in each layer.  This helps to show which points or lines are the most concentrated.

Chapter 5: Finding What’s Inside

Chapter 5 discusses the importance of mapping and why it is important to see what is located inside an area.  By mapping a specific area it allows for the viewer to be able to see specific patterns and to have an idea of what is occurring.  A map condenses and summarizes a specific feature or thing in a location.  By having this map it allows us to be able to see where in an area there is more and less of something.  When deciding what is inside of your map it is important to take into consideration the data that you are using.  It is also important to think about whether you are finding what’s inside a specific single area or finding what’s inside several areas.  A single area would be easier to monitor as it would give specific summarized information.  With multiple areas it would be more useful for making comparisons.  Another important thing that this chapter talks about is considering whether features inside are discrete or continuous.  Discrete features are unique and identifiable features and something that you can easily list or count.  Continuous features on the other hand aren’t as straight forward and instead represent a variety of different things.  GIS is helpful when trying to decide what information you may need from the analysis such as asking the question of whether or not you need a list or a count or a summary.  GIS can be used to find out if a specific individual feature is inside an area.  There are three ways of finding what’s inside; those being drawing areas and features, selecting the features inside the area, and overlaying the areas and features.  Drawing areas and features is useful as it allows for you to have a visual representation of which features are inside or outside the area.  Selecting the features inside the area is useful for getting a list or an overall summary of the features inside a specific area or group of areas.  Overlaying the areas and features is useful for finding which features are in a specific area. 

Chapter 6: Finding What’s Nearby

Chapter 6 discusses the importance of finding what is nearby a feature and how to do so.  Using GIS you can find what is nearby a feature and you can set a specific distance.  By monitoring what is nearby it allows more information to be able to plan.  To find out what is nearby you can measure straight-line distance, measure distance or cost over a network, or measure cost over a surface.  Kind of similar to the previous chapter but it emphasizes that you need to have an idea of what information you want from the analysis.  There are three ways of finding what’s nearby: that is by using straight-line distance, distance or cost over a network, and cost over a surface.  With straight-line distance you have to specify the main feature that you want to use as the source and what distance you want the GIS to look into for finding the surrounding features within this specific distance.  This is useful for when you need to create a boundary.  Another way of finding what is nearby is by distance or cost over a network.  Another way of finding what is nearby is through cost over a surface.  This method is useful for calculating overland travel costs.  The easiest method for finding what is nearby is straight-line distance.  Straight-line distance is a simple way of seeing which features are in a given distance of the main source feature you want to find what is nearby.  The next thing this chapter talks about is creating a buffer.  In order to create a buffer you have to specify the source feature and then the specific buffer distance; this helps for finding what is inside a specific boundary or area.  Once this buffer is created then you can use it to select what features you want to fall within it which allows for you to get a summarized list or count of the features.  Overall these chapters have focused more on the content of the maps in comparison to previous chapters from last week which focused on the creation of maps.

Chapter 1

This chapter did a lot of introduction to GIS. Going along with the reading we did last week helped me to better understand the basic level things that GIS is about. I think until I start to familiarize myself with the actual software and see what certain things do it will be a bit difficult to understand. While the reading gets my brain thinking about it, I can’t really wrap my head around everything fully. This chapter did a good job of explaining what GIS analysis was (before reading I still wasn’t quite sure). It became clear that geographic patterns and relationships between features is a big part of GIS analysis. I believe that the idea behind GIS analysis is to make visual representations of these patterns and relationships. As humans it seems that we need to see things to understand them. By Using GIS analysis we are able to connect the dots between certain attributes of an area. By using different types of data we can find relationships between things, or provide evidence that there is no relationship between certain features. It was interesting learning about the vector and raster models. Vector models tend to be more precise and are good when it comes to showing fixed features like a mountain range is. But if you were trying to show different elevations of a mountain range using a vector model would get confusing. This is where you would use the Raster model with pixels. Raster models are good but if your pixel size is too large then you lose some information if the pixels are too small then you take up alot of storage space. It was interesting to learn that there are certain things that are good about each model.

Chapter 2

While reading this chapter it seemed to me that it focused on the building blocks of making maps, or at least the things you have to think about and do when making a map. Being able to understand why it is important to map where things are, deciding what to map, preparing your data, making your map,  and analyzing geographic patterns are all important if you want to get the most out of your GIS analysis. As I was reading, it made sense that it is good to understand what you are looking for when you are getting ready to make a map. It seems that there is always some sort of question or problem trying to be answered or solved, and that is why a map is being made. For example if a law enforcement agency wants to know where the most crimes are happening in the area of a given period of time, so they record where each crime is taking place and then from there they can see where a majority of crimes are happening. The audience seems to be a crucial part in deciding what kind of map to make and how to present it. Knowing what kind of categories you want to present on your map is important. I understand that each feature that you want to have visible on your map has a code that identifies its type of feature. The way I understand it there are larger areas of features, for example zoning areas like, rural, residential commercial, etc. within those categories they get split down further. “Rural” may encompass more specific features like, rural residential and agriculture & forestry. However when expressing the more specific features on a map having too many features in a given area can make the map very difficult to understand and “busy” so in some cases less is more.

 

Chapter 3 

I recognised in this chapter that it focused more on the quantitative features of map making. When representing quantities on a graph, different sizes of shape, different gradients, and colors are used to depict different features of the map. Quantities can be shown in the form of counts, and amounts, ratios or ranks. The total amounts are shown as counts. Totals are the value associated with a feature. These two, counts and amounts can be mapped for discrete features or continuous phenomena.  Some times when we are mqppign quantities we are looking at quantities in a given area, like anual snowfall in a place. In this case we would not use counts and amounts we would use ratios. Fro example it would be anual rain fall per square mile. When using ranksin a map you are orderign the features of the map from highest to lowest. I enjoyed the part of the reading about contour lines. I fel like those are a very common thing to see on maps and it was interesting to learn about them. Contour lines have to be big enough to show accurately the features that you want to show but not too small that you cant tell what you are trying to represent. Over all this chapter did a great job of explaining more about making maps.

 

Chapter 1

The first chapter of the book by Andy Mitchell goes over the fundamentals of GIS analysis, emphasizing the importance of understanding geographic features and patterns which can be used to find relationships in the data on a map. The chapter defines key concepts like geographic patterns, which can be random, clustered, or evenly spaced, and spatial relationships such as proximity. These concepts are important when someone is looking at a map and is trying to decipher what they are looking at, where the map location is, and where it is in relation to other existing locations. He also defines key terms such as categories, ranks, counts, amounts, and ratios which are all continuous values and are used when making maps.  A key takeaway for me is how GIS transforms raw data into insights by combining statistical and visual analysis. I am not a very mathematical person, so this entire concept is foreign to me, but I am interested in learning more. For example, geographic features can be categories into discrete, continuous phenomena, or data summarized by area. Discrete features can vary immensely, one example being crime locations, and are best represented using vector models. Continuous data is more suited for raster models. This chapter also explores map projections and coordinate systems. It’s interesting how the curvature of the earth needs to be taken into account, as larger projections will distort geographic attributes unlike the smaller scaled maps. This makes me wonder how GIS professionals deal with challenges posed by inconsistencies in data quality when performing large-scale analyses.

Chapter 2 

Chapter two delves into why and how to map in order to make a map that makes sense. This chapter emphasizes why it is crucial to map the location of features to reveal patterns that inform decision making. An example of this is identifying areas with high crime concentrations and can affect urban planning. The chapter details the importance of clarity in map design and highlights how basic maps showing where features are can uncover important patterns. Symbols and classifications also play a key role. Mitchell states that a good rule of thumb is that no more than seven categories should be displayed on a map at once… however this can change depending on the size of the map. This chapter helped me appreciate even more how GIS has shaped everything around us. I like the real world examples provided. One important one is the police department examples. I wonder how much harder their job would be without GIS. What I thought was interesting was the importance of balancing detail and simplicity. The decision about what data to use and what background color all shape the narrative of the map.

 

Chapter 3 

This chapter explores the importance of mapping quantities to uncover relationships and support decision making. By using counts, amounts, ratios, or ranks, GIS can add depth to geographic analysis. This chapter was very interesting to me because it combined technical explanations with real world applications to things that are important to me such as resource distribution. Visualization methods like graduated symbols, color shading, and 3D perspectives were introduced as tools for effectively communicating data. I found the section on ratio mapping compelling, as it demonstrated how averages, proportions, and densities provide meaningful comparisons across diverse regions. One interesting observation was that larder areas should not solely rely on counts but also use ratios to present a fairer analysis.

This chapter’s explanation of classifications methods, such as natural breaks and quartiles was really interesting. I am a stranger to all of these and am excited to learn more. These methods group data into classes, allowing patterns to emerge. It was interesting to compare visual examples, as they revealed how different methods tell distinct stories using the same data. This reinforced the creative aspect of GIS. This chapter deepened my appreciation for GIS, but also made me feel a little more overwhelmed. There are so many different uses for GIS and I wonder what GIS professionals decide which classification methods to use depending on the audience or goals they have. I know that this will be a useful tool in the future.

Chapter 4: 

Chapter 4 is all about understanding and managing data in GIS. It explains two main types of data: vector and raster. Vector data includes points, lines, and polygons, like roads or lakes, while raster data is made of a grid of cells, often used for things like elevation or temperature maps. Both types of data are essential for mapping and analysis. The chapter also talks about attribute tables, which store information about the features on a map. For example, you could have a table showing population numbers for each county. It explains how to clean and organize this data, like fixing errors, removing duplicates, and formatting it correctly. These steps are crucial for making sure your maps and analyses are accurate. Another important concept is data joins. This is when you combine outside data, like census statistics, with your map features using shared identifiers. This lets you add more detailed information to your maps. The chapter’s tutorials help show how these concepts work in practice. The big takeaway is that working with GIS data takes attention to detail because even small mistakes can lead to big problems in your analysis. Questions to think about: How can you best organize large datasets? And how do you make sure the data from different sources is accurate?

Chapter 5: 

Chapter 5 focuses on using GIS to find patterns and relationships in data. It introduces tools like buffering, which creates zones around features, and overlay analysis, which combines layers to find overlapping areas. For example, you could use buffering to find homes within a certain distance of a school, or overlay analysis to see where flood zones and neighborhoods intersect. The chapter also explains spatial relationships like proximity (how close things are) and containment (what’s inside a boundary). These ideas help answer questions like “What’s nearby?” or “What areas are affected?” Geoprocessing tools make it easier to do things like merge datasets or select specific features based on criteria. The tutorials give examples of real-world uses, like analyzing public transit access by combining maps of bus routes and population density. This shows how GIS helps solve problems in urban planning, environmental studies, and more. Questions include: How can these tools be used for different scales of analysis? And what are some limits to what current GIS tools can do?

Chapter 6: 

Chapter 6 gets into more advanced GIS topics like modeling and making predictions. It introduces suitability modeling, where you evaluate locations based on multiple factors. For instance, you might find the best spots for a solar farm by looking at sunlight, land use, and distance to power lines. Another method is interpolation, which estimates values in areas where you don’t have data by using nearby points. This is useful for predicting things like rainfall or pollution levels. The chapter also covers cost distance analysis, which calculates the difficulty of moving across a landscape. This is helpful for planning paths around obstacles like steep hills or rivers. The tutorials show how to use tools like weighted overlay, which lets you prioritize different factors in your analysis. These powerful methods require careful planning to avoid errors or bad assumptions. Key takeaways include the importance of checking your models for accuracy and thinking about the ethical implications of using GIS for predictions. Questions that come to mind: How can you test if your models are reliable? And what happens if people misuse predictive maps?

Chapter 1

Chapter 1 introduces us to the capabilities of ArcGIS Pro. The chapter focuses on describing the ArcGIS Pro interface effectively in order for us to understand what it is like to work with spatial data and analyze maps. It introduced a couple of definitions we must know, such as feature classes, rasters, file geodatabases, and projects, as well as a couple of tutorials for the ArcGIS Pro.  The file geodatabases clicked for me as a “home” for all my spatial data. It’s great knowing there’s a system to keep everything organized when working on complex projects. The step-by-step tutorials simplify the whole process for someone who is a beginner. This chapter does a great job introducing beginners to a technology like GIS and at the same time, it gives us the opportunity to practice. In addition, the examples that were used, such as the analysis of healthcare access in underdeveloped areas, make the content more relatable to the audience. One of the things that I found interesting in this chapter is the 2D and 3D maps. When we analyze something on a 2D map we have less information compared to a 3D map.  I had no idea that satellite images could be integrated into maps so easily, but learning that rasters are made of tiny pixels was fascinating. One question that came to mind when reading this chapter was what other fields could use these GIS techniques and help them develop. Reading about poverty risk areas and healthcare access reminded me of a conversation I had with a friend who works in public health. She once mentioned how hard it is to realize which communities communities are underserved without the right tools. This chapter, however, showed me that GIS could be that tool. I’m excited to move into the next chapters and learn how to create maps from scratch. I also want to explore 3D mapping more.

Chapter 2

Chapter 2 got me thinking about the science behind map design. The data needs to be carefully crafted onto the map. This chapter talked about thematic maps. I realized that these maps are around me during my everyday life without realizing it. I learned about how to balance the figure and the ground of a map and how to make it stand out. It made me realize how much thought goes into the maps that we often don’t realize. In addition, it was the first time I heard the word choropleth, however, I had seen these types of maps before. It is amazing how the same dataset can look so much different by dividing the data differently. There was one part that I found tricky and that was the definition queries, as it reminded me of coding. I realized that designing a map is a big responsibility because the choices that the creator makes will shape how people will view this data. This chapter made me realize how maps can be creative and technical at the same time. Also, I especially liked the vivid colors. It’s so satisfying to see the patterns that are created as the shades darken or lighten and how bright colors make the subject stand out. One thing that I liked too was labeling, as there is so much detail involved and it makes so much difference for the map. I’m looking forward to experimenting more with the tools in ArcGIS Pro. I want to get better at finding the balance between complexity and clarity, which is something that this chapter emphasizes a lot.  I’m excited to try creating more choropleth maps with different data to see how they compare. I also want to revisit 3D mapping and push myself to learn how to make it more intuitive.

 

Chapter 3

 

Chapter 3 was all about making maps usable and impactful for end users, and it gave me a whole new appreciation for how maps go from a tool for analysis to something you can share with others. This chapter connected with the previous chapters and consequently, the previous chapters made more sense. I hadn’t realized how all the elements that are needed to make a map come together and create this clean layout. Building layouts and charts was very interesting to me. Specifically learning how to build layouts made me feel like I was putting the last touches on something that I was going to publish after. ArcGIS makes it really easy to share maps online and that is something really important for someone like me who has no experience with things like that. I had heard about StoryMaps but I didn’t know much about them. I learned that they combine images, texts, and videos and that made me think about how can I use this for the projects that I have for school. I found it a bit overwhelming to figure out the best placements for all the elements in a layout. I was wondering how will I know if there is too much clutter etc. I loved the concept of online sharing but I am curious about how much control I can have after I publish the map. In general, I was wondering how much detail is too much or too little. What stood out to me in this chapter was how much thought I should put when making maps and how much detail is needed. Designing a map is a skill that I should develop but I think that following the instructions and tutorials in the book will make the process easier. I want to try publishing maps to ArcGIS Online in the future, so I am excited to see what I will learn next.

 

Will White 

Week 2 Assignment 

 

Chapter 1: The Rise and Relevance of GIS

Over the last two decades, Geographic Information Systems (GIS) have become significantly more prevalent, largely due to advancements in technology and the internet. While traditionally associated with mapping, GIS now serves as a tool for solving complex global problems across various fields. This broad applicability makes GIS an essential skill for professionals, regardless of their primary discipline, and is one of the reasons I pursued learning about it. A key concept in this chapter is understanding attribute values, which are crucial in GIS analysis. These include categories, quantities, ranks, and counts. While categories and quantities are straightforward, ranks stood out to me as an intriguing but somewhat subjective metric. Since ranks are often used when direct measurement isn’t possible, I wonder how their subjectivity affects the accuracy of the resulting analyses. Another important topic is the process of forming a GIS analysis, which mirrors the scientific method. This involves steps like framing questions, gathering data, choosing methods, processing data, and interpreting results. The chapter also highlights two types of geographical phenomena: discrete (buildings) and continuous (elevation). This distinction is fundamental to understanding how data is represented and analyzed. One concept that particularly resonated with me was the idea that maps translate our three-dimensional world onto a flat surface, inevitably introducing distortions. This made me question whether 3D mapping technologies could provide a more accurate representation for larger areas. Overall, this chapter emphasizes the evolving role of GIS in problem-solving and the foundational skills needed to harness its potential effectively.

 

Chapter 2: Mapping Patterns and Features

Chapter 2 explores the reasons behind mapping locations and how this process reveals patterns that enhance understanding and decision-making. Mapping where features are located helps identify relationships and determine areas requiring action. For example, layering features with distinct symbols allows patterns to emerge, tailored to the map’s purpose. A key takeaway is the importance of clarity and audience-focused design in mapping. Maps should include only relevant information to avoid confusion and ensure they effectively convey the intended message. Proper preparation is crucial, including ensuring all geographical locations have accurate coordinate data or are linked to the GIS database. This process reminded me of how critical precision is in data input, much like using a calculator where errors often stem from human mistakes. Another intriguing concept is how symbols and classifications are used to represent data. Symbols must align with the goal of the map—whether to reveal patterns or aid in presentations. For instance, adding a legend to explain symbols or assigning colors to specific data ranges helps the audience interpret the map with minimal effort. GIS’s ability to transform raw data into meaningful visualizations is an impressive advancement, enabling deeper insights into geographic patterns. This chapter reinforced the importance of thoughtful design and the relationship between the data’s purpose and its visual representation.

 

Chapter 3: Mapping Quantities and Their Implications

This chapter delves into why it’s essential to map quantities and how doing so can uncover relationships and inform resource distribution. Mapping the most and least of something—using counts, amounts, ratios, or ranks—adds depth to geographic analysis and supports strategic decision-making. One notable point is that the purpose of the map—whether exploratory or for professional presentation—should shape its design. For example, during the exploratory phase, patterns may emerge that can later be refined into a generalized map to highlight key insights. Adding quantitative data enhances this process, revealing trends that might otherwise remain hidden. The chapter introduces various visualization methods, such as graduated symbols, color shading, and 3D perspectives. Each approach has strengths and weaknesses. For instance, color gradients effectively display ranges at a glance, while 3D perspectives can illustrate elevation or density in a way that’s intuitively grasped. I’m fascinated by the flexibility GIS offers in customizing these representations to suit specific needs. Patterns in data often reveal transitional changes, high and low values, and relationships between features. For example, mapping resource usage across a region could highlight areas needing intervention. This chapter highlights the power of GIS in not just visualizing data but also deriving actionable insights from it.

Chapter 1: 

This chapter is about getting started with ArcGIS Pro, Esri’s tool for creating and analyzing maps. It introduces key terms like feature classes, which are groups of map elements like roads or parks; raster datasets, which are images made of pixels like satellite photos; file geodatabases, a format for storing spatial data; and project files, which organize all the resources in one place. The tutorials walk through basic tasks like navigating maps, turning layers on and off, and adding base maps. One important takeaway is the distinction between “figure” (the main data you’re focusing on) and “ground” (the background that provides context). For instance, you might layer population density data over health clinic locations to analyze if the clinics are in the right places. A key lesson here is that GIS makes it easier to see patterns and relationships in data. Although the concepts are fairly straightforward, using the software might take some hands-on practice to fully grasp how everything works together. The tutorials do a good job of introducing these ideas in a beginner-friendly way. Some questions that come to mind are: How do geodatabases compare to older formats like shapefiles? And what are some tips for keeping projects organized, especially for large datasets?

Chapter 2: 

Chapter 2 dives into designing maps that are clear and effective. It focuses on thematic maps, which are used to answer specific questions, like identifying areas with limited access to resources. The chapter explains how to use colors, symbols, and other design tools to make maps that highlight important data without overwhelming the viewer. A major topic here is choropleth maps, which use colors to represent data like income levels or population density. The chapter introduces classification methods like Natural Breaks and Quantiles, which divide data into groups to make it easier to visualize patterns. Another important idea is balancing the map’s “figure” and “ground” elements so that the main data stands out while background details remain subtle. The chapter also emphasizes the importance of simplifying your map to avoid confusing the audience. For example, removing duplicate labels and using muted colors for less important layers can make a map much easier to read. This raises questions like: How can we use automation to make designing maps faster? And how do we ensure that maps are both accurate and visually appealing?

Chapter 3:

This chapter focuses on sharing maps with others in a way that’s easy to understand. It highlights tools like ArcGIS StoryMaps, which combine maps, text, and images to tell a story, and Dashboards, which display live data in a clear and interactive format. These tools make it possible to create engaging and informative visuals that cater to different audiences. The tutorials show how to design layouts that are user-friendly and visually striking. For instance, you can use bright colors and simple charts in a dashboard to make trends stand out. StoryMaps are ideal for presentations and reports because they provide context alongside the map data. One key takeaway is the importance of tailoring maps to your audience. Whether you’re creating a detailed dashboard for analysts or a simple StoryMap for the public, it’s crucial to think about what the end user needs to see. Questions to consider include: What are the limitations of StoryMaps for larger projects? And how do dashboards handle live data without lagging or crashing?

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.

Chapter 1

With GIS it is so fascinating that you are able to predict and prepare for future outcomes using any model you create. Mapping has come a long way, from inaccurate drawings when people would sail around and map the area, all the way to being able to create new maps and find patterns within these maps to more easily understand your surroundings. I like how simple and straightforward it is performing this analysis, just find the data and choose a method then see your results. It seems pretty straightforward with set rules you follow. The different types of features are simple to understand with clear directions of what they are and what they look like. The chapter explained how you can have different types of maps, like vector or raster, they can have harsh lines showing the barriers of different layers, but also soft layers blending them together. Although this can cause information to be lost because of the change in cell size and can affect results of the analysis. It’s important to have all the data layers in the same map projection and coordinate system to make sure you have accurate results. I wonder if there is a way to change the distortion you would get when mapping a larger area, if you can calculate for the curvature of the earth. The categories are good, there isn’t one word for everything but groups of words that mean the same thing and can help describe specific things to break it down or generalize it to see the bigger picture. There are also ranks, which put things in order from high to low. Counts and amounts show the actual number of features on the map, it lets you see the value to compare it to other features. Finally, ratios show the relationship between two quantities divided by one quantity, the map will be able to more accurately show the distribution of features.

Chapter 2 

In Chapter 2 we learn to map where things are, we decide what to map, and analyze geographic patterns. We were able to find what we’re looking for and where to take action. I can use a map to identify individual features or look for patterns in the distribution of the features, the maps are able to identify and help find patterns in any information you input into it. Mapping where things are can help one see a visual concentration of the data they are using and solve their problem, or find out if it was just random occurrences and then you would need either more information or change the method you are using. It is important for the map to be appropriate for the audience you are showing it to, if it is for someone who is just learning about this it should be short and not clouded with information that isn’t necessary to them. If it is someone who needs to know a lot of information in one spot it should be well organized with a good system to identify what they are looking for. The chapter talks about making sure to have geographic coordinates input and assign them to your data, you can put it into the GIS database, or it might already exist in another program or in the database. Basic maps can use the same symbol, this can help someone notice patterns easily and solve their problem or question. GIS can draw symbols to identify places or draw linear features that describe streets, rivers or sidewalks, it can also fill plots of land with color or patterns. When you map an area that is large in comparison to the size of the features, it’s best to not use more than 7 categories because it will make the patterns difficult to see, if there are less categories it will make the patterns clearer. The chapter states how it is important to use statistics to measure and find the relationships between your features. 

Chapter 3 

In chapter three, we learn about comparing places based on quantities so we can see which places meet our criteria. We learned what we need to map, understanding quantities, making a map, and looking for patterns. When we map based on quantities and add a level of information past mapping the locations and features, we will be able to see patterns much clearer and realize what we need to do. Learning how to map features it is important to know what they are called. Discrete features can be individual locations, linear features, or areas. Continuous phenomena can be defined areas or surface continuous values, like areas displayed using graduated colors. Data summarized by area is displayed by shading each area based on its value or using charts to show the amount of each category in each area. In this chapter they talk about the importance of making sure your map is intended for the audience in mind and how the information on your map should represent that. Changing the way the question is framed and how you present your data will help reveal specific patterns. It is also important to understand quantities, the amounts ratios or ranks on your map. Counts and amounts will show the total numbers. Ratios show the relationship between two quantities, and are created by dividing one quantity by another. The most common ratios are averages, proportions, and densities. Averages help compare places that have few features and many features, you can create an average by dividing quantities that use different measures. Proportions show what part of a whole each quantity represents, to create a proportion you divide quantities that use the same measure. It’s important to note that proportions are often presented as percentages. Finally, densities show where features are concentrated, to calculate a density you divide a value by the area of the feature to get a value per unit of area. You can create ratios by adding a new field to the layers data table and calculating new values by dividing two fields containing the counts or amounts. 

Chapter 1: Introducing GIS Analysis

Chapter 1 discusses what GIS analysis is along with the types of geographic features and how they are used.  “GIS analysis is a process for looking at geographic patterns in your data and at relationships between features” (Mitchell 22).  GIS analysis is used to figure out why things are where they are and allows for data to be processed in a way that allows you to visually see how it correlates.  There are three types of geographic features, those being discrete, continuous phenomena, and summarized by area.  These geographic features have an effect on the analysis process.  Discrete features allow for the actual location to be highlighted.  Continuous phenomena is continuous data that are values such as precipitation or temperature that can be measured at any part of the map.  Features summarized by area is data that is summarized in a way that counts the total number of specifics such as the total population for example.  There are two ways of representing geographic features.  Those two ways are using different models called vector and raster.  The vector model appears to be more organized with each geographic feature being in a row that is in a table.  The raster model on the other hand the features are represented in a flush and continuous way.  Each geographic feature has a specific attribute that gives information as to what the feature is.  The different types of attribute values according to the book are categories, ranks, counts, amounts and ratios.  Categories allow data to be organized in groups which helps to condense the information.  Ranks put features in order from high to low and are specifically used when it’s hard to get direct measures.  Counts and amounts both show a total number and allows you to see what actual value of a feature is.  Ratios show the relationship between two quantities by dividing one by another.  An important part of GIS analysis is data tables.

Chapter 2: Mapping Where Things Are

Chapter 2 focuses on how maps are made, used and analyzed.  Maps allow for people to be able to see where or what something is.  By looking at these individual features it reveals patterns that can then further be analyzed.  By using these patterns it can answer questions related to individual features.  GIS can be used to map the location of different types of features to see whether certain types of these individual features occur in the same place.  The most important thing about maps is that they must use certain keys and categories to allow for the person viewing to be able to easily process the information that is being presented.  Using specific locations is also important when mapping in case someone viewing it is unfamiliar with the location.  This chapter further explains how to prepare data for creating a map and lists the most important steps being to assign geographic coordinates, and category values.  The geographic coordinates and category values allow for the information to be more identifiable to the GIS system.  For creating maps you have to use this information and tell the GIS which features you want to be shown and what symbols to attribute to them that will be drawn on the map.  For mapping a single type you use the same symbol; this is often seen on basic maps that just focus on a specific feature and what patterns can be revealed.  The GIS uses the geographic coordinates to draw the features at the coordinate that is listed.  To map areas the GIS uses these coordinates to create an outline which is then filled with a specific color or pattern.  Another way of mapping is using a subset of features which allows for all types of a specific category values to be shown which can reveal patterns because not all features are shown.  While this is helpful for mapping features in a very specific location sometimes this isn’t helpful as more context is needed.  The book uses an interesting example of types of zoning and how it might be beneficial to see all the different zones in a lighter color to be able to see the areas around in order to highlight how much area of the map this zone takes up.  To map larger areas you would have to take into consideration the scale of the map and the amount of categories that would be used and how you can group them in order to maintain the easy readability of the map.

Chapter 3: Mapping the Most and Least

Chapter 3 focused on explaining why you have to map the most and least.  This chapter also gives further information about mapping.  The reason for mapping the most and least is to be able to reveal a relationship between places.  Mapping the amount can be crucial as it gives a bigger picture besides just showing where something is which is what mapping the locations of a feature is.  Going back to the idea presented in Chapter 1 related to geographic features you can map quantities that are associated to discrete features, continuous phenomena and the data summarized by area.  By taking these geographic features into account it helps for deciding how to present a map.  I feel as though this chapter is very statistics based and focuses on how to properly document and map a specific quantity of a feature.  The chapter then further talks about how it is important to understand quantities and how when mapping the most and least you should assign specific symbols that correlate with the features that are based on the specific attributes of these quantities.  Relating back to Chapter 1, the specific attribute values can also be used here to map the most and least.  Count or an amount can be used to see the value of a feature.  Ratios can be used to help identify and reveal relationships between two quantities.  Ranks are helpful towards putting features in a specific order which is from high to low.  Taking these quantities into consideration allows for the next step which is to decide how you want this data to be displayed on the map.  I think to be able to determine which attribute value would be useful you would have to take into consideration the data you have.  Once you figure out how to classify and organize the data then a map can be created as it places the information that is given and in turn reveals patterns related to what was inputted.