Geography 291: Geospatial Analysis with Desktop GIS

Chapter 1- Tutorial 1.1

This tutorial was the easiest, and relatively self-explanatory in my opinion. However, it took much longer than needed as I started figuring out the software and where everything was. I also had trouble with connecting my hard drive into the computer to save, but ended up figuring that out with some help from a classmate. Once I got through the set up portion of GIS it was much more smooth sailing. The actual tutorial began by showing how to overlay maps with the other included data in Allegheny County. What I found interesting was how you could clear everything that is outside of the map to just show what is inside. It made it much cleaner to look at. This reminded me of the previous chapters read of how when creating a map it is important to think about the audience and what would be easy for them to understand. This map ended up being very easy to read and understand while I was constructing it. The left sidebar that lets you turn the specific layers on and off. For this one specifically, it had you select the Urgent Care Clinics, FQHC Clinics, and Poverty Risk Area, as well as the landforms and streets in the area. It also lets you reorder to have specific layers be on top of each other. One part I had trouble with here was right clicking rather than left clicking and the difference between the two. The book was very helpful in explaining when right clicking was needed for the next step. One specific question I had during this tutorial was how the data was already included into the system. I was wondering if we will be shown how to input our own data in the future of this class. Overall, this chapter was explained very well in a step-by-step manor that allowed me to create the graph inputted below.

Chapter 2- Tutorial 2.1

This tutorial was my favorite of the three done this week. I liked all the customization options and colors shown to put onto the graphs. I really liked how we did the whole process ourselves of going from a blank, black and white map to the colorful one inserted below. I also found it interesting how you can change the border thickness, color, and even the color of the water. While doing the extra step of choosing the water color, I scrolled through and saw all the different customization options, and I enjoyed seeing all the options it gives. I thought this was a really cool way to get the information across in a clean way. This part of the chapter left me wondering how GIS is able to know the information and tell what is land and what is water. My guess is that is has something to do with the information inputted into it for each tutorial and the data behind the scenes. However, I found it extremely convenient that the software is smart enough to already know the options that can be selected. The only issue I had at this point was knowing where everything was. The coloring step was very repetitive, but I still needed to refer back to the instructions multiple times to remember where everything was. Into the next few tutorials of this chapter it showed how to label different features, create a definition query, and create a choropleth map. When adding the labels, I liked how they used the pastel colors, gray borders, and bold labels. This made the map very aesthetically pleasing, and it was easy to see each of the components. This chapter was a lot more complex than the previous two, but I was able to complete it in less time than the last one.

Chapter 3- Tutorial 3.1

This tutorial was the hardest one of the three in my opinion. This one took more time than the last two tutorials together, and was not super smooth sailing. I first had trouble with getting the two specific maps and accidentally grabbed two of the blue ones multiple times. When deleting to try and get the green, I accidentally deleted the new layer portrait and had to completely start over. To do this I had to delete the entire tutorial and resave a new one from the original chapter three folder. Once I got back into the new tutorial, I had an easy time redoing it and going back into the New Layout tab to select the size for the background the maps are placed on. I also was having trouble getting the maps into the right spot, before I realized that the rulers are available to use. Once I put the guides in, looking at the picture and the rulers made it a lot easier to get the pictures into the place the tutorial wanted. I also liked how you could go to each specific map and choose the specific dimensions rather than guessing on the size. I also was confused on whether or not I did the Legend right. I think I did it right, but I moved on to the next part of the steps. The easiest part of this map was adding the text above each map, I had no trouble with this part! That was the last step I did on this tutorial after being frustrated by all the mistakes and troubles I kept having. However, I read the rest of the tutorial and the next steps made sense on how to continue. This chapter had multiple examples that I would not expect to be done on GIS, and it was really cool continuing to see all the options and customizations that are possible. Overall, in the three chapters this was a good introduction to GIS and the software. While I had lots of confusion, most of the steps were understandable with the steps in the books.

 

Chapter 1:

The first chapter of the ArcGIS Pro Tutorial textbook went over the basics of using the application. I found the chapter easy to understand and extremely helpful, as it was the foundation that helped me better understand the rest of the textbook. I was able to understand the layout of the app, as well as how to navigate maps within the app. One of the more useful sections to me was the one on working with tables on attribute data and how to manipulate said data from within the application. I also found the section on working with 3D maps, because I didn’t think we would be covering that material in this chapter. Overall the chapter had a lot of good foundational knowledge, and it prepared me for covering the rest of the assigned chapters.

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Chapter 2:

This chapter was more content-heavy than the first, and focused more on how data can be manipulated within ArcGIS. I did enjoy it, and found it easy to understand. I found it easy to grasp the use of definition queries to make a subset of map features, creating 3D scenes and dot densities. It did make me wonder if there is a maximum number of queries that can be applied on an attribute at one time. We also covered the use and creation of bookmarks, and I wondered if there was a maximum number of bookmarks that could be applied to a map.

 

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Chapter 3:

This chapter went over how information processed in ArcGIS can be presented and shared to those who do not have the application. It also allowed me to get acquainted with the ArcGIS website and how to share data there under your account name. It also covered how to create and customize legends, charts and graphs within GIS as well as how to share them in a way that is viewer friendly and easy to understand. My favorite section was the one that covered the creation and customization of dashboards. One question about the different ways we will be using the ArcGIS website in the future, and if 3D data could be shared on the site.

Chapter 1:

 I Learned about a feature class, a raster dataset, a file geodatabase, and a project. I learned more about ArcGIS as a system and what the tutorials that we are doing are helping us understand and determine. For chapter 1 specifically, I worked with finished ArcGIS maps centered around Urgent care clinics in Allegheny, Pennsylvania with a total of 4 tutorials that I had to run through. Starting with tutorial 1, I learned how to do a myriad of skills including understanding what a book mark is, location the contents pane as well as what is means and includes, and learning how to save a project so that the information you started and worked with is collected on your device if needed for future use. I then learned how to add and remove a base map as well as the definition of what a base map is and how it is utilized in ArcGIS. I learned how to turn layers on and off through using the contents pane and subsections within that. In the first tutorial, I had a lot of issues exporting a map layout to my computer because I wasn’t using a desktop. This was my first time using a lot of these skills so a big part of my experience was trial and error as well as annoyance that I think was warranted, whether that be at my computer, the instructions, or honestly myself for choosing this course. A good outcome out of this is that because I figured out different skills and methods to doing things, I was in turn able to help others that were also confused on what to do or how to do something when it came to starting up the app or the assignments. I had issues opening up and using the 3D map on my computer after it had worked perfectly the first time so I had to do that work at a later time throughout the week in the GIS computer lab. 

 

Chapter 2:

 

In chapter 2, I learned more about map design and specialization through 8 different tutorials. This chapter was centered around thematic maps with some 3D map usage in a chapter that I had trouble opening on my computer. In these tutorials, I worked with classifying data through codes with qualitative values including low, medium, or high, with the values being mutually inclusive. In the first tutorial, I used symbology through colors as a way to show differentiation and detail within the maps. In tutorial 2, I labeled features and used pop-ups as a way to identify graphic elements like the names of neighborhoods or bodies of water.  I had to specify font, size, color, and placement through labels that are created from attributes which are an important part of cartography and information in a map. I learned how to filter  and create definition queries as well as how Definition Queries differ from Selection By Attribution, with a definition query being used to filter layer features as opposed to selecting a temporary feature to then work with. In tutorial 4, I learned how to create choropleth maps for quantitative attributes which are needed to break a numeric attribute into fewer or less classes. In order to symbolize map features, you only need the maximum set of values (breaking points). In this example, I made a choropleth map showing what households are receiving food stamps. In this chapter, It seemed a little easier to navigate the app and understand where things were and how they were supposed to be used in correlation to what the instructions were telling me to do. I did have issues at times when trying to complete the your turn section and having to relocate all of the information that I was taught, having to look back in the chapters and even resort to google when I couldn’t find the answers I needed. I will say that I am a bit scared or apprehensive about having to make maps of my own after learning about what they entail and all of the steps I will have to take. 

 

 

 

Chapter 3: 

In this chapter, I learned about how to build layouts and charts, how to share maps in ArcGIS online, how to utilize ArcGIS story map, and how to use the arcGIS dashboards. This chapter seemed pretty full circle through using the knowledge of what I learned in past tutorials in the first tutorial of chapter 3, as a means to make a layout and legend for data that someone else transfigured. This chapter was based around how you format and share data with other people, whether that be simply through your work or what sites you present said work on as a means for others to understand, analyze, and observe. I first learned how to build layouts and charts in chapter 1 through map framing and placement. I didn’t find this particular assignment as hard as I thought I would. When I had read that we could be inserting a map and displaying it on our own, I got scared that maybe ArcGIS pro had loosened the reins a bit too far,  especially for someone who still gets confused about the contents pane and how to structure the layout of pictures. In this tutorial I also learned how to structure and place legends that correlate with maps, though I’m pretty sure I messed up on the second map legend because it somehow ended up being vertical instead of horizontal and I had no idea how to fix it. In tutorial 2, I learned how to share and publish maps online through web maps. In tutorial 3, I learned how to create stories that include text, maps, images, videos, and other things. These are intended to be read by individuals. Through using ArcGIS storymaps, you can create briefings that include a series of slides that have short talking points, interactive maps, and other content that is used for showing work to others. It was really interesting to see and understand the work that goes into creating and posting maps with data that you’ve collected (even if for these examples, I was using pre-collected data and maps).

( I accidently skimmed over the fact that I had to add pictures so I only added 1 for the first 2 chapters, and 2 for the 3rd one)

Chapter 4:

This chapter gets into the details of mapping the density of a feature. Meaning the map shows the locations of the highest/lowest concentrations of the feature- a mapping style that is very good for observing patterns. Similar to the previous chapters, being aware of the information you’re looking for from the map, and what the features are is a key thing to keep in mind before and when building the map. Chapter four really begins to step out of the correlation aspect between features and tip into a causational mindset of asking questions and developing factual statistics based on an aspect of the map. The textbook goes into detail about all the different ways to map through density, from using points, lines or by area to visualize the map- to measuring specific features, versus their mathematical value. Each method can be placed onto a map in various visual representations, like a dot map or by color blocking areas. I personally find the color blocking to be a much easier, more comprehensible map. Although, I do recognize that there may be specific reasons for conveying a map through a dot map, and appreciate the simpler graphical plotting it takes rather than the area’s calculated steps. This chapter also explains that in relation to a specific location the density and population can be two very different things. The population may be the same, however, the density could be scaled way in or out depending on the size of the area. Think if Texas and California had the same population. Texas is larger, so the density would be more spaced out, while California’s would be a bit more crowded and localized. Chapter four explains how to display density surfaces, which are usually displayed through raster layers, commonly good at representing point/ line concentrations on a map. Continuing off this, the maps can be calculated/ determined through these methods: Cell size (coarse and fine), search radius (generalized vs localized), calculation method (a simple method- only in radius areas, weighted- mathematically), and units (areal units where the density value is calculated). Compared to the next two chapters, this one was relatively basic- and contained an amount of generalization similar to the past chapters, albeit with more depth.

Chapter 5:

Chapter five explains how to make maps within specific areas and to analyze that data from inside areas on a map. Like all the other chapters, it stresses the importance of defining what it is that you are trying to analyse or get information of- if it’s a calculation from single or multiple areas, or from a discrete or continuous feature. The distinction between these two features determines whether you’re making a map with a uniquely identifiable feature or a continuous and seamless geographic feature. Again, it is important to know before you create the map what kind of results you would like to obtain (a list, count, or summary). Knowing this will alter how the map looks at the end of its mapping. I found it interesting that you could decide to manually leave certain features out of the map/ data set. Like, some features can extend outside the area boundary (rivers or roads), so understanding if the information would benefit from keeping those features within the area data, or not is a good skill to develop. It is also good to note that certain results require these partial boundary features to be included in order to complete the data (example being lists and feature counts). The textbook describes three ways to make the calculation of this inside area. These are: Drawing areas on top of features (map contains a strong boundary of the area), selecting features inside an area (a subset of features from within an area, and is good for summaries), and making an overlay area with features (a mixed method, and is good for comparisons). This section contains examples of what each method is good for and their comparisons, which is very helpful in understanding how each one works, and which ones to use in practice. In this chapter, it provides further detail on how to actually create these area maps, with separate explanations between discrete areas and continuous ones. It explains that GIS can create reports (tables or lists) based on the data of the completed map and area. That it can also make statistical summaries like counts (total numbers), frequency (table/ bar/ pie chart, number of features with a given value) and summaries of a numeric attribute (summary, average, median, standard deviation). Chapter 5 provides clear and distinct step by step tutorials on how to use/ analyse the data acquired and other steps within map making. I also appreciate the call backs to previous chapters, instead of just repeating the information, the textbook references where you can find it and moves on. This kept the chapter from being too repetitive and not getting stuck in past information.

Chapter 6:

Chapter six focuses on a different use of GIS, of finding what goes on within an area and distances around that area in a certain range. It also showed an ability to monitor data within a range, to see the changes and develop a continuous data set. A key component of this chapter’s analysis is through traveling range, the calculation of this data through the measurement of distance, time or cost. Ways to measure this is through straight-line distance, measure distance over a network (streets/lines, connected plots) and measure cost over a surface. This cost is most commonly time, but can also represent money (the literal cost), the effort taken, or travel costs- which are the more precise measurements over the other distance measurements. One thing I thought was interesting was mentioning that maps can differ depending on planar/ geodesic methods, aka flat maps vs. curved maps following the earth’s curve. This is something that when you stop to think, would obviously be different from one another, but because most people are so used to planar flat planes, isn’t a big thought. Following this, once again the concept of localized or global maps is something to keep in mind when creating your analysis. Know the basic, groundwork information before beginning on your map. Another call back to the previous chapter is the list of features, counts, and summary statistics. It repeats certain information in further detail, only better ingraining it into my memory. Like the previous chapters, there are a lot of technical things that are actually quite grounded in common sense. For example, the ability to determine cost ranges through singular and several ranges, or visually creating a map with either inclusive rings or distinct bands. It is simply the technicality of engaging the GIS software to make/ calculate the maps with these features that can be confusing, and need solid explanations. I liked the clarity on three main ways to find nearby features, although by the end of the chapter it did feel repetitive between them. Like, by the end I wasn’t fully confident which method or style the textbook was explaining how to map out. A lot of the instructions are more or less similar to one another- or at least have one thing in common, so that’s helpful. One thing I keep thinking of when reading all these chapters is that I’m quite glad that the GISystem does most of the calculations for me… I would for sure mess up the map if I had to do the calculations myself. It makes me think about how people might have worked with maps and calculating features back before the system was built, how they must have had to learn to do all the math themselves and map it by hand! Finally, I said this for chapter 3, but I love how the textbook includes comparisons between the two options. It was relevant to all these chapters. It makes everything very clear- able to distinguish and figure out which mapping method I should use and why. One question I had regarding the ability to set max distances was if you could also specify a minimum distance, and what reasons someone might have to do so?

GIS Tutorial for ArcGIS Pro: Chapter 1

The first chapter takes you through step-by-step on how to complete the first tutorial through ArcGIS Pro. Downloading the chapter was easy once you learned how to do it, and I really liked how the process was so thorough. I completed Tutorial 1-1 and felt like I had a decent understanding of the rest of the work we had to do. It seems like the most there is to do is just following the directions, and that will be really helpful in the projects to come. Some parts were a little confusing and I had to go back and make sure I did everything correctly, so it seems like the biggest part of this is just making sure that you’re paying attention. 

I also liked how it gave us examples of what the maps and graphs were supposed to look like! It definitely helped keep me on track. One of the biggest components was recognizing where everything was on the website. For example, the “Ribbon” at the top features most of the main functions, and that is what Chapter 1 seemed to focus on the most. I also liked the “Your Turn” parts of the demonstration as well, that truly helped me find where everything was and helped me remember, even though it simply just had you do the same steps again. 

Tutorial 1 was focused on health clinics and the poverty and population densities, which was a good one to start. It was not overly complicated and the rest of the tutorials throughout the chapter removed different layers, added features, zoomed in on pixels, and things like that. It also told us how to select different FQHC’s using the control button, and that helped a lot. Overall I thought this section was pretty easy once you got into it! It did take a long time to get everything going, but after that it was good. I have attached two screenshots from my work throughout this chapter. 

GIS Tutorial for ArcGIS Pro: Chapter 2

Chapter 2 was focused primarily on how to create a “thematic map”, which is defined as a map that tries to help define or solve a problem. There are a lot of layers that require attention to detail and “symbology”, which is when ArcGIS Pro uses attribute features and drawings to make figures on a map. I completed Tutorial 2-1, where we primarily focused on changing the different colors on a map of Lower Manhattan. I liked this section because it showed us how to change the color many times, and also gave us a shortcut on how to do it. It also gave me a way to check my work with the finished product located at the end of the tutorial. 

I liked this tutorial because it then showed me how to change the different layers when you want one off or if you want a few more combined. We were able to change the Object ID in one of the next tutorials as well. This chapter also included the “Your Turn” sections, which was good to practice with too. Neighborhoods and the surrounding areas were the primary focus of this chapter, and I like how each one focuses on a different section and appearance. It’s cool that there are different maps for each specific problem or experiment that people are working on. 

We also could do charts with this too! Tutorial 2-6 showed me how to make a histogram which was neat. I’m excited about using this for our final project in the future. This chapter did go by faster, I think because I had gone through the first one and kind of learned where everything was at. I was still having trouble locating things on the “Ribbon”, but I think it’ll just take some time to get used to. By the end of it, I was going through pretty well and was able to locate a lot of features. And all the colors were pretty! I attached a screenshot of my first tutorial of this chapter. 

GIS Tutorial for ArcGIS Pro: Chapter 3

The final chapter for this section was a little more in-depth for me, but still went fairly quickly. I was able to easily access the tutorials through the ArcGIS Pro icon on the computer, and luckily I didn’t have any issues downloading the book onto my external hard drive (Hopefully it stays that way). And this tutorial was focused on making different kinds of maps, which was cool! I felt experienced by the end of it, especially in how to make bar graphs. The two maps were fun to play around with in Tutorial 3-1, and I felt like it helped me better understand how to create maps. 

The first tutorial was longer but had a lot of useful steps. We were taught how to make a layout with two maps and two legends on it, which will be helpful for our final project. Again, I liked the “Your Turn” sections and how it let us complete a section without using direct instructions. It was informative on how to create titles and different papers within one project. I was confused at first on how to create another layout page, but I just had to look harder underneath the “Ribbon” and its underlying sections. 

The chart was also a little difficult at first, because some of the instructions were in different numbers and I skipped over them by accident. However, I figured it out! I liked how we could do the Map Viewer on the website itself, and how it’ll eventually be uploaded into that section. It’s also nice how this book is so useful and easy to come back to if you need any help in the future. Learning how to create a briefing was neat, and even though this chapter began to get more in-depth, it was still fairly easy to navigate with the through instructions. I attached two screenshots of my work from this chapter as well.

 

Chapter 4
This chapter has been helpful in assisting me in understanding how a GIS maps density.  Mitchell discusses how there are various ways in which density is mapped. There is defined area
density and density surfaces. Defined area density includes dot density mapping, in which the number of features represented by the dots is chosen by the analyst, as well as the location of the
dots inside the defined area. I learned that the final product can be greatly impacted by the choices the analyst makes, especially because the dots do not show the exact location of the
features. Shade density mapping is also included in defined area density and is greatly impacted by the classification methods. Quantiles and equal intervals, discussed in the first few chapters,
come into play again in this chapter, as they play an important role in the final product. However, density surfaces display the density differently because they create a surface based on the search radius from each point. I learned that the final product can be affected by the cell size because it can be coarse or smooth depending on the choices the analyst makes. Mitchell discusses how density surfaces can show subtle patterns that defined areas might not show, but they require extra work and care. I learned that the final product can be greatly impacted by the choices the analyst makes and that density surfaces require extra care. I also learned the importance of using the same classification methods when comparing multiple density maps. One thing that caught my attention is the importance that the analyst has in the final product, as their decisions may affect the final product to a large extent.

Questions:
1. When should a dot density map be used over a density surface?
3. How do the classification methods stop or create false density patterns?

Chapter 5
Chapter five discusses what is inside an area.  Mitchell states that if the analysis is done on one area, the goal is usually to summarize or monitor what is going on inside the area. If the
analysis is done on several areas, the goal is to compare the amount or kind of information inside each of the several areas. There are three ways that this can be done: listing what is inside the
area, counting what is inside the area, and summarizing the attributes of what is inside the area. The third method involves adding up or averaging the attributes of the features inside the area.
One problem that Mitchell presents that I had never thought of before is how to determine whether or not to count features that are only partially inside the area. The second problem is
how the boundaries of the areas are represented. In some cases, the boundaries are represented with an outline, and in other cases, the interior of the area is shaded to help identify the area as a
whole. This, in my opinion, affects interpretation because, with the boundaries, the focus is on the separation, and with the shading, the focus is on the area as a whole. What I got from this chapter was the importance of consistency. For example, the boundaries, if one is represented differently from the other, then the two areas are not being compared fairly. Mitchell is able to
connect this chapter to the previous ones by showing the use of the concepts discussed in the future. This chapter has helped me understand that area analysis is simple but detailed, requiring
a lot of decisions.

Questions:
1. How do you determine whether partially included features should be included in an area?
2. What methods of mapping are best suited to represent the results of boundary-based analysis?

Chapter 6
Chapter six of the book discusses how GIS solves the problem of what is near a feature. This is another important problem that occurs in spatial analysis. In this chapter, Mitchell
explains that there are three different ways of measuring what is near a feature. One way is by straight line distance. This is the simplest method to use, but it is not always realistic since it
does not take into consideration any obstacles that may be encountered along the way. The second way is network distance. This is more realistic since it considers what path one has to
follow. The third one is cost over a surface. This is more advanced since it considers many different factors that may influence movement. The path that one has to follow may be difficult
even though it is straight. There are also buffers, which are used to define what is near a feature by creating a buffer around a feature and defining what is a certain distance away. Buffers can
be used to represent distance, time, or cost, depending on the analysis. The reminder about using planar versus geodesic distance was important to me because it is crucial for obtaining accurate results. Smaller areas can be analyzed using planar methods because the curvature of the Earth is insignificant, but as the area gets larger, it is crucial to use distance to obtain results that accurately represent the Earth’s curved surface. Another topic that Mitchell reviews is earlier concepts such as counting or summarizing features within zones, demonstrating how each
chapter builds on the previous one. What stood out to me is how proximity analysis, although simple at first, can become complex depending on the real-world situation. Different issues call
for different approaches, and if the wrong one is used, it could lead to the misrepresentation of the level of nearness of something. This also made me think of how easy it is to misrepresent the
distance between two points on a map if one does not take into consideration the real situation.

Questions:
1. When is straight-line distance sufficient to be used on its own?
2. How do buffers change depending on the units used, such as distance, time, or cost?

Chapter 4: Mapping Density

• Why map density?
  • Mapping density shows distribution with uniform units
    • Larger tracts may have a larger number of people, but be more spread out
• Deciding what to map
  • Features: density of features such as number of houses
  • Feature values: density of values relating to features such as number of people per house
• Two ways of mapping density
  • By defined area: use if data is already summarized by area
    • Dot map
      • Each dot represents a specified number of features
      • Distributed evenly throughout area rather than clustering
      • Make sure that dots are large enough to convey information, but small enough to not obscure information
    • Shaded
      • Each area is shaded based on density, but it doesn’t show centers of density in large areas
    • Calculating a density value for defined areas
      • Add a new field to feature data table, assign density values by dividing the value by area of plot
  • By density surface: use if you have individual locations and need precise views
    • • Created in GIS as a raster layer – each cell gets density value
      • Provides the most detailed information, but takes the most effort
    • Creation
      • Cell size: units per cell, larger cells process faster but are less specific, smaller cells take more time but show a smoother surface
      • Display
        • Graduated colors: different shades of the same color, don’t use too many shades
        • Contours: lines such as that on a topography map, too few lines shows little detail, too many lines make it hard to read

I personally don’t like dot maps where the specific density is not shown and points are scattered across the area. I much prefer other types of density maps since, as a viewer, I am used to dots being used when there is a precise location shown and average values being shown with graduated colors. Dot maps that don’t show precise location are not as visibly appealing as graduated color maps showing the same thing, and I feel that they are more confusing to read.

Chapter 5: Finding What’s Inside

• Data features to consider:
  • How many areas?
    • Single area: monitor activity and summarize information such as service area around a facility
    • Multiple areas:
      • Contiguous: bordering each other
      • Disjunct: not connect to each other
      • Nested: area within an area
  • Are the features discrete or continuous?
    • Discrete: unique features
    • Continuous: seamless, must be summarized
  • Information needed from analysis
    • List, count, or summary
    • Completely or partially
  • Finding what’s inside
    • Drawing areas and features
      • Map shows boundary of area and features
      • Quick and easy, visual only, doesn’t give information about features inside
      • Making:
        • Discrete areas
          • Area shaded with light color and boundaries drawn on top emphasizes features
          • Area on top of boundaries emphasizes area
          • Outer boarder of area drawn with thick line, boundaries drawn in different colors shows discrete areas by category
        • Continuous features
          • Boundary drawn on top, details drawn in separate colors
    • Selecting the features inside an area
      • GIS selects a subset of features within the area
      • Tells information about features inside a single area, but doesn’t tell several areas as separate
      • Making:
        • You specify features and areas, GIS checks where each feature is and displays whether it is inside the area
        • Data table can be used to get information about features within specified area
    • Overlaying areas and features
      • Combines area and features into new layer or compares the two layers to get statistics
      • Displays information about features within several areas, but requires more effort
      • Making:
        • GIS tags each feature with a code for which area it is in, list of features or summary of attribute can be accessed
        • Attributes are stored permanently in the feature data table, so this can lend to deeper analysis

“Overlaying areas and features” maps seem the most interesting to me, but are clearly difficult to make as well. I hope I get to work on that during this course. I find interactive maps like that very cool, since they provide the most information in a shorter amount of time once set up.

Chapter 6: Finding What’s Nearby

• Defining Analysis
  • Defining near: is near measured by general area (100ft radius) or travel time?
    • Distance or cost: travel costs are costs such as money, time, and effort
  • Flat plane or using earth’s curves – smaller scale can operate on a flat plane, but larger needs curvature
  • How many cost ranges?
    • Inclusive rings: nested cost ranges
    • Distinct bands: 1-100ft, 100-200ft, 200-300ft ect
• Finding what’s nearby
  • Straight-line distance: within a circle around the area
    • Quick and easy, but gives approximation
    • Seems most helpful for less precise work like figuring out the general coverage of a store
  • Distance or cost over a network: actual travel times or cost along features like roads
    • Gives more precise cost over network, but requires accurate network layer
    • Most helpful for more precise work over roads or other transit lines, shows the actual time that it takes and can show traffic too
  • Cost over a surface: actual travel times or cost over an area not defined by lines like roads
    • Combines several layers to measure “open-world” travel cost, but requires data preparation
    • Most helpful for non-constrained travel such as walking in a forest rather than following side walks

This chapter is really cool since they’re not really maps all showing the same information in different ways like previous chapters, but showing really different information; they’re not really interchangeable because of the different uses. It’s also interesting how much information is needed to complete some of these; to create a cost over a surface map for travel in a forest, you would have to have data about the surface cover of the forest. To make a distance over a network map, you need an accurate network layer, and if accounting for traffic, you have to have information about traffic patterns in each place. While these are widely available to us now, it’s wild to think about how much information gathering has gone into that and is ready to be build upon.

Chapter 4

This chapter really made me think about how much more there is to GIS than just putting points on a map. One of the main things I took away was that it’s not enough to just know where something is—you also need to know what’s inside an area and how it’s distributed. At first, this seems simple, but the chapter made it clear that summarizing data can be tricky depending on whether it’s discrete or continuous. For example, counting animal nests is different from summarizing rainfall across a region. That distinction really stood out because it made me realize that even small details about the type of data change the approach entirely. I also liked the part about percentages and densities. Mapping totals can be misleading if areas are different sizes, which reminded me of what we talked about in the last chapter. If you don’t standardize the data, the map can exaggerate or hide patterns. I didn’t think about it much before, but even a small change in how data is summarized can completely change the story a map tells. Another thing that stuck with me was how tables, charts, and maps work together. A table can give exact numbers, but a map shows patterns more visually. Deciding which one to use really depends on the question you’re asking, which goes back to the idea that GIS is as much about thinking as it is about tools. Overall, this chapter made me see GIS as a way to organize complexity. It’s not just about showing locations—it’s about understanding patterns and relationships.

Chapter 5

The reading for chapter 5 got me thinking about how “near” isn’t always as simple as it sounds. Distance can mean so many things—straight-line, travel distance, or even time—and choosing the wrong one can totally change your results. I never really thought about that before. The chapter explained that defining nearness is one of the first decisions you have to make in a GIS analysis, and that really stuck with me. I liked the discussion on buffers because it’s simple but powerful. Creating a zone around a river or road seems easy, but choices like how big the buffer should be or whether overlapping buffers merge can make a big difference. It reminded me again that GIS isn’t automatic—every step involves interpretation. Another part that stood out was straight-line distance versus network distance. Straight-line is faster, but it doesn’t always reflect reality. For example, animals or people usually can’t move in a perfect straight line, so network distance gives a better picture. This made me realize that picking the wrong method can give misleading answers, even if the calculations are correct. Overall, this chapter showed that proximity analysis is about understanding relationships, not just measuring space. It made me think about how this could apply to endangered species or habitat studies, where knowing what’s nearby can inform decisions about conservation. This chapter took the idea of distance further by showing that distance isn’t always about how far apart two points are—it’s also about cost. I thought this was really interesting because two places could be physically close but take a long time to get between because of terrain or obstacles. That idea made me think about animal movement, human travel, or even conservation planning. The concept of a cost surface really stood out. By assigning different “costs” to different areas, GIS can figure out the easiest path or total effort needed to get somewhere. I liked this because it’s like GIS is simulating the real world, not just showing it. It also made me realize that cell size matters—a smaller cell gives more detail but takes more computing power, so there’s always a trade-off. Another thing I noticed was how important it is to set limits on distance or cost. Without boundaries, the analysis could cover the whole area and give way too much information, which can get overwhelming. It reminded me again that GIS isn’t just about making maps—it’s about asking the right questions and making decisions that matter. Overall, this chapter made me see GIS as more than mapping. It’s a tool for modeling real-world problems and thinking about movement, accessibility, and patterns. It made me wonder how I could apply this to tracking wildlife or studying how roads affect habitats.

Chapter 6

The last section emphasized how mapping quantities adds another layer of meaning beyond simply showing locations. One of the most important points this chapter made was explaining the difference between mapping raw totals versus using ratios or densities. In the beginning, mapping totals may seem straightforward; though, the chapter explained how this can be misleading. This scenario is especially common when areas vary in size. Larger areas can appear more important simply because they contain more, not because they are more concentrated. Given this context, it made me realize just how easily patterns can be exaggerated or minimized depending on how data is presented. Moving along the reading, I found the discussion on classification particularly interesting. The fact that the same data can look completely different depending on how classes are created made me think about how much influence the mapper has over interpretation (once again). Choosing natural breaks, equal intervals, or quantiles is not just a technical decision. This decision is interpretive and made from that of a human individual. Once more, these decisions reinforce the idea that GIS analysis involves judgment, not just calculation. Another aspect that stood out to me was how outliers can distort a map if they are not handled carefully. One unusually high or low value can change how all other data appears, which again highlights the importance of understanding the data before mapping it. Reading through this chapter made me more aware that maps showing “the most and least” are powerful, yet also risky if created without careful thought. In other words, the users of GIS are responsible for creating maps with intention and meticulous work. It reinforced that GIS is not about producing visually appealing maps, but about presenting information in a way that is accurate and intentional. 

 

Chapter 4: 

       Chapter 4 focuses on mapping density through various methods, including defining why you should map density, deciding what kind of density to map, and how to actually map density. In terms of GIS mapping, density refers to the concentration of features or values within a given unit of area/distance. A density map lets you measure designated features by concentration using a uniform aerial unit like hectares or square miles, so the concentration distribution can clearly be observed. A hectare is a metric unit of area equal to 10,000 square meters.

        When discussing why it’s important to map density, Michell gives a multitude of reasons. One being that density maps can help show you where the highest concentration of features/data is located. This makes density maps useful for observing patterns as opposed to observing individual features/locations. These maps are also useful for mapping areas that have a wide variety of sizes. For example, when mapping the number of trees within separate forests, the larger forests may appear to have more trees due to the larger area they take up. However, when mapping for the density of the trees within the forests, you may see more concentrated areas of trees within the smaller forests that are represented through density mapping. 

    As stated in previous chapters, it’s important to consider what information you want to get from the map before creating it. This will help you decide what methodology to use when creating the map. When mapping density, consider whether you want to map direct features or feature values, as the resulting maps can look very different from each other. There are two ways you can map density: mapping the density by area, or creating a density surface. You should map by defined area if you already have data that is summarized by area, or for comparing certain areas with defined borders. On the contrary, you should create a density surface if you want to see the specific analytical concentration of point/line features. Question: What do you do when a data point falls exactly on an existing defined boundary line?

Chapter 5:

         Chapter 5 discusses map/data analysis through the lens of mapping what’s inside. But what does the book mean when it says “finding what’s inside”? It is trying to say that we can identify which geographic features fall within the boundaries of other features using spatial relationships for the purpose of analysis. When in practice using real-life data, this means determining whether points, lines, and polygons are contained within a specific area. This map analysis involves monitoring what’s occurring inside a designated area, or even comparing different areas based on what they contain. In simple words, we are summarizing what’s inside an area using GIS. 

        According to the book, this can be achieved in a multitude of ways. For one, you can draw an area boundary on top of the existing features. Or you can use an existing area boundary to select and analyze the features inside it. You can even combine the area boundary and its features to create a summary of the area. Just like in previous chapters, the method you choose to use for creating your map depends on the data that is available to you and the information you are looking to gain from creating the map. When taking this into account, the type of data you have matters. For example, finding what’s inside a single area vs what’s inside multiple areas can result in different analytical findings, as you can compare multiple areas to each other for deeper data analysis.

         There are three ways of “finding what’s inside” that the book highlights, as I listed previously. In order to draw an area boundary on top of the existing features, all you really need is datasets that show the boundary of the area and the features it contains. To select for and summarize features within an area, you also need datasets that show the boundary and the features it contains, but you will also need the attributes of the features you wish to summarize available. You will need this same set of things in order to perform an overlay of areas and features.  Question: Why does it matter whether you’re working with points, lines, or polygons when figuring out what’s inside an area?

Chapter 6:

      Chapter 6 discusses how GIS mapping can be used as a tool to analyze what is nearby to an existing feature, allowing you to find out what may be occurring within a specific distance from a feature as well as monitor events within that particular feature’s range. This can be useful for various purposes. For example, finding out what’s within the traveling range of a feature can help the observer define the area that can be served by a facility. An ambulance station can do this to find out how far away possible incoming neighborhood calls are to the specific station. Being aware of what is in the traveling range of a feature can also help with designating areas for a specific use relating to the feature being observed. For example, mapping the traveling range around a lake could allow scientists to identify surrounding wetland areas suitable for conducting environmental protection.

     According to the book, you can conduct what was previously described using various methods. One being straight-line distance, in which you specify the feature being analyzed by GIS to measure the direct distance outward from that feature, thus creating an area of surrounding features within that distance. This approach is recommended when you need to create a boundary/select for features around a specific source. To perform this method, you need a layer for the source feature and a separate layer for the surrounding features. Another method you can use is measuring distance/cost over a network. This means to determine the distance or travel cost from a specific source location along a linear feature. This approach is recommended for finding what’s possible within a travel distance/cost of an area located on a fixed network like a road. To perform this method, you need the source feature location, a layer containing surrounding features, and a network layer. Please consider that each part of the network needs an attribute providing its length or cost value. These can either be created manually or chosen from a provided network. Question: Could barriers like rivers or highways affect the analysis of what is nearby to an existing feature?

 

Chapter 4

Chapter four discusses how to map density. Density shows the highest concentration of a feature. It is useful for showing patterns on a map and in areas that vary in size. Using GIS, you can either map the density of points, lines, or data from a specific area that has already been summarized. You can create a density map based on features by area or density surface. When mapping by defined area, you can map density graphically, using a dot map, or by calculating a density value for each area. A density surface is usually a raster layer in GIS. Each cell gets a density value. This method gives the most detail, but takes the most effort. Mapping density by area should be used if your data is already summarized by area, while a density surface should be used if you have individual locations, points, or lines. On a dot density map, it is common to display the dots for smaller areas, but provide the boundaries for larger areas. This keeps the data easy to read. There are four parameters that affect how the GIS calculates the density surface. The cell size determines how coarse (large cell) or smooth (small cell) the patterns appear. The search radius determines how generalized the patterns are, with a larger radius providing more generalized patterns. The GIS counts only the features within the search radius, which creates overlapping rings. When using the weighted method, it gives more importance to features closer to the center of the cell, which results in a smoother density surface. The units you choose should be appropriate for the features you are mapping. A density surface is displayed with graduated colors or contours. Graduated colors use a different shade for each value. The most common classifications are natural breaks, quantiles, equal intervals, and standard deviation.

Chapter 5

Chapter five covers mapping what’s inside to see if activity occurs in an area or summarize activity in several areas to compare them. If an activity does occur within a specific area, action needs to be taken. Through summarizing multiple areas, you can document where there is greater activity happening. You can do this by drawing an area boundary on top of the features, selecting the features inside the boundary, or combining the area boundary and features. Single areas can be a service area, a buffer that defines a distance around a feature, an administrative or natural boundary, a manually drawn area, or the result of a model. Multiple areas can be contiguous, disjunct, or nested. Discrete features are unique and identifiable, such as locations, linear features, and discrete areas. Continuous features are seamless geographic phenomena, such as spatially continuous categories and continuous values. Within an area, GIS can provide you with a list of features, the number of features, or a summary based on feature attributes. If a feature is partially outside of an area, you can choose whether to include it or not. If you need a list or count, include the partial features. If you need to know the amount of something within an area, include only features that are entirely in the area. There are three ways to find what’s inside: drawing the area and features, selecting the features inside the area, and overlaying the areas and features by creating a new layer with the GIS. Drawing should be used if you only need to see the features inside a single area, selecting is used if you need a list of features fully or partially inside the area, and overlay is good for multiple areas or if you need a list or summary of values.

Chapter 6

Chapter six discusses mapping what’s nearby so you can see what’s within a set distance or range of a feature. Finding what’s within a set distance shows the features inside an area within a set distance. Traveling range can be used to define the area served by a facility. You can measure straight line distance, measure distance or cost over a network, or measure cost over a surface. You may have the option of calculating distance assuming the earth is flat (planar method) or using a curved earth (geodesic method). Planar is used for small distances, and geodesic is used for large regions, such as a continent. Once you identify the features near a source, you get a list, count, or summary based on their attributes. You can specify a single range or multiple ranges by creating inclusive rings or distinct bands. Inclusive rings are useful for studying how the amount increases as the distance increases. Distinct bands are useful if you are comparing distance to other characteristics. Straight line distances are used to see which features are within a given distance of a feature. Creating a buffer allows you to see what’s within the distance of a source. Using selection is similar to a buffer, but the GIS doesn’t create a boundary. You can have the GIS calculate the distance between each location and the closest source, which is useful for seeing which source is closest and comparing the distance with other factors. When making the map, you can have the locations color-coded by distance or source, a spider diagram, or use graduated point symbols. Streets are common for finding what’s nearby. Each street segment is tagged with an impedance value, the most common being distance, time, and money.