Getting to Know ArcGIS Ch. 1,2

    This is probably the my favorite reading so far in this class.  In this reading it focuses more on actually using the GIS program, that we are using, itself and not so much the concepts behind it.  In chapter 1, entitled “Introducing GIS,” it talks a lot about the ability of being able to take a single map and break it down heavily, possibly into just one object type such as just roads.  It says that in GIS that the program does not just use this map or that map, but all the maps that are available.  I think that this is really cool to think about.  It talked about how every map is divided up into layers, which make up a collection.  Each map is made up of vector data, which is made with certain parts.  These include:

• Polygons
• Lines
• Points

Polygons are areas that can picture very large volumes.  Lines and points are for objects that are too small to be polygons.  Points are exact locations, where lines are very thin long areas.  Maps are also in different scales depending on how large the area is that a person wants to view.  The map is also divided up into a XY plane which is used to have exact locations for everything on the map.  In the real world these are called longitude and latitude.

In chapter 2, which is entitled “Introducing ArcGIS Desktop,” it explains that there is a lot of different types of GIS software out on the market.  Some of these include:

• ArcView
• ArcEditor
• ArcInfo

These systems are divided into two groups which are:

• ArcMap
• ArcCatalog

I did not know that there is different forms of GIS software out there.  Is the ArcGIS software that we will soon be using, one or all or even a completely different program from these other Arc software programs.

Mitchell Ch. 5, 6, 7

     In chapter 5, which is entitled “Finding What’s Inside,” talks about what is in a GIS map that you do not see pictured directly on a map.  The main non directly visual part of a map is the exact numerical data of the map.  This is entered into a database, such as a spreadsheet, before it is made into visual data on a map.  This keeps data very organized and together so that it can be worked with easily.

A couple of terms that I learned while reading this chapter were discrete and continuous.  Discrete means that a part of a map is unique and identifiable, like a city.  Continuous means that a part of a map is a seamless, or undefined, geographic object on a map, such as elevation change.  Another technique that I learned was that you can take a given area and only map whole objects that are inside of it, or just the parts that go through it, or even the whole parts that are associated with part of it being in there.

In chapter 6, which is entitled “Finding What’s Nearby,” talks about how to use GIS maps to relate what is near a certain place, object or area.  This can be done a couple of different ways.  For example:

• By lines connecting the two
• By shadings that change their color as distance increases for an area
• By radius circles
• By symbols that represent a numerical distance
• By shaded travel ways by distance

Like everything else in GIS the creator of a map must know what to use on a map to make it work and picture what is trying to be conveyed.  For example if you have a location and you want to know the radius of traveling twenty minutes from it in any direction.  At first a straight line radius circle would be produced around the area, but this may not be realistic in the real world.  Instead by mapping a only by pathways would give a more realistic area from the original location.  In some places in a typical circle you may not be able to get to in twenty minutes, and also you may be able to get farther in straighter, more direct routes.  In real world applications, such as map-quest, this is all that they do.  They determine what the realistic distance between places is and how long it would most likely take to get there.

In chapter 7, which is entitled “Mapping Change,”  discusses why maps change and how to map the change on them.  Maps mostly only picture a certain point in time, and for maps to stay up to date they have to be constantly updated.  Maps can picture this change on them by either having certain areas as different colors depending on the time that the data was taken or ignoring that there was a change picture it the same way as the original data.  Also the data can either be communicative, like all the places where fire have happened in a town in history, or circular, like within a month seeing all the data for specific hour of the day.  This ability over time seems to be a great way to do research, with the ability to divide data up on a time scale, and just not having a boatload of data that is not on a time scale at all.  Even though this is not the only way to do research, it does put a whole new perspective on a data set.

Mitchell Ch. 2, 3, 4

     In Chapter 2, which is entitled “Where Things Are,” discussed maps and legends and how they relate to one another.  The chapter explained that a legend works best when it has no more than seven colors to separate the map by.  If there are no than seven then this causes the viewer not to have too many differences to look at once and to make the map easier to read.  Also having larger areas makes less changes in shaded areas on a map which makes it easier to read.  Many parts to maps seem to have a trade off, either it is easier to read with less data and can look nicer or it can be very detailed and can become hard to decipher.  A balance must be reached on a map.  Also putting short text labels on the map as well as having color differences instead of shapes for data points can make a map easier to read.

In chapter3 , which is entitled “Mapping the Most and Least,” discusses what needs to go on map and a better understanding of the balance between what is and is not needed.   There are a few different ways to picture information on a map so that it can be viewed.  These include:

• Graduated symbols
• Graduated colors
• Charts
• Contours
• 3-D perspective views

Each of these different style maps have advantages and disadvantages to them.  It is up to the creator of the map to decide which style map is most appropriate for each group of data.  Another example of a balance that must be reached for a map to be most efficient is the size of the plotted data.  If the points on a map are to close in size it can be hard to distinguish between them, but if they are correlated by size of the data with the point size it can obscure individual locations.  Another very important part is organizing the data on aGIS database is break off intervals.  These include:

•  By natural breaks
• By quantiles
• By equal intervals
• By standard deviation

In chapter 4, which is entitled “Mapping Density,”  explains how different mapping concepts, can be applied to one another to produce new and different layers to a map.  For example on a map any given area can be used with the data points on it to produce a density for that given area.  So a given map can have data points on it as well as contour lines to give even more information.  For the contour lines it is good to have the smallest boxes possible to have the smoothest lines on a map.  Unfortunately like everything else there is a trade off, the smaller the boxes the longer the data takes to process.  Also for contour lines they need to have a large enough radius to be able to be picked up and connected to other points around them.  So if for example there are two similar data points a mile of each other and the defined radius is only one forth of a mile then the data will not be connected.  One other fact about contour lines is that when the lines are closer together then there is a more rapid change in data than when they are farther apart.

Schuurman Ch. 4 & 5

    In chapter 4, which is entitled “Bringing it All  Together,” really starts to talk about how the program of GIS works and how manage maps.  The chapter talks a lot about grids and how maps are divided into them.  Each grid square can have data in it, different than all the others.  The smaller the squares, the more precise the map is to reality.  Data squares can be overlapped with other data squares from the same area on a different map.  An example from the text is, one map has grid squares by area and another map by population, these two maps are laid on top of each other to calculate density.  From the example, density could not have been determined if there were not any grid squares, and also if either map had been seen on its own.

While I was reading I was not sure if I understood what a raster based system or raster data is.  Another thought that I have been having is that I have not been sure about is if all GIS systems are 2D representations like on physical paper maps or can it also be 3D like a physical model of a town.

In chapter 5, which is entitled “Where do We go from Here,” discusses technical processes of how to use GIS and also research that involves GIS.  I found it very interesting how Schuurman discussed that if a wrong letter is entered into GIS, that something totally different than what is wanted could appear.  For example it was discussed how a zero could be mistaken for the letter o, or that “;.” could be typed where only “;”was wanted.  These small mistakes are very hard to find and fix, which in the end change your final product.  I have had a good amount of experience with Microsoft Access which has the same amount of precision in the data entry  it sounds like.  If a word is so much as misspelled, or if an abbreviation does not have a period at the end of it, the data will be read as something totally different.  For the factor of precision, Schuurman discusses that it is very hard to cram a project into the night before it is due.  It is very hard to be able to keep the precision needed in the data.  I am not planning on waiting till the last day for anything, but I am really going to make sure that I do not in this class.

Schuurman Ch. 2 & 3

     This was a very tough reading for me with my limited knowledge of GIS.  It had many ideas and concepts that were way over my head.  Chapter 2 discussed how we interact with GIS and how it works in the world, and chapter 3 discussed more about the data that goes along with GIS.

     In chapter 2 the reading begins with a little history how humans have perceived GIS over the years and then moved onto how it interacts with us.  I found it interesting how Schuurman said that GIS maps can present the information stored in their system in many different ways for us to interpret it.  I’ve run into this instance before in my life.  I was in a social science class once that told me though interpretation of maps that Earth does no have a high amount of land used by humans and that there are many natural resources left.  With being a science major I am constantly being told that we are running out of resources and that humans are consuming and taking over all the land which I have also seen interpreted from maps.  So with the same data it seems that there can be more than one perspective on how to perceive the same thing (such as social science vs natural science view of the world).

     While I was in chapter 2 I ran into the words epistemological and ontological and I was not sure what they meant.  I did however learn that GIS is like a layer cake, (Schuurman’s description) with the ability to over lay different informative maps on top of each other to show a new map with both of the original data sets on it.

      In chapter 3  I learned that all maps are represented by tables full of data.  Images in GIS are represented by values on a table.  Also the way that the data lays, causes different representations of the same data set.  An example of this is could be described with temperature being featured with different degree ranges being different shades over the state of Ohio. Depending on the intervals, such as by 2 or 10 degrees, areas could be not correctly interpreted for the actual temperature in a specific area.  If the interval are 10 degrees, data could show that the whole state is at the same  temperature, but in reality the actual difference between Cleveland and Cincinnati could still be 10 degrees in difference, which is a fairly large temperature deviance.  This is not to be blamed on humans for the misinterpretation of the data, but as Schuurman puts it “The Devil is in the Data.”

GIS Analysis Ch.1

    The first chapter of Mitchell’s book, which is entitled “Introducing GIS Analysis,” is the beginning of the overview to basic GIS. It explains how different features appear on the screen, which can include the following:

• Linear Features
• Panels
• DotsGrids

I found it very interesting how it was talking about map shadings, that show such things as elevation, are not always wanted to be shown in the highest number of pixels possible. I would have thought the higher the pixel content the better the quality. This is not entirely true. Although it is necessary to have enough pixels to show the detail so that it is not just a bunch of boxes, too many pixels could be even worse. For example having a high number of pixels can cause for very large memory space that causes large files to be too big for transfer. Also if there are too many pixels there can be different shades of colors that run together and cause for confusion where one ends and another begins.

The only problem that I came across was that I was a little confused on the difference between continuous and noncontinuous values in the reading.

Mapping Environmental Justice

This GIS project, on Environmental Justice in Delaware Co. PA was on the issue of different areas and how the social science and the natural science interact together. I found it very interesting how south part of the county had many factors that were predominately found there and no where else. These included:

• Very low income
• Non Caucasians
• High unemployment
• Low education
• Young age
• Most air emissions
• Most water discharges

So GIS can correlate that all of the above factors are connected and can be found in the same area. This is only part of the situation. Now that it is known what is wrong it is time to figure out how to fix it. That was what the other part of the report explained was possible ways to fix the environmental problems and help the people that are living there.

During this report I figured out a lot of new terms. Green spaces means, undisturbed land that is still very natural and undeveloped. Also riparian buffers are green spaces next to water sources that have little affection by pollution. Brown-fields are industrial and commercial sites.

My only question from this report is,” Are we going to have our report look in this fashion when we are done with it?”

Class Projects 2000-2005

     I thought that most of these projects were really cool that students have done, and they gave me a bunch of possible ideas for personal projects if the Galapagos idea does not work out.  I had no idea that OWU was that involved with the bike paths going in around Delaware.  Such as the ones over next to Kroger and over to the Mingo Park.  I was not sure exactly what a watershed was when I was reading the project on the Delaware Run.

     The coolest project in my opinion was the one on the geographic look on where OWU students were from.  This looked into also what the distribution of students that were accepted into the university and which ones actually came.  I thought that a possible project could be a look at the distribution of students, based on hometown, and how their area’s interest in attending OWU had changed over time.  This would look into the issue of has the distance from OWU changed over the past 150 years of who has come to study at OWU.  I thought that this could be a possible project that I could work on.

Geographic Information Systems and Science

Just when I thought that I had recovered from being blown away the first time with the power of GIS, here it is again with even more applications that I would have never even thought to connect with GIS. The introduction to Longley’s book emphasized the basic principle and applications of GIS and the second chapter, entitled “A gallery of Applications,” dove more into the how GIS affects us everyday. I never knew that On-star, the call in directions company, was run on a GIS system, so does this mean that other programs such as Google Earth, Map-Quest, and vodeedoo.net are all GIS systems? What about a step even past that, are all maps, hard-copy or digital, GIS run? I also did not really understand either what the difference between GIS and GI-Science was, or if they were the same thing?

I found it very interesting how he talked about that one of the first teams to be called into ground zero on 911 was a GIS crew. On the news we heard about all of the work done by the fire, police, and rescue, but we never heard about the people mapping out the entire area and decided the courses of action to take created by maps. The more and more I learn about GIS, it seems that it is hidden more and more in our world, with the common population unaware of it. Why is that?

The reading also talked about the history of GIS a bit. It seems amazing that the first GIS system was used in Canada in the 1960s for monitoring the nation’s resources. How can something as old as that be so unknown? There was also the section on the infrastructure of decision making that I found very interesting. Most of these terms I actually thought were the same, but now I see that they are actually quite different. These are:

• Data- numbers, text, and symbols
• Information- anything that can be digitalized
• Evidence- validated information
• Knowledge- information with interpretation added on to it
• Wisdom- advice given

The reading also listed the six parts of a GIS. This seems very simple, but it is at the core of how GIS works and without one part it could spell doom for the entire system.

• People
• Software
• Data
• Procedures
• Hardware
• Network

So I think that I will draw this post to a close. With the packet being so big, I think that I could post on it to the same about of hours that it took to read it. I will end with the note from the reading that GIS has grown a lot in the past to this point in history and will continue to grow even bigger in the future with its influence on man kind.

Geography Matters

    For my first ever reading and exposure to GIS, past that it means Geographic Information System, I learned that there are applications of GIS everywhere in the world that we live.  From Schuurman’s essay I found that GIS seems to almost run the world that we live in, even though people like me, before this class, have no idea of it.  The sheer power and ability to bring information is almost unlimited.  From government agencies using it with international affairs to scientists using it to predict how nature works.  In my Island Biology class my professor told us of a scientiststuding kelp forests around the world used GIS to predict where unknown forests would be located.  One place that it reported was on the East side of Isabella island in the Galapagos.  So he went to that location and sure enough he found one.

With all of these applications of GIS out there, I almost feel stupid for never hearing of it before.  It seems very logical that GIS is the driving force for almost everything in the world.  Over the next semester I hope to have my eyes opened even more the applications and the limitless power of GIS.