Thursday, May 6, 2010

Lab 4: ArcGIS Tutorial: Getting Started
























At first, I did not realize how useful ArcMap would be in spatial analysis. I thought it was just a map-making program. After getting to work with ArcMap, I realized that it does have several potentials and that it is a great tool to use in GIS. However, the program's abilities also reveals several pitfalls in GIS that also need to be addressed. ArcMap is more than just a map-making tool, and although it took me a while to learn how to use it at first, there are definitely many ways to geographically represent places and factors associated with them in maps.

Learning how to use ArcMap was difficult at first. I was just following steps and did not think I could remember everything. So going through the tutorial a few times helped me cement basic concepts and remember the components and aspects of creating a digital map. I was really surprised to see how many things go into making a digital map. ArcMap is really useful because it allows you to map things that are not necessarily concrete objects in space, like the noise contours in the tutorial. This allows people to make more complex and detailed spatial analyses based on more than just the physical location of physical objects. It also allows people to focus in on the subject or area of interest and helps keep things organized. I never really thought about focusing on a small, specific area with boundaries, like the shape of a county before.

ArcMap also allows people to modify the maps they create at different scales. This is one of the advantages of making a map digitally because you can zoom in on details to work more easily with them. And it also allows people to work with different features in their maps separately (by making certain layers visible or invisible) which makes working with the data, like editing, a lot easier. Another spatial analysis tool ArcMap brings to GIS is its ability to create graphs, which puts numbers and the association of things into perspective. GIS has a lot of potential in its ability to combine and store a lot of data in an organized manner. After working with the tables in the tutorial, I have never realized how detailed and vast data can be. GIS allows users (with the additional tool of ArcCatalog) to create their own data (which can all be put into a geodatabase), which can be joined with other data because of its organizational structure. This makes it easier to work with different files and different data (with different attributes in tables) from different users. ArcMap also lets people make calculations with the attributes from the features in their maps to create new attributes. It even allows them to alter the way features are represented based on their attributes and change data (by deleting or creating a new value) by editing it through the editor toolbar so they can show exactly what they want to display in their maps.

With the many useful tools for spatial analysis that GIS offers through ArcMap, there are also pitfalls. Anyone can make a map, and their map will not necessarily be useful to another person. People make maps to suit their own needs. Also, with ArcMap, anyone can make a map showing what they are interested in, but their map may not be accurate. With all the editing tools in ArcMap, it is very easy to change or get rid of data that a person does not want to show in their map or which may affect the purpose or the point of their map. So things may not be correctly represented spatially (objects, like roads, may be missing) and values can be skewed or completely wrong. Hence, there are pitfalls as well as great potential in GIS. People need to look at maps with an appreciation but with a critical eye. And they must understand the value of a map (the time and effort it took creating it) and be able to use it wisely (where its purpose can be of most help in a given situation).

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