Lab 4: Digitizing

The use of heads-up digitizing is a valuable tool that allows users to create their own primary data sources in ArcGIS. By finding an image from a pre-existing source, as we did with the map of 1999 Iraq from the University of Texas' Map Library, it was easy to make shapefiles to correspond to the geographical features portrayed on the image. And by creating these new shapefiles from scratch, not only were they given individual names and IDs for our later use, but we could specify, and sync, their coordinate systems to make future use of the digitized data function more smoothly.
The process of digitizing, while simplistic, is tedious and requires steady focus and concentration. To create accurate shapefiles in the likeness of Iraq's provinces, cities and rivers, careful and precise editing must be done to the existing map picture using a trace tool. The task sounds easy enough, but even basic map designs such as this require some painstaking effort. It can be immensely difficult to determine the exact locations of bends in a river or curves in a provincial polygon, especially when zooming in only shows the blurred pixels of the original image. Tracing the international border of Iraq was quick, but making the provinces within by cutting the polygon was a bit of a nuissance. The polygons snapped to the border and completed themselves for the most part which was easy enough, but because they had been cut from the larger Iraq polygon that polygon had to be remade and reimposed onto the map around the new provincial polygon shapes.
The process of digitizing is a crucial skill for GIS users because it helps to create new sources of information where there had been none previously. Even though images of the locations may already exist, digitizing has allowed the creation of new point, line and polygon shapefiles, available for use in the creation of new maps (as seen above). From simple tracing, and naming, of objects in an image, new data sources are created and accessible for use, making mapping as simplistic a process as adding the data and giving it a title. My hope is that we practice this technique more so that we can hone a skill which can eliminate needless failed attempts at "downloadable shapefile" research and allow us to just create the spatial data we require for later mapping assignments.