Geographic Information Systems
Lab 1
Goals and
Background:
With the knowledge and skills
that I gained by working through the tutorials, and listening and taking notes
at lecture, I was able to examine the task in front of me and accomplish it. By
learning about ArcGIS and the tools that come along with it, I was able to use
coordinate systems, shapefiles and so much more to do the task at hand. The
goal of this lab was to examine the different projections of the same shapefile
and see how it was distorted base on which projection it was. It was evident to
see which projections distorted shape, or which distorted distance and so on.
Secondly, the other part of the lab was to address an issue of two shapefiles
not being compatible. With the skills I have gained, I was able to locate the
issue, fix it, and make the two shapefiles compatible.
Methods:
In order to start this lab, I
obtained my data from the files presented to me on d2L placed there by Dr. Wilson.
After successfully downloading it, I connected to a folder from ArcMap in order
to access it from then on. Executing the plan to show different projections,
one by one I created new data frames for the projections and added the necessary
shapefiles. After the shapefile had been added to each data frame, I changed
the projections to the one indicated by going through the data frames
properties. The projections I used included:
GCS_WGS_1984
World_Mercator
World_Sinusoidal
World_Equidistant_Conic
World_Robinson
Next to finish my
map, I added north arrows to the maps that it was appropriate. Also, I added
the States shapefile, selected the State of Wisconsin through the attributes
and exported that as its own shapefile. I then projected it in the NAD_1983_UTM_Zone_16N
projection. Lastly, in a different data frame I added the states shapefile
again and added the stroads_miv5a to overlay it. After fixing the projection
issue, it overlaid nicely.
On the second map,
I began by selecting the Central_WI_Cts.shp and adding it to a black map. I
then added the Lower_Chip_strms.shp. Initially this did not show up. Accessing
the issue, I realize they were missing projection information. I solved this by
putting both into the GCS_North_American_1983 geographic coordinate system as
that is what the metadata called for. Next, using the Define Projection tool, I
put both into the NAD_1983_StatePlane_Wisconsin_Central_FIPS_4802_Feet
coordinate system. This solved my problem. I finished my map by adding an appropriate
north arrow and legend.
Results:
As seen in Figure
1, each world shapefile has been projected to a coordinate system as labeled
under it. From this, one can see how different projections show different
things. Left up to the cartographer, he/she gets to decide what should or shouldn’t
be distorted by selecting the projection. Also in Figure one, at the bottom,
one can see more regional projections on the United States and the state of
Wisconsin. Lastly, in Figure 2, one can see the end result of the problem
between the Wisconsin Counties and the River systems in those counties. Both in
the same projection, they seamlessly form a quality
map.
Figure 1
Figure 2
Comments
Post a Comment