Lab 3 – Greg FitzGerald

LAB 3 – Greg FitzGerald

• When loading the Middle Schools as locations for the network analysis, what was the setting used to set the location position? What does this setting do?

The setting used to set the location position was “Use Geometry”. This setting loads locations through using a spatial search and allows you to set the search tolerance of the network analysis.

• Comparing the boundary of the City of Albany with the Service Areas for the facilities, please comment on some of the possible objections to the numbers produced by your analysis and a means to address these concerns.

Some possible objections are that there are a few polygons that are inside of a service area, but excluded. This could be due to a lack of data about the streets in these locations. Some of these happen to be very close to the school and yet still not in the service area. Some of the buffer areas are able to cover these locations so it would appear some of the street data is incorrect.

• What are some other methods of addressing the MAUP issue between the service areas and the census blocks that you can think of?

Using another form of data other than census blocks would address the MAUP issue. Using something that is based on equal areas other than census blocks would allow for more accurate service areas. Another solution would be to create centroids from the data.

• What is the difference between using ‘hierarchy’ and not using it in creating network analysis service areas?

The difference is seen in the shape of the service area. Hierarchal analysis’ generate quicker analyses however the shapes tend to be less accurate. When using hierarchal service areas, it will generate generalized polygons, and detailed without hierarchal service areas.

• What are the differences between the euclidean buffers and the service areas for each school? Which is more realistic?

The buffers simply display a certain distance around an area, in this case it is the middle school and there is a one mile buffer around each middle school. The service area takes into account the roads shows a perimeter of a polygon where every point in that polygon is within four minutes of each middle school. Service areas is a more realistic and effective tool.

Table 1: From the joined Taxlot and Zoning Layer

Table 2: From the Middle School Service Area

REPORT

The total areas (sum acres and mean acres) of the taxlots for each zoning category were generated using the Summarize tool and the two separate datasets that were joined. By joining the Taxlot datasets and the Zoning dataset, the parcels were given attributes as to what zoning each taxlot was, as well as the totals for type of zoning (as seen in the table). The MAUP issue was handled by changing the polygons from the joined Taxlot and Zoning into centroids/points. Points address the MAUP issue as they either have to land inside the service area or outside of it, while the polygons/zones could be inside and outside the service areas. For the service area, I choose to use the detailed area rather than the generalized area, due to it is more accurate because it does not use hierarchy. The service areas were very similar, so using the more detailed one seemed logical. The service area for each of the middle schools were very similar, however North Albany middle school was an outlier. North Albany Middle School had only an area of 241, while the rest hovered around 1,600. This is about 70% smaller service area. The same applied to the perimeters of the service areas. The buffers were smaller than each of the service areas, with the exception of North Albany Middle School. Calapooia Middle School and Memorial Middle School were the only buffers that overlapped. The data used came from ESRI, Albany School District, and AssessorGeoDataBases according to the metadata.