Potenciales refugios en jamaica plain-ma

Assignment 4 - GIS Data Quality Assessment
Research Paper







Wars of nations are fought to change maps. But wars of poverty are fought to map change.
~Muhammad Ali





C Danilo Morales
UEP-0232-01 - INTRO TO GIS
Research Paper
March 8, 2012

Project Description
The project I am working on is an analysis of potential shelters in the Jamaica Plain area. The shelterscould be use in case of a natural disasters or other emergency. My goal in this project is to identify schools, where the space could be use as temporary shelter. The mean criteria needed to identify these shelters are: infrastructure, mobility and utilities. Elements of mobility include: walkability, public transit and car accessibility. In terms of infrastructure, space is needed. Also, in termsof utilities water, electricity and heat are needed. Finally, in this project we will analyze the location information of schools, accuracy of the streets and train stations in Jamaica Plain.
The positional accuracy of data needs to be within two hundred feet due to that more of the schools are big and notorious buildings. The data must be totally complete and quite up-to-date for the studyarea, so as to capture most of the recent streetscape improvements, within the past two or three years. Connectivity is not important, except for the appearance of completeness at a 1:500 scale. Data layers for analysis will include geocoded school addresses, building data from the city of Boston, Hydrology MassGIS, MBTA stations.

Figure 1, it illustrates the location of the project, in JamaicaPlain, MA.

Street Centerlines: TIGER 2010 and the City of Boston
The difference between the census data and the city of Boston is minimum. For the most part, the two sets are nearly equal and they match the streets. I would say that that the city of Boston data set street centerlines tend to be slightly more precise than the census data set.
Figure 2, below, shows the City of Bostondataset in blue and TIGER line in orange at Glenvale terrace. Here we can see one of the few mistakes in this area of analysis. The difference between these two data sets is 8 feet. This discrepancy does not affect the map viewer’s understanding of the location of the schools. Therefore, we can conclude that the accuracy of both data sets is good enough and they could be use for the current project.Figure 2. Glenvale Terrace, Boston street centerlines (blue) and Census TIGER line files (orange)


Hydrography: City of Boston and TIGER
In this section hydrological layers from Boston and census 2010 were compared to the aerial imagery. The City of Boston data matches the aerial photographs almost perfectly. However, the census dataset shows around 50 feet difference from the aerialimagery. But, this mistake about the positional accuracy of the census data perhaps happened because this picture was taken in the end of the summer, when the amount of water in the pond is in its lower point.
For the current project, both datasets could be useful. The census data, and the Boston data are relatively accurate. Most of the people could be able to find the pond if they would needwater in an emergency case. Jamaica Pond has a 1.4-mile walking trail that circles the perimeter of the pond, and there are almost 11 acres of forest cover in the park. In the present project knowing the names of surrounding streets to the pond could be useful to find the pond in a map. Also, The Jamaica Pond Community Boating building is in the map as a reference.
Figure 3, below, shows theBoston’s data in dark blue and the census data in lighter blue.


Optional Data Layers: Schools, Buildings, and T-Stops
Schools
In order to determine the positional accuracy, schools locations were geocoded using the ArcGIS North America Geocode service. There are seventeen schools in Jamaica Plain. The general address locations of the schools are pretty accurate while making a random location...