Lauren Tuttle

2/19/08

GEOG 370

Lab 3

20

Part I


  1. All four data layers have the following dimensionalities of polygon geometry type, NAD 1983 StatePlane New York Long Island FIPS 3104 Feet projected coordinate system, Lambert Conformal Conic projection, geographic coordinate system: GCS North American 1983 and datum: D North American 1983. Shorelines could be considered also as a line geometry type even though the actual shoreline physically is a polygon. Census dots could be considered as a point geometry type even though the physical area in which the census information is collected is considered a polygon.

Landmarks could also be points depending on scale

The classification and number of classes used are quantile and 4, respectively. The breaks in the data are at 78%, 96%, 99% and 100%. These breaks were used because a majority of the population lies on the upper end from 0% to 100%. If the populations are graphed, then the bell curve is shifted to the right.

4. The measurements levels of data mapped are ratio. Through creating a choropleth map, each population is given a value or in other words, a range, in which it belongs to. This range is based on each population’s relationship to the total population. This data is also ratio because there cannot be negative data and it is on an absolute scale.

5. The two types of thematic maps covered in these exercises are dot density and choropleth. Dot density maps are useful when wanting to show count data such as human population. Each population is representative by the density and size of the dot. Choropleth maps are useful when wanting to show a percent or ratio of something. In this exercise, the ratio of minority population to the total population is determined and shown.

Dot density = variation in spatial density

Part II

Layout view map is saved under Lab 3 as PartII.jpg. Here is a print screen of the layout view map.