Monday, March 23, 2015

Week 11 - Spatial Analysis of Vector & Raster Data/Vector Analysis

Weeks 9, 10 and 11 covered spatial analysis of vector and raster data, though there was no map created in weeks 9 and 10. In week 11 we created a map of DeSoto National Forest, with campsite areas that follow a number of specific restrictions. 

Using ArcMap I created buffer zones of certain size around lakes, rivers and roads, than using the Union tool I combined them into a single layer. Then using Erase tool I removed all the possible campsite areas that were also conservation areas. Each step created a new file, which I added to my geodatabase file.

Thursday, March 19, 2015

Module 10: Dot Mapping

In Module 10 we learned to create a dot map in ArcMap. The map on the left shows the population distribution of South Florida. The population dots are placed over a map of cities and water features of South Florida. 

Large part of the lab assignment was to create a good balance between the dot size and dot value. This is important because if the dots are too small, they appear insignificant, but if they are too large they will bleed together and appear as a blob rather than a dot map. Dot values matter, because if the values are too small, you will have too many dots and the map will be too crowded and difficult to interpret. If the value is too large dots will misrepresent the data, both due to the rounding to the nearest value, and due to spatial distribution. Too few dots will make the data appear as if it was only present in specific areas, rather than distributed over a larger area.

Sunday, March 8, 2015

Module 9: Flowline Mapping

The map this week shows migration statistics for the year 2007. The thickness of the flowlines is proportional to the number of people coming from each region/continent. The inset map of United States shows percentage of immigrant population in each state.

There were two base maps provided for the lecture, and the data came from the U.S. Office of Immigration Statistics. All the work was done in CorelDRAW. This work consisted of drawing the flowlines, setting region/continent colors, setting up background image, adding text, and creating legend for the inset map.

Sunday, March 1, 2015

Module 8: Isarithmic Mapping

Continuous Tint 
Maps created this week show the 30 year precipitation in the state of Washington. Both are isarethmic maps, one using continuous tint, and the other using hypsometric tint with contours. Both maps use the same color ramp.
Hypsometric Tint with Contours
Both maps were created using ArcMap. Continuous tint map was very straight forward, as the data was already in the appropriate form, and only required a choice of a color ramp. The hypsometric tint map required the data to be classified. I chose manual classification with ten classes. once my data was classified I used the Contour tool to add the contour tool to add the contour lines, using the same ranges as I did for the data classification.