GIS5935 Module 15-- Dasymetric Mapping

-
For this last module, we explored methods in Dasymetric Mapping.

Dasymetric Mapping is "the process of disaggregating spatial data into finer units of analysis using ancillary data to help refine locations of population of another phenomena." This type of analysis basically helps look at where populations of a certain demographic(s) are concentrated within a set of boundaries. It may sounds like a fairly straight forward process, but it turned out more complex than expected...

The first two parts of the lab were great exercises and stepping stones, per se, in introducing us to the process and mind set of actually perform a dasymetric analysis. First I performed an Areal Weighting analysis that required to produce a population estimate for areas within a Basin. This was followed by another Areal Weighting exercise this time with ancillary data which produced a population estimate for children within certain school districts.
I will admit that the last part got the best of me while attempting to solve. Using populations from the previous exercise, I had to allocate those numbers to line up with a raster of imperviousness in order to get a rough estimate, a more precise one this time, for populations of children in certain school districts. While my methodology took a rough turn, I was able to produce a map displaying school district boundaries (in blue), Census Tract areas (black lines), and raster of imperviousness. The areas with higher populations are in red.







Comments

Post a Comment

Popular posts from this blog

Module 6- Proportional Bivariate

-
Image
This last module dealt with proportional bivariate mapping methods. Below is a proportional map reflecting negative and positive values for the increase and decrease in the number of jobs across the U.S. We had to convert the negative values into positive values for this purpose, which allowed to symbolize is proportional to the positive values for comparison. I selected a light bright blue hue to represent the loss of jobs and a warmer purple hue to represent jobs gained. For this particular symbology need, the challenge was not so much the quantity of the values I wanted to communicate. The challenge was finding a balance and gain a better understanding of how to use color themes for that purpose. Initially, I had considered using red and blue (as in hot and cold), but it felt too political and not related to the subject matter. The main exercise for this module demanded that we create a bivariate map displaying the relationship between obesity and physical inactivity perc
Read more

Module 4- Color Choropleth

-
Image
This week's module dealt with Choropleth mapping and color theory. Not being an artist, this was somewhat intense and thought-provoking. Our lab was great in walking you through the process of selecting the right color theme for a map. First, we covered some exercises in color ramp progressions. Below is an example displaying three varying gradients using the same base dark green hue. Original intervals: 51, 26, 31. In the Adjusted Progression, I reduced the previous intervals by -10 and added the values to each new set of RGB values. This appeared to make the hues above a shade darker. The adjusted progression is noticeably a shade darker in hue than both linear progression and ColorBrewer. ColorBrewer is also slightly more green, you can notice this change on the lightest color. I’m unsure what the formula used to produce those hues is, but they exhibit a bit more saturation within the hue. For the main lab exercise, we had to create a map displaying the change in the cou
Read more

GIS5100 Week10: Final Project

-
Image
My final project was dedicated to finding suitable areas for a new Elementary School site in Riverside County, California. I started out by compiling 5 pieces of key datasets: County Assessor parcel data, California Schools, Fault zones, Roads, and Public sites. First I performed euclidean distance analyses on four of them in order to produce zonal raster for preferred areas. A weighted analysis based on prioritizing safety shows that ideal areas fall within Hemet, Menifee, and Palm Springs Unified School Districts. Final analysis results show how active school sites are distributed, where all vacant parcels of at least 5 Acres or more lie, and recommended areas for a new school site. The two circled were determined to be the most suitable after analyzing results from weighted overlay analyses and locations of parcels. Additional setbacks are anticipated as more conditions are implemented to the list of mandatory criteria needed to finalize parcels. Looking b
Read more