Embossing

Another between classes project. John Nelson is one of my favorites for mapping tips and his website is one of my goto's for inspiration.

 https://adventuresinmapping.com/

After watching his 'How to emboss and imagery basemap' video I decided to give it a try.

BEFORE

AFTER

Very cool and a lot of fun!

PostGIS 6105 Lab 6

 Interpolation

In this final lab, were were building off the last water quality lab. This time we added sample sites and sample data collected on different dates to interpolate the water quality across the grid.

We wrote SQL to combine the 2 provided sample tables into 1 table and them wrote additional SQL to add a new column onto one of our existing tables. We completed an additional 5 SQL tasks to get all the data needed for our choropleth map. As with the other labs in this course, I have omitted the specifics on the SQL to avoid interfering with other students completion of this course.

We were asked to create an ERD for this water quality scenario. I used Lucidchart to complete mine. I still find myself regularly overanalyzing my ERD's and struggling for the right relationship term.

Below is my completed choropleth map:

GIS6105 Lab 5

 Tessellation

For this lab, we were provided with a scenario of a high school science teacher who wanted to be able to map the changes in water quality over time from samples collected by students. We first organized and populated our database making sure we used the correct SRID. We connected to our PostgreSQL Database from within ArcGIS Pro and viewed the difference from direct data additions. 

Our next task was to create a fishnet using Postgres in PgAdmin. Once the fishnet was successfully created our goal was to get that grid fitted only to the study area. Our final task was to take our resulting map and create a layout. The SQL developed was not included as that would compromise the efforts of other students.

GIS6105 Lab 4

 Performing common GIS operations within PostGIS

We began by creating a new schema in PgAdmin and importing spatial datasets with the correct SRID. Afterwards, we wrote SQL using the ST-Buffer function to create 1/2 mile buffers around points. We then used overlay operations to find census block that fell within 805b meters of a specific location. Once we had those blocks we used ST_Union to combine them. Below are my results:

GIS6105 Lab3

Vector Operations

For this lab our first assignment was to revise the ERD we created in our prior lab. 

 I had already included attributes and spatial data types in my original ERD. The main change that I made was the relationship between beaches and parcel sales. After working on lab 3 it became clear that there is a direct relationship between proximity to the beach and the parcel sales. In my original ERD I did not have any relationship between beaches and parcel sales.

Next, we were asked to write and run SQL that would return parcel point parcelid and associated distances to the beaches line. We also had to visually check the points distances using ArcGIS Pro.

Our next task was to write and run SQL to find real home values. The results of our query were expected to return pin and real price columns.

GIS6105 Lab 2

Physical Spatial Database Design

In this lab we were provided with a scenario for Beaches and house values. Or first task was to create an ERD using 4 identified entities. I used Lucidchart to make my crows foot ERD.

 

The next task we were given was to write an run SQL to create an inflation_index table. Once that was successfully completed we had to import data to fill our tables and provide screenshots of the results. (We utilized a LIMIT clause to stop at the first 10 results)

After completion, we had to determine the correct SRID for our ShapeFile and properly import it into the PGSQL database. Once this was accomplished we again utilized the LIMIT clause to list the first 10 records from the resulting table.

This class was my first exposure to PostGIS. Much of the code reminds me of Python which I found to be intimidating. 

 

Digitization

 In between classes one of my volunteer projects was to take older maps, both handwritten and ArcMap in origin and digitize them for conversion to ArcGIS Pro and ArcGIS Online.

So for example, the below image (tiff) was a map generated with ArcMap and had handwritten notes:

When digitizing you want to have a minimum of 3 control points for a first order affine, 6 for a second order, and 10 for a third order. The higher the transformation order, the more complex the distortion can be corrected (ESRI Documentation).

For my mapping purposes, 10 points were used for the complete map. Below is a screenshot for part of the resulting digitized map in ArcGIS Online.

REFERENCES:

ESRI (2023) Overview of Georeferencing. ESRI ArcGIS Pro Documentation. https://pro.arcgis.com/en/pro-app/latest/help/data/imagery/overview-of-georeferencing.htm