Python Demo

This was the first time that we used python to complete different tools in ArcGIS, python is a skill that is very important in the GIS world and is a skill worth knowing. For this python script we needed to use python to clip, project, and import different rasters into a geodatabase that we had created. The process was pretty straight forward and was nice to get a taste of what coding python is like and how it can be used to complete many different tasks. Below is the python script that was written to complete three tasks regarding different rasters.

Figure 1: Python Script for clip, project, and importing rasters to a geodatabase

Data Gathering

Goal

The goal of this assignment is to become more familiar with the process of collecting data ourselves from different resources, by downloading the data, joining the data, and projecting the data from these different sources into the same coordinate system using python. Also building and designing a geodatabase from scratch to store all of the data in. For this project we are doing all of this to Trempealeau County which is located in Wisconsin. 

Objectives

In this project there were four main objectives that needed to be completed these four objectives are listed below:

Objectives:

1. Download data from several different websites

2. Import data, join tables, merge data and view data

3. Write a Python script to project, clip and load all data into a geodatabase

4. Write a technical report about the data sources and their accuracy

General Methods

In order to obtain all of the data that was needed to complete this project we needed to find different data sets from different sources. In order to collect these data sets we needed to go to several different locations on the internet and download each data set separately. Once we have all of the data downloaded we would then need to unzip all of the data to a certain location or in this case the file that we want all of our data to be located so than it will be easy to find and well organized. Below are all of the site locations for the data that was collected. 

Sources of Data:

US Department of Transportation

http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_atlas_database/index.html 

USGS National Map Viewer

http://viewer.nationalmap.gov/basic/ 

USDA Geospatial Data Gateway

http://datagateway.nrcs.usda.gov/

Trempealeau County Land Records

http://www.tremplocounty.com/landrecords/

USDA NRCS Web Soil Survey

http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm

After all of the data was collected the next step was to import the SSURGO data that we collected from the NRCS Web Soil Survey. Within this data were a vast amount of tables and we needed to import the data from one of the tables to another by using Microsoft Access, which is an application that helps you edit databases. After this step was complete we then needed to create a python script that would project, clip and import all of the data into the geodatabase that we designed and created. The script that was written imported all of the rasters that was collected from the different sources into the geodatabase, while also clipping them to the borders of  Trempealeau county and giving them the same coordinate system as the study area. Below is the figure 1 which is an image of the python script that was created to project, clip and import the rasters to the study area. 

Figure 1: Python Script

Data Accuracy

Figure 2: Metadata for all the data used

Final Maps

Conclusion

This assignment was very educational, it gave me a good idea of what work in this field is going to be like when having to collect my own data which can be easy at times while also being difficult at other times when trying to organize all of the data and tables. It was also a good experience when creating a geodatabase from scratch and what that process entails. The use of python was also a new experience, it was an eye openeing moment where we used python to complete different tools in ArcGIS. Overall this assignment went well and was a good learning experience.