Alright. Your task is to map out some GPS data and make some interpretations based upon combining a couple of different layers. I highly recommend that you carefully read through the entire lab before starting, just so you have a clue as to what you're trying to accomplish.
As a GIS guy/gal, this lab is representative of the sort of thing that happens all the time: you were handed an excel file by someone who asked for pretty maps and some interpretations of the data. Never assume that person has their sh#@ together, knows anything about GIS, or even can give you good data. It is up to you to figure out and handle issues.
This lab will require you to ask questions and be critical of all the data. It's NOT a cookie cutter lab that you can accomplish without spending some time thinking.
The base information is a file of point locations (plants) collected by plant ecology students in the fall of 2019 out at the Manastash Ridge hike. The data was collected from about the irrigation ditch to the top of the ridge along two trails. I already deleted the points that were clearly way outside the study area. There's also a 3 foot DEM of the area (downloaded from a WA LiDAR site). DEM stands for "digital elevation model" - if is a raster layer in which the value of each cell is the average elevation within the cell. If you're not familiar with the area, remember we looked at it in the earlier Google Earth labs - goto GE and take a look to familiarize yourself with the area.
Start by copying the full Manastash folder from the data drive onto your flash drive.
Open up the excel file. Sheet one has all the x,y points and a number denoting the plant species observed; the other sheet has info about the species. Pro tip, you might want to get the species names, both common and latin, associated with the main x,y sheet as two new columns. Copy/paste is your friend.
Q1: What coordinate system did they use to collect this info? Which Datum? (take your best guess if you can't figure it out from the info given). Note, you now get to fiddle around with importing the data. If it doesn't show up in the right place, you chose the wrong coordinate system, datum, or got your X and Y wrong. Once you get everything in the right place, you will know the coordinate system and datum!
Close Excel. It's now time to get this data into Pro. Fire up Pro and start a new project. Be sure to set it to the Manastash folder on your flash drive.
Goto Map - Add data (but click the little arrow thingy below the add data button). Select X,Y point data. The geoprocessing window will pop up. Select your input table as the Excel file. Now, Pro and Excel have a love-hate relationship. Sometimes it works, sometimes not. If you get an error adding the excel file or things don't work properly, go back to excel and export sheet 1 as a comma separated by value (.csv) file. This is basically a text file. And they pretty much always work. But not always. Welcome to the world of data....
Input the easting, northing, and your coordinate system/datum (click on the little globe thing) based on Q1. If things show up in the right place, all is good. If not, you screwed something up somewhere.... try again.
You should now see a bunch of dots on the basemap out at the ridge. Let's first save this data in GIS format. In Pro, right click on the file name and goto data - export features. We'll put this in the empty geodatabase that Pro automatically creates. Navigate to your manastash folder and find that .gdb file. Next, name the layer whatever you want (the next thing in the window to fill in). Run it.
Now, remove the table-to-point file, just to get it off your window.
Let's add a little more data. There's a DEM (in .tif) format. Add it using the add data button. If it looks a bit psychedelic, goto symbology and stretch to a greyscale (or other scheme of your choice). But elevation by itself is kinda boring. Especially for display. So, let's make a hillshade layer. Goto analysis - tools, then search for hillshade. Use the spatial analyst tool that pops up. Select your input dem. Put the hillshade into your geodatabase again. Accept the other defaults. Again, this will look best in greyscale.
You should now have a nice shaded relief layer of the area. Let's get slope and aspect as well. Same process with a different search terms as for hillshade.Take a close look at all these layers and make sure the output makes sense to you. Note, if the output doesn't make instant sense to you, click the little blue ? in the geoprocessing box and you will get all the explanation you need.
Alright. The next question will be... are there any relationships between the plants and slope, aspect, or elevation? We will only partially answer these questions in this lab. But first, we need to get the slope, aspect, and elevation of the land where each plant point was collected. Back to your search for the right command. Type in 'extract multi' and you'll see what you need "extract multi values to points" - yeah, I had to google things to find the right command. Fire it up. Your plants layer is obviously the point features. Now, get your DEM, slope, and aspect layers in as your input rasters. Give the field names something useful.
Now, take a look at the attribute table of your plants layer. You should have, associated with each point, a species key, northing, easting, elevation, slope, and aspect. And the object ID, which is just a unique ID given to each point by Pro. If this were a stats class, we could go a bit nuts with this. However, I just discovered charts!
Remember, that original spreadsheet had both the common and latin names for the plants we're looking at (species key, second sheet).
So. Let's make some graphs and interpret them. Right click on your plants filename on the left side. goto create chart - scatter plot. Make X your species key. Make Y elevation. Repeat this process for slope and aspect.
Now, there's a fun glitch a couple of people found. But only a couple. If you can't make this chart, it's because the values you imported from the DEM, slope, and aspect are not considered "numeric" by Pro. To fix this, view the attribute table and right click on one of the fields - and select fields. Change the number format of your slope, aspect, and elevation to numeric.
Turn off the regression line, as it's utterly meaningless. Export these three charts as jpg images (the export button at the top of the chart) - note, you will need to type in your filename and ".jpg" to get a jpg image. Note.. the first time we ran this lab, a few students had problems with the charts not showing up in Pro. Save your work, completely quit Pro down, and then re-open your project. The charts should be there. No clue why this happens occasionally. But never underestimate the power or rebooting software/computers.
Now, let's do some interpretation!
Q2: Are there any relationships between the different species and elevation, slope, or aspect? Be sure to use common names. If so, which species, where, etc? In short, is there any useful information on any of these charts? Don't just say "yes/no, there are(nt) relationships" - say exactly what they are.
Last, it's time for a pretty map. With more info than usual! Your basic map will be the hillshade and the plants. Color code by species key. In your legend, include both the latin and common names. Also, insert small photos of the 5 most common species (insert -- picture). You'll have to find the pics online (and be sure to reference your sources!). Don't forget all the usual cartographic niceties. Also, turn off that default Pro basemap - not only will things draw faster, but you won't get all that junk text at the bottom of your page. Remember to make your map area (bounded by the plants points) as large as possible.
Q3: What issues with the data did you encounter? How did (or would) you overcome them? Were there any challenges with making the map? What were they? How did you overcome them? Another pro tip here, yes, there are issues with all the data. But you have to pay attention.
Q4 - Feedback! Any particular glitches or anything? In short, give me some feedback to make this better (unless it's already awesome, of course). Thanks!
Turn in your map and (on separate sheets of paper) the answers to the four questions and your charts.