[MUSIC] Hello everyone, welcome back. In this lesson, I'm going to show you how to find some common datasets that you might want to use in your GIS analysis. When I teach a in-person class on a theme, I usually like to give people a sense for the datasets that they might want to use and show them where to find those datasets. In a class like this though, where you could be anywhere in the world, that's a little less relevant to you, because I can't necessarily guess what datasets you might want to use and you can't tell me. So, what I want to do instead is show you how to find some data on your own. One of the most common questions I hear when people start out in GIS is, okay, so I know how to do this analysis, but where did all this data you gave me to work with come from? Similarly people also wonder how to create data. It's not usually one of the first things we teach, because you need to have some other fundamental concepts first before you can understand how to create data appropriately. You won't create data on your own until the next course, but in this course I want to show you at least how to find some data sets that you can use in your own work. So first, I want to highlight a resource that we provide in this course that you may or may not have missed. In week one, there's a reading called Resources and Help for GIS. And if I open that up, it's really simple. But if I click Resources and help.pdf here. It will bring up a PDF that has a ton of different links and information that could be helpful to you when you're starting in GIS. And if I scroll down a bit to the bottom of the second page here. There's a section on data and a lot of this is US specific but I've done some work to try to gather some listings of global data that might be useful to those of you anywhere else in the world. Some things that are really commonly needed are terrain data. So here are some listings of terrain data for those of you elsewhere in the world. Similarly there is a listing for world borders and another one for geo names, names of places around the world. Up above here there are some listings for world wide GIS data sources from the United States Geological Survey, they do a lot of world wide remote sensing, and some other work, creating data sets that span the whole globe. So that link will help you find some of their data sets. And then there's also a link to another listing of jis data sets from a professor at Humboldt State. Finding data is kind of its own art, and you'll get a hang of it, but mostly it's about searching the web thoroughly and about asking the right people if you can't find the information you need. Some of the data that you are hoping exists for your analysis will exist and will be free to access and other data won't. If you have a budget you will often find commercial providers of data, but those costs can add up pretty quickly. So instead, when you can't find the data you need, I often would recommend that you take a look at some of the websites up here for help, some of these communities and check in with them. The StackExchange community or the GeoNet community or if you know people who do your line of work or are on email lists that work with GIS or with your specific field. Send a message out, ask those people for help, they may know where you can find the data that you need. Just like with everything, when you do that, be respectful, give a good example of what you are trying to accomplish in addition to the data you think you need, and that's how people will be able to best help you. So while the data sets that I showed you down below were much more for download and analysis on your local machine, in recent years, web services, layers that your computer just downloads to use only the part that it needs, have become much more important and much more available. And has been providing these within Arc GIS for your use too. So if I switch to ArcMap here and we go to the Add Data section, we'll take a look at a section that we haven't used so far in this course which is Add Data From AcrGIS Online. This is a repository of datasets from other users and directly from Esri that could be useful to you. It'll often show you some featured data, or you can search for data on your own. So, since I was giving the example of elevation data since it's so commonly needed, let's search for elevation and see what comes up. Let's not only search in UC Davis. Let's search world. So what we get here is we get a bunch of base maps that we've already seen. Things like World Shaded Relief. But we also get elevation contours for King County. Who knows which King county that is. But somebody has published some data here. So it can be difficult to search through sometimes but once you find the data you need, it can be really helpful. And we can get multi-directional hillshades, which are nice as base maps as well. And, if we go down here, we can see a terrain layer, a multi-resolution layer providing access to elevation values for use in analysis with functions for slope, aspect, and hillshade. What's really cool about this is that since it's an image service we can analyze this data without directly downloading it to our machine, ArcGIS handles all the download of the data as it needs it and then we can work with it just like if we had it locally. What's also really cool about this layer is that it's a global terrain layer. So, no matter where you are in the world, you have a base terrain layer to use in your analysis. Down here, there's a 30 meter terrain layer. But that's just for North America. This other one is for the entire globe. So let's take a look at it really quickly. I'll click on it. And if I wanted to browse it I could click details. And look at the properties, and look at the comments to see what other people are saying about it's reliability, things like that. And then I can click add. And it will take a moment, but the data will be added to my map. As the table of contents and then here it is, it's terrain layer for the whole world. Now we can explore this data just like we would with any other data. If I use the zoom tool I can take a look at the Himalayas here. And it'll take a moment to come up because it's loading it. But we can zoom around and explore global elevation information. We can also access this layer's properties just like we would with anything else and modify its display information. Look at the source information here. See its projection, all the same stuff we can do with our regular layers. Not all web service layers allow this, but this one does. And lastly, if I want to do some geoprocessing, I can open up the toolbox, and I can go to say a special analyst tool which helps me deal with rosters and go to the surface toolbox to make a slope raster, and if I do a slope tool, I can select this as the input raster. Now, in reality, what I would need to do, since this is an image service and it's going to want to process the whole area, is I need to set some environment settings. And if I had another layer loaded here, I could use that for processing extent. And that way it's only going to process the part that's of interest to me. So if you have a study area boundary or some area of interest, you could set that as your processing extent and then you can work with image service there. Okay, that's all I'm going to show you for this lecture. In this lecture we just did a quick overview of different locations you can find data based upon the reading that we gave you earlier in this class, and a quick introduction to adding layers from Arc GIS online into your analysis. Finding data is its own challenge that you will always be trying to master. But it's a great skill to have to be able to search on Google or whatever search engine you like and to be able to ask people for help and find the data that you need for your analysis. See you in the next lecture.
