Understanding GIS. David SmithЧитать онлайн книгу.
7)Close the Catalog view (large middle pane). Keep the Contents and Catalog panes open.
Insert a new map
1)On the Insert tab, click New Map.
A new map is added to the project using the Topographic map by default.
On the right side of the application is the Catalog pane. This pane contains all the maps, data, tools, and other resources associated with the project.
2)Open the Catalog pane (if necessary), and expand the Maps item.
Note that a new map simply named Map has been added to your project.
3)Rename the new map by right-clicking Map in the Catalog pane and clicking Rename. Type Lesson1a and press Enter.
Change the basemap to Streets
1)On the Map tab, change the basemap by clicking the Basemap button
2)Click the Streets basemap.
The World Street Map basemap layer is added to your Lesson1a map. It has an entry in the Contents pane on the left. Again, click the View tab, if necessary, to open the Contents pane.
The Map tab at the top of the application includes tools for navigation, layers, selections, inquiries, and labeling. As different tabs are selected—Insert, Analysis, View, Edit, and Share—different tools will appear on the ribbon. Additional contextual tabs, including Appearance, Labeling, and Data, will appear depending on the tasks that you are performing.
Zoom in to Southern California
Now you’ll zoom in to your area of interest.
1)Experiment with navigating the map with the mouse.
A.Push the scroll wheel forward to zoom in.
B.Pull the scroll wheel back to zoom out.
C.Drag in any direction with the left mouse button to pan.
D.Drag up with the right mouse button to zoom out.
E.Drag down with the right mouse button to zoom in.
F.Press and hold the Shift key and drag a box with the left mouse button to zoom in.
G.In the map window, use the Shift key to drag to draw a box around Southern California, as shown in the figure.
Your box doesn’t have to match exactly.
2)Zoom in again to get closer. When you see city names and major roads, pan (left mouse button) to center the view on the Los Angeles area.
3)Keep zooming in (try the Fixed Zoom In button
4)If you zoom in further than you want, zoom out (pull the scroll wheel back), or click Fixed Zoom Out
You probably noticed that no streets were visible at the global scale, and that as you kept zooming in, more and more detail appeared. This is because the basemap is a multiscale map—really, a set of maps that turn on and off to display features and symbology that are appropriate to your map scale.
The figure shows Greater Los Angeles, an area that includes scores of incorporated communities and nearby cities.
Basemap layers
Basemap layers show reference geography such as street maps, imagery, topography, and physical relief. The ones available in ArcGIS Pro are remotely hosted map services that you can navigate, view, and use as backdrops to other data. Basemaps are stored at multiple scales, so that as you zoom in or out, you see different amounts of detail. As you navigate a basemap, the various pieces of it (called tiles) that compose your current view are stored locally on your computer in a “display cache.” When you zoom or pan to a new area, the map may be a little slow to draw, but anyplace you return to will redraw quickly, because the data comes from your cache, not from the remote server.
Add a layer of project data
On top of the basemap, you’ll add a layer from the data that has been put together for this project and is stored on your computer. In lesson 2, we’ll talk more about where this data comes from and how to acquire data of your own.
1)In the Catalog pane, right-click Folders and click Add Folder Connection.
2)Browse to your UGIS4 folder and select the ParkSite folder. Then click OK.
Selecting a folder adds a new folder connection to ParkSite.
3)After making the folder connection, expand ParkSite\SourceData and then ESRI.gdb, and finally the Boundary item.
4)Drag the City_ply layer to your map. Default layer colors vary, so don’t worry if the color of your layer looks different from the figure.
We’ll discuss GIS data formats in the sidebar “Representing the real world as data” in lesson 2. For now, you just want to dig down to your data.
When the layer of city boundaries is added to the map, it may zoom to the full extent of the dataset. If so, click the Previous Extent button
Each city in the layer is called a feature. These features are polygons, which are one of the three basic shapes used to represent geographic objects in a GIS. (The others are lines and points.)
In the Contents pane, the order of entries matches the drawing order of layers in the map. City_ ply is listed above World Street Map, and on the map, the cities cover the basemap. You can control a layer’s visibility with its check box in the Contents pane.
5)In the Contents pane, select the check box next to City_ply.
The layer is turned off.
6)Select its check box again to turn the layer back on.
Set layer properties
Every layer has properties you can set and change. For example, you just changed the visibility property of the City_ ply layer.
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