Topic 8: Regions 第八讲 区 域

Chapter Outline 15.1 Introduction 15.2 Geographic Regions Uniform Regions Hierarchical Regions The Regions Approach to Implementing Geographic Regions Integrated Coverage 15.3 Applications of the Regions Data Model: Incorporating Spatial Scale in GIS Analysis Studies of Ecosystems Box 15.1 Map Scale and Spatial Scale Modifiable Areal Unit Problem 15.4 Create Regions Create Regions Interactively Create Regions by Data Conversion Box 15.2 Convert a Text File with x-, y-Coordinates to a Region Subclass Create Regions by Using a Related Table Create Regions by Using Regions-based Commands Drop or Convert Regions Attribute Data Management with Regions

15.5 Regions-based Query and Overlay Box 15.3 Boolean Operations to Select Regions 15.6 Regions-based Tools in ArcInfo Workstation

Applications: Regions Task 1: Display and Query Regions in ArcMap Task 2: Create Regions from Existing Polygons in ArcMap Task 3: Create Regions from Existing Polygons in ArcInfo Workstation Task 4: Create Regions by Using Regions-based Commands Task 5: Tabulate Region Overlaps Task 6: Perform Regions-based Overlay

A nested hierarchy of counties and states in the conterminous United States

This illustration shows burned areas in the Lochsa River Basin in Idaho for 1919, 1929, and both years. Notice that burned areas for 1919 overlaps with burned areas for 1929.

This illustration shows a single region subclass that contains three regions: 1919 burned areas, 1929 burned areas, and areas not burned. The 1919 region overlaps with the 1929 region, as allowed in the regions data model.

This illustration shows three region subclasses: 1919 burned areas, 1929 burned areas, and burned areas for both 1919 and 1929.

A soil map with the suitability values of 1, 2, and 3

MAKEREGION can create a noncontiguous region from the selected polygons that have the suitability value of 1.

To create a region from arcs that make up the polygons with the value of 1, first select the arcs (red lines) and then use the MAKEREGION command.

Polygon 11 shares arc 1 with polygon 12. Arc 1 must be selected and processed twice to complete the hierarchical data structure of arcs, polygons, and regions used by the regions data model.

REGIONJOIN creates regions from a related table. Soils1-ID relates the region subclass’ attribute table (a) to the suitability table (b). Table (c) is the attribute table of the new region subclass.

A one-to-many relationship exists between the region subclass’ attribute table (a) and the crop table (b) for soils1-ID = 10. REGIONJOIN creates a stack of 3 regions for soils1-ID = 10: 2 are shown in the first 2 records of table (c), and the third is merged with the region for crop = 2.

all.pat - attribute table for the polygon coverage all all.patveg - attribute table for the region subclass veg that resides in the polygon coverage all all.patsoil - attribute table for the region subclass soil that resides in the polygon coverage all all.patelev - attribute table for the region subclass elev that resides in the polygon coverage all The PATs of the integrated polygon coverage all and its region subclasses, veg, soil, and elev

Logical expressions are used on the two region subclasses as shown by different line widths in (a) to simulate the overlay methods of union (b), intersect (c), and identity (d). The shaded areas represent the output.

The XOR connector retains map features of the two region subclasses in Figure 15.12a except features in the overlapped area. The shaded areas represent the output.

The NOT connector excludes map features that fall within strmbuf in Figure 15.12a. The shaded areas represent the output.

REGIONBUFFER combines map features from the input coverage (a) into the output polygon coverage (b).

USGS hydrologic units National Hierarchical Framework of Ecological Units, U.S. Forest Service Canada’s national ecological framework l

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