Interpretation guide of natural geographic features from ETM+ Landsat imagery and aerial photography
Introduction
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The purpose of this project is to create a visual interpretative guide to the natural geographical entities in the geospatial database (GDB) using Landsat7 ETM+ imagery and aerial photography. The methodology and information fact sheet were developed by Provencher and Dubois (2004a), and the application of this procedure to a test case has already garnered a consensus among the staff of CTI at Sherbrooke (Provencher and Dubois (2004b). The meanings of the sections of the fact sheets are explained in the Glossary.
The eight natural entities in the GDB (Centre for Topographic Information, 2004) fall under eight themes that are grouped into three domains: hydrography, landforms, and vegetation (Table 1). In practice, for interpretive purposes they are often subdivided further and represented by 17 fact sheets.
Table 1: Hierarchy of natural geographical entities
| Domain | Theme | Sub-theme | GDB entity | Fact sheet |
|---|---|---|---|---|
| Hydrography | ||||
| Watercourse | ||||
| Perennial watercourse | Permanent water | 1. Permanent water | ||
| Alluvium | Intermittent water | 2. Intermittent water | ||
| Waterfall | Water disturbance | 3. Waterfalls and rapids | ||
| Rapids | Water disturbance | 3. Waterfalls and rapids | ||
| Waterbody | ||||
| Perennial freshwater body | Permanent water | 1. Permanent water | ||
| Alluvium, rocky surface | Intermittent water | 2. Intermittent water | ||
| Saltwater | Permanent water | 1. Permanent water | ||
| Alluvium, rocky surface (tidal flat) | Intermittent water | 2. Intermittent water | ||
| Reef | Water disturbance | 4. Reef | ||
| Wetland | ||||
| Tundra pond | Saturated soil | 5. Tundra ponds | ||
| Palsa bog | Saturated soil | 6. Palsa bog | ||
| Marsh, swamp, and uniform peat bog (wetland) | Saturated soil | 7. Wetlands (marshes and swamps, peat bogs) | ||
| String bog | Wetlands | 8. Wetlands (string bog) | ||
| Landforms | ||||
| Glacial landform | ||||
| Glacial debris | Landform | 9. Glacial debris | ||
| Esker | Landform | 10. Esker | ||
| Moraine | Landform | 11. Moraine | ||
| Glacier, glacial ice cap, and ice shelf | Permanent snow and ice | 12. Permanent snow and ice | ||
| Periglacial landform | ||||
| Polygonal soil | Landform | 13. Tundra polygon | ||
| Pingo | Landform | 14. Pingo | ||
| Littoral landform | ||||
| Barrier beach and spit | Landform (sand) | 15. Barrier beach and spit | ||
| Eolian landform | ||||
| Dunes | Landform (sand) | 16. Dunes | ||
| Vegetation | ||||
| Wooded region | ||||
| Wooded region | 17. Wooded region | |||