According to the spatial scale differences of geomorphology, geomorphology can be divided into several different spatial units.
1. Astral landform: occupying the whole earth, it is the largest landform, including two units: continent and ocean.
2. Giant landforms: covering tens of thousands to hundreds of thousands of square kilometers, including mountains, plains and other units, such as the Himalayas and the Brazilian Plateau.
3. Large landform: covering hundreds to thousands of square kilometers, including individual mountains and basins.
4. Middle landform: occupying dozens to hundreds of square kilometers, such as independent peaks.
5. Small landforms: occupying several square kilometers to dozens of square kilometers, such as valleys, river valleys and crescent dunes.
6. Micro-landforms: from a few square centimeters to a few square kilometers, it is the smallest unit of complex landforms, such as depressions and shallow ditches.
Micro-landforms and small landforms can be called separated forms, while overall landforms, giant landforms, large landforms and medium landforms can be called compound forms, which are composed of separated forms. In fact, there are no strictly defined boundaries between various landforms.
Topography refers to the ups and downs and steepness of the surface morphology. Include the absolute height and relative height difference or slope of the surface morphology.
Terrain refers to the general name of the shape and landform of ground objects, specifically refers to the various ups and downs of fixed objects distributed above the surface, and the topography is not the same. The five main landforms are plains, plateaus, hills, basins and mountains. Except the plateau, the other four landforms have different degrees. These landforms are different from the first and second types. They are different from each other in the form of adjacency at the same level, and the meaning of adjacency itself is exclusive and inclusive.