Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Built Environment (hierarchy name)
4. Single Built Works (hierarchy name)
5. single built works (built environment)
6. [single built works by specific type]
7. [single built works by function]
8. hydraulic structures
9. [hydraulic structures by function]
10. dams (hydraulic structures)
11. [dams by construction]
12. earth dams

Anotations

Scope note:

Dam constructed of multiple types of soil material, such as clay, fine sand, rocks, and silt. The fill is zoned by systematic distribution of materials according to their strength and permeability characteristics, generally built over an impervious core. In cross section, the dam is divided into zones, with the central zone made of relatively impervious clay, and transition zones used to cover both faces and prevent piping through cracks.