Which concept indicates a legal rights transfer distinct from public appropriation?

The concept that indicates a legal rights transfer distinct from public appropriation is the conveyance of property. This process involves the transfer of ownership rights of real property from one party to another through a formal legal process, typically via a deed. Conveyance encompasses the procedures and legal frameworks required to effectuate a change in property ownership.

Easement by necessity refers to a specific right allowing landowners to access their property through a neighbor's land when no other access is available. While it does involve a legal right, it differs from outright property ownership transfer.

Riparian rights concern the rights of landowners whose properties are adjacent to water bodies, typically focusing on the use of water, but not involving the transfer of property ownership.

Adverse possession is a legal doctrine that allows a person to claim ownership of land under certain conditions, such as continuous and uninterrupted use without the permission of the original owner. While it can result in a form of property transfer, it operates under specific circumstances rather than a standard conveyance process.

In summary, while each of the concepts has its own implications in property law, the conveyance of property is distinctly characterized as the direct transfer of ownership rights, separate from the issues of public appropriation and other property rights mechanisms.