What should be employed to mitigate blast damages at a search area?

The most effective choice for mitigating blast damages at a search area is the use of revetments. Revetments are structures that provide protection from blasts by absorbing and dissipating the energy of an explosion. Commonly constructed from earth or other materials like sand and gravel, revetments are designed to redirect the force of a blast wave and protect both personnel and equipment in the vicinity.

Employing revetments can effectively reduce the impact of explosive forces, thus minimizing damage and injuries in the area. Their design can vary depending on the anticipated threat level and the specific environment in which they are used, which adds to their versatility as a protective measure.

The other options, while useful in certain contexts, do not provide the same level of protection as revetments against blast effects. Sandbags can offer some protection, but they are more effective for containing spills or providing temporary barriers rather than mitigating the force of an explosion. Concrete walls are strong but can be rigid and may not effectively absorb the energy from a blast. Barriers can help limit access and prevent unauthorized entry but do not offer substantial protection from the effects of blasts. Thus, revetments are the best choice for directly addressing the threat of explosion-related damages in a search area.