Physical protection measures
Physical protection measures include but are not limited to, integrated land use planning, drainage, erosion protection, vegetation and ground improvement techniques, barriers (earth ramparts, artificially elevated land, anchoring systems, retaining structures), and offshore or onshore walls to reduce the energy or the loads induced by geohazards (e.g. landslide, rock slide, tsunami, floods).
Buildings need to be designed (and placed in locations) to withstand the impact forces of geohazards and to provide safe dwellings for people. Land can also be elevated to ensure that buildings are above a critical height, for example, to protect against tsunami danger.
Physical protection barriers may be used to stop or delay the impact of the geohazards, reduce the maximum reach of its impact, or dissipate the energy of the geohazards. On land, such barriers may include "soft" structures in the form of dikes or embankments, or "hard" structures like vertical concrete or stone block wall. Offshore, the structures could be jetties, moles or breakwaters, or even submerged embankments. Any measures need to be part of a community's master plan and subjected to analyses to assess and circumvent any negative environmental impact.
If a well-functioning and efficient warning system is in place, warning and escape are probably the best way to prevent loss of life due to geohazards. Developing functional networks of escape routes and safe places could include a number of different measures, strongly dependent on the local context.
Area, village, or city analyses should provide a maximum tolerable distance from buildings and activities to a safe place, and assess how to achieve this maximum distance. Distances between buildings and safe areas could be shortened by reducing the escape routes, or by establishing new safe areas as artificial escape hills and safe buildings that are accessible to people at large.
ICG will contribute to the development of templates for communities to assess and select physical protection measures. The above descriptions are only examples of possible measures. A multitude of considerations needs to be taken into account when preparing templates that are to be implemented in real-life cases. Local conditions are determinant in many cases. A "how to" and "do's and don't's" guideline will be prepared.
A recommendation for "best practice" for physical protection measures was prepared towards the end of the second five-year period of ICG, in the EU-sponsored FP7 Project, SafeLand.