Principal geological hazards along the Arabian Gulf Coast

Abstract EN

This paper reviews the principal geological hazards that have been identified and investigated along the Arabian Gulf Coast of Saudi Arabia, and recommends further studies to establish remedial measures.

The three major hazards considered are the collapsing, swelling, and corrosive behavior of the sabkha environment: erosion, abrasion, and deposition prob- lems associated with moving sand and subsidence problems related to sinkholes are consi- dered.

Coastal sabkhas along the Arabian Gulf cover extensive and strategic areas.

Interaction of sabkha soil with groundwater forms salt crusts which show wide zonal variations in composi- tion.

Dissolution of water soluble salts by runoff waters and groundwater weakens the soil and may cause it to collapse under load.

Conversely, salt recrystallization in the crust may cause the soil to swell.

Salts also cause corrosive damage to concrete structures and road surfaces.

Both sand drift and sand dune movement associated with the Jafurah sand sea are perhaps the most important hazard along the Arabian Gulf Coast where the mean wind speed is the highest in Saudi Arabia.

This phenomenon, coupled with the abrasive action of sand, causes severe damages to engineering works.

Limestones and dolomites are the main rock types cropping out in the Eastern Region.

Sin- kholes are created as a result of the chemical leaching of these rock units by percolating waters.

Construction sites along the Arabian Gulf Coast have suffered from the hazards of subsidence associated with the sudden surface collapse of the soil and rock overlying these solution cavities.

Detailed hazard (or risk) maps are recommended to identify the location and magnitude of all potential geological hazards, and farther to suggest suitable remedial measures.

Formation of a technical advisory committee to assist the local Government in future planning is also suggested.