Development of sustainable solutions to sand encroachment on roads in Kuwait using numerical modeling

Abstract

Site reconnaissance of the threat of sand encroachment in Kuwait outlined major roads that were closed or partially closed for long periods of the year. These roads are AlSubia, AlWafra–Mena Abdallah, and AlWafra-AlZoor. Site surveys of the affected roads were undertaken to investigate the types and thicknesses of accumulated sand layers that were exposed to wind erosion. Soil samples were also collected to assess the particle size distribution. Wind data over the past 35 years were analyzed, which indicated that the prevailing direction is northwest with an average speed of 6–8 m/s. A preliminary concept design based on a composite system of natural and artificial elements was developed to be a sustainable protective system, which included double porous fences and green belts as major elements. Testing of the concept design model was performed in a virtual wind tunnel with different fence porosities and afforestation systems with the aid of the Autodesk Flow numerical model. Virtual wind tunnel results revealed that adopting 50% porosity led to the optimum wind reduction (≈75%), no turbulence area, and maximum sheltered area with no sand accumulation over the fences. The final design adopted was a composite made of artificial fences, green-belt trees, and gravel-stabilized areas, accompanied by removing the street barriers, achieving the aerodynamics concept to provide a long-term sustainable solution for the sand encroachment in those areas.