الوصف الكامل

Sandy beaches dominate most temperate and tropical shorelines, including the coasts of the Sultanate of Oman. The focus of much human activity, both economic and recreational, they are dynamic environments formed and continually modified by the interactions between three elements: sand supply, waves and tidal energy. Sand can be supplied from terrestrial and marine sources and is then sorted by waves and tides, so that beaches are in dynamic equilibrium between erosional states following storms and accretional states following calm weather. This dynamic equilibrium is a critical part of natural coastal defence against storms; wave energy is neutralized in moving sand off- and onshore. Beaches are also usually characterized by longshore sand transport driven by oblique wave approach. Longshore transport is easily disrupted by coastal engineering structures. Sea level rise associated with climate change is also a factor impinging on sandy coasts worldwide. Al Batinah coast, about 200 km in length, is heavily settled. One of the most fertile areas in Oman, it has a shoreline made up more than 90% of sandy beaches. Al Batinah beaches are mesotidal, tide dominated with low wave energy and limited littoral drift of less than 100,000 m³ per year. All beaches have reflective upper shores and broad tide-dominated terraces on their lower shores. These vary in detail from place to place and are being continuously modified by the longshore transport and wave-driven movement of sand. There is a split at Widam with longshore drift eastwards east of this point and westwards west of it, probably coupled to broader circulation in the Gulf of Oman. Al Batinah coastal plain has been experiencing rapid development over the past three decades. Residential housing, industrial, agricultural and fishing activities have been concentrated along the coast. Infrastructure, including roads, corniches, markets, mosques and fishing harbors are also constructed along the coast. Thirteen recharge dams have been built on the major wadis in Al Batinah and adjacent areas. The net effect of the dams is the reduction of terrestrial sediments supplied to the shore. The corollary of the coastal structures and the recharge dams is potential changes in the longshore sand transport as well as accretion and erosion patterns along Al Batinah coast. Erosion of some of the Al Batinah beaches in recent decades has prompted several studies and requests for information and advice. This report summarizes the findings of one such study, the most broad-based and interdisciplinary investigation in this area to date.