![]() ![]() California’s coastal harbors can be divided into three general groups based on their long-term annual dredging volumes, which range from three harbors that have never been dredged to the Channel Islands Harbor where nearly a million cubic yards is removed on average annually. Half Moon Bay, Moss Landing, Monterey, Redondo-King and Alamitos Bay). Santa Cruz, Oceanside, Santa Barbara, Ventura, and Channel Islands harbors) while other harbors require little or no annual dredging (e.g. California’s littoral drift rates and directions are now well known and understood, however, and have led to the need to perform annual dredging at many of these harbors as a result of their locations (e.g. bay, estuary, or lagoon) that could be the basis of an improved port or harbor. Rather, they were built where a need existed, where there was a history of boat anchorage, or where there was a natural feature (e.g. Almost all of California’s ports and harbors were constructed without any knowledge or consideration of littoral drift directions and rates and potential future dredging issues. California has 26 individual coastal ports and harbors, ranging from the huge sprawling container ports of Los Angeles and Long Beach to small fishing ports like Noyo Harbor and Bodega Bay. Each of these industries or activities requires either a port or harbor. As such, natural forces in the years after implementation provided a significant contribution to the growth in dune volume and related safety against flooding.Ĭalifornia is a major shipping point for exports and imports across the Pacific Basin, has large commercial and recreational fisheries, and an abundance of marine recreational boaters. Our results show that the Hondsbossche Dunes nourishment, built with a natural slope and wide beach, created a positive sediment balance in the dune for a prolonged period after placement. Simultaneously, the dune volume has increased and the dune foot migrated seaward at the entire nourished site, regardless of whether the subaqueous profile gained or lost sediment. ![]() The initially wide beaches (i.e., up to 225 m) are reduced to about 100 m-wide. ![]() The slope of the surfzone is adjusted within two winters to a similar slope. The man-made cross-shore beach profile rapidly mimics the characteristics of adjacent beaches. However, over the five-year period, net volume losses from the project area were less than 5% of the initial nourished sand volume. A significant coastline curvature is created by the nourishment leading to erosion in the central 7 km bordered by zones with accretion. This paper presents the evolution of this newly created sandy beach system in the first 5 years after implementation based on bathymetric and topographic surveys, acquired every three to six months. The nourishment was built to replace the flood protection function of an old sea-dike while creating additional space for nature and recreation. The Hondsbossche Dunes project is a combined shoreface, beach, and dune nourishment of 35 million m3 sand. These nourishments can be implemented at sandy beach systems, but can also be used to reinforce gray coastal infrastructure (e.g., dams, dikes, seawalls). Sandy nourishments can provide additional sediment to the coastal system to maintain its recreational or safety function under rising sea levels. ![]()
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