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Environmental Engineering for Coastal Shore Protection


Quiz Questions

1.Beach berms are built naturally by waves to about the highest elevation reached by average storm waves. When storm waves erode the berm and carry the sand off shore, the protective value of the berm is reduced and large waves can overtop the berm. The width of the berm at the time of a storm thus influences the amount of damage a storm can inflict.
True
False
2. Hard corals (Scleractinians) are more sensitive than soft corals (Octocoralians) because they are not as capable of cleansing themselves of heavy sediment loads and are easily smothered.
True
False
3.The schematic diagram of storm wave attack on beach and dune is illustrated in ____________________.
Figure 4-2
Figure 4-3
4.Placement of equipment such as dredge anchors and pipelines can damage environmentally sensitive habitats such as coral reefs, sea grass beds and dunes. Damage to coral reefs has been caused by dragging of anchors or other equipment across a reef.
True
False
5.Sediments on most beaches range from fine sands to cobbles. The size and character of sediments and the slope of the beach are related to the natural forces to which the beach is exposed and the type of sediment available on the coast. The beach sediments may be in equilibrium due to the prevailing physical forces, or they may be eroding or accreting. When material is newly deposited on a high-energy beach, it modifies the beach sand/water interface and generally sand grain-size distribution, and may increase the suspended sediments of the adjacent near shore waters depending on the type and particle size of sediments deposited.
True
False
6.Species comprising marine bottom communities on most high-energy coastal beaches are adapted to periodic changes related to the natural erosion and accretion cycles and storms. Organisms adapted to unstable near shore bottom conditions tend to tolerate perturbations better than those in more stable offshore environments.
True
False
7.Figure 4-5 represents the _____________________.
Reef fauna near outer edge of second reef off Golden Beach, Florida
Nesting sea turtle
8. ______________ may have vertical, curved, stepped, or sloping faces. Although they protect the upland, they often create a local problem. Downward forces of water, produced by waves striking the wall, can rapidly remove sand from in front of the wall.
Seawalls
Groins
9.Steel sheet pile bulkhead is illustrated in __________________.
Figure 5-1
Figure 5-2
10._______________ armors the existing slope face of a dune or embankment. It is usually composed of one or more layers of quarry stone or precast concrete armor units, with a filter layer overlaying a graded soil slope. Revetments are of little benefit if placed at the toe of a marginally stable slope since they are usually only a protective armor and not a retaining structure.
Jetties
Revetment
11.Quarry stone revetment is illustrated in _____________.
Figure 5-3
Figure 5-4
12.Bulkheads and revetments can reduce the area of the intertidal zone and eliminate the important beach or marsh habitat between the aquatic and upland environment. The result can be a loss of spawning, nesting, breeding, feeding, and nursery habitat for some species.
True
False
13.Concrete combination stepped and curved-face seawall with public access points is illustrated in ______________.
Figure 5-4
Figure 5-5
14.Jetties are structures used at inlets to stabilize the position of the navigation channel, to shield vessels from wave forces, and to control the movement of sand along the adjacent beaches so as to minimize the movement of sand into the channel. The sand transported into an inlet will interfere with navigation depth. Because of the long shore transport reversals common at many sites, jetties are often required on both sides of the inlet to achieve complete channel protection. Jetties are built from a variety of materials-timber, steel, concrete and quarry stone.
True
False
15.Breakwaters are wave energy barriers designed to protect any landform or water area behind them from the direct assault of waves. However, because of the higher cost of these offshore structures as compared to onshore structures (e.g. seawalls), breakwaters have been mainly used for harbor protection and navigational purposes.
True
False
16.The erosion and accretion patterns in association with detached and attached breakwaters are illustrated in _________.
Figure 5-7
Figure 5-8
17.General shoreline changes associated with single or multiple groins is represented in _________________.
Figure 5-10
Figure 5-11
18.Salt marsh plants rely heavily on exposure to direct sunlight and will not grow in shaded areas. Therefore, any overstory of woody vegetation present at a site should be cleared above the planting area and landward to a distance of 3 to 5 meters (10 to 15 feet).
True
False
19.Typical seagrass and generalized method of making transplant unit is represented in _________________.
Figure 6-4
Figure 6-5
20.The suitability index curve for substrate type for juvenile Atlantic croakers Habitat Suitability Index model is represented in _____________.
Figure 7-7
Figure 7-8