This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Environmental Ocean Technology – Coastal Hazards Mitigation – Set 3”.
1. Groins constructed in series are called _______________
a) Jetties
b) Groin field
c) Berm
d) Groin notch
View Answer
Explanation: Groins are constructed with different materials depending upon the demography, cost of construction and availability of materials. Groins constructed in series are called groin fields that restrict the wind-driven propagation of sand.
2. _____________ guard against the permanent loss of sediment from the coastal system.
a) Terminal groins
b) Trapezoid groins
c) Boat jetties
d) Breakwalls
View Answer
Explanation: Terminal groins are protective structures prevent the permanent loss of sediment from the coastal sediment. Generally it is constructed at the down-drift side of the sediment transport system.
3. High-profile groins allow the waves to transport sand across the structure.
a) True
b) False
View Answer
Explanation: High-profile groins effectively block the tides and waves from transporting sand over the structure while low-profile groins let the waves and tides to transport sand across the structure, on the down-drift side.
4. Bulkheads are examples of _________________
a) shore-parallel structures
b) shore-perpendicular structures
c) revetments
d) wave hazards
View Answer
Explanation: Bulkheads, breakwalls and revetments are examples of shore-parallel structures that are constructed both onshore and offshore. These provide mitigation for long-term erosion, wave hazards and flood hazards.
5. _____________ can prevent the undermining of a sand dune.
a) Bulkhead
b) Onshore breakwall
c) Offshore breakwall
d) Revetment
View Answer
Explanation: Bulkheads are onshore parallel structures that are constructed of metal around homes. Houses have sand dunes on their boundaries to mitigate for coastal hazards, bulkheads constructed around prevent weakening of the sand dunes.
6. Revetments are _____________ structures.
a) circular
b) rectangular
c) sloped
d) layered
View Answer
Explanation: Revetments are sloped structures constructed of heavy material, that protect upland from erosion (wave- and scour- induced). The structure induces wave breaking and decreases wave runup.
7. The structure of a revetment is built in _________
a) increasing order of grain size
b) decreasing order of grain size
c) increasing layer thickness
d) decreasing layer thickness
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Explanation: The structure of revetments is considered on a stable slop with appropriate porosity. Impermeable filter fabric is placed on top of the soil and structure is built in layers of increasing grain size.
8. ____________ are constructed when reduction in wave heights and allowance for sand movement is desired.
a) Submerged breakwaters
b) Emerged breakwaters
c) Floating breakwaters
d) Hardened dunes
View Answer
Explanation: Submerged breakwaters are constructed when reduction in wave impact as well as allowance for sand movement is desired. There are three types of breakwaters namely submerged, emerged, and floating breakwaters.
9. _________________ is the process of construction solid core in the center of a man-made dune system.
a) Dune hardening
b) Dune runup
c) Layering
d) Scouring
View Answer
Explanation: Dune hardening is the process of constructing a solid core in the center of a man made dune system. The hardened dune acts as a shore-parallel barrier to high intensity storms in coastal areas.
10. Viscous drag mats are also called ______________
a) breakwalls
b) geotubes
c) biodegradable structures
d) artificial seaweeds
View Answer
Explanation: Viscous drag mats are constructed of buoyant, high-strength plastic strands woven into anchored mats placed on the seabed. These are also known as artificial seaweeds that protect against strong currents near the shore.
11. Viscous drag mats can reduce scour around submerged pipelines.
a) True
b) False
View Answer
Explanation: Viscous drag mats, also known as artificial seaweeds work extremely well in reducing scour around submerged pipelines and the bottom of drilling rigs. They however provide limited protection in low wave energy coastal environments.
12. Geotubes retain _______________ while allow _____________ to percolate through.
a) water, sand
b) gravel, sand
c) sand, water
d) gravel, water
View Answer
Explanation: Geotubes are porous textile tubes that retain sand and allow water to percolate through, leveraging the effective mitigation of various shore protection structures. Geotubes are not protection structures themselves.
13. By careful management of ______________ resources, long- and short-term erosion can be maintained and reduced over time.
a) water
b) material
c) sand
d) fossil fuel
View Answer
Explanation: By carefully managing our sand resources long- and short-term erosion can be maintained along with other coastal hazards. Most of the coastal resource management efforts are therefore aimed at insuring adequate distribution of sand along the coastline.
14. Forced sand bypassing involves use of _______________
a) mechanical methods
b) biological methods
c) chemical methods
d) beach scrapping
View Answer
Explanation: Forced sand bypassing involves the use of mechanical methods such as hauling and mining to evenly distribute the sand along coast. In this way the sand is moved around a barrier or across a pump.
15. Beach scrapping is a technique to move ________________
a) sand dunes
b) small amount of sand
c) floaters/ buoys
d) impediments
View Answer
Explanation: Beach scrapping involves moving small volumes of sand that accumulate in the intertidal zone (from the low water line at low tide) of a coastline that experiences frequent currents.
Sanfoundry Global Education & Learning Series – Marine Biotechnology.
To practice all areas of Marine Biotechnology, here is complete set of 1000+ Multiple Choice Questions and Answers.
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