Coastal Processes: Understanding Coastal Dynamics and Environmental Challenges, Study notes of Earth Sciences

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Coastal Processes

• (^) It is the region where the land processes and the sea meet and interact.
• (^) It is constantly changing and is shaped by different natural and human processes.

COASTAL ZONE OR COAST

Knight’s Point, an example of a coastal area

• (^) Waves are undulations in water surface as a result of wind.
• (^) Wave action may result in erosion of rocks or the deposition of sediments along coasts.
• (^) Waves can be destructive or

WAVES AND WAVE ACTIONS

An example of wave action that can be tapped for recreation

Destructive waves

• (^) These are waves associated with high- energy conditions where seaward flow of waves (or backwash) overpowers landward flow (swash). An example of a destructive wave in action

• (^) Tides are the variations in the water level of oceans as a result of gravitational effects of moon and sun in relation to Earth.
• (^) Tides can be observed or predicted on a daily basis.

TIDES AND STORM SURGES

• (^) Storm surges are the production of exceptionally high levels of coastal water by strong onshore winds and low barometric pressures caused by storms.

• (^) Erosion refers to the process of removing sediments.
• (^) Coastal erosion involves processes causing debris and rock material along coasts to wear off and be carried away.
• (^) Accretion is the process of increasing the area of land along coasts as a result of deposition and sedimentation.
• (^) Submersion is when the sediment is submerged under water and eventually replaced back to its original location.

COASTAL EROSION, ACCRETION AND

SUBMERSION

• (^) Abrasion is a form of erosion on rocky shores resulting from waves hitting the coast or windblown sand hitting rocks.
• (^) Attrition is the breaking and wearing down of debris from cliffs and rocky shores because waves agitate the materials.

MAIN PROCESSES THAT CAUSE COASTAL

EROSION

• (^) Saltwater intrusion is the movement of seawater into coastal freshwater aquifers.
• (^) It is directly affected by the water supply, and thus, happens naturally to

SALTWATER INTRUSION

A visualization of saltwater intrusion

• (^) Freshwater extraction exceeds the natural recharge rate, particularly in densely populated coastal areas.
• (^) Improper land use and management.
• (^) Over-extraction of groundwater for crop irrigation on-going industrial processes.
• (^) Slow recharge due to low precipitation and warm temperatures

CAUSES OF SALTWATER INTRUSION

Coastal zone or coast is the region where the land processes and the sea meet and interact. 4 3 Coastal erosion is the wearing off of debris and rock materials along a coast. 5 Accretion is the deposition and sedimentation that may increase the land area of along coasts. 6

Tides are the variations in the water level of oceans. 7 3 Saltwater intrusion is the movement of seawater into coastal freshwater aquifers. 8 Storm surges are the production of exceptionally high levels of coastal water by strong onshore winds and low barometric pressures caused by storms. 9

HOW DOES OVERPUMPING LEAD TO SALT

INTRUSION?