A Study on Coastal Processes and Landforms

1. INTRODUCTION

The coastal areas are an interface between the lithosphere and hydrosphere. Coastal ecosystems are great habitats for endless amount of vegetation. Coastal areas are one of a kind and run of the mill land masses flanked by the seas and oceans.

The oceans greatly affect the Earth and its climate. Coastal zones are not static but rather unique conditions. They include change of mass and energy through waves and flows. Shorelines are constantly exposed to both continental and maritime procedures. Waves, tides and flows are exceptionally powerful geomorphic specialists. The erosional and depositional work of the sea waves can make numerous stupendous landscapes along the outskirts of the mainlands. Contemplating the coastal landforms are fascinating perspectives with regards to geomorphology.

When we talk about the coastal zone, the principal thing to think about is the coastline. A Coastline speaks to the limit between the continental land masses and the maritime water masses. A Coastal zone is the progress zone between earthbound habitat and the marine habitat. It is the interface among land and maritime water. Coastal belts might be wide or slender. They likewise differ with reference to their slant, shoreline profile, shake types, climate and vegetation. The climate of a coast is essentially constrained by the land and sea breezes. The climate is likewise constrained by the stickiness of produced by the marine waters. In the event that we take a gander at the profile of a sea coast , we can see a shoreline having a place with the landward side. The width of this shore may differ from spot to put. Along the coast, there are two particular zones detectable in multi day. They are the high tide line and the low tide line. The normal water level between the high tide and the low tide is the mean sea level. At the point when there is an extreme storm, the water line may come well over the high tide line in a shoreline. Coastal belts are additionally separated into three divisions as: ► Backshore region ► Foreshore region and ► Offshore region The backshore is inland of the between tidal zone and is normally over the impact of the waves. The near shore (now and then called the breaker zone) is the place the waves break; the seaward zone is farther to sea and is past the impact of the waves.

The Backshore region speaks to the shoreline zone beginning from the farthest point of storm wave, above high tide shoreline. This zone incorporates a wave cut terrace and a storm scarp. Shoreline is the essential region where a great part of the geological procedures occurring. Shoreline is the inclining part of the coast normally existing underneath the berms. This region is halfway uncovered by the discharge of waves. Swash zone is where the waves discharge

Berms are sediments stored over this region by swash and discharge activities of waves. Shoreline Berms exist over the wave-cut terrace. A berm is a seat like component containing sands. The landward side of the berm contains a belt of sand ridges. There are summer and winter berms. Aggregation of sand during summer shapes the mid-year berms. This is the Sun-washing zone with wave stored sediments. A Sea bluff may exit above wave-cut terrace.

The Foreshore region is the region between high tide water zone and low tide water zone. It incorporates a Beach face and a shoreline terrace. The surf zone exists above shoreline terrace. Toward the finish of the surf zone, the breaker zone begins. The foreshore might be a sandy foreshore, shingle foreshore, sloppy foreshore or a rough foreshore. The Breaker zone is where the approaching waves turned out to be precarious, raising to a pinnacle and separating. Breaker zone is a significant zone inside which waves moving toward the coastline start breaking. The breaker zone is additionally part of the surf zone. The Surf zone is a significant zone where the waves of interpretation happen after the waves break. Sand Bars are made, inside the waters, along the zone of wave breakers. The moving water masses shape the abundance amounts of debris sediments into arranged and layered stores. Long shore flows happen in this zone, which run parallel to the coastline.

The Offshore region speaks to the zone of maritime shallow water zone broadening completely inside the continental rack. It starts after breaker zone. At the base, it incorporates the long shore troughs and long shore bars.

When we go to a coastal region, we hear the nonstop sounds of the waves and their developments on the coastal belts. Waves are the powerful powers following up on the coastal zones. They reference to reality. Waves can do the two procedures. are extremely powerful systems with productive and dangerous. Waves get their energy from the breeze. As the breeze blows over the surface of the sea, it makes erosion. This frictional drag causes water particles to turn and their energy is moved forward as a wave. While the water pushes ahead, the water particles come back to their unique position. As a wave achieves the shallow water region, grating between the sea bed and the base of the wave makes it back off. Its shape turns out to be more curved as opposed to roundabout. The highest point of the wave, At the point when the wave breaks, the water surges up towards the raised pieces of the shoreline. This development is called as the swash. At that point it descends gradually in reverse. The development of a similar water, withdraw the shoreline, is called as the discharge.

There are three primary factors that influence the quality of a wave: 1. The quality and speed of the breeze. 2. The term of the breeze - this is the period of time for which the breeze has blown. 3. The get - this is the separation over which the breeze has blown. The ascent and fall of oscillatory waves in a vast water reflects the round movement of water particles. Swells are smooth, adjusted waves that movement outward from a storm focus. Sea waves are ordered into two kinds based on the profundity of maritime waters. They are : ► Oscillatory waves (these are the waves in profound water) and ► Translatory waves (these are the waves in shallow water). Waves are a standout amongst the most significant powers in forming the coastline. In view of their activities, two primary kinds of waves have been perceived. They are: 1. constructive waves and 2. destructive waves. Valuable waves are low energy waves that will in general touch base at the coast at a rate of under 8 waves for each moment. Helpful waves are little in tallness. They have a solid swash and a frail discharge. This implies useful waves will in general store material and develop a shoreline. Ruinous waves have a lot higher energy and will in general touch base at the coast at a rate of more than every moment. They are a lot bigger in tallness than valuable waves, frequently having been brought about by solid breezes and a huge bring. Dangerous waves have a frail swash yet a solid discharge so they disintegrate the shoreline by pulling sand and shingle down the shoreline as water comes back to Seismic sea Waves called Tsunami are one more power of oceans. A wave starts from the profound oceans and achieves the mainlands as massive solid waves. These are annihilating water wave produced by an undersea tremor.

Oceans are assortments of dynamic water masses. Sea waves are powerful geological specialists, acting from the shorelines to the coastal belts. Vertical and level developments of water keep on happening both at the surface and at profundity consistently. Over some stretch of time, wave activity in the surf zone will in general plane off the whole zone. This procedure is known as marine planation. This is a moderate procedure. There are such a significant number of different highlights shaped along the coastline because of different hydrodynamic activities of waves on the sea side and streamlined activities wind on the landside. Sea waves can disintegrate, transport and store the marine sediments dependent on different factors and procedures. Disintegration, transportation and testimony occur on the two sides of the shoreline. Coastal rocks like bluffs are likewise exposed to wave activities. Sea bluffs are interesting highlights found in certain spots.

The consolidated impact of waves, flows and tides result in an assortment of gradational procedures acting in the coastal zone. Coastal disintegration occurs as: ► hydraulic activity, ► corrosion (or) scraped spot, ► attrition, ► corrosion (or) arrangement and ► water weight. Pressure driven activity is the effect of moving water on the coastal rocks. It is brought about by the immediate effect of waves on the coasts. Huge weights can work as water and air are compacted into the stone breaks. The most significant one is scraped area. Scraped area (or) consumption is a sort of disintegration occurring with the assistance of apparatuses of disintegration. In water suspension coarse sands, stones, cobbles and rocks are utilized by the waves to assault the coastal rocks. Steady loss is a procedure coastal disintegration. Corrosion (or) Solution is the chemical change of rocks which are solvent and because of their contact with the seawater. Arrangement is locally significant particularly where dissolvable shake is uncovered along the shore. Because of intermittent wetting and drying a wide scope of chemical procedures occur on the coastal rocks which lead to both physical breaking down and chemical decomposition. Number of coastal highlights is framed by the activity of these sea waves. Coastal sediments are liable to various scenes of disintegration, transportation and affidavit, however a net seaward transport happens on a worldwide scale. The profound sea floor turns into the resting place for earthbound sediment disintegrated from the land. Shoreline floating transports sand grains along the shoreline as waves strike the shore at a diagonal edge. Sediment is conveyed landward when water surges over the shoreline as swash. Sediment is conveyed back toward the sea as discharge. The nonstop up surge and discharge conveys sand in a crisscross like development along the shore.

Landforms of coastal regions are characterized into two noteworthy gatherings as erosional landforms and depositional landforms. The eminent erosional landforms of the coasts are: ► Sea bluffs ► Sea caverns ► Sea Arches ► Sea stacks ► Wave-cut scores ► Wave-manufactured terraces. The most far reaching landforms of erosional coasts are sea precipices. Wave disintegration undermines soak shorelines making coastal precipices. A sea bluff is a vertical cliff made by waves smashing straightforwardly on a steeply slanted slant. These exceptionally steep to vertical bedrock bluffs extend from just a couple of meters high to many meters above sea level. Their vertical nature is the consequence of wave-actuated disintegration close sea level and the resulting breakdown of rocks at higher rise. Pressure driven activity, scraped spot, and chemical arrangement all work to cut a score at the high water level close to the base of the precipice. Consistent

caverns are noticeable headlands where wave refraction assaults the shore. A sea curve frames when sea caverns converge from inverse sides of a headland. In the event that the curve crumples, a mainstay of shake stays behind as a sea stack. Seaward of the withdrawing precipices, wave disintegration frames an expansive erosional stage called a wave-cut seat or wave-cut stage. After the steady granulating and battering, disintegrated material is transported to neighboring straights to move toward becoming beaches or seaward stopping as a wave-fabricated terrace.

Dissolved sediments along the coasts are transported as floats. Longshore Drift is one significant system. Longshore Drift are powerful geomorphic operators. They can dissolve, transport and store coastal sediments. Longshore float dissolves and stores sand masses persistently along the shoreline. The sand that is expelled from one point along the shoreline is supplanted by sand dissolved from some different zones. Longshore float comprises of the transportation of sediments like mud, residue, sand and shingle. The float occurs along a coast at an edge to the shoreline. This is essentially reliant on the overarching wind course, swash and discharge. This procedure happens in the littoral zone, and in or near the surf zone. The procedure is otherwise called longshore transport or littoral float. Littoral transport is the term utilized for the transport of non-durable sediments, for example principally sand, along the foreshore and the shoreface because of the activity of the breaking waves and the longshore current.

Tides are standard coastal procedures. About every single marine coastline experience the cadenced ascent and fall of sea level called tides. The day by day wavering in sea level is a result of the gravitational fascination of the Moon and Sun on Earth's oceans and it fluctuates in degree around the world. Tidal activity is a significant power behind coastal disintegration and testimony as the shoreline relocates landward and seaward. Tidal Currents are in charge of mechanical arranging of sediments under the water. During a high tide water moves landward as a flood flow. During low tide water subsides seaward as an ebb and flow. The prominent depositional coastal landforms are: ► Tombolo ► Barrier islands ► Mud Flats.

A shoreline is a territory of sediment collection. They are presented to wave activity along the coast. Beaches morphology changes from season to season. There are two fundamental shoreline types. One is called as dissipative shoreline and the other one is called as intelligent shoreline. Together with the halfway sorts, there are six noteworthy microtidal shoreline types. The intelligent shoreline happens when conditions are quiet or potentially the sediment is coarse. There is no surf zone. The waves flow upon the intelligent beaches. It reflects a noteworthy piece of the approaching wave. At the point when greater waves cut back a shoreline and spread out its sediments to shape a surf zone, the intelligent beaches make a series of halfway kinds. At the point when wave activity is exceptionally solid and additionally sediment molecule size is fine, the dissipative shoreline type is made. This sort has a level and maximally disintegrated shoreline. The sediments are put away in a wide surf zone that may have different sandbanks parallel to the shoreline. The halfway kinds are described by high transient variability, sand stockpiling both on the shoreline and in the surf zone and sandbanks and troughs. Beaches are grouped into three classifications as high, low and moderate energy beaches. Normally, high energy conditions win during summer months. The wave heights are normally expected to increment after the beginning of monsoons. These produce significant changes in the shoreline morphology.

A sand spit is a standout amongst the most widely recognized coastal landforms. A sand spit is a linear aggregation of sediment that is joined to land toward one side. Sand conveyed parallel to shore by longshore float may in the end stretch out over a straight or between headlands particularly where water is moderately quiet. Spits are ordinarily stretched, slender highlights worked to a few meters high above sea level by the activity of wind and waves. make the sediment gather, because of the loss of capacity to transport the sediments by water. The term bar alludes to a long tight sand dike shaped by wave activity. Littoral float from an island may shape a tombolo, which is a sand bar interfacing the island with the mainland. Spits can stretch out over the mouth of a straight, however wave activity is generally sufficiently able to wash sand out to sea or be kept in the embayment. They may bend into the narrows or stretch crosswise over associating with the opposite side as a baymouth bar. At the point when the cove is deterred by a bar it turns into a tidal pond. Basic spits comprise of restricted finger of sand with a solitary rise edge that lengthens in the downdrift heading. Twofold spits can frame if float transports sand in two ways crosswise over and bay, or if a baymouth boundary is cut by a tidal channel. Wave refraction toward the finish of a spit will transport sand to shape a recurved spit. Complex spits structure when an abundant supply of sediment is transported by both the sea and narrows flows. Different lines of hills can be shaped by wind transport of sand over the spit.

A tombolo is a depositional landform in which an island is connected to the mainland by a thin real estate parcel, for example, a spit or bar. Tombolos are shaped by wave refraction. Coastlines paralleled by offshore limited portions of sand rises, salt bogs and beaches are known as hindrance islands. An assortment of hindrance related highlights could be seen along the shoreline.

Geological Oceanography is the subject which manages the investigation of the maritime covering, continental edges, sea base help, sea bowls, maritime edges, break valleys, Island bends, sea water, marine sedimentation, topography of corals, shoreline structures and procedures, water masses , components influencing sea course, waves and flows, tides and energy coastal disintegration and floating of sediments, sea level changes, depositional conditions and marine stores. Geological oceanography is additionally worried about the event of oil-traps and energy sources, structural developments submerged emissions, mud volcanoes and effects of tidal waves. Chemical Oceanography is the investigation of everything about the chemistry of the sea , conveyance and elements of the components, isotopes, atoms and particles. Remote ocean biology and marine contamination are likewise the other two noteworthy significant areas of concentrate under biological oceanography. Spilotro, G. (2013). Shoreline variations and coastal dynamics: A spaceetime data analysis of the Jonian littoral, Italy. Estuarine, Coastal and Shelf Science. 129: pp. 124-135. 2. Almonacid-Caballer, J., Sánchez-García, E., Pardo-Pascual, J.E., Balaguer-Beser, A.A., Palomar-Vázquez, J. (2016). Evaluation of annual mean shoreline position deduced from Landsat imagery as a mid-term coastal evolution indicator. Marine Geology. 372: pp. 79-88. 3. Aristizábal, O., Betancur, J., Vásquez, C. (2015). Erosión y sedimentación de la línea de costa entre Turbo y Necoclí, Golfo de Urabá. Undergraduate Thesis, Universidad EAFIT, Medellín, Colombia. 4. Bernal, G., Montoya, L.J., Garizábal, C., Toro, M. (2015). La complejidad de la dimensión física en la problemática costeras del Golfo de Urabá, Colombia. Gestión y Ambiente. 8 (1): pp. 123-135. 5. Botero, L., Mancera, J.E. (2016). Síntesis de los cambios de origen antrópico ocurridos en los últimos 40 años en la Ciénaga de Santa Marta (Colombia). Revista Academia Colombiana de Ciencias. 20: pp. 465-474. 6. Briceño, L.A. & Vernette, G. (2015). Manifestaciones del diapirismo de lodo en el margen colombiano del Caribe. Geofísica Colombiana. 1: pp. 21-30. 7. Burkett, V. & Davidson, M. (2014). Coastal Impacts, Adaptation, and Vulnerabilities: A Technical Input to the 2012 National Climate Assessment. Island Press, London (England). 8. Campbell, C.J. (2016). The Santa Marta wrench fault of Colombia and its regional setting. In: Saunders, J.B. (Editors.). Transactions of the Fourth Caribbean.

M.A. in Geography, MDU, Rohtak