Please enable JavaScript.
Coggle requires JavaScript to display documents.
GLOBAL ELEVATION 11/5/26, Salinity Stratification in Estuaries, Gloabal…
GLOBAL ELEVATION 11/5/26
World's population
Over 33% percent lives within 100 km of the sea
Around 898 million people live in low elevation coastal areas (land areas up to 10 meters above sea level)
More than 70% of the world's megacities are located in coastal areas
Trade by sea or rivers
https://www.researchgate.net/profile/Barbara-Neumann/publication/273440105/figure/fig8/AS:341304543334417@1458384752849/LECZ-Population-in-the-year-2000-and-for-2030-2060-per-country-scenario-C-Population.png
Salinity Stratification in Estuaries
Salt Wedge: River Vol/Volume of Tides > 1
Freshwater will float on the denser ocean water without experiencing much mixing adn as a result, a wedge of oceaning saltwater is seen to intrude into the estuary
Highly Stratified: R/V = 0.1-1
Dreshwater movement in the upper layer against the stronger tidal current produces strong current shear at the interface = net upward transport of mass and salt known as entrainment
https://o.quizlet.com/rktdHEzdp.sOON5dgfCMlQ.jpg
Slightly Stratidied: R/V=0.005-0.1
Tidal current is now so strong that water movement becomes turbulent everywhere
Vertical salinity profiles show gradual salinity increase from the surface to the bottom, with a max in the ccert grad near the interface between two layers
Vertical well-mexed
: R/V < 0.005
Salinity increases towards the sea but does not vary with depth
Penetration of salt into the estuary is achieved entirely by turbulent diffusion against the mean flow
The distinction between upper and lower layer can no longer be made
Inverted Statification: R/V < 0
Estuarine water becomes more saline than the incoming high tide water, so the incoming water stays on top while the highly (hypersaline) saline estuarine water moves down and outward away
Salt-plug Estuary
Salt water and freshwater
Combination of a positive and a negative estuary
Salinity shows a maximum somewhere within the estuary at all depths ("salt plug")
Gloabal Coastal Ocean
Global Mean Sea Level (GMSL) rate
Philippines
Largest rates of 4.5-5 mm per year ovserved east of the islands Leyte and Samar, and Mindanao and along the south western coasts of the central and western visayas
Philippine Coastal Envt
Coastline among the longest in the world 36289 km
965 coastal municipalities and 25 coastal cities
60% of the population live within these coastal municipalities
CIRCULATION IN THE SURF ZONE
https://upload.wikimedia.org/wikipedia/commons/c/c1/Schematic_representation_of_the_shoreface_profile.png?utm_source=en.wikipedia.org&utm_campaign=index&utm_content=original
Longshore current: Zigzag movement of water in the surf zone
Zigzag pattern of sediment movement along a beach creating longshore transport
Longshore Transport: Longshore currents are caused by waves approaching shore at a small angle, moving water parallel to the shore
https://rwu.pressbooks.pub/app/uploads/sites/7/2017/08/figure13.2.1.png
Longshore drift - movement of water and sediment down a beach caused by waves coming in to shore at an angle
Rip Current - A rush of water that flows rapidly back to sea
https://isleofpalmsmagazine.com/wp-content/uploads/NOAA-rip-current-tidal-pattern-example-750x420.webp
Cavite Spit
Land mass is just compacted sediment that stabilized
Assignment: Use google earth too... check if over the years there are groids
