1. 하구및 연안생태Coastal management
2015 년 가을학기

2. Estuarine geomorphology and physical oceanography
Circulation patterns
Stratification
Mixing and flushing
Time scale; when hydrodynamic changes occur quickly relative to biological, geological and chemical transformations
Dominant controlling factors for estuarine ecological processes
Organizing of estuary
Classification of estuary
Physical characteristics of estuary

3. Glaciation cycles LGM; 15,000 yr Current level in 5000 yr
Estuaries are common in broader coast line: 80~90% east coast of US; 10~20 % in west coast.
During glaciation period, estuaries are rare !!
Because sea level is in continental shelf
During last 1 My, only 10~20% of the time presented in current conditions
current estuaries  filled with sediment  quickly disappear; for geological point of view “extremely short !”
In current condition. Takes 9,500 yr to fill up
Fill-up didn’t happen, because, sea level rise + erosion of sediment

4. From lagoons to deltas Geological development of estuary
Glaciation cycling
Sediment supply
Climate variability
Regional and local geology
Marine energy input; wave + tides
Lagoons : marine wave actions; behind barrier island; sand sized sediments; S. Texas
Deltas: produced by river processes
Protrude into a receiving basin
Fine grained silt sediments
Estuarine lagoon, estuaries, estuarine deltas ;wave energy + river input combinations

5. From lagoons to deltas
Davis (1973) continuum of estuarine types : from lagoons to delta.
Lagoons : marine wave actions; behind barrier island; sand sized sediments; S. Texas
Deltas: produced by river processes
Protrude into a receiving basin
Fine grained silt sediments
Estuarine lagoon, estuaries, estuarine deltas ;wave energy + river input combinations

6. Estuary settings
An estuary is a partially enclosed body of water formed where freshwater from rivers and streams flows into the oceans, mixing with the seawater.
Although influenced by tides, estuaries are protected from the full force of the ocean waves, winds and storms by reefs, barrier islands or fingers of land, mud, and sand
Can be bays, lagoons, harbors, and inlets or sounds.

7. Estuary definition
“estuary” is of sixteenth century origin, derived from the Latin word aestuarium meaning marsh or channel.
An estuary is a semienclosed coastal body of water that has free connection with the open sea and within which seawater is measurably diluted with freshwater derived from land drainage (Pritchard 1963).
연안 환경에 속하는 수역으로 강물이 바다로 유입하고 강의 어귀는 만의 형태를 이루어 해수가 조석작용에 의해 혼합 희석됨으로써 광염성 생물 종들이 서식할 수 있는 곳.

8. Estuary definition Fairbridge (1980)
an estuary is an inlet of the sea reaching into a river valley as far as the upper limit of tidal rise, usually being divisible into three sectors: a) a marine or lower estuary, in free connections with the open sea; b) a middle estuary subject to strong salt and freshwater mixing; and c) an upper or fluvial estuary, characterized by freshwater but subject to strong tidal action.
The limits between these sectors are variable and subject to constant changes in the river discharges

9. Pritchard (1963) and Fairbridge (1980)
For Pritchard it is the upstream limit of salt penetration
for Fairbridge it is the upstream limit of tidal penetration, which in an un-modified estuary will always be further inland.

10. A new defnition (Day et al.1987)
An estuarine system is a coastal indentation that has a restricted connection to the ocean and remains open at least intermittently.
tidal river zone
mixing zone
Near shore turbid zone; between mixing zone and the seaward edge of the tidal plume at full ebb tide
 included adjacent coastal waters

11. Dynamic boundaries Boundaries change position continuously
Tidal cycles; spring neap tides
Annual cycles
Geologic time scale
Freshwater discharge
some estuaries does nto have all the zones
Cancun bay; no tidal river
Amazon river; no mixing zone