Glossary

A

  • aboriginal – inhabiting or existing in a land from the earliest times or from before the arrival of colonists
  • Acadians – descendants of French colonists who settled in Acadie (a colony of New France in northeastern North America in what is now eastern Canada) during the 17th and 18th centuries; many Acadians were deported during the Grand Dérangement (“great expulsion”) to various American colonies and some migrated to present day Louisiana, where they developed what became known as Cajun culture
  • alluvial soil – soil deposited by water
  • Atchafalaya – combination of Choctaw words “hacha” and “falaya,” meaning “long river”
  • Atchafalaya Basin – largest river swamp in the U.S., containing almost one million acres of bottomland hardwoods, swamps, bayous and backwater lakes
  • Atchafalaya National Heritage Area – 14-parish region in south-central Louisiana designated by Congress in 2006 as an area with significant natural, cultural and historical resources

B

  • backswamp area – the section of a floodplain where deposits of fine silts and clays settle after a flood - Backswamps usually lie behind a stream's natural levees
  • backwater flooding – upstream flooding caused by a restriction or blocking of flow downstream
  • bald cypress – a deciduous North American conifer tree with exposed buttress roots and ball-shaped cones, typically growing in swamps and on water margins
  • barrier islands– an island that provides some protection from storm surge
  • bayou – a marshy outlet of a lake or river?
  • brackish water – water that has more salinity than fresh water, but not as much as seawater
  • bluff – a steep cliff, bank or point of high land that juts out next to a body of water
  • bluff lake – a type of lake that forms in areas between the bayou bank and the higher bank that runs along the edge of a river’s drainage area (ex. Spanish Lake)
  • bousillage – a mixture of clay earth and Spanish moss used in French Louisiana by colonists in the 18th to 19th centuries to help insulate buildings?

C

  • cfs (“Cubic feet per second”) – measurement for river flow – ex. Mississippi River’s average flow is 470,000 cfs
  • chenier – a beach ridge usually composed of sand-sized material resting on clay or mud – chenier is the Louisiana French term for the oak tree belts that mark the distribution of the ridges in the Mississippi Delta region
  • Chitimacha – American Indian tribe that still occupies some of its original land in areas of the Atchafalaya Basin, primarily on their reservation in St. Mary Parish
  • confluence – the junction or meeting of two rivers
  • convergence – a location where airflows or ocean currents meet
  • conveyance canal – a permanent waterway designed to convey stormwater runoff?
  • coulee – a gully or ravine usually dry or intermittent but becoming sizable during rainy weather
  • crevasse – a breach (break) in the embankment of a river or canal
  • crevasse splay channels – an alluvial outspread deposit formed where an overloaded stream breaks through a levee (artificial or natural) and deposits its material (often coarse-grained) on the floodplain
  • curvilinear – consisting of or bounded by curved lines
  • cypress knees – the cone-shaped exposed growths on the buttress roots of a bald cypress tree
  • cypress (old-growth) – Cypress trees predating the era of heavy harvesting that took place between 1870 and 1920

D

  • dam – a barrier constructed to hold back water and raise its level – the resulting reservoir is usually used in the generation of electricity or as a water supply
  • delta – a triangular tract of sediment deposited at the mouth of a river, typically where it diverges into several outlets
  • delta cycle – a dynamic process whereby a river deposits sediment at its outfall, growing a delta lobe and eventually, seeking a shorter path to the sea, abandons its previous course and associated delta
  • delta-building – the building of land from sediments deposited by the flow of a sediment-rich river as it enters an open bay
  • deltaic – pertaining to or like a delta
  • distributary – a branch of a river that does not return to the main stream after leaving it
  • dredge – to deepen (a waterway) with a machine that removes earth usually by buckets on an endless chain or a suction tube

E

  • escarpment – bluff-like shelf that divides an area into floodplain and prairie?
  • ecosystem – a biological community of interacting organisms and their physical environment
  • estuarine bay – a partly enclosed body of water along the coast where one or more streams or rivers enter and mix freshwater with seawater

F

  • flatboat – a cargo boat with a flat bottom for use in shallow water; this type of boat could only travel downstream and was usually taken apart and sold for lumber upon reaching its final destination
  • floodplain – an area of low-lying ground adjacent to a river, formed mainly of river sediments and subject to flooding
  • floodway/spillway – a channel or passage for floodwaters of a river
  • flood stage – the level at which a body of water’s surface has risen to a sufficient level to cause inundation of areas not normally covered by water

G

  • geomorphology – the study of the physical features of the surface of the earth and their relation to its geological structures
  • Gulf Intracoastal Waterway – the portion of the Intracoastal Waterway located along the Gulf Coast
  • gully – a trench that was originally worn in the earth by running water and through which water often runs after rains

H

  • headwaters – a tributary stream of a river close to or forming part of its source

K

  • keel-boat – a long, slender cargo riverboat propelled by oars and setting poles; could be maneuvered both downstream and upstream (though difficult to move in this direction)

L

  • Laurentide Ice Sheet – ended with last ice age about 11,700 years ago
  • levee – an embankment built to prevent the overflow of a river
  • lock – a short, confined section of a canal or other waterway in which the water level can be changed – used for raising and lowering vessels between two gates
  • loess – wind-blown silt

M

  • marsh – an area of low-lying land that is flooded in wet seasons or at high tide and typically remains waterlogged at all times
  • mast – the edible vegetative or reproductive part produced by woody species of plants (ex. trees and shrubs) that wildlife species and some domestic animals consume
  • meander – a bend in a river – a meander forms when moving water in a stream erodes the outer banks and widens its valley – the inner part of the river has less energy and deposits silt – this process results in a snaking pattern
  • Mississippi River – the largest river in the U.S.

N

  • natural levee – a ridge of sediment deposited naturally alongside a river by overflowing water

O

  • oxbow lake – a horse-shoe-shaped bend formed when a meander of a river gets cut off from the main stream

P

  • packet boat – a small boat designed for domestic mail, passenger or freight transportation in European colonies and their colonies, including North American rivers and canals – used extensively during the 18th and 19th centuries
  • parent soil – soils that have inherent structure and minerals from underlying geologic material
  • pirogue – a long narrow canoe made from a single tree trunk
  • Pleistocene terrace
  • pontoon bridge – a floating barge connected by a pivot arm to a fixed point along the shoreline – a mechanical system swings the bridge to the riverbank when the channel is open to boat traffic. When closed, cars can drive over the bridge.
  • portage – to carry a boat or its cargo between two navigable waters

R

  • raft/logjam – a flat buoyant structure of timber – in the case of the Red River, massive rafts (logjams) developed and were so thick that they acted as bridges for pedestrians crossing?
  • ravine – a landform narrower than a canyon and often the product of stream-cutting erosion
  • relict – a thing that has survived from an earlier period or in a primitive form (ex. Bayou Teche is a relict channel of the Mississippi River)
  • river swamp – area of waterlogged land adjoining a river (ex. The Atchafalaya Basin is the largest river swamp in the U.S.)
  • rookery – a breeding colony of rooks, typically seen as a collection of nests high in a clump of trees

S

  • salt dome – a dome-shaped structure in sedimentary rocks, formed when a large mass of salt has been forced upward – these structures often form traps for oil or natural gas
  • sedimentation – the process of settling or being deposited as sediment (ex. when rivers carry sediment and gradually build land)
  • shallow draft vessel – a boat or ship with a keel which is not far below the waterline
  • shoals – natural submerged ridges, banks or bars
  • skidder canals – radial canals through the swamps where loggers used massive winches to pull trees to a central loading point
  • slough – a wetland, usually a swamp or shallow lake, often a backwater to a larger body of water
  • Spanish moss – a tropical American plant that grows as silvery-green festoons on trees, obtaining water and nutrients directly through its surface
  • stagnation – the state of not flowing or moving
  • steamboat – a boat propelled by a steam engine, especially a paddle-wheel craft used widely on rivers in the 19th century
  • storm surge – a rising of the sea as a result of atmospheric pressure changes and wind associated with a storm
  • subsidence – the gradual caving in or sinking of an area of land
  • swamp – an area of low-lying, uncultivated ground where water collects; a bog or marsh

T

  • tidal marshes and lagoons – (ex. Lake Hatch – in the middle of Mandalay National Wildlife Refuge)
  • topography – the arrangement of the natural and artificial physical features of an area
  • tributary – a river or stream flowing into a larger river or lake
  • Turnbull’s Bend – when a meander of the Mississippi River intercepted the Red River, turning it into a tributary and eventually leading to the creation of the Atchafalaya River as a distributary

U

  • U.S. Army Corps of Engineers – a U.S. federal agency charged with delivering public and military engineering services. It is involved in a wide range of projects to strengthen U.S. security, energize the economy and reduce risks from disasters. Known in Louisiana for dams, canals and flood protection

W

  • watershed – an area or ridge of land that separates waters flowing to different rivers, basins or seas – Ex. the Atchafalaya River watershed
  • wetland – land consisting of marshes or swamps; saturated land
  • Works Progress Administration – WPA; renamed in 1939 as Work Projects Administration – employed millions of people to carry out public works projects, including the construction of public buildings and roads

bird in swamp