Envirothon Aquatics Quizlet

How much of Earth is covered by water?

2/3

How much of Earth's water is soil moisture?

3.8%

Unsaturated zone/Vadose zone/Zone of Aeration:

above the water table, pores filled with air

Water Table

the top of where the pores are filled with water, highest level of groundwater

Capillary Fringe

above water table, pores are somewhat filled b/c of adhesion + cohesion

Saturated zone/Phreatic zone

the region below the water table where pore space is filled with water

Porosity

Empty Pore Space/Total volume of geologic formation, affected by grain sorting, shape, compaction

Permeability

Rate at which water can flow through

-depends on size + connectivity of pore spaces

Aquifer

body of rock/unconsolidated sediment that stores water, permeable & porous. Saturated

-best aquifer is well sorted, well rounded, large particles

Unconfined Aquifer

no boundary, water table free to rise/fall

Confined/Artesian Aquifer

Aquifers covered by an impermeable and confining layer impeding water flow in or out, specific recharge zones, often under pressure

Aquitard

saturated, intermediate water holding capacity/permeability

Aquiclude

Saturated, relatively impermeable/low water holding capacity

Artesian Well

A well in which water rises because of pressure within the aquifer

Infiltration

water enters subsurface

Percolation

water flows through the ground

Interflow

subsurface runoff - sideways movement of water in unsaturated zone

Throughflow

interflow that returns to the surface

Hydraulic head

mechanical energy available, Elevation head + Pressure head

Potentiometric surface

surface that water would rise too if no pressure/confining surface

Soil Water

Water in unsaturated zone

As soil dries,

it is harder to remove water from it

The smaller the particles,

the more surface area = the more tension for equal amount of water

Field Capacity/drained upper limit

soil moisture left in soil after being drained for a few days.

Wilting point

soil water content when plants start to wilt

Plant Available water

field capacity - wilting point

Soil moisture deficit

amount of water (in mm) needed to fill soil back up to field capacity

Catchment/Watershed

area for which all the water flows into one waterbody

Divides

highest ridges that separate different catchments

Lotic

moving waters (rivers, streams)

Lentic

still waters (lakes, ponds)

Ephemeral

only flows after rainfall

Intermittent

only flows when water table is high (late spring-early summer)

Perennial

flows year round

Fastest location in a stream

just under the surface

Fastest location in a meandering stream

Thalweg/cut bank side of stream just under surface

Discharge

velocity x cross sectional area, Affected by gradient, channel size and shape, channel roughness and amount of water

Substrate

type of substance on the bottom of the stream

Rectangular

on substrate with rectangular joint

Dendritic

on uniform substrate with a gentle slope

Trellis

substrate with parallel ridges/valleys from folding

Parallel

on uniform steep slopes with weak substrate and no vegetation

Radial

generally on volcano

Braided channel

generally high sediment load, lots of bars that shift

Meandering channel

most mature streams, Straight

Ways streams can erode

Scour (from abrasion w/suspended sediment), Breaking and Lifting, Attrition, Dissolution

Attrition

process of erosion that occurs during rock collision and transportation

Stream carries sediment via

Dissolved Load, Suspended Load, Bed Load (saltation)

Competence

largest size particle river can carry. Dependent only on velocity

Capacity

total volume of particle river can carry. Depends on discharge

When does deposition happen?

river no longer has the competence to carry sediment

Headwaters

erosional zone, streams are fast and cut v-shaped valleys

Transfer zone

amount of erosion= amount of deposition

Depositional zone

at low elevations, sediment deposited and river meanders

Base level

how far down stream can erode. Ultimate base level = the ocean

Does discharge and velocity increase/decrease as you go downstream?

increase

Photic

sunlit upper waters-> light dims to 1% of surface

Aphotic

no light

Littoral

near shore, emergent plants

Limnetic

well-lit, open surface waters farther from shore, depth to which sunlight can penetrate the water

Benthic

lake bed

Lakes in the Northeast are generally...

DIMICTIC - they mix once in fall and once in spring.

Lake temperature layers

epilimnion, metalimnion, hypolimnion

Lakes in Summer

surface is heated. Lake stratified into three layers by temperature

Lakes in Fall

surface is cooled. lake becomes isothermal and overturns

Lakes in Winter

surface is cooled and ices over. Coldest water & ice at top, warmer water at bottom

Lakes in Spring

surface is warmed to 4C, lake becomes isothermal, overturns

Water is densest at what temperature?

4C

Isothermal

having a constant temperature

Consequences of Stratification

deeper waters (hypolimnion) can become hypoxic or anoxic, can accumulate toxic gases (ie H2S as a result of anaerobic decomposition)

Overturning

mixes the water, giving the deeper waters oxygen, and bringing nutrients to the shallow waters.

-If this happens to fast, could kill life because the toxic gasses are introduced too quickly

What are wetlands (Clean Water Act definition)

areas inundated by surface or groundwater, long and frequent enough such that it supports vegetation adapted for saturated soil

What are wetlands (Manual definition)

land that is saturated for at least part of the year, with hydric soils and a special vegetational type

What makes a wetland?

Hydrophytic vegetation

Hydric, gleyed soil( <2 chroma)

look for water @ the surface, channels, etc. <6.6 ft of water

How are wetlands formed

Either paludification or terrestrialization

Paludification

generally with bogs, moss grows and traps water

Terrestrialization

eutrophication

Swamps

Wooded Wetland

-wet for part of year

-trees often dormant

Bogs

spongy peat deposits & Sphagnum moss

-Anaerobic, slow decomposition

-Nutrient poor, low in oxygen -> carnivorous plants, good for preservation

-Very acidic. Fed only by precipitation

Fens

Similar to bogs, but less acidic and more nutrients because also partially groundwater fed.

-carex and ephiorum moss

Marsh

dominated by grasses, wet the entire year

Vernal pool

temporary pools that form in springtime. Important nurseries for amphibians

-fairy shrimp + blue spotted salamander

Wetland benefits

-Improved water quality: filters out pollutants

-Reduces sedimentation

-controls erosion

-Flood Control: wetlands slow water and store it

-Water Supply: helps recharge groundwater

-Habitat: provides habitat for many endangered species., Important nurseries for fish and resting areas for migratory birds,

-Economic Benefits: timber, mammals, birds, shellfish,

-Recreation: for people (a lot of birders help economy), education, research

-Important in nutrient cycling, provides an anaerobic environment which is needed for many processes

Estuary

Where saltwater meets freshwater

Mudflats, tidal marshes, mangrove swamps, etc

TYPES OF ESTUARIES by geology/formation

Tectonic Estuaries

Bar Built Estuaries (lagoons)

Fjord-Type/Glacial

Coastal Plain/Drowned River Valley

TYPES OF ESTUARIES by stratification

Vertically Mixed

Partially Mixed

Stratified Salt Wedge

Stratified Fjord Type

Hypersaline

Estuarine Circulation

freshwater flows at surface from head to mouth, saltwater flows subsurface from mouth to head.

Tectonic estuary

formed when a depression along a fault line fills with water (e.g. San Francisco Bay)

Bar-built estuary

lagoon separated from ocean by sand bar or barrier island

Fjord

a narrow inlet of the sea between cliffs or steep slopes

coastal plain/drowned river valley

formed when sea levels rise + fill existing river valley, most common type

Pelagic

open water in the middle of a lake

Profundal Zone

deep water below light penetration level

photic

sunlit upper waters from surface to where light dims to 1% of the surface

lake ontogeny

lake successional process

What percent of water on earth is ocean/freshwater?

96.5%, 2.5% (other saline water = 0.9%)

What percent of freshwater is ice caps/glaciers?

68.7%

What percent of freshwater on earth is groundwater?

30.1%

What percent of freshwater on earth is surface freshwater?

1.2%

What percent of surface freshwater is lakes?

20.9%