The lake retention time for a body of water with the volume 2,000 m3 (71,000 cu ft) and the exit flow of 100 m3/h (3,500 cu ft/h) is 20 hours.

Lake retention time (also called the residence time of lake water, or the water age or flushing time) is a calculated quantity expressing the mean time that water (or some dissolved substance) spends in a particular lake. At its simplest, this figure is the result of dividing the lake volume by the flow in or out of the lake. It roughly expresses the amount of time taken for a substance introduced into a lake to flow out of it again. The retention time is particularly important where downstream flooding or pollutants are concerned.

Global retention time

The global retention time for a lake (the overall mean time that water spends in the lake) is calculated by dividing the lake volume by either the mean rate of inflow of all tributaries, or by the mean rate of outflow (ideally including evaporation and seepage). This metric assumes that water in the lake is well-mixed (rather than stratified), so that any portion of the lake water is much like any other. In reality, larger and deeper lakes are generally not well-mixed. Many large lakes can be divided into distinct portions with only limited flow between them. Deep lakes are generally stratified, with deeper water mixing infrequently with surface water. These are often better modeled as several distinct sub-volumes of water.[1]

More specific residence times

It is possible to calculate more specific residence time figures for a particular lake, such as individual residence times for sub-volumes (e.g. particular arms), or a residence time distribution for the various layers of a stratified lake. These figures can often better express the hydrodynamics of the lake. However, any such approach remains a simplification and must be guided by an understanding of the processes operating in the lake.

Two approaches can be used (often in combination) to elucidate how a particular lake works: field measurements and mathematical modeling. One common technique for field measurement is to introduce a tracer into the lake and monitor its movement. This can be a solid tracer, such as a float constructed to be neutrally buoyant within a particular water layer, or sometimes a liquid. This approach is sometimes referred to as using a Lagrangian reference frame. Another field measurement approach, using an Eulerian reference frame, is to capture various properties of the lake water (including mass movement, water temperature, electrical conductivity and levels of dissolved substances, typically oxygen) at various fixed positions in the lake. From these can be constructed an understanding of the dominant processes operating in the various parts of the lake and their range and duration.[1]

Field measurements alone are usually not a reliable basis for generating residence times, mainly because they necessarily represent a small subset of locations and conditions. Therefore, the measurements are generally used as the input for numerical models. In theory it would be possible to integrate a system of hydrodynamic equations with variable boundary conditions over a very long period sufficient for inflowing water particles to exit the lake. One could then calculate the traveling times of the particles using a Lagrangian method. However, this approach exceeds the detail available in current hydrodynamic models and the capacity of current computer resources. Instead, residence time models developed for gas and fluid dynamics, chemical engineering, and bio-hydrodynamics can be adapted to generate residence times for sub-volumes of lakes.[1]

Renewal time

One useful mathematical model the measurement of how quickly inflows are able to refill a lake. Renewal time is a specific measure of retention time, where the focus is on 'how long does it take to completely replace all water in a lake.' This is modeling can only be done with an accurate budget of all water gained and lost by the system. Renewal time simply becomes a question how quickly could the inflows of the lake fill the entire volume of the basin (this does still assume the outflows are unchanged). For example if Lake Michigan was emptied, it would take 99 years for its tributaries to completely refill the lake.[2]

List of residence times of lake water

The residence time listed is taken from the infobox in the associated article unless otherwise specified.

LakeLocationBasin countriesResidence time
Stausee FerdenFerden, ValaisSwitzerland36 hours
Lake Wohlen / WohlenseeCanton of BerneSwitzerland2.1 days
Lake HévízHévízHungary3 days
Lake St. ClairGreat LakesCanada, United States7 days (2-30 days)
Lake ArapuniNorth IslandNew Zealand1 week
Milton PondStrafford County, New Hampshire, York County, MaineUnited States11.1 days
Gibson LakeGibson Generating Station, Princeton, IndianaUnited States2 weeks
Råcksta TräskStockholmSweden2-3 weeks
Lake SagamiKanagawaJapan0.05 year
Lake CristallinaTicinoSwitzerland2-4 weeks
Northeast PondStrafford County, New Hampshire; York County, MaineUnited States23.7 days
Brandy PondNaples, MaineUnited States34 days
Champagne PoolWaiotapu, North IslandNew Zealand34 days
Prospect reservoirProspect, New South WalesAustralia30-40 days
SicklasjönStockholmSweden0.1 year
Devils LakeLincoln County, OregonUnited States0.15 years
Lough DergShannon River BasinIreland0.15 years
Derwent WaterCumbriaUnited Kingdom55 days
Lake Biel / Bielersee / Lac de BienneCanton of BerneSwitzerland58 days
VeluwemeerFlevoland, GelderlandNetherlands2 months
HacksjönTullingeSweden0.2 years
Kamloops LakeBritish ColumbiaCanadaca. 0.2 years (20-340 days)
Malham TarnNorth Yorkshire, EnglandUnited Kingdom11 weeks
Lac d'AnternePassy, Haute-SavoieFrance90 days
Graham LakeHancock County, MaineUnited States3 months
Grand Lac de ClairvauxJura department, Franche-ComtéFrance3 months
LaduvikenDjurgårdenSweden3 months
Esthwaite WaterLake District, CumbriaUnited Kingdom0.26 years
TrehörningenHuddinge, Southern Stockholm CountySweden0.27 years
Lac de DivonneDivonne-les-Bains, AinFrance100 days
Lake Lesina / Lago di LesinaProvince of Foggia, ApuliaItaly100 days
SeeweidseeCanton of ZurichSwitzerland100 days
HüttnerseeHütten, Canton of ZurichSwitzerland120 days
Lake Lauerz / LauerzerseeCanton of SchwyzSwitzerland0.3378 years
Morris LakeHalifax Regional Municipality, Nova ScotiaCanada4.1 months
Sobradinho ReservoirSobradinho, BahiaBrazil0.35 years
Balch PondCarroll County, New Hampshire; York County, MaineUnited States136 days
MagelungenHuddingeSweden4-5 months
Russell LakeHalifax Regional Municipality, Nova ScotiaCanada4.6 months
LoweswaterLake District, CumbriaUnited Kingdom150 days
LappkärretStockholmSweden5 months
Lough FeeaghCounty MayoIreland0.47 year
EgelseeBubikon, Canton of ZurichSwitzerland180 days
Lac de VouglansJura, Franche-ComtéFrance180 days
MettmenhasliseeCanton of ZurichSwitzerland180 days
AlbysjönStockholmSweden0.5 year
Chesuncook LakePiscataquis County, MaineUnited States6 months
Clinton LakeDeWitt County, IllinoisUnited States6 months
Flagstaff LakeSomerset County and Franklin County, MaineUnited States6 months
Lake Coeur d'AleneNorthern IdahoUnited States0.5 years
Lac de Saint-PointDoubs department, Franche-ComtéFrance200 days
KyrksjönBrommaSweden7 months
Newnan's LakeGainesville, FloridaUnited States0.6 years
Staples PondTemple, MaineUnited States8.2 months
Lac CornuChamonix-Mont-Blanc, Haute-SavoieFrance250 days
Lac du BréventChamonix, Haute-SavoieFrance250 days
Lake Silvaplana / Silvaplanersee / Lej da SilvaplaunaEngadin, GrisonsSwitzerland250 days
Loch AweArgyll and Bute, ScotlandUnited Kingdom0.7 year
LångsjönStockholmSweden9-10 months
Lake Sarnen / SarnerseeObwaldenSwitzerland0.8 years
Lake LovozeroKola Peninsula, Murmansk OblastRussia10 months
DrevvikenStockholmSweden10-11 months
MörtsjönHuddingeSweden< 1 year
JudarnBromma, StockholmSweden11 months
Coniston WaterLake District, CumbriaUnited Kingdom340 days
UllswaterLake District, CumbriaUnited Kingdom350 days
Khanka LakeHeilongjiang Province, China and Primorsky Krai, RussiaChina, Russia1 year
Lake MononaDane County, WisconsinUnited States1.1 years
Long LakeMaineUnited States1.1 years
Mooselookmeguntic LakeFranklin County, MaineUnited States1.1 years
GreifenseeCanton of ZurichSwitzerland408 days
Nainital LakeUttarakhandIndia1.16 years
Manasbal LakeKashmir ValleyIndia1.2 years
Lake Zurich / ZürichseeZürichSwitzerland440 days
TegernseeBavariaGermany1.28 years
Deer Creek ReservoirUtahUnited States1.3 year
OrlångenHuddingeSweden1.33 years
Haweswater ReservoirLake District, CumbriaUnited Kingdom500 days
Loch ShielLochaber, Highland, ScotlandUnited Kingdom1.37 year
Lake Walen /Walensee / Lake Walenstadt St. Gallen, GlarusSwitzerland1.4258 years
Keoka LakeMaineUnited States1.5 years
Kootenay LakeBritish ColumbiaCanada1.5 years
Lake Murten /Lac de Morat /MurtenseeCanton of Fribourg, VaudSwitzerland1.6 years
Oeschinen LakeBernese OberlandSwitzerland1.61 years
Lac de LessyHaute-SavoieFrance600 days
East Grand LakeMaine / New BrunswickCanada, United States1.7 years
Lake IkedaKyūshū islandJapan1.7 years
Lake PoyangJiujiangChina0.173 years[3]
Faaker SeeCarinthiaAustria1.8 years
Ossiacher See / Lake OssiachCarinthiaAustria1.8 years
Varese Lake/Lago di VareseProvince of Varese, LombardyItaly1.8 years
Long Lost LakeClearwater County, MinnesotaUnited States1.8 years
ÄltasjönÄltaSweden1.8 years
Lake Thun / ThunerseeCanton of BerneSwitzerland684 days
Green LakeMaineUnited States1.9 years
GömmarenHuddingeSweden1.9 yrs
Loch LomondDunbartonshire, Central ScotlandScotland, United Kingdom1.9 years
Lake BalatonHungaryHungary2 years
Lake RotoroaHamilton, Waikato, North IslandNew Zealandapprox. 2 years
Lake TūtiraHawke's Bay, North IslandNew Zealand2 years
TürlerseeCanton of ZurichSwitzerland730 days
PfäffikerseeCanton of ZurichSwitzerland2.085 years
Caniapiscau ReservoirQuebecCanada2.2 years
Lake Sils / Silsersee /Lej da SeglEngadin, GrisonsSwitzerland2.2 years
WilerseeCanton of ZugSwitzerland2.2 years
Great PondMaineUnited States2.3 years
Moberly LakeBritish ColumbiaCanada2.4 years
PäijänneJyväskyläFinland2.5 years
Lake ErieNorth AmericaCanada, United States2.6 years
Rangeley LakeFranklin County, MaineUnited States2.6 years
Lake Brienz / BrienzerseeCanton of BerneSwitzerland2.69 years
Ammersee / Lake AmmerUpper BavariaGermany2.7 years
Großer Plöner SeeSchleswig-HolsteinGermany3 years
Paudash LakeHaliburton County, OntarioCanada3 years
Moosehead LakeMaineUnited States3.1 years
TrekantenStockholmSweden3.1 years
Great East LakeCarroll County, New Hampshire; York County, MaineUnited States3.3 years
Lake ChamplainNorth AmericaCanada, United States3.3 years
Flathead LakeMontanaUnited States3.4 years
Lake Lucerne /VierwaldstätterseeCentral SwitzerlandSwitzerland3.4 years
Lake WinnipegManitoba, CanadaCanada3.5 years
Lac de PaladruIsèreFrance3.6 years
Lake Hallwil / HallwilerseeAargauSwitzerland3.9 years
FlatenSouthern StockholmSweden4 years
Lake Annecy / Lac d'AnnecyHaute-SavoieFrance4 years
Lake Maggiore / Verbano / Lago MaggioreLombardy and Piedmont, Italy; Canton Ticino, SwitzerlandItaly, Switzerland4 years
Todos los Santos LakeLos LagosChile4 years
Lake Baldegg / BaldeggerseeCanton of LucerneSwitzerland4.2 years
Lake Iseo / Lago d'IseoLombardyItaly4.2 years
Lake Constance / BodenseeGermany, Switzerland, AustriaGermany, Switzerland, Austria4.3 years
Corey LakeMichiganUnited States4.4 years
Elk and Beaver LakesSaanich, British ColumbiaCanada4.4 years (Elk Lake),
Lake ComoLombardyItaly4.5 years
Lake MendotaWisconsinUnited States4.5 years
Sea of GalileeGalileeIsrael5 years
Walden PondMassachusettsUnited States5 years [4]
BannwaldseeAllgäu, BavariaGermany5.2 years
Sebago LakeCumberland County, MaineUnited States5.1 to 5.4 yrs
Kennisis LakeHaliburton Highlands, OntarioCanada5.26 years
Bay LakeCrow Wing County, MinnesotaUnited States4-7 years
Lake Biwa / 琵琶湖Shiga PrefectureJapan5.5 years
Jordan PondHancock County, MaineUnited States6 years
Lago di MergozzoPiedmontItaly6 years
Lake OntarioNorth AmericaCanada, United States6 years
Lac la NonneAlbertaCanada6.5 years
Lago di CandiaProvince of TurinItaly6 or 7 years
ÄgeriseeCanton of ZugSwitzerland6.8 years
Loch MorarMorar, Lochaber, Highland, ScotlandUnited Kingdom6.87 years
Lake PowellUtah/ArizonaUnited States7.2 years
Millstätter See / Lake MillstattCarinthiaAustria7.5 years
Moose LakeAlbertaCanada7.5 years
SchaalseeSchleswig-HolsteinGermany5 to 10 years
Iliamna LakeLake and Peninsula Borough, AlaskaUnited States7.8 years
Lac du BourgetSavoie, FranceFrance8 years
Odell LakeKlamath County, OregonUnited States8 years
Lake Lugano /Lago di LuganoTicino, LombardySwitzerland, Italy8.2 years
Lake Neuchâtel / Lac de Neuchâtel / NeuenburgerseeRomandySwitzerland8.2 years
Lake Orta /Lago d’Orta /CusioPiedmontItaly8.9 years
WeissenseeCarinthiaAustria9.2 years
Quesnel LakeBritish ColumbiaCanada10.1 years
Schweriner SeeMecklenburg-VorpommernGermany10.1 years
Lake TaupoTaupo District, Waikato region, North IslandNew Zealand10.5 years
Wörthersee / Lake WörthWest of KlagenfurtAustria10.5 years
Lake ChelanWashingtonUnited States10.6 years
Lake GenevaSwitzerland, FranceSwitzerland, France11.4 years
Lake WakatipuQueenstown-Lakes District, Otago Region, South IslandNew Zealandc. 12 years
Higgins LakeMichiganUnited States12.5 years
Crescent LakeKlamath County, OregonUnited States13 years
Yellowstone Lake Yellowstone National Park, Wyoming United States 14 years
Lake Zug / ZugerseeCentral SwitzerlandSwitzerland14.7 years
MüritzMecklenburg-VorpommernGermany15 years (?)
Western Brook PondGros Morne National Park, Newfoundland, Newfoundland and LabradorCanada15.4 years
Lake Sempach / SempacherseeCanton of LucerneSwitzerland16.9 years
Skaneateles LakeNew YorkUnited States18 years
Cayuga LakeNew YorkUnited States18.2 years
Bear LakeIdaho, UtahUnited States19.6 years
Green LakeGreen Lake County, WisconsinUnited States21 years
Lake Starnberg /Starnberger SeeBavariaGermany21 years
Lake HuronNorth AmericaCanada, United States22 years
Lake Garda / Lago di GardaNorthern ItalyItaly26.8 years
Waldo LakeCascade MountainsUnited States32 years
Crystal LakeBenzie County, MichiganUnited States30 to 60 years
Lake ColumbiaJackson County, MichiganUnited States47 years
Okanagan LakeBritish ColumbiaCanada52.8 years
Lake OhridAlbania, Republic of Macedonia70 years
Lake MichiganMichiganUnited States99 years
ArendseeSaxony-AnhaltGermany100 years
Gull LakeAlbertaCanada>100 years
Lake YosemiteCaliforniaUnited States121 years
Great Bear LakeNorthwest TerritoriesCanada124 years
Crater LakeOregonUnited States157 years
Lake SuperiorNorth AmericaCanada, United States191 years
Caspian SeaAzerbaijan, Iran, Kazakhstan, Russia, Turkmenistan250 years
Lake BaikalSouthern SiberiaRussia330 years
Lake TahoeCalifornia, NevadaUnited States650 years
Lake TiticacaPeru, Bolivia1343 years
Lake EucumbeneSnowy Mountains, New South WalesAustralia1953 years
Lakes QabanKazanRussia 2000 years
Lake TanganyikaBurundi, DR Congo, Tanzania, Zambia5500 years
Lake VostokAntarctica13300 years

See also

References

  1. 1 2 3 Duwe, Kurt (2003-01-03). "D24: Realistic Residence Times Studies" (PDF). Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas. EUROLAKES. Archived from the original (PDF) on January 26, 2007. Retrieved 2007-12-11.
  2. Wetzel, R. G. (2001). Limnology 3rd Edition. New York: Academic Press.
  3. "Poyang Lake". International Lake Environment Committee Foundation. Archived from the original on December 13, 2013. Retrieved February 13, 2014.
  4. Colman, John A and Paul J. Friesz. "Geohydrology and Limnology of Walden Pond, Concord, Massachusetts". USGS. Retrieved 2020-07-07.

Further reading

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