Bathymetry and morphometry of pampean shallow lakes: an approach to the origin and productivity

SEITZ, C.; VITALE, A.J.; PERILLO, G.M.E.

Gamin

Workshop; GLEON 18; 2016

GLEON

Lakeproductivityisdeterminedbythreeprincipalfactors,lakemorphology,climaticconditionsandwatershed?ssoilcharacteristic.Inthisstudy,themorphometriccharacteristicoftwoPampeanshallowlakesisanalyzed.LaSalada(39°27´45.27"S-62°42´10.89"W)andLaBarrancosa(37°20´13.17"S-60°6´33.95"W),arelocatedintheBuenosAiresprovince,Argentina.Theobjectiveswere:determinetheoriginoftheseshallowlakesbasedonmorphometriccharacteristicrelatedwithregionalgeomorphology;analyzethedynamicsbetweenthemorphometriccharacteristicsandtheexternalandinternalfactors(climaticvariability,wind,etc;suspendedsolids,zonation,etc.);toanalyzehowslightdifferencesinmorphometrydrivesdifferentresponsesintheseshallowlakeswhichhaveasimilarorigin.Abathymetrywasmadeusinganopensourceacousticprofilerinstalledoveranautonomoussmallboat.Thetrackandtheacousticprofilerwererecordedat5Hz.ThebathymetricmapsandmorphometricanalysesweremadeusingGISsoftware.ThemorphometricanalysesweremadefollowingtheHakånsonL.(1981,2004,2012),TimmsB.V.(1992),andContrerasF.I.(2011)criteria.Themorphometricparametersindicateaneolicoriginforbothshallowlakes.TheBarrancosa´smeandeptheuphoticzoneislowerthanLaSalada.Despitethis,BarrancosaislessaffectedbytheresuspensionofsedimentthanLaSalada.Thestudyshowsthatthemorphologicfactorisoneofthemajorresponsibleforchangesontheseshallowlakes.TheresultsshowthatsmalldepthchangescouldaffecttheET-areaandconsequentlythelakeproductivity