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TeacherNoteHudsonRiverSalinityMappingActivityIntroduction:ThisisastudentcompletedDataVisualizationactivity.Withcomputergraphicsbeingaccessibletostudents,moreandmoreoftenstudentsarebeingexposedtodataingraphicvisualizations.Datavisualizationhasbecomeanactiveareaofteaching,yetoftenthestudentshavenotconsideredthatthereisnumericdatasupportingtherepresentations.Thisactivityisdesignedtobeabridgethatcarriesthestudentsfromreviewingthenumericdatatoturningthosenumbersintocolorgraphics.Activity:Thisactivitycanbedoneasananalysisofasingleyearofsalinitydata,orasacomparisonbetweentwoyearsofdata(2008and2009).ForeachyearofdatayouwillfindalistingoftheRiverMilessampled,andthesalinityforthatlocationrecordedinppm.Onthebottomrightcornerofthedatasheetyouwillfindasalinitycolorschemefortheactivity.Thiscolorschemewillbewhatthestudentsusetocreateacolorvisualizationofthesalinity.Aselectionfromtherecordedsalinityhasalreadybeenmarkedonthemap.Forthecolorvisualizationstudentswillworkwiththesalinitiesrecordedonthemap.Using6colorsofcrayon(red,orange,yellow,green,blueandpurple)createavisualizationofthesalinitygradientintheriver.Oncethestudentshavecompletedtheircoloringhavethemanswerthefollowingquestions:

1. Whyisthesouthernpartoftheriversaltierthanthenorthernpartoftheriver?(Answer:tidalinfluenceoftheAtlanticOcean)2. WhyisEastRiversaltierthantheHudsonRiveratthesamelatitude?(Answer:theEastRiverconnectstosaltwaterbodies–LongIslandSoundandtheAtlanticOcean.TheHudsonconnectsfreshwaterfromtheSouthwithsaltwaterfromtheAtlantic.)3. Studentscanlocatetheirschoolsamplingsiteontheriver.Nowletslookatthenumericdatasheet.4. Weoftenrefertothesectionoftheriverthatisnotconsideredfreshorsaltwateras

‘brackish’.Forouractivitywewillrefertosalinitiesbetween17000ppmand100ppmasbrackishwater,lessthan100ppmasfreshwaterandgreaterthan17000ppmassaltwater.Usingthenumericdatahavestudentsdrawalineacrossbothendsofthebrackishsectionoftheriver.

5. Referringbacktotheirownsamplingsiteontheriver,istheirsiteinthefreshwater,brackishorsaltwatersectionoftheriverusingourdefinition?

6. Ifyouareusingthe2008datalookatRM6at79thSt.BoatBasin.Thisgroupcollectedasamplefromthesurfaceandfrom40feetdeepinthewater.Lookatthedifferenceinthesalinitiesbetweenthesurfaceandthe40ft.deepsample.Whywouldtherebeadifference?

(Answer:Saltwaterisdensersothesaltwatercominginfromtheoceanflowsunderneaththefreshwatercomingdownfromthenorth.)

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7. Ifyouareusingthe2009datalookatRM11atFortWashingtonPark.Thereweretwodifferentgroupssamplingatthissite,oneintheAMandoneinthePM.Lookathowthetidebringsahigherconcentrationofsaltintotheriverwhenitfloods!

IFYOUDECIDETOHAVEYOURSTUDENTSCOMPAREDATAFROM2008AND2009Havetheclassworkinteamsoftwo‐givingonepartner2008andonepartner2009data/activity.Havethemcompletetheactivityandthenhavethemlookatthetwoyear’smapssidebyside.Askthemtomakealistoftheirobservationsofthedifferencesandsimilaritiesbetweenthedatacollectedinthe2years.Studentswillseethattheoverallsectionsoftheriverwecallfreshandsaltystayrelativelyconstant,butthattheactualsalinityreadingsintheseareasoftheriverwillvarywithweather,andtoalesserextentwithtide.Thebrackishsectionhashigherinternalvariability,againasaresultoftheweatherandtides.Ifyouweretolookattheweatherfor2009youwouldseethattherewasaraineventthedaybeforeoursamplingthataddedafreshwaterpulsetotheriverasthewatersheddrained.Thisimpactedtheuppersectionoftheriverfirst,whichisshowninourdata.*Notethatsmallvariancesinthedatafromlocationtolocationarenotunexpected.Theycanresultfromtheresolutionofoursamplingmethods,thevariationintimewhenthewaterwassampled(timeinthetidalcycle),aswellasthelocationofthesamplingsite(someofthesitesarebyfreshwatertributariesthataddafreshpulseofwaterintotheriverbytheirsite).

35 ppm

26.3 ppm

39 ppm

26.3 ppm

26.3 ppm

Salinity Data for 10/8/09 A Day in the Life of the Hudson River

35 ppm

5000 ppm

3000 ppm

135 ppm

53 ppm

58 ppm

61 ppm

53 ppm

3000 ppm

6000 ppm

6500 ppm

9000 ppm

12000 ppm

22000 ppm

22000 ppm

27000 ppm

30000 ppm

25000 ppm

16750 ppm

13000 ppm12000 ppm

22000 ppm

30000 ppm

Standardized Saliniity 10/8/09

RM Site Name

Total Salinity - ppm notes

153 Green Island 35.0144 Rensselear Boat 26.3138 Henry Hudson Park 26.3133 Schodack Island 26.3127 Stuyvesant Landing 26.3115 Cohotate Preserve 3597 Ulster Landing 3992 Kingston Point Park 3578 Quiet Cove 5376 Waryas Park MHCM 61

76Waryas Park AHS*- 2- surface and 40 ft. depth 35

61 Long Dock Beacon 5861 Newburgh Landing 4460 Dennings Point 6158 Kowawese 9357 Cornwall 5355 Little Stony Point 81

53#a Garrison Landing 81 avg. 13553#b Garrison Landing 190

41 Verplanck 300036 Croton Point Park 450032 Ossining 500031 Nyack Beach 500030 Nyack Memorial Park 3000

25E Irvington 600025W Piermont Pier 7000

18 Habirshaw Park 650013 Engelwood Boat Basin 900011 Fort Washington Park AM 9750 low tide11 Fort Washington Park PM 14000 flood tide5 Pier 96 130005 Pier 96 13000

4b Intrepid 120004 Pier 84 12000 30000-21000 RED3 Christopher Street 15000 20000-11000 ORANGE2 Pier 40 - Harbor School 18500 avg. 1675010000-8000 YELLOW2 Pier 40 - River Project 15000 7900-2100 GREEN

Har14 Inwood Park 9000 2000-70 BLUE Har13 Swindler Cove 12000 69-0 PURPLEHar10 150th Street 10000ER 4W Solar One Stuyvesant 21000ER 4E Newtown Creek 22000

ER 1W ER Empire Fulton 22000ER 0.5 Southstreet Seaport 22000

-7 Verrazano Bridge 25000-6.5 Canarsie Park in Jamaica Bay 27000

-9 Brighton Beach- NY Bight 30000 -11 Breezy Point - NY Bight 30000

DIRECTIONS

NOTE: Hudson River Miles are displayed on the map on the West side of the river in increments of every 5 miles.

Using crayons you will color in salinity in the sections of the river on the map. The colors to use for the salinity ranges are listed below. Match these ranges to the amounts from the 2009 'Day in the Life of the Hudson River' event posted on the map. You can also look at the compete list of values on this sheet. Do you see any trends in the data? Why do you think the Data on the East River is different from the data on the Hudson River at the same latitude? (hint - think of what two bodies of water the East River connects.) Why do you think the data from AM and PM is different at Fort Washington Park? (Hint look at the tides)