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Patternsin Natural Systems:Rivers 4 * e
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E X P E C T A T I O N S o identify major river systemsof the world and describe their drainagepatternsas either dendriticor trellis r identify patternsin physicalgeography,usingthematic maps r draw cross-sectional diagramsof river profiles 4 * * * A
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Gatewaysto the Continents ivers are one of the most important physical features because they play a huge role in shaping our world. Rivers have cut channels between mountains, created deep gorges,and flooded large areasof land. Rivershave provided us with food, transportation, and sourcesof fresh water. Rivers influence the land use around them. and are continually changing the landscape. The St. Lawrence River played a vital role in 66 are part the settlement of Canada. By following the St. ,Riuers liaes and our Lawrence and continuing througn ,niG."., ,^^-^,,o!our heritase. Thet are the threads , r
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Many large cities are located or
that bind1he Tiurtcof natureand humanity together; that make
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For example,winnipeg,Montru"t,ri"ltlirll." London, ind Moscow were all built on the banks
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of rivers. Look at the map on page 243. Each continent has at least one major river. J.o".
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C HAPT
E R 8 : Patterns in Natural S\sterns:Riaers
RiverProfile
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The water in a river seemsto flow continuously, but it has a beginning and an ending. The source, or headwaters,is the location where the river begins. This is usually a series of underground springs or melting glaciers. Most of the water in a river comes from surface runoff due to rain or snow. In some areas, springs bring groundwater to the surface, and this water too is added to the river.
$*et Flla On Morch 29,1848 the enormousomount of woter fhot flows over NiogoroFolls every secondwos reducedto o mere trickle. This wosnot an engineeringfeot, but o noturolevent cousedbyhugeice flows thst blockedthe flow of Loke'Eriainto the NioguroRiver.
Riversmay havemore t h a n o n e s o u r c eS. m a l l s t r e a m cs a l l e dt r i b u t a r i e s flow into progressively l a r g e rs t r e a m su n t i l a river is formed.
f l o w i n t ot h e nel of a river tributaries.
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Watcr drains fi-om tl're highcst point o{'l:rrrcl in an arca to the lolvcst. I{ivers llorv fronr ther hieh grotrnd to thc lorv. Vrtr c:rn see ()n :l map, like the onc on this page, that t'ivcr-s flow in difl'crent" dircctions. Sonrc flor' north, while others fkrw south. Thc height of' land that diviclcs two dif ferent drainage systems clr drainage basins ancl sends one rirrel or-re way ancl ,t^uu the othcr in a cliIl'ercnt clirection is ; knowrr as thc divide. The Oak Ridges Moraine, just north of' Torotrto, cliviclcs trvo clrzrinagebzrsins.This moraine is the height of land betlveerr rivers that clrain north to Lake Simcoe ancl rivers that dr:rin south to Lake Orttario.
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Click on lllustrationof Earth's Sur{acenear the bottom of the screen.Write down any words that appear in the diagramthat you don't know.Look rhem up to discovertheir meaning. Now visit
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a n d c l i c ko n 3 - D lmagesandAnimationnearthe bottom of the page.Click on 3-D Animation. ChooseOak RidgesMoraine3-D Animationon the left side of the screen. C l i c k V i d e of o r W i n d o w s o r Q u i c k T i m e Movie.Sit back and enioy a simulated flightover this moraine.
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C HAPT
Riaers E R 8 : Patterns in Natural Systems:
The Great Divide .rtArrac, One of the most well-known heights of land in i -e North America is the Great Divide. On one side of zl1'this divide, the water drains north to the Arctic Ocean, or east to the Atlantic Ocean, and on the other side water drains west to the Pacific Ocean.
Why do you supposethat geographers describethis d i v i d ea st h e drainage GreatDivide?
Faet Fll* On CutbonkPossin GlacierNotionol Pork lhere ore lhree streomsso close together thot you con pour woter into oll three ot the some time. Onestreom will carry the woter to HudsonBoy.onother to the Pocific Oceon, ond the third to the Gulf af Mexico.
66 Cross high lands Where utaters diuide Tbfarazuay ocea.ns And trails of days gone by We're following the stars zaith a paddle in our hands ,2 Let's see Canada hy canoe. Canadaby Canoe Whipper Music:DavidWhipper/Haze Whipper Lyrics:Kirk Whipper/Haze
?d. A RoyalFlushin Saskatoon an ugly noticed in 1988,people Oueen Elizabeth ll wasto visitSaskatoon bouta weekbefore River exactly of the mightySaskatchewan brownpatchof waterflowingdownthe middle wherethe Oueenwouldbe passing. the hotelwherethe discovered that the oldestand mostfamoushotelin Saskatoon, Citvofficials quickly, the city Very River. wasflushingrawsewageinto the Saskatchewan Oueenwouldbe staying, visitthe hotelwashooked streetswereclosedoff, diggingbegan,andjust hoursbeforethe Oueen's up to the city'ssewersystem.
U N I T 2:
Patterns in Physiral Ckog'aph1
Major tiver Systemsof the World Every continent has several major river systems - the main channel of a river and all of the tributaries that flow into it. These rivers drain large areas of land, and are the focal points of many communities. Each of the major river systems takes water that runs off from a continent and drains into one of the oceans. See the map of Rivers of the World in the Map Appendix, on page 243.
SuperlativeRivers
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before emptying into the Mediterranean Sea. Although the Amazon River in South America is not as lons as the Nile River, it drains the largestarea of land in the world. The Amazon River
is 6570 km in length, and drains more than 6 million km, of South America' some geographers t{istory Fola r1no, trme,Africawasknown have estimated that there as rheDork L'ontinentto Europeans are 15 000 tributaries feedbecause theyknewso littleaboutit. Evenin the middle1800s, the into the Amazon' The sourceof the Nilewasunknownto European geographers. n gntish 1ng Amazon contains one-fifth missronary, Dr.DavidLivingstone, undertook to find it. Hewent of the world's fresh wateq exploring andforseveralyears nobodyin Britainheardfrom him and is so vast that ocean A searchpartywassentout underthe leadership of Henry liners can travel two-thirds MortonStanley, who did find Livingstone, in 1871.At that of its course' momenr, rneyweretheonlyEuropean people in that part o f A f r i c aW . h e nS t a n l eayp p r o a c h eLdi v i n g s t o n e , h es a r d" D r .L i v i n g s t o nI ep,r e s u m eT. h" i s greeting hasbecome famous. i
T h eNi l e v al l e yan d t h e N i l ed e l t ar a n ka m o n gt h e w o r l d ' sm o s tf e r t i l e f a r m i n ga r e a sS. i n c el 9 6 8 , t h o u g h ,E g y p t i a fna r m e r s a r e u s i n gm o r ea r t i f i c i a l f e r t i l i z e rosn t h e i rs o i l .U s e a n e n c y c l o p e dti oa f i n d o u t w h y t h e y n o w h a v et o do this.
C HAPT
Riaers E R 8, Patternsin Natural Systems:
TheColoradoRiverflows t h r o u g ht h e G r a n d Canyon.Why do you t h i n k r i v e r sa r e such considered i m p o r t a np t hysical features?
www.infoplease.com Click on Wodd, then Geography, ' then PrincipalRiversof theWorld. ; Which rivers in their list match ' the ones in your list from question 2 in 1l the Check Back on this page?Why do , i: you think there is a differencebetween their list and yours? .
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North American Rivers North America has many important river systems. The St. Lawrence River is a major Canadian commercial transportation route. In western Canada, the Fraser River is famous for its volume, power of wateq and rugged scenery.The Mississippi is the longest river (3779 km) in the United States,and drains almost all of the plains between the Rockies and the Appalachian Mountains. The Colorado River in Arizona, U.S., is famous for the Grand Canyon and the Hoover Dam. ' t - r r r - - - l -
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youcomptete FindI thischart. America onpase24etohetp ,. ;::il:t;ap of North I fromeach continent. Include rivers andinclude 10laroe rivers.
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I { i r c r s v s t c l r ) sl i r r r n t ' < l r r r l t l c x ' ( I] t l r c t ) l l 1 t ( ' l ' r r( s) l l l h ( ' s u l ' [ ' 2 r (O oal'th. ,\nr livcl is r'onlirrrrallv rlltrkiltg its c'trlvt:slurgcr'.()tr thc slip-off s l o p e o l ' l l r c r - i v c r ,r r u r l c : r ' i lils r l c l t o s i l r : r l . ()rr thc cut-off slope, thr t'ru-r-t:nt\\'ciu's 'l'lris t l r c l r : r r r k: u v l r r ' . l t ' s r r l l si n t l r r ' ( u l \ ( ' i r t c ' r ' t ' u s i ni rgr -s i z t ' .( ) r c r ' l i r n c . i l ' t l r t ' r ' i r c r ' r':rllcl is n'irlc ()n()ugll.lrrrut' lool)s, ()r' meanders. r':tn [irrrrr. T l t c ' s t 't n c ' : r r r r l t : ro-Ist c r r l t c c o r r t ' s ( ' l ) : l 'fhc r:rtcrl {i'orrr Ihe' r'ivcr'. rivcr' llous ? r ( ' l ' ( ) sl lsr t ' n a l r o u , s l t ' i l l o l ' l a r t r l l r t l l r t ' b : t s co l t h c n r c u n c l c r 'l .r r r r lc r c r r t r r i r l l rl h t ' n r c l r r r c l t 'its' t r r 1o [ ' [ ' ( l ' o r nl l t c r r c u ,( - ( ) l lsr ( ' 'fhis ('r'orrl('u s n ('n('l()s()(l ol' llrt' r'ivcr'. pir:r:r'oI u,alcr ctrllcrl an oxbow lake.
Waterwantst o g o s t r a i g h t a n d h i t st h i s bank.Theflow of water erodest h e b a n k
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R i r e l s n i l h u p c l r b l c c l b e d : r n c lb a n k ()llcn firt-tnsorncthing r:ullcrl lr braided pattern. llr':ritlcrl rivers lravc rrurrrvsnr:rll i s l : r n c l st l r i r t s p l i t t h t ' l l o u , o l w a t ( ) l 'i l t t ( ) 'I'hcsc sc\'o|alS1r('runs. s t r o a r n s( ) l - ( ' 1 l l u l n e l s : r r - t : . j o i r t c;rrlr r crl l i v i r l c c ls ( ' \ ' ( ' l - :tlilr r r c s , I i r r r r r i n g: t b r i r i r l c r l l ) l r t t ( ) l ' n .
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C H APT E R 8,
Rians Patterns in Natural Systerns:
DrainagePatterns There are different types of river drainage patterns, that is, the pattern formed by all the tributaries that feed into the main channel. The drainage pattern is affected by the underlying rock - the rock beneath the earth that the river flows over. Different types of rock erode at different rates. Soft rock (e.g., limestone) erodes more easily and faster than hard rock (e.g., granite).
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DendriticDrainagePattern Most rivers have a dendritic drainage pattern. Imagine a leaf. All the veins connect to the main vein in the centre of the leaf. Think of the main vein as being the main channel of the river, and the small veins as being the tributaries. Tributaries join the main branch of the river in a V-shapedjunction. The V points downstream. Dendritic drainage patterns usually occur in gently sloping areaswhere all the underlying rock is about the same hardness so that it erodes or wears away in a uniform manner. Most of the rivers that drain into Lake Ontario have a dendritic drainage pattern.
TrellisDrainagePattern Some rivers have a trellis drainage pattern, that is, a rectangular pattern where the tributaries flow perpendicular to the main branch of the river. These tributaries are very often located where there are bands or rows of hard rock and soft rock. Tributaries travel along the areas that erode faster (softer rock) and break through the hard rock where they can.
Trellis Drainage Pattern
Theseare two commonriver patterns.Canyou think of another patternthat riversmay have?Hint: Thinkabout the St. LawrenceRiver.
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pattern. I drainage 1. Drawa picture of a riverthathasa trellis pattern of drainage page the 252. Describe on I 2. Lookat themapof SouthAmerica theAmazon River. I I
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U N I T 2t
Patterns in Phlsical Gngraphy
Understanding Concepts
Research and Communication Skills
Q In yourownwords,definetheseterms: a) source of a river b) mainchannel c) tributary d) mouthof a river
the AmazonRiver, or the Mississippi @ Locate River, in the MapAppendix or the NileRiver, at the backof thisbook.Discover andname: a) its source b) its length c) its mouth d) the important citieson the river e) Giveoneinteresting fact aboutthe river. fl Drawa sketchmapof the river.
howa meander iscreated. Include a @ Explain labelled diagram in youranswer. a wordwebfor all the thingsrelatedto @ Create a river.Startwith the wordRIVER in the centre. finda map(a roadmapwould @ In yourlibrary, begood)of a rivernearor in yourcommunity. Sketchthisriver,andlabelyoursketchusing the correctterms. @ Usean atlasto find the ten longestriversin the world. a) Listthemin orderof length. b) Givethe direction eachflowsin. c) Nameonemajorcity eachriverpasses through, or near.
@ Visitthe Websitewwwga.usgs.gov/edul andclickon Menufor all Earth's mearth.html Thenclickon Rivers WaterTopics. andStreams. Readthissectionandreporttwo factsbackto yourclassthat youfoundaboutrivers.
C HAPT
E R 8 z Patternsin Natural S\stems:Riuns
&tapasidGl*be Skills
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ffi a) Usingan atlas,listten majorriversin
ffi Createa posterthat illustratesthe many ways w e u s er i v e r sT. h i n ka b o u t l e i s u r ea c t i v i t i e s , and other uses. industry,food, transportation, G i v ey o u r p o s t e ra t i t l e t h a t t e l l sh o w i m p o r t a n t flversare to us.
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Canada. b ) S o r tt h e s er i v e r si n t o t w o c a t e g o r i e sh:i g h u s ea n d l o w - u s eE . x p l a i nh o w y o u d e c i d e d w h i c hc a t e g o r yt o c h o o s e . Lookat the sketchbelow. a ) N a m ee a c hf e a t u r et h a t i s s h o w nw i t h a n a r r o wa n d a l e t t e r . b ) W h a t i s t h e d r a i n a g ep a t t e r no f t h e r i v e r that flows throughSouthCity?EastCity? c) Namethe sourceof South River,EastRiver, a n d M o o nR i v e r . d ) N a m et h e l o c a t i o no f t h e m o u t ho f e a c h river.
Tours s} You'vebeenhiredby GlobalRiverAdventure to designa brochurefor their upcomingadventure tour.Youcanchoosethe river.Makethe ng. brochure inviting, exciting,and interesti dangers, Includemaps,placesof interest, activities, that will givethe potentialclients and pleasures i n f o r m a t i oann dw i l l m a k et h e mw a n tt o s i g nu p .
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