Coastal Lanscapes

1977 - Groynes built to stop longshore drift from south to north

            Cliff regraded & drainage channels installd to produce gentle more stable     

            slope

           Slope planted with gorse & nettlesto stop people climbing on cliff

            Sea wall built to protect the soft London clayat the bottom of the cliff

1998 -300 tonnesof Leicester granite placed aaround TOWER BREAKWATER

1999 BEACH REPLENISHED with sand & gravel from Harwich Harbour

Terms - Watershed = the boundry of the river basin Confluence = the point 2 rivers meet .Tributary - a stream the joins a larger river .Source - start of a river MOUTH where a river meets thge sea

Describe 3 process used by rivers to erode their beds

1Hydrauli action - the pressure of water againsts the banks & beds of river , including compressed air in ceacks - as water gets into cracks it compressess air in the cracks - putting pressure on the rocks & pieces break off

2 Corrasion - Particles being carried by the river thrown againsts its banks

3 Corrosion - Chemical Reaction between rocks types in river water .

Process of biological weathering

 Seed is dropped in a crack soil is trapped around it - seed germinates - puts out roots wich crack/break the rock apart

Soil creep

Slowest downhll movement - gravity pulls water in the soil - soil particles move with water heavy rainfall causes faster downhill move - slope has ripples called Terracettes

Slumping

 Happens when a bank slips into a river , common where river passess through clay . Dry weather makes the clay contract & crack- when rain falls -water gets into cracks absorbed making it heavy- suil becomes saturated - rock is weakened & slips into river pulled by gravity . rock has slipped on the slip plane of rock .

key terms page 49

Waterfall formation

Draw Plunge pool formed by force of water . Deepened by Corrasion as sediment being carried by water scraped against the bottom & sides . 2

2 Soft Rock erroded by slash back caused by Hydraulic action 3 overhang has fallen due to lack of support & pull  of gravity . waterfall retreats up stream to leave a gorge .

Interlocking Spurs 

are barriers of hard ressistant rock which the river cannot easily erode . the river weaves its way around them .

diagram 

meander & ox- bow lakes diagrams pg 51

Flood plain

area flat land on either side of a river

when 2 muck water in the river this area will flood as water moves out of the river onto the land .. the water on the land is shallower - therefore more friction & sediment is dropped.

the water drops the heaviest material on the banks - lighter material ie silt further away . deposited material forms floodplain

Levee - a high bank at the side of a river which is built up at times of flood .

Physical causes of river flooding=Valley has steep slopes -water will move into rivers quickly causing freq flooding . Areas formed from impermeable rocks - floods often . Rain over a no of days ground becomes saturated-excess water flows stright in rivers causing floods  .Heavy snowfall & sudden rise in temps rapid thaw - rivers unable to cope with amount of water.  

Human causes = vegetation removed from slopes - less interception - water moves quickly to rivers .a dam could burst meaning nmore water in river channel flooding river & land.famers who pough up & down slopes instead of around the hillside -channels created by pough allow rain water t travel faster . tarmac in urban areas rainwater cannot soak into ground runs to drains causes rivers t flood

removal of vegetation is classed as human & physical cause of river flooding It is humans that remove vegetation . But this stops the physical process of interception

explain how urbanisation & deforestation causes rivers to flood

urbanisation - building of towns the ground is covered in tarmac & concrete -cannot soak up rainwater so it flows straight t drains & rivers -causing flooding

Deforestation - Removal of trees means less interception takes place so there is more surface run off floods

 EXAMPLES -Explain the afects of river flooding  

BULGARIA river Danube flood  2006-2 mill people affected/ 20 killed  by flood as their homes were destroyed.. Large areas of farmland destroyed leaving  food shortages  . road impassable bridges & train lines washed away .

Mexico 2007 river Grijaiva - 1 mill people affected  70 % state under waterall crops destroyed  , sand bags rond La Venta Archeaological Site 

** remenber people & environment factors - IMPORTANT

Building Design -houses protected Sockets high up walls , doors light weight can be moved upstairs , concrete floors instead of wood , yaht vanish on wooden skirting proctective against water . property built on stilts 

Planning - flood risk assessment has to be carried out in certain areas b4 PLANNING PERMISSIOIN GRANTED. 2010 a new law passed all new housing in flood risk areas be resisstant t flooding . Defra departm for environment food & rural affairs responsible for deciding which areas going t be defended & funding avail yto help prevent flooding .Forcasting Met office FORECASTS FLOOD WARNINGS TV RADIO weBSITES  - RING FLOODLINE Education govern provide info via websites flood watch - codes advising public what to expect & do .