10 - impacts of humans on coastal processes

Question 1

what is integrated shoreline management

Answer 1

integrated shoreline management plans consider the coast holistically rather than on local scale

consider large scale sediment cells rather than just protecting one area

Question 2

how do conservation schemes protect

Answer 2

• global frameworks (world heritage sites eg great barrier reefs)
• establishment of marine reserves at national scale
• development of sites of special scientific interest

Question 3

factors affecting success of managed realignment

Answer 3

• estuary size and shape
• degree of wave exposure
• tidal regime
• current land use
• public perception
• research of the site ‘science’
• positive site management

Question 4

what is managed realignment

Answer 4

allows sea to flood areas that were previously protected

areas serve both flood defence and for wildlife conservation

seen as new way of adapting to rising sea levels

Question 5

positives of managed realignment

Answer 5

• more sustainable , produces new salt marshes and mudflats
• encourages natural protection
• provides possible reduction in cost of protection relative to employing hard engineering schemes

Question 6

positives of managed realignment 2 (increased…)

Answer 6

• increased intertidal width
• increased conservation potential
• retained naturalness of estuaries
• increased protection against sea level rise
• cheaper as lower value land flooded visit income potential rises

Question 7

problems of managed realignment

Answer 7

• danger of modifying tidal processes
• experimental technique that may fail
• complexity of compensation issues
• uncertainty about hydrological processes
• poor public perception of ‘giving up’
• can only be used on certain estuaries
• environmental values can be over estimated

Question 8

what is dredging and how does it impact the coast

Answer 8

• dredging for aggregates, sands and gravels taking place on variety of scales for shoreline protection and to improve shipping lanes and port access
• fine grain particles are released during dredging and these settle and affect turbidity of water and suffocates filter feeders
• when harbours dredged of mud it is taken out to sea and dumped offshore affecting ecosystems

Question 9

what can lead to sand dune erosion

Answer 9

• highly fragile environments
• human impacts eg urbanisation, golf courses, agriculture, forestry, mining, and tourist activities lead to sand dune erosion

Question 10

how can sand dunes be utilised

Answer 10

• conversion (new land use)
• removal (of sand for other uses)
• utilisation (using current resource for activities eg tourism)
• external (outside influence, eg removal of sediment supply from hard engineering)

Question 11

how does urbanisation influence sand dunes

Answer 11

urbanisation puts a layer of tarmac over the sand rendering the dunes immobile

campsites, barbecues, sand mining lead to dune break down

Question 12

what are the three main management approaches for dunes

Answer 12

1. heavily degraded areas require complete reconstruction
2. less severely degraded dunes can be restored and repaired
3. cause of problems tackled with holistic solutions

Question 13

what is the main objective of medmerry management as a positive impact of humans on coasts

Answer 13

to combat flooding coastal realignment has been used by surrendering land to sea

Question 14

what is involved in the medmerry realignment

Answer 14

costing £28m in West Sussex, 7km of new sea walls will be built up to 2km inland
by letting waters in it reduces risk of flooding for hundreds of homes and surrendered land provides new habitats for many species

Question 15

what was the scale of the medmerry coastal realignment

Answer 15

450,000 cubic metres of earth dug up
7km of new earthen defences built from soil
60,000 tonnes of rocks imported by ship to reinforce works
10km new drainage ditches/ponds installed
2 carparks, 4 viewpoints and 10km of cycle paths been constructed
350 homes, 2 holiday parks and water treatment works increasing protection

Question 16

what are the three key objectives of medmerry

Answer 16

1) sustainable flood risk management
2) creation of compensatory intertidal habitat
3) involvement of local communities

Question 17

what are some benefits of medmerry to humans

Answer 17

• around £90m direct economic benefit expected
• maintenance costs less than old shingle bank
• local economy received boost from increase in green tourism
• extended season for caravan parks generating income and jobs

Question 18

how does the great yarmouth demonstrate a negative impact of humans on coasts

Answer 18

• coastal erosion increased by dredging as it removes important sediment
• sediment starvation occurs
• in some cases dredging by modifying water depth induces wave refraction resulting in modifying longshore and crossshore sediment transportation patterns

Question 19

how has medmerry affected places further down

Answer 19

Winterton beach has suffered from increased quicker coastal erosion and sea defences have also affected regular replenishment as more is drawn down from shoreline

Question 20

what is the zandmotor project in the netherlands and what does it do

Answer 20

• mega nourishment of large artificial sand bank up to 5m above sea level, ‘building with nature’
• supports dune flood defences
• gradually supplies sediment to both sides using natural processes
• large scale experiment for innovative coastal management
• new habitat above and under water
• eco dynamic design as natural processes transport sediment downdrift

Question 21

what are facts and figures involved with zandmotor

Answer 21

21.5 million m3 of sand
2 miles by 1/2 mile above water
1 year construction designed for 20 year life
cost £60m

Question 22

how is zandmotor good for nature

Answer 22

• depositing a large amount of sand in one operation reduces repeated disturbance as natural forces (waves, tides, wind) transport sand to right place
• it also builds up stronger dunes to withstand inevitable rising waters
• leads creation of unique natural and recreational area that wind and sea currents will transform continuously
• area is an appealing habitat for a range of flora and fauna.