the rhone delta

Question 1

length of coast

Answer 1

90km

Question 2

deposition per year

Answer 2

26 million tonnes of sediment in 1900
1.5 million tonnes in 2000 due to human influence

Question 3

discharge

Answer 3

1,500m3 per year but can reach 6,000 m3 year in stormy conditions

Question 4

geology

Answer 4

silt (fine unconsolidated sediment)
no faults or folds in rocks
no discordant or concordant coastline (all unconsolidated material)

Question 5

when was the delta formed

Answer 5

7000 years ago when sea level rose after the last ice age

Question 6

wave or fluvial dominated

Answer 6

wave dominated delta
so lobes of sand change shape by LSD

Question 7

prevailing wind and fetch

Answer 7

NW (0m fetch)
small fetch (max 9000 km)

Question 8

flocculation

Answer 8

small suspended particles group together at the mouth of the river

Question 9

tidal range

Answer 9

microtidal
0.3m

Question 10

short term change to delta

Answer 10

human intervention
west to East LSD
tidal range of 0.3m
erosion from waves and storm events

Question 11

medium and long term change

Answer 11

change in volume of sediment from two rhone rivers
sea level rise of 2mm year
aeolian transport limited to sandy spits
human intervention

Question 12

cell 1

Answer 12

SW-NE LSD
gracieuse spit formed

Question 13

cell 2

Answer 13

W-E LSD
no spit due to water from grand Rhone

Question 14

cell 3

Answer 14

LSD from two directions converges
Beauduc spit and bar formed

Question 15

cell 4

Answer 15

long distance LSD
E-NW
L’Espiguette spit

Question 16

high levels of sediment accumulation impact on landforms

Answer 16

gently sloping landscape
0.3-3 degrees

Question 17

lagoons

Answer 17

formed when LSD moves sand to from bars
closed system

Question 18

Dunes

Answer 18

aeolian transport
behind beach
face SE

Question 19

brackish landforms

Answer 19

salt water marshes
e’tangs

Question 20

sediment source

Answer 20

70% coastline supplies sediment for Beauduc and L’Espiguette
sand from the Rhone provides sediment for Gracieuse spit

Question 21

human intervention

Answer 21

slat farms and Marseilles port are protected by artificial river dams
minimal

Question 22

future of the Rhone Delta

Answer 22

2mm year sea level rise
caused inc erosion
winds from SE cause larrge wave surges which combined with decreased sediment input from rives, cause distort equilibrium
costal retreat of 2-8m year and therefore groynes, rip rap ad sea walls