people and deltas

Question 1

how many deltas are there worldwide?

Answer 1

1813

Question 2

what percent of the total area of the world do deltas cover?

Answer 2

0.6%

Question 3

what percentage of the world population do deltas hold?

Answer 3

4%

Question 4

how has the delta’s population grown from 2000 to 2020?

Answer 4

237 million to 322 million

Question 5

what percentage does the delta population grow each year?

Answer 5

1.59% each year.

Question 6

how many people are there per km in 2000 and 2020?

Answer 6

322 people to 422

Question 7

what percentage live between 3-6 m elevation?

Answer 7

24%

Question 8

what determines the delta elevation?

Answer 8

the aggradation rate and how it rapidly builds up. natural conception rate, mass loading rate, eustatic SLR rate, anthropogenic compaction.

Question 9

how does natural compaction affect deltas?

Answer 9

moving so much sediment, it pushes and bends the layers. flexes the layers. ocean crust bends due to the weight and squeezes water out of the pores.

Question 10

how does mass loading effect deltas?

Answer 10

books on a shelf. the wet sediment id difficult to move around with. the more you load, the more pressing and adding weight. therefore, sinking elevation

Question 11

how does eustatic SLR rate effect deltas?

Answer 11

deltas can effect local sea rise. edge of delta is a changable position.

Question 12

SLR stand for?

Answer 12

sea level rise

Question 13

how does anthropogenic compaction effect deltas?

Answer 13

lowers elevation A LOT. if you build on a delta, extract fossil fields, natural gas, etc- gas and fuels migrate to below sea level. this can reduce elevation 3x as fast as the mass aggradation rate.

Question 14

what are the reasons for delta subsidence?

Answer 14

sediment supply, anthropogenic extraction, natural mass loading, relative SPR, vegetation distrubance.

Question 15

what is sediment supply?

Answer 15

natural flooding, mostly upstream but also from the ocean. dams, levees, channels. flooding is needed to get rid of the extra sediment.

Question 16

what is vegetation disturbance?

Answer 16

loss of marshes or mangroves, less able to trap sediment.

Question 17

what are the 3 different tyeps of deltas?

Answer 17

natural, engineered, nature-based

Question 18

what is a natural delta?

Answer 18

wetlands, land can rise in balance with sea level throughout accumuation.

Question 19

what is engineered delta?

Answer 19

embanked land with human land use like agriculture, cities, harbours, industry. land rise through sedimentation is prevented by flood-protectin structures like damns or dikes.

Question 20

what is nature-based deltas?

Answer 20

river cahnnels and open water in wetlands, with areas of human land use.

Question 21

what does ACI stand for?

Answer 21

anthropogenic conditioning index

Question 22

what does HEI stand for?

Answer 22

hazardous event index

Question 23

what does IDI stand for?

Answer 23

investment deficit index

Question 24

what are the risk trends for deltas worldwide?

Answer 24

this is mixture of ACI, HEI, and IDI.

Question 25

what are the estimated future changes in exposure and vulverability for selected deltas?

Answer 25

IDI and ACI, indicate a change in time due to increased in exposire and increase in vulnerability based on the difference between current and future estimates.

Question 26

why are human landscapes vulnerable?

Answer 26

where fluvial, oceanic or atmospheric processes render significant stretches of human-occupied land vulnerable to large changes and damage.

Question 27

what is the result of landscape processes?

Answer 27

directly impact economy by causing losses, changes in construction costs. indirectly impacting market behaviour, due to feedbakc to predictions by agents insude the simulation.

Question 28

what happened in 1953?

Answer 28

huge damage to Belgium and Netherlands, due to loss of landscape. this caused delta protection to start.