3.1.4 - Excess runoff

Question 1

Theory 1: Bergeron findeisen process

Answer 1

Clouds at high altitude contain water and ice crystals.
Ice crystals grow rapidly attracting vapour from eater droplets.
Ice crystals fracture by high altitude air.
More water condenses accelerating growth.
Ice crystals become too large falling to the ground and melt.

Question 2

Theory 2: Collision process

Answer 2

Super sized condensation nuclei (super water droplets) fall and collide with smaller droplets absorbing them.
Rapid fusion and raindrop growth.
E.g. unexpected downpours and flash flooding.

Question 3

Land use change and runoff

Answer 3

Urbanisation - impermeable surfaces
Deforestation - higher flood risk as no interception

Question 4

River basin management

Answer 4

Increased overland flow and flood risk

Question 5

LONDON - RIVER THAMES

Answer 5

Thames estuary 2100: management accounting for climate change, sea level rise and aging defences.

Question 6

CAPE TOWN - TABLE MOUNTAIN

Answer 6

Low rainfall from 2015-2018.
Water used for agriculture instead of being made available for people.
Dams less than 1/4 full.
Limited tourism.
Desalination.