6 - Surface Hydrology

Question 1

Runoff

Answer 1

unconfined flow of water across land
- Occurs when there is more water than land can absorb
Human interventions (e.g. concrete) dominate over climate change effects

Question 2

What are the types of runoff?

Answer 2

1. Infiltration - the process by which water on the ground surface enters the soil
2. Saturation - occurs when all pore spaces in rock or soil are completely filled with water
3. Interflow
4. Subsurface return flow

Question 3

How is runoff measured?

Answer 3

Gauges (placed in rivers, measures variation in water level after rainfall), simulators (measure how much water makes It through soil) and remote sensing (determines where rain falls and land use type)

Question 4

Buffer zones

Answer 4

patches of land adjacent to rivers, streams and drains removed from intensive production and containing permanent vegetation

Question 5

Intertidal zones

Answer 5

salt marshes, mangroves, sea grass and coral reefs

Question 6

Diurnal

Answer 6

one high tide and one low tide each day

Question 7

Semi-diurnal

Answer 7

two high tides and two low tides each day

Question 8

What is tidal range determined by globally?

Answer 8

1. Shape and geometry of the coastline
2. Location of sun and moon (most important)
3. Positions and configurations of continents - in NH continents are closer thus constricting ocean

Question 9

Delta

Answer 9

a river delta is a landform shaped like a triangle, created by deposition of sediment that is carried by a river and enters slower moving or stagnant water

Question 10

Why do deltas form?

Answer 10

The gradient of a channel decreases as it reaches the coast. Flow expands and decrease in energy/flow velocity. The sediment drops out of flow and is deposited which layer upon layer forms land. When enough sediment is present it pushes its way into the coastline.

Question 11

Estuary

Answer 11

a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean

Question 12

What are dunes determined by?

Answer 12

Amount and size of available grains, wind/water speed and direction, wind frequency and presence of vegetation

Question 13

What are the biggest threats for river pollution?

Answer 13

1. Agricultural run off (N)
2. Surface run off from roads (chemicals)
3. Industrial contamination (heavy metals)

Question 14

What are the biggest threats for coastal pollution?

Answer 14

Industry, tourism, urbanisation, agriculture and aquaculture
- Pollutants = plastics, nutrients, metals and organic compounds
Illegal dumping and BBQs also pollute

Question 15

Salt intrusion

Answer 15

movement of saline water into freshwater aquafers which can lead to groundwater quality degradation including drinking water
- Soil salinization at coast
Intrudes into aquifers - irreversible

Question 16

PFAS

Answer 16

forever chemicals which resist natural breakdown. Cause cancer etc. only a few banned at EU level

Question 17

Microplastics

Answer 17

small plastic pieces less than 5 mm which can be harmful to ocean and aquatic life