Introduction

Question 1

extent of the hydrosphere

Answer 1

15 km in the atmosphere to 1 km in the earths crust

Question 2

Hydrologist challenges

Answer 2

• manage resource quality and quantity
• protect fresh water from degradation
• mitigate against water based natural hazards

Question 3

Global water stores

Answer 3

Oceans
Freshwater = 2.5%

Freshwater:
- surface water = 1.2%
- groundwater = 30%
- glaciers = 69%

Surface water:
- ground ice = 69%
- lakes = 20.9%

Question 4

residence time

Answer 4

average time for a water molecule to pass through a store
- very long for groundwater

T = mean stored/ mean input or output

Question 5

catchment water balance fluxes

Answer 5

• precipitation
• interception by vegetation
• infiltration into soil
• evaporation
• plant transpiration
• surface runoff
• interflow = lateral movement in unsaturated zone
• percolation = down from upper soils to GW
• gw

Question 6

catchment definition

Answer 6

area where water collects and drains at a common point

satisfies mass balance

Question 7

measure rainfall

Answer 7

Rain gauge: point scale with frequency of days
+ high precision, cheap, low maintenance
- only one point

Weather radar: ~1km2 scale, f ~ 5mins
+ high space time resolution
- expensive, inaccurate, sensitive to topology and climate

Satellites: ~1km2 scale, f ~ days
+ global coverage
- expensive, inaccurate, low space-time resolution, sensitive to cloud properties

Question 8

measure soil moisture

Answer 8

TDR
+ high measurement quality
- point scale, prone to damages

Neutron Probe

Satellite
+ global coverage
- inaccurate, sensitive to vegetation

Question 9

measure GW

Answer 9

Monitoring well
+ high measurement quality
- high cost
- low spatial coverage

Question 10

measure ET

Answer 10

• lysimeter
• eddy covariance system
• satellite

Question 11

measure streamflow

Answer 11

Translate depth to Q

Weir to create critical flow and measure Q
+ high quality, easy and cheap
- weirs can obstruct natural flow, need to construct rating curves