Droughts Flashcards Preview

Hydrology > Droughts > Flashcards

Flashcards in Droughts Deck (12):
1

Aridity

a perennial state of water shortage

2

Drought

a sustained and regionally extensive occurrence of below average water availability

3

What drives drought?

- weather
- catchment characteristics
- human drivers

4

Weather impact

- lack of precipitation
- surplus of evaporation
- reduced snowpack
- anticyclone: sinking air mass, persistence due to blocking pattern
- positive feedback of soil moisture (high temps, increased evap, higher temps)

5

Catchment characteristics impact

- geology (rock type, soil type)
- geomorphology (slope)
- land use and land cover

6

Human drivers

- farming (excessive irrigation)
- deforestation
- erosion

7

Drought categorisation

- meteorological: atmospheric demand
- hydrological: availability for runoff
- agricultural: plant demand

8

Standardised precipitation indices

a deficit of precipitation impacts on soil moisture, steam flow, reservoir storage and ground water level etc. on different time scales

9

Human causes of vegetation change

- overgrazing
- collection of fuelwood
- positive feedback
- bad agricultural practices

10

Climate changes

- ocean temperatures changes
- reduced monsoon intensity
- shift in ITCZ

11

Impacts of drought on the environment

- increased fire risk to: blanket bog, upland and lowland heaths
- abstraction for agriculture can worsen effects
- negative effects on habitats: implications for species

12

What can we do against drought?

- education of population
- good and sustainable agricultural practices
- reduce erosion and soil degradation
- improve forecasting and monitoring
- integration of science into policy