Deficit in the Water Cycle Flashcards
What is meteorological drought?
An extended period of lower than average rainfall for the region.
What is agricultural drought?
Insufficient moisture to maintain crop yields.
What is hydrological drought?
Shortage in water supplies in surface and groundwater stores.
What is the seasonal precipitation variation in winter?
Precipitation is greater than potential evapotranspiration, so the soil water store will start to recharge until it is fully recharged.
What is the seasonal precipitation variation in spring?
Precipitation is greater than potential evapotranspiration. All the space in the soil has been filled and so it is in surplus. Groundwater gets recharged, overland flow can occur leading to floods.
What is the seasonal precipitation variation in summer?
Potential evapotranspiration exceeds precipitation. The water store is being used by plants.
Soil moisture store gets used up and any precipitation likely to go into the soil rather than into river channel so rivers dry up.
What is the seasonal precipitation variation in autumn?
There is a deficit of soil water, plants either wilt or adapt to survive dry conditions.
What is the El Niño Southern Oscillation?
Impacts on weather patterns around every 7 years, resulting in meteorological drought in some regions.
How does climate change affect the soil moisture budget?
Climate change results in long-term declining precipitation and meteorological drought.
How does aquifer depletion cause deficit in the water cycle?
Water is extracted from groundwater stores faster than it is replenished, which can reduce water levels in rivers and lakes.
How does surface store depletion cause deficit in the water cycle?
The use of water reduces river discharge and the size of inland bodies of water.
What are both groundwater and surface storage used for?
Domestic water consumption, irrigation of crops and industrial use.
What is the impact of over-extraction of aquifers?
It can cause land subsidence and a long-term reduction in storage.
What is a natural aquifer recharge?
Reducing extraction allows recharge by the percolation of precipitation and surface water to the aquifer.
What is artificial aquifer recharge?
Water is added to the ground surface or pits and basins are flooded, increasing the percolation rate.
The other method uses injection wells - water is pumped into the aquifer via a well.
