Water Flashcards
What is the global water budget?
the annual balance of water fluxes and the size of water stores
What is one type of non-renewable water source?
Fossil water
What is the drainage basin?
the area of land driven by a river and tributaries
What is the watershed?
the boundary of the drainage basin
What is orographic rainfall?
water vapour is forced up the mountain and it cools and condenses due to altitude. Precipitation then occurs over the mountains
What is cyclonic rainfall?
warm and cool air meet and as warm air is less dense it rises and condenses
What is conventional rainfall?
normally happens in a 24 hour cycle where insolation starts evaporation which leads to precipitations later in the day
Factors which factors which affect basin flows and fluxes?
Infiltration, interception, rainfall, overland flow, percolation and evaporation/transpiration
Physical factors which affect a drainage basin
Climate, soil, geology, relief and vegetation
Human factors which affect a drainage basin
Urbanisation, dams, deforestation and over grazing
Factors which impact river regime
Size of basin, precipitation, geology, temperature and human activities
What is a drought?
an extended period of deficient rainfall relative to the statistical multi-year average for a region
What is a meteorological drought?
occurs when long-term precipitation is much lower than normal
What is an agricultural drought?
occurs when there is insufficient soil moisture to meet the needs of particular crops at a particular time
What is a hydrological drought?
occurs when there are deficiencies in surface and subsurface water supplies, measured in rivers, lakes and groundwater
What is a socio-economic drought?
occurs when the water demand for social and economic purposes exceeds water availability
What are the physical causes of drought?
ITCZ, Mid-Atlantic blocking anticyclones, ENSO and other general processes (intense solar radiation)
What is the ITCZ?
A belt of low atmospheric pressure located around the equator moves north and south of the equator seasonally
wet seasons= when it arrives
dry seasons=when it moves away
What are Mid-Atlantic blocking anticyclones?
Precipitation is created when warm tropical air rises over cold polar air
These anticyclones bring stable conditions with little precipitation (heat waves) and forcing rain-baring depressions out
What is the ENSO?
El Nino is a naturally occurring large mass of very warm seawater in the equatorial Pacific Ocean
Warm moist air is pushed from South America to Australia by ocean currents, creating precipitation
What are human causes of drought?
over abstraction, reservoirs/dams, deforestation, overgrazing, enhanced greenhouse effect and urbanisation
What is an ecosystem?
an interconnected community of living organisms within a defined physical environment
What is a biome?
the specific geographical location where animals and plants interact
What are benefits of wetlands to humans?
research, tourism, aesthetics, education, freshwater source
What are benefits of wetlands to the environment?
maintain the hydrological cycle, habitats, high biodiversity, photosynthesis
What is flooding?
when a river exceeds bankfull discharge
What are human causes of flooding?
deforestation, global warming, urbanization, overgrazing
What are physical causes of flooding?
increased precipiation, natural disaster, impermeable rocks, rise in temperature, topography
How does climate change impact inputs and outputsof the hydrological cycle?
Increased evaporation, intense rainfall, flash flooding in urban areas, sea levels rising by 1m by 2100
What is water insecurity?
the capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality of water for sustaining human well being and socio-economic development
What are the 3 types of hard engineering?
desalinization, dams/reservoirs and redirecting water/transfer projects
LEDC drought case study
Sahel,Africa
MEDC drought case study
SE Australia
Percentage decline of rainfall in Australia
80%
Ecosystems affected by drought
Everglades (wetlands) Pinon Pines (SW USA)
Percentage of pine trees destroyed by bark beetles?
90%
Social impacts of UK storms
5200 homes affected (Desmond)
40 schools closed
2 deaths
Economic impacts of UK storms
Cost £50 million to help homes affected (Desmond)
9000 business properties flooded (Eva)
Major travel disruption (Frank)
Environmental impacts of UK storms
Landslides (Eva)
Water conflict case study
the river nile
Geopolitical issues around the river nile
Population estimated to double from 300 million to 600 million by 2030
Egypt is 95% dependent on the Nile but other countries such as Ethiopia are largely reliant for crop irrigation
Large scale water management
Three Gorges dam
Social impact of the Three Gorges dam
1.3 million people forced to relocate
Economic impact of the Three Gorges dam
HEP, tourism of scenic area lost, accessible shipping, cost $22-39 billion
Environmental impact of the Three Gorges dam
Reguates water flow and decreases flooding, reduced reliance on coal power stations
Sustainable water supply scheme/ technofix?
Chinas south to north water transfer
What percentage of water in the north of China comes from the south?
70%
