Water Flashcards
what is a closed system
where energy can travel into, within, and out of the system
what is an open system
where energy and matter can travel into, within, and out of the system
what is a store/resevoir
a place where water is stored
what are flows
the processes that move water from one store to another
what is a flux
a flow with a quantity
what system is the hydrosphere
a closed system
what powers the global hydrological cycle
solar radiation and gravity
what are the top 3 stores of water on Earth
- oceans
- ice caps and glaciers
- groundwater
what is an aquifer
a manmade underground water store
what is inflitration
when water travels through soil
what is percolation
when water travels through rocks due to gravity
what is the cryosphere
the frozen parts of the planet
what is permafrost
- soil that has been frozen for more than 2 years in a row
- may be in patches or large areas
what are proportional flow lines
lines where as the quantity of water increases, so does its size and/or width
what are residency times
the average amount of time water molecules stay in a store
where are the longest residency times found
- ice caps and glaciers
- groundwater
- deep oceans and seas
where are the shortest residency times found
- biospheric water
- atmospheric water
- soil
why are residency times important
- help to manage water supplies
- increases the vulnerability of an area
what is a drainage basin
the area of land being drained by a river system
what is a watershed
the boundary of the drainage basin
What factors affect the inputs, stores, flows, and outputs of a drainage basin
- climate
- soil effects
- relief
- vegetation
- geology
- human impacts
What factors affect Precipitation (drainage basins main inputs)
- form
- amount
- intensity
- seasonality
- distribution
what is orographic rainfall
- when the relief of the land forces water to rise and fall
- usually has a wetter side
what is convectional rainfall
- buoyant parcels of humid air rise as the surface is heated
- warm air cools, condenses, forms clouds, and precipitates
- dry mornings and wet afternoons
What is frontal rainfall
- warm air masses rise above cold, denser air
- cold air moves one way and precipitates
what are the 3 main causes of precipitation
- orographic
- convectional
- frontal
what influences the amount of precipitation
- rates of convection (climate, pressure belts)
- monsoon climate
- continentality
- mountains (orographic rainfall)
what is a monsoon climate
distinctive wet seasons (2-3 months)
what is continentality
distance from the sea
which places are usually wet
places where air meets and rises
which places are usually dry
places where air meets and falls
How can humans disrupt the flows and stores within a drainage basin
- infrastructure (sewage, HEP, irrigation)
- groundwater extraction
- deforestation
- arable farming
- pasture farming
- urbanisation
- global warming
- lakes and resevoirs
How does deforestation impact the hydrological cycle
- increase in throughfall + decerase in interception = more overland flow
- decrease in evapotranspiration = less humidity and atmospheric moisture
- soil compaction = impermeable soil
what does soil moisture surplus mean
there is more rainfall arriving than leaving
what does soil moisture saturation mean
water is used up and decreases
what does ‘maximum annual temperatures’ mean
the hottest time and increased rates of evapotranspiration
what does soil moisture deficiency mean
all the water is used up and there are more outputs than inputs
what does soil moisture recharge mean
more rainfall is arriving than leaving
what does field capacity mean
soil is full and can’t store anymore
what is a river regime
the difference in the discharge of the river through the year
what does discharge mean
the volume of water that flows past a point in a river per second
what facotrs affect a river regime
- geology
- altitude
- land use
- climatic differences
what is a simple river regime
when a river has a high flow in one part of the year and a low flow in the other
where are simple river regimes found
in smaller rivers or climate zones
what are complex river regimes
rivers with multiple high and low flow periods
where are complex river regimes found
larger rivers or rivers than run through multiple climate zones
what factors influence the shape of a hydrograph
- geology
- shape
- relief
- land-use
- vegetation
what are the characteristics of flat hydrographs
- gentle rising limb
- long lag time
- low peak discharge
what are the characteristics of flashy hydrographs
- steep rising limb
- short lag time
- high peak discharge
what factors in flashy rivers determine the shape of their storm hydrographs
- passes through multiple climate zones
- intense rainfall
- impermeable rocks
- non-absorbant and hard soil (clay based)
- high altitude and relief (mountainous, steep)
- circular shape
- tributaries meet at one point
- a lack of vegetation
- saturated antecedent conditions
- more urban areas
what factors in flat rivers determine the shape of their storm hydrographs
- prolonged low intensity rainfall
- permeable rocks
- absorbant/porous and soft soil
- low altitude and relief (gentle plane)
- long shape
- tributaries meet at different points
- trees, shrubs, etc. in the area
- unsaturated and dry antecedent conditions
- less urban areas
- more dams/river management
why were Sustainable drainage systems (SuDS’s) introduced
introduced to reduce surface runoff produced by rainfall
what are meterological droughts
shortfalls in precipitation due to short-term variability in the long term average
what are hydrological droughts
reduced stream flow and groundwater levels due to reduced inputs of precipitation and high rates of evaporation
what do hydrological droughts cause
- reduced storage in lakes and resevoirs
- salinization
- poorer water quality
what are agricultural droughts
when rainfall deficiency from meterological drought leads to a deficiency in soil moisture and soil water availability
what do agricultural droughts affect
- plant growth
- reduction in biomass
what are famines
a humanitarian crisis where widespread failure of agricultural systems lead to food shortages, leading to severe environmental, social, and economic impacts
what can be measured to monitor and record droughts
- rainfall
- temperature
- soil moisture
- river flow
- surface and groundwater storage extraction rates
- time scale of drought
what are the physical causes of drought
- short fall in rainfall
- heatwaves
- late monsoon seasons
- ENSO cycles
- climate change
what are the human causes of droughts
- populaiton increase
- growth of industry
- deforestation
- contamination
- soil degredation
- salt water encroachment
- over abstraction
- climate change
WHat happens during El Nino Southern Oscillation cycles
- trade winds either flip or weaken
- this causeshot water to move towards S.America and make it wetter
- cold water upwells and is pushed towards SE Asia and Australia, making it drier
what happens during La Nina Southern Oscillation cycles
- usually occur after ENSO (lasts for 1 year)
- trade winds become more intense
- hot water is pushed owards SE Asia and Australia and causes intense rainfall
- cooler water upwells at S.Americamaking it cooler and causes more rainfall
what are ENSO cycles
a natural climatic cycle (2-7 years) where surface temperatures in the South Pacific change
what does the atmospheric circulation model show
- hot air meets at ITCZ and rises (wet)
- hot air meets cold air and sinks (dry)
- cold air meets and rises (wet)
what is the Intertropical Convergance Zone
the place where trade winds meet (near the equator)
what are the implications of the ITCZ
- places can be without rain if the ITCZ drifts or is late
- rainfall in equitorial nations are affected by seasonal shifts
- there are possiblities of severe droughts and floods in nearby areas
what is a monsoon
- a particularly wet season that lasts for around 7 months
- hot air rises and cold moisture replaces it
what is a blocking high pressure system
- when a high pressure system stays stationary over a place for a prolonged period of time
- causes a lack of rainfall
- can block more unstable weather moving in
- low pressure systems move around them causing other places to experience the rain
what is the Indian Ocean Dipole
the difference in sea surface temperature on either side of the Indian Ocean, altering rainfall patterns in the region
what happens during a positive IOD
waters in the Eastern Indian Ocean become cooler than normal, while waters in the west become warmer
what are the effects of positive IOD
- warmer water = rising warm, moist air = intense rainfall and flooding in E.Africa
- reduced atmospheric moisture over cooler waters of the eastern Indian Ocean turns off one of Australia’s most important rainfall sources
what is an ecosystem
a community of organisms that interact with each other and their environment
what are the impacts of droughts on forests
- foliage loss
- impaired growth
- increased forest fire rates
- turn from carbon sinks to sources
- crop failure
- biodiversity decline
what are the value of wetlands
- water sponges (slow releases = slow flood hydrographs)
- filter and clean water
- critical habitats
- stores carbon
- protects coasts from ice and storms (absorbs wave energy)
how do droughts impact storms
- increased tree mortality rates
- reduced biodiversity and habitats
- deliberate fires spread out of control
- acidification
- severe cracking and compaction
- loss of organic matter
- enhanced GHG emisions
what meterological causes make some areas experience surpluses in water
- intense storms
- flash flooding
- extreme monsoonal rainfall
- extreme snowmelt
what human causes make some areas experience surpluses in water
- land use within cathcment area
- mismanagement of rivers through hard engineering
What are some human causes of flooding
- mismanagement of hard engineering
- deforestation
- agriculture
- land use
- urbanisation
What are some physical causes of flooding
- multiple low pressure systems
- monsoons
- rainfall
- ENSO
- IOD
- shape of drainage absins
- relief
- soil and rock permeability
- snow/ice melt
what is the jet stream
- fast moving air which moves north and south
- a driving force which determines the direction of depressions and their speed of movement
how is climate change influencing the hydrological system
- reduction of cryospheric water
- increasing evaporation events and rainfall events becoming more intense
- more frequent, severe, and longer droughts in some places
what is water security
the capacity of a population to sustainably access adequate quantities of acceptable qualities. Water which is potable and unpolluted. Water which is preserving the ecosystem in a way that is politically peaceful and stable
what is absolute water scarcity
- if a nations renewable water resources are less than 500m^3/capita(year)
what is water stress
- if a nations renewable water resources are between 1,000 and 1,700m^3/capita
what are renewable water resources
the long-term average total of internal and external renewable water resources
what are internal water resources
the discharges or rivers and the recharge of aquifers generated from precipitation
what are external water resources
generated outside a country and include inflows from upstream countries and parts of a water body divided by a border
what is water scarcity
- if a nations renewable water resources are between 500 and 1,000m^3/capita
what are the human causes of water stress/scarcity
- industry dominance
- unequal disrtibution
- salt water encroachment
- development and infrastructure levels
- political tensions and conflict
- river management
- pollution and contamination
- over-use (population changes, industrialisation)
- changes in living standards
- water system and usage inefficiency
what are the physical causes of water stress/scarcity
- prolonged droughts and heatwaves
- ITCZ changes
- climate cycles and variability
- contenentality
- seasonality
- high pressure blocking systems
- ENSO
- bacteria growth in hotter waters
what is desalination
the extraction of salt from sea water to create potable water
what are the costs of desalination
- creates brine
- chemicals are dumped into the sea
- lacks key minerals
- high energy cost
What are some soft engineering strategies that maintain water supplies
- drip and smart irrigation
- nutrigation and fertrigation
- waste water mangement
- rainwater harvesting
- protecting and enhancing water storing ecosystems
- preventing leakages
- national education schemes
- scaled pricing
- adapted agriculture
- importing water storing foods
what is Integrated Water Resource Management
- a policy setting out that water resources are an integral component for ecosystems, a natural resource and a socio-economic good
- promotes the coordinated management of water, land and related resources in a sustainable way
