Water Cycle Flashcards
why are there concerns about safe potable water?
only 3 percent of the worlds water is freshwater with 79 percent of this water being locked up in ice or glacier
the cryosphere has experienced depletion over years therefore mixing the freshwater sources with salt water
this means there is a decreasing level of potable water as salt water is inadequate for human consumption without desalination at high costs
define sublimation
conversion between solid to gas without becoming a liquid
define ablation
the removal of snow and ice from a glacier or iceberg by melting or evaporation
define accumulation
the build up of a glacier due to the input of snow which is compacted into ice
explain the role of cryospheric changes in the water cycle
- the cryosphere is a major water store
- during an period of cooling the cryosphere will grow in size due to accumulation so sea levels fall
-during a period of warming the cryosphere will decrease in size as the ice undergoes ablation, returning the water to the sea and causing rising sea levels - overall cryospheric processes have a regulatory role in sea levels
outline the stores of water operating in a hill slope
-interception storage is when precipitation lands on vegetation or other structures before reaching the soil. this is a temporary store of water as collected water may evaporate quickly or fall from vegetation as throughfall
-surface storage is the total volume of water held on the earth’s surface in puddles, ponds and lakes
-groundwater storage is water stored underground in permeable rock strata
outline flows within the water cycle operating on a hill slope
- infiltration occurs when the water moves from the surface and down through the soil until is reaches the groundwater. the infiltration capacity refers to how quickly infiltration occurs which is influences by soil saturation or land use
- surface runoff occurs when water runs directly over the ground which might occur when the soil is saturated or there are impermeable surfaces
- groundwater flow is when water moves through permeable rock under the force of gravity. This is the slowest flow of water on a hill slope
outline an example of a positive feeback loop in the water cycle (albedo effect)
- increased global temperatures result in increased melting of the snow and ice
- this causes a reduction of surface albedo due to a decrease in the amount of white surfaces
- this means that more sunglight is absorbed by the land and the sea instead of being reflected to back
- this causes the global tempeartures to increase further which causes greater mleting of the snow and ice
describe the location of the amazon rain forest
the amazon rainforest is located within the Amazon river basin in the South American continent. It covers almost 8 countries including Brazil and Peru. It is situated a few degrees south of the equator.
how has deforestation increased in the amazon rainforest?
- the amazon rainforest has experienced a rapid increase in the rates of deforestation which is greatly attributed to a growing global population over recent years which contributes to greater demand for agricultural processes, logging, and settlement growth. under the past four years of the Bolsonara government, the Amazon rainforest has seen 2 billion trees felled and an estimated loss of 23 percent of the Amazon rainforest biome in the following eight years if Bolsonara’s policies continue unchanged.
how does agriculture affect the water cycle
World demand for food is expected to rise by 60 to 100 percent by 2050, driven by a growing global population. modern agriculture is integral to supply food to the global population however the practice has largely impacted the hydrological cycle. the River Tyne’s upper course is situated in the rural areas of Northumberland in which the land is predominantly used for commercial farming. through arable farming the surface runoff rates can increase as post-harvest fields are bare of vegetation thus minimising the interception rates. Subsequent precipitation can then exceed infiltration capacities of the soil resulting in increased overland flow.
how does deforestation affect the water cycle (atmospheric moisture)
-vegetation contributes to the atmospheric moisture levels through evapotranspiration. The moisture in the atmosphere attributes to the formation of clouds which cycle water back onto the rain forest through precipitation. this moisture can travel globally influencing rain patterns in south eastern Europe and china.
- through the widespread removal of the trees during deforestation, in the amazon rain forest the rate of evapotranspiration has declined, with the forest flux rate of transpiration falling by 1km3 per year over the decade. this has lead to a less humid environment and a subsequent reduction in rainfall which promotes droughts and desertification to occur.
-through a rise in drought periods, the arid environment is vulnerable to the spread of wildfires with such fires materialising in 1997 to 1998 in conjuction with the dry conditions created by el nino. these fires burnt acres of fores through Brazil, Columbia and other areas and researchers warned that 400,000 km2 of the Amazon rainforest were suseptible to the threat of fire
how does rock type influence the water cycle
if a river catchment predominantly consists of an impermeable rock type, such as slate, the rock prevents water from permeating the ground therefore constraining the water to rapid overland flow.
in contrast a river catchment which consists primarily of a permeable rock type will encourage a slower transfer of water via groundwater flow as the water can infiltrate the ground surface.
urbanisation alters the permeability of the land through the construction of impermeable surfaces such as buildings and transport routes. The River Tyne’s lower course, which is situated in the north east of england, is utilised predominantly for infrastructure including residential housing and industry which was developed between the 13th and 20th centuries due to the Tyne’s major role in the coal industry to drive industrial development. this means infiltration processes are impeded and surface run off is greater.
how do seasons influence the water cycle
-UK rainfall has a tendency to be greater during the winter and autumn months. in these seasons the precipitation rates are greater than the evapotranspiration rates therefore resulting in a water surplus. The greater amount and duration of the precipitation means that the drainage basin will experience greater saturation of the soils leading to the soil reaching its field capacity and impeding infiltration. Subsequently, the river regime of this basin would present a rapid increase in river discharge during the winter months. On June 28th 2012, Newcastle Upon Tyne received months worth of precipitation in just two hours. As a result this contributed to £70 million worth of damage in the area surrounding the river Tyne.
describe the relationship between the carbon and the water cycle.
-increased levels of atmospheric carbon dioxide promote a greater greenhouse effect therefore contributing to higher temperatures on earth and greater ablation of snow and ice
-carbon dioxide may become dissolved in the rainwater causing the formation of a weak carbon acid that falls as acid rain and contributed to chemical weathering of carbonate rocks
-the photosynthesis process relies on precipitation and the absorption of carbon dioxide in order to conduct the chemical reaction.
-greater levels of carbon dioxide contribute to ocean acidification as they become less alkaline as carbon dioxide becomes dissolved in the water.
