Water Flashcards
Suggest one reason for the differences in the growth of electricity generated from solar power (China and EU countries). (3)
The EU has seen a slower growth rate. This is due to EU countries having to come to agreements as many countries are joined together and EU may be prioritising other matters such as climate change or finding other renewable resources that are more effective, such as wind power.
Assess the impacts of climate change on the flows (processes) in the hydrological cycle. (12)
Climate change is caused by the increase in CO2 and methane emissions from human uses and combustion of fossil fuels. This has caused the greenhouse gas effect and affected the hydrological cycle by the distribution of temperature and precipitation.
Climate change causes temperature to increase, causing global water cycle to become very intense. It means the weather is very wet or very dry. There is more evaporation and transpiration, so more water vapour is in the atmosphere and deficiencies on surface of water so more extreme droughts occur such as in California where 13 months of continuous drought occurred and $44.7 billion was lost in the agricultural industry.
On the other hand, if evaporation intensity increases, precipitation also increases, so in some parts to the world, harsh precipitation has caused mass flooding. Such as in Pakistan, where 1/3 of the country was submerged in 2022 and $10 billion damage had been caused to the agricultural industry.
Increased temperature, causes glaciers to melt which temporarily increases the river flows, and the stores of the cryosphere decreases.
In conclusion, climate change does have a natural linked process to hydrological cycle. The greatest impact climate change causes on the cycle is the process of evaporation and precipitation as aformentioned.
Explain one impact of an El Niño event on the hydrological system. (3)
During El Nino the figure shows that the precipitation levels will drop in North Brazil, meaning less river flows, high chance of drought so more crop failure and rising food prices.
Explain how the physical feature of a drainage basin affect the shape of storm hydrography. (6)
Storm hydrograph shape depends on the physical features such as size, density , drainage, soil etc).
Main features of a hydrograph:`
Once the rainfall starts, the discharge begins to rise - rising limb
Peak rainfall and peak discharge is shown. The time between this is called lag time, which is needed to ensure water can move from ground to river.
Falling limb occurs when the discharge of rainwater begins to decreases. Eventually the rivers discharge returns to normal.
The shape of a hydrograph can vary from one river to another due to physical characteristics. Rock type, drainage basins with impermeable rocks will mean water reaches river more quickly so a steeper rising limb and shorter lag time. This concept is the same for less vegetation.
Topography, steep slope means more flow so reaches river quickly which creates a steeper rising limb and a shorter lag time.
Assess the role of physical factors in influencing the pattern of future water stress (12)
By 2040, from the figure, we can see that there is a higher demand than supply for water which has caused stress. This can be due to enhanced climate variability, and the demand due to increasing population and improving living standards.
A physical factor is climate change, which increases temperature so evaporation is faster and causes extreme droughts or extreme floods. Places like the Middle East which is already arid, would have extreme water stress due to this. This goes for parts of US and Australia as well.
The distribution of precipitation , also affects water stress. As some places have months of water shortages due to droughts occurring and lack of rainfall, such as California where major droughts occurred for 14 months.
Due to rapid economic growth and industrialisation in places such as China and some of South East Asia, there is water stress and water is needed to cope with the population rise and for factories to run.
Overuse of water due to development and higher standards of living due to more wealth has caused water stress and caused some items (such as agricultural food) to be more expensive and on demand. This can be seen on western countries such as Spain and UK.
Human has a role in water stress as well as physical but physical may play a more significant role as precipitation and water availability in stores need to be available in the first place. Hydrological cycle plays a fundamental role.
Explain the relationship between precipitation and soil moisture (3)
As precipitation decreases the soil moisture increases (negative correlation). From April to June where soil moisture is used, evapotranspiration is higher than precipitation levels meaning water is being used from the soil moisture store to meet the demand.
Explain why land use changes can increase flood risk (6)
As the economy and population grows during the 20th century, land use have been changed from agricultural and natural landscapes to industrial and urban purposes, to meet the living standards for the people. These human activities have impacted the hydrological cycle and caused increase flood risk.
For example, in Houston, millions have flocked to the metropolitan area and developers have paved over crucial areas of prairie land that once absorbed huge amounts of rainwater with tarmac, this has made water impermeable and more vulnerable to flooding. This caused mass flooding and $5 billion damage in the tropical storm Allison.
Houston has 600,000 acres of flood absorbing land, recent development has caused 150,000 acres to only be left due to building of houses and apartments to accommodate for the population.
In addition, overgrazing of previously forested areas for usage of land results in faster run off and higher peak discharge as less interception by vegetation which increases the risk of flood. As well as blocked drains, saturated ground all which fuelled the extreme flooding that occurred in Cumbria 2015.
Evaluate the view that large-scale water management projects often create more problems than they solve for people and the environment. (20)
Because of the wide range of players involved in the use of water resources, there are inevitable conflicting views to large scale water management which sometimes causes problems.
Nearly 60% of the world’s major rivers are impeded by large dams, such as the Mekong. These dams collect water and reduce water shortages for that country however it causes problems such as it being immense cost and the disruption downstream of the transport of silt, and less water. 2 million people suffer from drinking unsanitary water from the pollutants.
Yet these schemes often alter the water quality and cause conflicts with downstream users who can no longer utilise the resource such as those farmers on the River Colorado in Mexico as well as destroying ecosystems such as the delta of the river Colorado.
Can also cause transboundary conflicts - Palestine (rawabi) and Israelis for development of water .
In conclusion, water is a finite resource and with the points aforementioned it is almost inevitable that large scale water management will cause problems for people or the environment.
