Water Cycle EQ3 Flashcards
Human factors diminishing water supply
Human activities can lead to both diminishing supplies and rising demands
Quality:
- Humans can pollute groundwater supplies, with it’s impacts felt especially in developing countries
- The pollution of surface waters is an issue in many emerging, industrial countries for example China. 300 million people use contaminated water daily and 190 million people suffering from water related illness annually. 75% of lakes are considered polluted
- Common types of pollution into water sources include untreated sewage disposal, fertilisers, industrial waste. In India, only 20% of waste is treated before being dumped into rivers
Quantity:
- Rising demand for water fuelled by population growth results in reduced water supply, as well as increased affluence in emerging countries allows for more consumer products that are water intensive
- The energy industry requires increasing amounts of water for new energy developments such as biofuels
Price of water is determined by a number of factors
- The physical cost of obtaining the water
- The degree of demand for water
- Level of infrastructure: in poorer countries, many have to rely on tankers and bottled water with vendors that charge almost twice than standard tap water
The Aral Sea- negative impacts of irrigation
- Aral Sea has been steadily shrinking and is now only 10% of it’s original size after the soviet government diverted much of the water from it’s main rivers for irrigation
- Fishing community once thrived in the region and employed 60,000 people but has now collapsed
- Health issues have been apparent in locals caused by the salt and dust from the dried-out seabed. The remaining parts of the sea are polluted with industrial waste and fertiliser run-off
- However, this irrigation scheme based on the Aral Sea have allows this poor countries to become one of the largest exporters of cotton
Water conflicts
When demand of water overtakes supply, and a number of players wish to use the same diminishing water supply, conflicts may occur
- Between 1948 and 2009, nearly 2000 international events occurs, with only 25% leading to any form on conflict and only 1.5% leading to serious wars
- The main cause of water conflicts is about the availability of water, especially regarding plans to divert water in a river basin that will effect another part of the same basin lower down. The other common cause of conflict are plans to build dams or canals and the impacts. Most actions against these plans are political protests, instead of military or terrorise acts
- The most likely scenario for conflicts to develop into wars are where river basins are transnational or where disputes over water are one item on the agenda for a wider war, for example Israel and Palestine.
Conflict on the Nile- International conflicts
- The 6700km long river is the largest in the world, and covers about 10% of the African continent
- 11 countries compete for the Nile’s water
- One of the key geopolitical features of the Nile basin is the large number of national borders that traverse it
- Currently over 300 million people live within the Nile Basin
- Egypt is dependent on the Nile for 95% of it’s water needs, while others states such as Ethiopia, need large supplies of water for cross irrigation, HEP and industrial processing
- For water conflicts to occur, there must be underlying water scarcity issues
- While many African countries do not have physical water scarcity, many suffer from economic scarcity, whereby they lack the capital and technology to exploit supplies
- Demands from growing populations and development combined with climate change could see a range of African countries potentially water scarce by 2025
- International agreements agreed by colonial masters has caused issues in terms of unfair allocation of water supplied, for example in 1929, the Nile Waters Agreement agreed that the majority of the water would go to Egypt and Sudan, and only 14% going to other countries
China’s South-North Transfer project
- The south of China is rich in resources but the North is not. To redistribute and even water supply, a diversion project began in 2003
-It is expected to cost close to $100 billion and take 50 years to complete - Central government will provide 60% of costs, with local authorities providing the rest
- Critics are concerned about the risks, such as ecological and environmental impacts, resettlement issues and worsening water quality
Mega dams
- Nearly 60% of the world’s rivers are impeded by a dam
- These dams have the ability to store 15% of annual global run-off, which would add a large supply of blue water
- Evaporation rates are high as many dams are located in arid areas
- With rising concerns about global warming, there is a move to renewable energy
- In developed countries, most attractive HEP sites are already in use, whereas many African countries have plentiful sites to construct dams, largely for HEP to fuel economic growth
Sustainable water management in Singapore
- This is a country that receives lots of rain, but has limited land for water collection and storage of rainwater, as well as high evaporation rates and lack of groundwater storage
-They have therefore invested in recycled water, known as NEWater and desalinated water - NEWater is high-grad recycled water. Singapore’s four NEWater plants can meet up to 30% of their water needs, and aim to meet 55% by 2060
- They have agreed until 2061 to import water from Malaysia
Smart Irrigation in Australia
- Smart irrigation aims to provide crops with a suboptimal supply of water causing mild stress during growth stage so they become less sensitive to moisture deficiency
- In Australia, smart irrigation of fruit trees yielded an increase in water productivity by approximately 60%, and a gain in fruit quality
