5.7B Causes of water insecurity

• The causes of water scarcity are both physical and human:

  • Physical variation in climate, salt water encroachment
  • Human - over-abstraction, water contamination, industrial pollution
• Physical causes of water insecurity:

  • Climate variation can lead to drought this reduces the amount of water available
  • Salt water encroachment occurs due to sea level rise when freshwater sources are contaminated by seawater and so become saline:
  • Tuvalu has experienced damaged crops and a loss of income, further encroachment could affect deep-rooted crops such as coconut and taro
  • Saltwater encroachment in the Maldives threatens drinking water supplies and has also damaged crops

  
• Human causes of water insecurity:

  • Over-abstraction occurs when more water is taken than is naturally replaced by precipitation
  • Many countries around the world are affected by over-abstraction:
  • Jakarta and Beijing are sinking as a result of past over-abstraction of groundwater which is causing subsidence

  
• Water contamination (human):

  • Over 2.4 billion people live without sanitation
  • In developing countries 90% of sewage flows untreated into water sources
  • Agriculture discharges large quantities of agrochemicals, organic matter, drug residues and sediment into water sources
  • As the world population increases so does the amount of agriculture, further increasing the agricultural pollution
  • In the EU almost 40% of water sources are impacted by agricultural pollution
  • Increased nitrates from fertiliser use leads to eutrophication
• Industrial pollution (Human):

  • Every year 300-400 megatonnes of waste is discharged by industry into the water system
  • In many countries factory waste is discharged into water sources untreated due to a lack of regulations and a failure to challenge industries 
  • It is estimated that 80% of China's groundwater is polluted
  • This has led 70% of rivers and lakes to be unsafe for human use