Case Studies

• Tropical rainforests have an annual rainfall of over 2000mm a year and an average temperature of 27 degrees
• Tropical rainforests are home to 200 million people and to about half of the world's species
• The rainforest water cycle is very unique, 75% of precipitation is intercepted by the dense forest canopy, around 25% is evaporated. Only half the rainfall intercepted by the canopy ever reaches the ground
• Deforestation can have large impacts on rainfall patterns. Forests being replaced by pasture and crops leads to a reduction in evapotranspiration and then there is reduced atmospheric humidity and less rain.
• The rainforests are a carbon sink as the climate conditions are ideal for plant growth, and this leads to an increase in the amount of CO2 absorbed from the atmosphere
• Wood is about 50% carbon, so rainforests are a huge carbon store
• The Amazon rainforest covers 40% of South America and is home to 20 million people
• Average discharge in the Amazon rainforest into the ocean is 175,000m^3 every second
• Around 50-80% of the water in the Amazon rainforest remains within the system, the rest evaporates and falls as rain in places as far as Texas
• The Amazon has an average annual rainfall of 2800mm
• The Amazon holds 100GtC in above ground biomass
• The Amazon is home to 1600 tree species
• The Amazon is a carbon sink, it absorbs 2.2 GtC/yr and releases 1.6 GtC/yr, but due to deforestation this could change
• Natural changes in the Amazon

  • Decrease in river discharge leads to a decrease in rainfall
  • Forest scrub which replaces trees stores 40% less carbon
  • As CO2 increases, trees grow and die much faster
• Human change in the Amazon

  • A football pitch sized area cut down every minute
  • Cattle ranching is responsible for 70% of deforestation
  • 30-60% of carbon is released when trees are burnt
• Rondonia is a state in Western Brazil which borders Bolivia. It is home to the protected indigenous settlement of the Uru-Eu-Wau-Wau tribe
• Social Effects of deforestation in Rondonia

  • Wildfires have led to an increase in air pollution which leads to an increase in health issues
  • Indigenous people are facing a 'war for survival' with basic requests being ignored
• Economic effects of deforestation in Rondonia

  • When Jair Bolsonaro was elected president, the Amazon was vulnerable to all types of exploitation, and this impacted Rondonia
  • People are migrating out of Rondonia for jobs, leading to an economic decline
• Environmental effects of deforestation in Rondonia

  • Increase in wildfires since 2018 is further deforestation
  • The area faced droughts in 2005 and 2010 due to a lack of water recycling following deforestation.
• IBAMA work in the Amazon to monitor deforestation and monitor that it isn't intruding into indigenous land
• REDD is a scheme in the Amazon which allows people to pay to offset their carbon emissions, the money is used to further protect rainforest and plant additional trees
• Rondonia is looking at learning indigenous practices such as 'black earth soils' (soils containing high levels of organic matter) and shifting cultivation, which is where crops are cycled to allow used ground to recover
• The Calder river flows for 400m and has a drainage basin covering 369 sqkm
• The Calder Valley is located in West Yorkshire
• The source of the Calder River receives 1500mm of rainfall, and the mouth receives 600mm of rainfall due to the source being much higher up and receiving a larger amount of relief rainfall
• Impacts of the 2015 Calder Valley floods

  • 4416 business damaged
  • 2781 houses destroyed
  • Losses of £47 million
  • Flood relief centres set up
  • Sewage floods
• Hard Engineering in response to the 2015 Calder Valley floods

  • £46 million spent at Mytholmroyd on raising river banks and moving a bridge
  • Reservoirs in the drainage basin kept no more than 90% full to prepare for extra water
• Soft Engineering in response to the 2015 Calder Valley floods

  • Slow The Flow: volunteer organisation which constructed so called 'leaky dams' in an attempt to slow the flow of water and reduce floor risk
  • Treesponsibility: volunteer organisation which played 10,000 trees to increase natural interception