Water & Carbon - Case Studies

• Middle Aire:

  • The Middle Aire operational catchment includes the urban areas of Keighley, Bingley, Shipley and Bradford. Despite this there are large tracts of unspoilt moorland, seemingly in touching distance of town centres. 
  • Bradford Beck (culverted in the centre) drains the highly urbanised basin of the city centre. 
  • Significant water management issues here include physical modifications, point source pollution and the flow of water from reservoirs.
• Lower Aire  (1/2):

  • Leeds is the third biggest city in the country and it dominates the lower Aire operational catchment.
  • The growth of the city has changed both the quality of the river and the channel through which it flows.
  • Historic pollution has been enormously reduced.
• Lower Aire (2/2):

  • Between Leeds and Castleford where the Aire joins the Calder there are important wetland habitats, sometimes the consequence of mining for coal. 
  • The final 20 km of the Aire below Chapel Haddlesey weir is tidal. 
  • Significant water management issues here include physical modifications and pollution from urban and transport sources.
• Upper Aire - Flooding:

  • This area is mainly rural with steep gradients. The communities of Earby and Gargrave are located within the sub-area.
  • The River Aire, Eshton, Earby and Broughton Beck cause river flooding.
  • Some communities are susceptible to rapid flooding from thunderstorms. The constrained channel and environmental concerns mean that further flood defences will be difficult, expensive and unsustainable.
  • The Environment Agency, the organisation who plan flood defences, need to reduce surface water runoff and reduce the risk of flooding locally.
• Upper Aire:

  • The Upper Aire catchment includes over 30 km of the River Aire from its source near Malham Cove to the confluence with the River Worth at Keighley. 
  • In between it is joined by a succession of small becks flowing off rolling, well-grazed hills. The Upper Aire valley is predominantly rural, with the market town of Skipton being the main urban area. 
  • Almost half of this catchment lies within the Yorkshire Dales National Park and tourism is an important part of the local economy. 
• Malham Tarn:

  • Land surface is covered in bare rock, has light vegetation and steep slopes
  • Makes flooding regime flashy 
  • Limestone surface
• Malham Tarn Catchment:

  • Malham Tarn Catchment is part of the Upper Aire Catchment 
  • Is the source of the River Aire, rainfall in the catchment flowing in Malharm Tarn before outflowing into Malham Beck and then into the River Aire 
  • River Aire flows through Skipton and then through former industrial towns of Keighley, Bingley, Saltaire and Shipley before Leeds. It joins the Calder at a confluence in Castleford.
• Why is the River Aire susceptible to flooding?

  • Very reactive river --> responds to rainfall quickly, causing a high peak discharge
  • Surrounded by a clay-like soil which is impermeable, increasing surface run off
  • Lots of impermeable surfaces because of urbanisation in the lower course
• The ITCZ:

  • The ITCZ (Inter-Tropical Convergence Zone) is the point where the 2 Hadley cells meet at the equator.
  • Here air pressure is low and evapotranspiration happens in huge amounts causing lots of rain, this in turn leads to the rich vegetation and biodiversity of the tropical rainforest
• Amazon Rainforest - Characteristics:

  • Amazon has a prevalent annual wet and dry season due to Latent Heat
  • Highest level of Precipitation is in March
  • Lowest level of Precipitation is in August
• ENSO (El-Nino Southern Oscillation):

  • An increase in atmospheric temperatures will increase the rates of evapotranspiration. Sea temperatures are expected to warm, particularly in the Pacific Ocean. ENSO may occur more frequently 
  • Inland, a decrease in precipitation during the dry season. Reduced rainfall and prolonged drought are features of an ENSO year. More intense rainfall during the wet season
• Amazon Rainforest and the Water Cycle -  Drivers of Change:

  • The Amazon rainforest has lost approximately 20.3% of its primary rainforest in the last 50 years.
  • 80% is due to cattle ranching. Other reasons include logging, mining and for housing
  • It is most apparent in the east and south east parts of Brazil and in the north-western arc in Colombia and Ecuador.
  • Between 2000 and 2007, 19,386km2 was being destroyed per year.  That rate is now 5-7 000 km2.
• Amazon - Carbon Sink/Source:

  • Amazon has been shrinking by 0.3% since 2000.
  • In a typical year the Amazon absorbs 2.2 billion tonnes of CO2, whilst emitting 1.9 billion tonnes through decomposition and respiration of organisms.
  • However its capacity to absorb carbon is declining. In the 1990s, the Amazon was absorbing 2 billion tonnes, by 2015 this had decreased to just 1 billion tonnes.
  • This is less than the total carbon dioxide emitted by Latin America in the same year.
  • No longer represents a continental carbon sink.
• Amazon - Carbon Sink/Source:

  • Decomposers will be largely absent from this environment
  • The Amazon is estimated to store between 80 and 120 billion tonnes.
  • Rainforests around the globe act as carbon sinks of around 1-3gtC/year.
  • Biomass of these rainforests have been increasing due to increased sequestration of co2 concentrations. This acts as a negative feedback loop.
  • It is assumed that increased co2 levels encourage biomass growth. However, although rainforests are growing quicker, they are dying much sooner.
• Soybeans (2/2):

  • Increasing demand = expanding soybean cultivation into new areas such as the forests in the Amazon region. Advances in farming methods and crop varieties have made it possible to grow soybeans profitably in tropical forests.
  • The UK imports more soybeans for animal food from Brazil than all the other countries combined 
• Soybeans (1/2):

  • Soybeans are an important industrial agrifood crop, primarily used for animal feed, human food, and production of biofuels.
  • However, only six per cent of soybeans grown worldwide go directly into food products for human consumption
  • Brazil is now the second leading soybean-producing country in the world 
• Amazon Rainforest - Facts (1/2):

  • The world’s biggest rainforest at 6.9 million square kilometres
  • The rainforest is home to the second longest river, which is approximately 6,400 kilometres long with its river basin totalling a length of 6.6 million kilometres.
• Amazon Rainforest - Facts (2/2):

  • Its climate is humid and hot, with mean monthly temperatures ranging between 25° and 27°C and rainfall averages approximately 2677mm per annum, which is x2.5 larger than the average annual rainfall of Leeds.
  • However, Southern and Eastern areas of the rainforest experience a short dry season, which leads to fuel being created, allowing for forest fires to occur quicker.
  • A majority of these forest fires are caused by loggers and ranchers in order to clear fields quicker, however this releases carbon dioxide that has been stored within those trees.