Week 1- Energy and environmental pollution Flashcards
What % of SOC do Peatlands typically store?
> 30%
Worldwide average of Peatland C density?
1450tC per ha
How much of C is stored globally in peat soils?
~550 Gt of C
What is Acrotelm?
Zone of living plants (e.g. sphagnum moss), partial aeration
What is the Catotelm zone?
No living plants, saturated , accumulating plan/humic materials
Structure of bog peatland?
Acrotelm- top. Catotelm- bottom
Where does accumulation occur in the bog peatland?
In the catotelm
Why does accumulation occur in the catotelm?
Because anaerobic decomposition under cold/wet conditions is very slow (< 1% of the aerated acrotelm)
What leads to aerobic decomposition in bog peatlands by micro-organisms?
Drying of peatlands/organic rich soil increases oxygen levels leading to aerobic decomposition by micro-organisms
What does decomposition in bog peatlands result in ?
Direct CO2 release and more leachable C upon re-wetting
What is the cause of increasing dissolved organic carbon (DOC) and total organic carbon (TOC)
concentrations of many rivers?
Drying of organic rich soils
Consequences of leachable C?
- Mobilisation of contaminates e.g. lead and mercury
- Greater load of contaminants to surface waters
- Implication for domestic water quality
- Costly treatment to remove organic matter and associated contaminant
What is a floating road?
A floating road on peat is a road built on soft, waterlogged peat soil, designed to distribute weight and prevent sinking.
Structure of floating roads?
One or two layers of geogrids: metal or polyester grids that the road
materials (gravel/stone aggregate) lock into, forming a stable layer that
distributes load and resists movement.
What is excavated peat used for in floating roads?
Excavated peat used to build up verges on sides of floating roads to aid water diffusion (run-off)
Peat Re-use - Acrotelm peat
If stored well, has potential re-use value. Ca be re-used for verge reinstatement along a track
What are borrow pits?
The pits dug for using their materials in the construction of road embankments or canal banks
What must a critical analysis of the carbon budget of wind farms include?
Indirect (location disturbance) and direct (operation) sources
Catotelm peat- reuse
- Few re-use options because it loses structural
integrity (>90% water) - Waste peat placed into the ‘borrow pits’ to create
wetlands - Disposal offsite needs waste license & treatment
Peat Re-use v Waste Peat
Types of hydro power
- Run-of-River
- Pump and store
- Large scale storage
What types of hydro power require the construction of dams?
Pump-and-store and large scale storage
How does large scale storage work in hydropower?
Long-term storage in hydropower means capturing a large volume of water for flexible, year-round electricity production, even across wet and dry seasons. It makes hydropower one of the most reliable renewable energy sources — almost like a giant natural battery!
How does “pump and store” work in hydropower?
In hydropower, “pump and store” means using electricity to pump water uphill to a reservoir when demand is low. Later, the stored water is released to flow downhill through turbines, generating electricity when demand is high. It’s a renewable way to store and manage energy.
What are the environmental concerns with run-of-river hydro schemes in Scotland?
These schemes often overlap with sensitive freshwater habitats. If not designed to maintain natural sediment flow, they can harm ecosystems, alter river channels, affect land use, and reduce scheme efficiency—prompting efforts to improve sediment management.
