water and carbon Flashcards
How has irrigation impacted the middle east
Water stores are at risk of depletion (1000s years old)
Rate of recharge is slower to the rate of use
Impacting transfer processes
Impact of the California fires
7641 fires in 2022
Rivers and Lake Mead dried up
Reduced water stores
Agricultural productivity reduced
Vegetation died - reduced transpiration, interception, infiltration etc.
High rates of evapotranspiration
Impacts of The Great Green Wall
restoring 100,000,000 hectares
Provides shade and litter - soils restored
More water held in the ground
Increases biodiversity
Food grown
Soil erosion/ desertification reduced
27000000 trees grown
250000000 tonnes of carbon sequestered
7500 Half moons created to trap water
Name what has taken place in the river Exe (human interventions)
Wimbleball reservoir
Peatland restoration
impacts of wimbleball reservoir on the River Exe
150 hectares
Supplies water to Exeter and Devon
Regulates water flow
Prevents peaks and troughs of water discharge
Reduces floods/ droughts
impacts of peatland restoration in the River Exe
drainage ditches dug
Made suitable for farming
Increases water flow to the river exe
Increases water content and restores saturated boggy conditions
Retain carbon stores
Peat dug as fuel = decomposition as it dries
Background information of the River Exe
82.7km long
Source in Exmoor
Mouth in Exeter
geology - 84.4% of the catchment is impermeable rock
Land use - 6.7% agriculture, 15% woodland, 3% peat bogs
High water balance due to impermeable rock, reduced percolation/ base flow (65%)
Impacts of deforestation in Indonesia
50% of original forest remains
70% deforestation in forests
30% in peatlands
Soils are a carbon source
Wildfires have resulted due to El nino destroying 8000 hectares - released black carbon/soot (holds 1000x more carbon)
Importance of soil in the amazon (brief)
40% sent to roots
carbon is fixed
absorbs/ stores carbon and water
decomposers
nutrient cycle
3 million species
50% world species in TRF
25% medicines are derived from here
Water cycle in the Amazon
2000mm
75% rainfall intercepted
32.5% is used and transpired
25% evaporates
trees intercept precipitation
impacts of deforestation on the water cycle
atmospheric humidity reduced, evapotranspiration decreases = 20% reduction in rainfall
more rainfall reaches forest floor = compacts = overland flow encouraged
soils dry out = become vulnerable to erosion as exposure to sun increases
little interception of rainfall = transpiration reduces
rates of runoff will increase
importance of The Amazon in the Carbon Cycle
50% wood is carbon
carbon sink
1.4 billion tonnes
human impacts/ impacts of deforestation on the Carbon Cycle
cattle ranching - 70/80% of deforestation, release methane, compact soil, move around, 37% soy is made in the Amazon (animal feed), need for meat
logging
slash and burn - combustion, releases carbon
less photosynthesis can occur
less decomposers in the environment
carbon from biomass is released
interconnectedness of the water and carbon cycle
loss of trees = reduces evapotranspiration = reduces rainfall = puts stress on other trees = increases risk of drought/ fires (impacts the carbon cycle)
feedback loop created - accelerates climate change - increase in frequency and severity of weather events = disrupts water cycle
mitigation strategies in the Amazon (politics)
- paris agreement in 2015, 196 countries agreed to reduce global warming by 1.5 above pre industrial levels
- dept reduction - USA and Brazil have converted £13.5 million into funding/ protecting rainforests, conservation and livelihoods supported
Da Silva helping to protect the rainforest
