Forestry: UN + World Bank fund programmes to protect rainforests REDD scheme fund 50+ partner countries World Wildlife Fund (WWF) + Amazon Regional Protected Areas (ARPA) supported by UN in brazil to protect forests. Covers 10% Amazon basin (areas strictly protected)...
• Deforestation Reduces C store in biosphere and carbon fixation by photosynthesis. Increased soil erosion declines soil C store. Forest trees transfer water by transpiration and reduced interception increases run-off (20-30%) leading to flooding. E.g – The Amazon...
Water: • Increased evaporation and atmospheric water store. Positive feedback of water vapour increases global temps, evaporation and transpiration. • Increased precipitation in urban areas leads to flood risks. • Water vapour is an atmospheric source of energy,...
Afforestation: • C sink, reduce atmospheric CO2, flood risks and soil erosion. • UN’s Reducing Emission from Deforestation and Forest Degradation (REDD) schemes encourage LIDCs to conserve their forests, now has over 60 official partner countries. Wetland Restoration:...
Monitored by Geographical Information Systems (GIS) and used to analyse environmental change. Regional variations in sources and sinks helps identify sequestration and emission management options. Vital to manage global challenges of climate change, water, food and...
Diurnal (daily) Changes – Water = Low temps reduce evapotranspiration at night. Convection rainfall significant in Tropical convectional storms occurs during the day. Carbon = Daytime photosynthesis by terrestrial vegetation and phytoplankton. Flux reversed at night....
For 1 million years the global climate has been unstable, with large fluctuations in temperatures at regular intervals. In the past 400,000 yrs there has been 4 major glacial cycles (cold glacials followed by warmer interglacials). Glacials and the water cycle = Sea...
Atmosphere: • Atmospheric CO2 has a greenhouse effect. • CO2 plays a vital role in photosynthesis by terrestrial plants and phytoplankton. • Plants are important C stores which extract water from the soil and transpire. • Water is evaporated from oceans to atmosphere,...
Location, Vegetation and Climate: Occupies 8 million km2 in N.Canada, Alaska and Siberia. Continuous vegetation in Boreal Forest (southern) to discontinuous (northern). Low biodiversity and NPP. Average monthly temps sub 0 prevent evapotranspiration (ground...
Human factors and the water cycle – The Aral Sea • Central Asia, used to be the fourth largest lake globally, now just 10% remains • Sea receded, rain stopped due to draining of the Syr Darya and Amu Darya rivers for Soviet cotton industry irrigation. • Division into...
Urbanisation – Water • Impermeable surfaces reduce infiltration. • Urban drainage systems remove surface water rapidly. • River water levels rise rapidly due to fast transfer of surface water. • Developments on floodplains reduce storage capacity and increase flood...
• High global dependency 80% global energy consumption • 10 billion tonnes CO2 released annually. • Transfer from geological stores to atmosphere and oceans. • CO2 atmospheric levels highest in 800,000 years, risen above 400ppm. Although anthropogenic carbon emissions...
Water: • Rising temp Positive feedback – More evaporation, atmosphere holds more water in clouds, increased absorption of long wave-radiation. • Decreasing temp Negative feedback – More atmospheric vapour in clouds cover, reflected solar radiation, less radiation...
Location, Vegetation and Climate: Straddles equator between the tropics. South America - 70% Brazil Brazilian Shield = large metamorphic field that limits infiltration and encourages surface flow. Tall, evergreen, hardwood trees. High NPP, biomass 500 tonnes/ha...
• Lithosphere – Sedimentary rocks (99.9%) and fossil fuels. • Hydrosphere – Oceans Surface layer phytoplankton photosynthesis and diffusion Intermediate and deep layer marine food chains and sea floor sediments Calcium carbonate shells • Terrestrial/biosphere organic...
The water balance: Precipitation = evapotranspiration + streamflow +/- storage • Precipitation forms when vapour in the atmosphere cools to its dew point and condenses to form droplets which aggregate and leave clouds. • Cumuliform clouds (high with flat bases) form...
Case Study- Mangawhai-Pakiri Coastline: Unintentional consequences of economic development Location = East coast of New Zealand’s Northland Peninsula. Reasons for economic development = High quality sand for modern economy; glass, concrete, beach replenishment...
Importance of water: • Creates benign thermal conditions. Oceans are 71% of the world’s surface and they absorb, store and slowly release heat. Clouds reflect 1/5 of insolation. Water vapour (potent greenhouse gas) absorbs long-wave radiation and maintains global...
Global water cycle: • Oceanic - holds 97% of global water with ¾ in ice caps. • Cryospheric water- high altitudes and latitudes Accumulation is input to a glacial system Ablation is output from melting. Sublimation is ice directly into water vapour. • Terrestrial –...
Beaches: Formed by the accumulation of material deposited between high and low tides. As sediment size increases so does beach angle. Storm beach – Storm waves hurl pebbles to back of beach. Berms – Smaller ridges that develop at high tide mark. Cusps – Small,...
Eustatic = Changes in volume of water in global ocean store. Isostatic = Changes in land-level. Physical factors include variations in earth’s orbit around the sun (400,000yrs), variations in solar energy (ll yrs), atmospheric composition due to volcanic eruptions and...
Raised Beaches and Abandoned Cliffs: Areas of former shore platforms that are left at a higher level than present sea level. • Inland from present coastline, possibly with abandoned cliffs, wave cut notches, caves, etc behind beach. • After emergence no longer...
Shingle Beach: When sea levels fell as the volume of land-based ice grows, areas of ‘new’ land emerged from the sea. As sea levels rose former coastal sediment is pushed onshore by wave action. • Sediment accumulates on new land due to river deposition, meltwater...
Case Study- Adelaide Metropolitan Beaches: Human and physical factors affecting coastal landscapes Location = City in S Australia, Indian Ocean and Great Australian Bight to the South. Unintentional changes = Littoral drift north and sand removed for development...
Wind: Aeolian energy is the primary source for other processes. Influence wave type created by frictional drag of wind on water. Fetch is the distance of open water the wind blows over and prevailing wind is the most frequent wind direction. Waves: • Formation =...
Sediment budget: The balance between inputs and the removal of sediment. Positive budget is accretion of material on shoreline, negative budget causes the shoreline to recede landwards. Human – Beach nourishment Offshore – Marine deposition Terrestrial – Fluvial (90%...
Mechanical Weathering: • Freeze thaw = Water expands in rocks by 10% when frozen. Pressure causes splits. • Pressure release = Underlying rock fractures parallel to surface as it expands when overlying rock is removed. • Thermal expansion = Rocks expand when heated...
Cliffs and wave-cut platforms: • High energy waves concentrate erosion at cliff base. • Cliff undercut to form wave-cut notch. • Undercut cliff collapses and retreats, leaving a gently-sloping forefront (wave-cut platform). • Wave cut platform extended by abrasion,...
Inputs = Kinetic energy from wind/waves. Sediment from weathering, mass movement and fluvial discharge. Outputs = Aeolian and marine erosion, dredging and mining and offshore sediment transfer. Throughputs = Stores of beach sediment and flows such as longshore drift....