POL469H1 Lecture Notes - Lecture 5: Evaporation, Food Security, Maya Civilization
Idsb02- Development and Environment
Tuesday Feb 7th 2012
Cell theory: Hadley, ferrel, polar
Climate change and future projections (vulnerable regions)
Mitigation and adaptation
REDD, Kyoto Protocol, Copenhagen etc.
ITCZ shifts (Drought in the Sahel)
This week! WATER:
Be able to describe regional climates from atmospheric patterns
We want to relate the above to the hydrological cycles and patterns
Key components of the water balance:
Evaporation – Sumer salt contamination; water movement up through soil profile
Transpiration – comes off plants
Precipitation – rain!
Run-off: erosion (water erosion mostly – some wind)
AET – actual evapotranspiration (limited off water)
PET – potential evapotranspiration (about energy- may not happen as water is limited)
The balance of these fluxes allows us to predict how much water there is
Equatorial hydrology – high precipitation and PET=AET because there is more water than energy
– water isn’t limited! In breaking the Sod reading the soil was eleuvial- these are present from
the waterways and this is the large discharge from drainage basins
Be able to tell her why soil is so susceptible to erosion!
Semi-arid Hydrology: slide
Water availability in Semi-arid regions:
Mid latitude hydrology: slide
Variable seasonally in hydrology - picture
The water table, groundwater, and surface water – know these terms and the differences
Soil zone phenomenon is salinization; major impact of over irrigation- major issue especially in
areas of high evapotranspiration
Drip irrigation – very precise irrigation at the base of the plant – doesn’t lose a lot of water. This
can help combat salinization
Irrigation uses 60% of groundwater resources
Mexico city is sitting on a major aquifer which has been drawn out for a very long time; the
result is they are sinking
Is this surprising that the four countries of China India USA and Pakistan have the highest
they are all in the STHPZ; and all have very large populations
Water management quantity and quality
Unconfined aquifers- percolated through soil moisture etc.
Unconfined aquifers are open to surface waters and can be easily contaminated
Water scarcity related to inputs and outputs (outputs are greater than inputs)
Midterm! Next week;
One hour in class short answer
True and false
What do you need to know?
4 chapters of the Ronald Wright book
Readings from the course reader – all the readings up to the deforestation reading
Sumer and Salinization
All the think about… sections of the lecture slides!
Sustainable development and the Lee paper
Soil erosion, properties, structure, stability, hydrology, CEC, food security, tropical soils,
temperate soil and comparability, solutions
Cell theory, hurricanes and monsoon etc.
Hydrological cycles, regional hydrology AET PET, equatorial mid latitude etc. regions, irrigation,