Civil and Environmental Engineering 2217A/B- Midterm Exam Guide - Comprehensive Notes for the exam ( 15 pages long!)
11 Oct 2017
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Numerous aspects of global system exponentially growing since industrial revolution: human population, pollution, food, industrial production. Growth rate is proportional to amount currently present. Important: suddenness with which a limit can be reached (and every system has a limit: nt = n0 (1+r)t. N0 = initial amount, nt = amount after t years, r = growth rate. Continuous (smooth, continuous function: n = n0 ert r = growth rate [time-1] Doubling time: time required to double amount, td 70/r(%) Half life (exponential decay: rate of decrease proportional to amount remaining, n = n0 e-kt, t1/2 = 0. 693/k. Used when quantity being modeled is the product of a number of individual factors. Ipat equation impacts = population * affluence * technology. Total growth rate is the sum of the individual growth rates of the factors. Example: carbon emissions = population * (energy/person) * (carbon/energy) How long resources last depends on quantity of resource and rate of consumption.
