A Sensitivity Analysis is a technique uscd to dctcrminc how different values of
ID: 108236 • Letter: A
Question
A Sensitivity Analysis is a technique uscd to dctcrminc how different values of an independent variable will impact a dependent variable under a given set ofassumptions. Typical sensitivity is defined in terms of the increase/decrease in the dependent variable as a result of doubling the independent variable. For example, to conduct a sensitivity analysis of the bathtub system, we might double the faucet flow rate, the drain area, or the area of the tub base, run the model and compare the new cquilibrium volumc to that of our referencc (pre-doubling) The calculation is as follows, Value 2 Value 1 100% Value A given system may have many independent variablcs, so there is an incentive to understand which the system is most sensitive to, particularly in natural systems. Part I: Mono Lake E Figure 1 illustrates a highly simplificd vcrsion of a lake in which there are 3 flows of watcr into the lake and 2 flows out. This lake serves as a source of fresh water for Los Angeles, so it is important to understand how different variables affect the height of the waterin the lake in order to prevent overuse that would have negative environmental consequences or even destroy this important water source. in iake flow past diversion points Figure 1. Simplified Versima of Mane Lake Systsu. MAE217 11 LaGuardia The results of a sensitivity analysis are provided in the table below. Calculate the sensitivity of this system to each of the variables listed. Variable Initial Value FinaValue Precipitation Rate 2638 2748 Export to LA 2638 Groundwater 26Explanation / Answer
sensitivity analysis of the precipitation rate is = 2748-2638/2638 *100 = 6.937%
sensitivity analysis of the export to LA is = 2565 - 2638/2638 *100 = -2.767%
sensitivity analysis of the groundwater out is = 2611-2638/2638 *100 = -1.023%
sensitivity of the system is = sensitivity analysis of the precipitation rate + sensitivity analysis of the export to LA - sensitivity analysis of the groundwater out
= 6.937% - 2.767% + 1.023%
= 5.193 %