Mathematical Applications: Assessing Risk and Subsidence
Calculating risk using the standard hazard equation and evaluating rates of land subsidence.
Example
Problem 1: Evaluating Subsidence Rates
A city built on thick clay deposits relies entirely on groundwater pumping. In 1990, the benchmark elevation of the city center was above mean sea level. By 2020, due to excessive groundwater extraction and subsequent clay consolidation, the same benchmark was surveyed at . Calculate the average annual rate of subsidence and project the elevation in the year 2050 if this rate remains constant.
Step-by-Step Solution
0 of 5 Steps Completed1
Example
Problem 2: Calculating Basic Risk
A regional planning commission is evaluating the risk of a major landslide affecting a newly constructed highway. Geologists estimate the annual probability of a major landslide (the Hazard) at this specific location is ( chance per year). The highway itself cost to build, but a major landslide would completely destroy a section, causing an estimated in direct repair costs and economic losses (the Exposure). Because the highway is the only route to a major port, its destruction would cause severe disruption; thus, its Vulnerability factor is rated at ( of the exposed value would be effectively lost). Calculate the annual Risk in dollars.
Step-by-Step Solution
0 of 4 Steps Completed1
Example
Problem 3: Comparative Risk Analysis
A city must choose between allocating funds to mitigate one of two different geological hazards affecting two separate neighborhoods.
Neighborhood A (Flood Hazard):
- Annual Probability () = ()
- Total Property Value () =
- Vulnerability () = (minor damage, mostly cleanup and drywall replacement)
Neighborhood B (Rockfall Hazard):
- Annual Probability () = ()
- Total Property Value () =
- Vulnerability () = (catastrophic structural destruction, lethal hazard)
Calculate the annual risk for both neighborhoods to determine which presents the higher economic priority.
Step-by-Step Solution
0 of 4 Steps Completed1
Case Studies: Geological Hazards
Understanding the devastating impacts of complex geological hazards on infrastructure.
Example
Case Study 1: Volcanic Hazards - Lahars and Bridge Design
A major international highway bridge is being constructed across a wide, shallow river valley whose headwaters originate on the heavily glaciated slopes of an active stratovolcano located upstream.
Step-by-Step Solution
0 of 3 Steps Completed1
Example
Case Study 2: Problem Soils - Differential Settlement on Expansive Clays
A large, sprawling residential subdivision consisting of hundreds of single-family homes is built upon a flat, arid plain composed almost entirely of thick, expansive smectite clay deposits (montmorillonite). The region experiences severe, distinct wet and dry seasons.
Step-by-Step Solution
0 of 3 Steps Completed1