Benefit-Cost Ratio

Retrofitting benefit/cost ratio maps

Ratio maps from the Retrofitting Benefit/Cost Ratio calculator require loss exceedance curves, which can be calculated using the Classical Probabilistic Risk calculator. For this reason, the parameters sourceModelTreePath and gsimTreePath are also included in this NRML schema, so the whole calculation process can be traced back. The results for each asset are stored as depicted in the table below.

Example benefit-cost ratio map output:

lon	lat	asset_ref	aal_original	aal_retrofitted	bcr
80.0888	28.8612	a1846	966,606	53,037	1.72
80.0888	28.8612	a4119	225,788	26,639	1.46
80.0888	28.8612	a6444	444,595	16,953	1.33
80.0888	28.8612	a8717	106,907	10,086	0.39
80.0888	28.9362	a1784	964,381	53,008	1.92
80.0888	28.9362	a4057	225,192	26,597	1.64
80.0888	28.9362	a6382	443,388	16,953	1.49
80.0888	28.9362	a8655	106,673	10,081	0.44
80.1292	29.0375	a2250	1,109,310	60,989	2.08
80.1292	29.0375	a4523	2,785,790	329,083	1.78
…	…	…	…	…	…

• interestRate: this parameter represents the interest rate used in the time-value of money calculations

• assetLifeExpectancy: this parameter specifies the life expectancy (or design life) of the assets considered for the calculations

• node: this schema follows the same node structure already presented for the loss maps, however, instead of losses for each asset, the benefit/cost ratio (ratio), the average annual loss considering the original vulnerability (aalOrig) and the average annual loss for the retrofitted (aalRetr) configuration of the assets are provided.