Flood depth-damage functions

Example: Vulnerability curves relating flood water depth to expected damage ratios or absolute losses, derived from statistical analysis of historical flood impacts.

Step-by-step guidance

1. Dataset-level metadata

Select the following values when describing your dataset:

• Risk data type: vulnerability

• Title: “Flood depth-damage functions for [asset types/region]”

• Description: Brief description of the damage functions, asset types covered, and data sources used for calibration

• Publisher: Organization or research institution that developed the curves

• License: Appropriate license

2. Resources

Add resources for your damage function files:

• Format: csv, json, or xlsx

• Spatial resolution: Not applicable (functions are asset-type specific)

• Coordinate reference system: Not applicable

3. Vulnerability metadata

Under the Vulnerability section:

Category

• Category: vulnerability

Hazard type and intensity

• Hazard type: flood

• Hazard primary type: flood

• Processes: Select applicable process(es):

  • fluvial_flood

  • pluvial_flood

  • coastal_flood

• Intensity measure: Typically fl_wd:m (flood water depth in meters)

Additional intensity measures (if applicable):

• v_fld:m/s (flow velocity)

• fl_fd:m3/s (flood duration)

Vulnerability functions

For each asset type, create a function entry:

Function specification:

• ID: Unique identifier (e.g., DF1_residential_1story)

• Relationship: vulnerability

• Function type: continuous, discrete, polynomial, or empirical

Damage scale:

• Type: relative (damage ratio 0-1) or absolute (monetary value)

• Unit: ratio (0-1 or 0-100%) or currency code (e.g., USD)

Function parameters:

• For polynomial/continuous: coefficients and equation form

• For discrete: water depth bins and corresponding damage ratios

• For empirical: look-up table of depth vs. damage values

Asset taxonomy

Link damage functions to asset types:

• Taxonomy source: GED4ALL, custom, or building classification system

• Taxonomy code: Specific code for each asset type

• Occupancy: Residential, commercial, industrial, etc.

Cost information

Specify what is being measured:

• Cost dimension: Select applicable:

  • structure (building damage)

  • content (contents damage)

  • business_interruption (indirect losses)

  • total (combined)

• Cost unit: Currency code (e.g., USD, EUR) or ratio for relative damage

4. Spatial coverage

Define applicability:

• Scale: global, national, or regional

• Countries: Select applicable ISO 3166-1 alpha-3 country codes if region-specific

• Description: Note if curves are calibrated using local historical flood data

Example data structure

Your damage function file should include:

For continuous functions:

• Asset type

• Occupancy category

• Flood depth range (min, max)

• Function type/equation

• Parameters/coefficients

• Damage dimension (structure, content, etc.)

• Units

Example CSV structure for discrete functions:

Asset_Type,Occupancy,Depth_m,Damage_Ratio_Structure,Damage_Ratio_Content
Single_family_1story,residential,0.0,0.00,0.00
Single_family_1story,residential,0.3,0.10,0.15
Single_family_1story,residential,0.6,0.20,0.30
Single_family_1story,residential,1.0,0.35,0.50
Single_family_1story,residential,1.5,0.50,0.70
Single_family_1story,residential,2.0,0.65,0.85
Single_family_1story,residential,3.0,0.80,0.95

Key considerations

• Clearly document the derivation method (empirical from insurance claims, expert judgment, modeling)

• Specify the currency and reference year for absolute damage values

• Include information about the historical events used for calibration

• Document assumptions about building values or replacement costs

• Note whether functions include damage to structure only or structure + contents

• Specify if flood duration or velocity effects are considered

• Include uncertainty information if available

• Reference source publications or insurance databases

• Clarify whether functions assume presence of flood adaptation measures