💧 Flood Damage
JRC depth-damage curve applied to building footprints and critical infrastructure. Flood depth drives both hazard scoring and vulnerability fraction. Return periods: 10yr, 100yr, 500yr.
CLIMATE HAZARD RISK ASSESSMENT
Floods
The Fiscal Threat: Translating Water Depth to Financial Loss
Flooding is the temporary inundation of land not normally covered by water. Flood types include riverine flooding (overbank flow from rivers), pluvial flooding (surface runoff from intense precipitation exceeding drainage capacity), coastal flooding (storm surge combined with sea-level rise), and flash flooding (rapid-onset inundation in steep or small catchments).
The ClimEmpower flood assessment translates flood depth into financial damage through the JRC depth-damage function (Huizinga et al., 2017). This moves beyond binary flood/no-flood mapping to produce a monetised vulnerability score per grid cell — directly usable by municipal planners and insurers. A displacement threshold of 0.5 metres flood depth is applied as the evacuation trigger for population risk.
More than 46 billion eurosTotal losses from the July 2021 western European floods
0.5 metresFlood depth displacement threshold used in ClimEmpower — evacuation trigger
METHOD OVERVIEW
The Fiscal Threat: Translating Water Depth to Financial Loss
The assessment combines a mapped climate hazard with the people, assets or ecosystems exposed to it and their vulnerability. Sector-specific indicators then produce the final risk result.
HHazardIntensity & extent
×
EExposurePeople & assets
×
VVulnerabilitySensitivity & capacity
=
RRiskPotential impact
Flood Damage
Layer structure, input variables and scoring logic for the floods risk maps.
H
JRC Depth-Damage Curve
Vulnerability function V = f(depth) · Monetary loss fraction 0–1
Monetary loss fraction
100%
75%
50%
25%
0%
00.511.522.533.544.55
Water Depth (m)
DAMAGE THRESHOLDS
Source: Huizinga et al. (2017) · JRC
< 0.1 mNegligible< 5%0.1–0.5 mLow5–18%0.5–1.0 mModerate18–35%1.0–2.0 mHigh35–52%2.0–3.0 mVery High52–71%> 3.0 mExtreme> 71%
RISK INDEX
1–1,000
Floods Risk Index
Composite result of Hazard × Exposure × Vulnerability, expressed on a common 1–1,000 scale.
Limited risk. Maintain existing good practices.
Low impact. Maintain adaptive capacity.
Noticeable risk. Precautionary planning is recommended.
Significant risk. Targeted intervention is needed.
Severe risk. Immediate action is required.
RISK FORMULA
Floods × Flood Damage
R_flood = H × E × VHH = FloodDepth_score (1–10 per return period)
FloodDepth_RP10w = 0.33
Flood depth — 10-year return period
JRC EFAS · Copernicus EMS · 100mFloodDepth_RP100w = 0.33
Flood depth — 100-year return period
JRC EFAS · Copernicus EMS · 100mFloodDepth_RP500w = 0.34
Flood depth — 500-year return period
JRC EFAS · Copernicus EMS · 100mEE = (Buildings + CritInfra) / 2
Buildingsw = 0.50
Building footprints (residential, commercial, industrial)
OpenStreetMap / Local cadaster · Building-levelCritInfraw = 0.50
Critical infrastructure (transport, energy, water treatment) in flood zone
Eurostat GISCO · OpenStreetMap · GeofabrikVV = DepthDamage_JRC(depth)
DD_funcw = 0.50
JRC depth-damage function: monetary loss fraction 0–1, scored 1–10 (<0.1m=1, 0.1–0.5m≈3, 0.5–1m≈5, 1–2m≈7, >2m=10)
Huizinga et al. (2017) · JRC flood damage model · Building-levelBldgMatw = 0.50
Building material and age (masonry > concrete in vulnerability)
Local cadaster / EMS damage models · Building-levelHHazard Variables3 variables+
Flood Depth Maps (JRC EFAS)
Return periods 10yr, 100yr, 500yr. Depth maps.
DATA SOURCEJRC EFAS · Copernicus EMS
RESOLUTION100 m
Extreme Precipitation Index (EPI)
99th percentile events. RCP4.5 and RCP8.5.
DATA SOURCEE-OBS / Copernicus CDS
RESOLUTION0.1°→100m
Topographic Wetness Index (TWI)
Secondary indicator for flood accumulation zones.
DATA SOURCEEU-DEM v1.1
RESOLUTION25 m
EExposure Variables2 variables+
Building Footprints
Primary exposure for Flood Damage index.
DATA SOURCEOSM / Local cadaster
RESOLUTIONBuilding
Critical Infrastructure
Transport, energy, water treatment in flood zones.
DATA SOURCEEurostat GISCO · OSM · Geofabrik
RESOLUTIONPoints/lines
VVulnerability Variables3 variables+
JRC Depth-Damage Function
<0.1m=1 → >2m=10. Monetary loss fraction 0–1.
DATA SOURCEJRC flood damage model
RESOLUTIONBuilding
Building Material & Age
Masonry > concrete in flood vulnerability.
DATA SOURCELocal cadaster / EMS damage models
RESOLUTIONBuilding
Topographic Slope
Steeper terrain = higher flow velocity = more stress.
DATA SOURCEEU-DEM v1.1
RESOLUTION25 m
Andalusia faces compound flood risk from multiple sources: riverine flooding along the Guadalquivir and Genil, flash flooding in the Ramblas of Almería and Málaga, and coastal flooding along the delta and estuarine zones. High-resolution flood hazard maps from the Guadalquivir River Authority and building-level cadaster data are available for this region, going well beyond the pan-European JRC datasets. A more elaborate risk calculation method has been established to make full use of this data.
The Andalusian method also places greater emphasis on Vulnerability over Hazard and Exposure, since this is the factor the region can influence most efficiently. This is reflected in the following risk calculation formula.
ANDALUSIAN WEIGHTING MODEL
R = H^0.2 × E^0.3 × V^0.5
H weight 0.2 · E weight 0.3 · V weight 0.5 · sum = 1.0Hw = 0.2Ew = 0.3Vw = 0.5
Vulnerability receives the highest weight (0.5) because building age and construction type are directly improvable through building codes, structural retrofit incentives, and flood-resilient design standards. Flood frequency (Hazard, 0.2) is determined by hydrology and climate; asset location (Exposure, 0.3) is constrained by existing development patterns.
ANDALUSIAN CLASSIFICATION TABLES — VARIABLE THRESHOLDS
HHazard layers (2)+
Flood Depth (JRC EFAS + CHG)
JRC EFAS · 100m + CHG SNCZI · 5–25mCHG Guadalquivir maps used for RP10/RP100 in the main basin (higher resolution than JRC). DANA-type events have shifted RP100 estimates upward in Málaga/Jaén ramblas — model updated with post-event survey.
RANGE / CONDITIONSCORECLASS
No flood / < 0.1m1No hazard0.1–0.5m3Low (wading depth)0.5–1.0m5Moderate (displacement trigger)1.0–2.0m7High> 2.0m10Extreme (structural damage)Extreme Precipitation Index
E-OBS v27 · AEMET observations · 0.1°Andalusia's Ramblas (ephemeral rivers in Almería/Málaga) experience flash-flood events of 200+ mm/24h. AEMET pluviometric stations are dense enough to downscale EPI to 5km for these catchments.
RANGE / CONDITIONSCORECLASS
< 50 mm/24h at P992Low EPI50–1004Moderate100–1506High (Ramblas trigger)150–2008Very high> 200 mm/24h10Extreme (DANA-type)EExposure layers (1)+
Building Footprints
Catastro (Dirección General del Catastro) · Building-levelSpanish Catastro provides construction year, floor count, and declared use for every building. This replaces generic OSM footprints and allows building-age vulnerability differentiation (pre-1980 masonry most vulnerable).
RANGE / CONDITIONSCORECLASS
No buildings in flood zone1No exposure< 10 buildings/100m cell3Sparse10–50 buildings/100m5Residential50–2007Dense residential> 200 buildings or critical infra.10Critical exposureVVulnerability layers (2)+
JRC Depth-Damage Function (calibrated)
Huizinga et al. 2017 + CHG post-event surveyCHG post-2024 DANA survey data calibrated the generic JRC curve for Andalusian building typologies. Pre-1980 load-bearing masonry common in Guadalquivir valley shows 40% higher damage fraction than JRC generic at 1m depth.
RANGE / CONDITIONSCORECLASS
< 5% monetary loss fraction1Negligible5–20%3Low20–40%5Moderate40–65%7High> 65% monetary loss10Extreme damageBuilding Age & Construction Type
Catastro (Dirección General del Catastro) · Building-levelCatastro year of construction used to assign structural vulnerability class: pre-1940 adobe/rubble = 10; 1940–1980 unreinforced masonry = 8; 1980–2000 confined masonry = 5; post-2000 RC frame = 3.
RANGE / CONDITIONSCORECLASS
Post-2000 RC frame2Modern / resilient1980–2000 confined masonry4Standard1940–1980 masonry7VulnerablePre-1940 traditional9Very vulnerablePre-1940 adobe / rubble10Extreme vulnerabilityOfficial flood hazard maps for RP10/RP100/RP500 at 5–25m resolution for Guadalquivir basin
Building-level register: footprint, floor area, year built, construction type, declared use for all of Spain
Dense station network in Andalusia for DANA-event EPI calibration and 99th-percentile exceedance mapping
Andalusia's Flood Risk Management Plan (Planes de Gestión del Riesgo de Inundación) — aligns with EU Floods Directive 6-year cycle
Engineered Flood Protection (Dykes, Barriers)
Infrastructure➜ Flood damage in protected areas minimised; excess water retained or diverted
Regions: OBZ, AndalusiaFlood-Resilient Buildings (Elevated Foundations)
Infrastructure➜ Reduces depth-damage fraction for buildings above 0.5m threshold
Regions: OBZ, SicilyIncreased Sewer & Drainage Capacity
Infrastructure➜ Reduces surface water accumulation during pluvial events
Regions: Central GreeceWater-Resistant Building Materials
Infrastructure➜ Post-flood recovery time and repair costs reduced
Regions: OBZResilient Transport Asset Design
Infrastructure➜ Transport disruptions from extreme weather reduced by up to 20%
Regions: OBZAgricultural Drainage Systems
Infrastructure➜ Flood duration and crop losses in flood-prone areas reduced by up to 20%
Regions: OBZFloodplain Restoration & Retention Areas
Environment & Nature➜ Urban flood risk reduced by up to 20%; water quality improved
Regions: OBZ, Sicily, AndalusiaPermeable Pavements & Surfaces
Environment & Nature➜ Surface runoff reduced by up to 10%; reduces pluvial flood peak
Regions: OBZ, Sicily, AndalusiaGreen Stormwater Infrastructure (Bioswales)
Environment & Nature➜ Stormwater infiltration increased by ≥5%; pollutant loads to water bodies reduced
Regions: OBZConstructed Wetlands & Retention Tanks
Environment & Nature➜ Attenuates peak flows; provides secondary water storage for droughts
Regions: Troodos, OBZ, AndalusiaAfforestation in Catchment Areas
Environment & Nature➜ Reduces peak flood flows; mitigates erosion and sediment transport
Regions: Central Greece, Sicily, AndalusiaNatural Coastal Protection Measures
Environment & Nature➜ Reduces intensity of coastal flood surge at shoreline
Regions: AndalusiaFlood Risk Mapping & Real-Time Monitoring
Governance & Planning➜ Provides up-to-date hazard maps aligned with EU Floods Directive 6-year cycle
Regions: Central Greece, AndalusiaMulti-Hazard Early Warning Systems
Governance & Planning➜ Enables timely evacuation above 0.5m displacement threshold
Regions: Central Greece, AndalusiaCommunity Flood Plans & Emergency Response
Governance & Planning➜ Reduces casualties; shortens recovery time by at least 20%
Regions: Central Greece, Sicily, AndalusiaClimate-Conscious Land-Use Planning
Governance & Planning➜ Prevents new development in high-hazard flood zones; lowers future E scores
Regions: OBZ, Central Greece, SicilyPublic Awareness & Education Campaigns
Society & Education➜ Improves individual flood preparedness and self-evacuation decision-making
Regions: SicilyHow measures reduce risk
Each measure targets one or more risk components. Governance and planning measures typically reduce Exposure (E) by keeping assets out of hazard zones. Nature-based and infrastructure measures primarily reduce Vulnerability (V). Early warning and awareness measures improve adaptive capacity — the fastest path to a lower risk score.