> For the complete documentation index, see [llms.txt](https://arcadia-15.gitbook.io/cra_toolbox_2026/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://arcadia-15.gitbook.io/cra_toolbox_2026/ctb-indicatorsanddata-indicators-and-data.md).

# Indicators and Data

Climate Risk Assessments (CRA) rely on a **transparent chain from datasets to indicators** and decision-relevant outputs. Within the ARCADIA Assessment Toolkit, indicators are used to operationalise the Hazard–Exposure–Vulnerability logic and to **compare a baseline (business-as-usual) scenario against an NbS/BGI scenario**. Tutorials provide the detailed, lab-specific data inputs and processing steps; the overview below focuses on indicator and data families that are replicable across regions, while keeping uncertainty and data limitations explicit.

## Indicators

Across the tutorials, indicators are grouped into (i) risk and vulnerability indicators, capturing the hazard signal and the spatial distribution of exposed and vulnerable receptors, and (ii) NbS/BGI performance indicators, capturing the change in risk drivers and impacts between baseline and NbS/BGI scenarios.

### Risk and vulnerability indicators

These indicators support screening, prioritisation and comparative assessment. Depending on the hazard, outputs may be expressed as maps (rasters/vectors), summary statistics over administrative or planning units, and scenario deltas.

### NbS/BGI performance indicators

Performance indicators describe the effect of measures along the risk chain (hazard attenuation, exposure reduction, vulnerability reduction), typically expressed as differences between baseline and NbS/BGI scenarios. Co-benefits relevant to the tutorials include soil conservation and water-quality regulation.

| **Indicator family**                    | **Definition (short)**                                                                             | **Typical output / unit**                                                       | **Relevant risk profiles**                  |
| --------------------------------------- | -------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------- | ------------------------------------------- |
| Extreme precipitation / heavy rainfall  | Event intensity or frequency proxies used to characterise short-duration heavy rainfall.           | Rainfall threshold exceedances; return-period layers; mm, mm/day                | Heavy rainfall; Pluvial flooding            |
| Flood hazard                            | Spatial characterisation of inundation potential under design events or scenario conditions.       | Flood extent; water depth/level; m; affected area km²                           | Flooding; Sea level rise (coastal flooding) |
| Drought hazard and water stress         | Indices or model-based proxies of precipitation deficit, soil moisture deficit or water demand.    | Drought index values; soil moisture proxies; irrigation demand; (index), mm, m³ | Drought                                     |
| Heat stress                             | Thermal exposure metrics for people and the built environment, including hotspot screening layers. | Temperature/thermal comfort metrics; heat days/tropical nights; °C; days        | Heat waves                                  |
| Slope instability / landslide potential | Stability or susceptibility proxies responding to rainfall-driven soil water conditions.           | Stability/susceptibility layers; probability classes; (index) / classes         | Landslides                                  |
| Exposure proxies                        | Spatial distribution of assets, population or land uses that can be affected by hazards.           | Land-use shares; asset layers; people/ha; m² of imperviousness                  | All profiles                                |
| Vulnerability proxies                   | Sensitivity and coping capacity proxies for exposed receptors (where local data are limited).      | Composite scores; typology classes; (index) / classes                           | All profiles                                |
| Runoff and water regulation             | Hydrological performance proxies relevant to retention/infiltration measures.                      | Runoff peaks/volumes; flow statistics; m³/s, mm, m³                             | Heavy rainfall; Flooding; Drought           |
| Soil conservation                       | Erosion and sediment-related proxies supporting assessment of land-based measures.                 | Annual soil loss; sediment proxies; t/ha/yr                                     | Heavy rainfall; Drought; Other perils       |
| Water-quality regulation                | Nutrient and pollutant transport proxies linked to runoff processes and mitigation measures.       | N/P load proxies; sediment-related proxies; kg, mg/L (where applicable)         | Flooding; Drought; Other perils             |
| Cooling and comfort co-benefits         | Change in thermal exposure due to greening/shading measures.                                       | Δ temperature / comfort metric; °C                                              | Heat waves                                  |

Table 1 - indicator families used across the CRA tutorials (high-level overview).

## Data

Tutorials combine local datasets with a limited set of European open-data sources for harmonised processing and comparability. The table below lists only the European datasets explicitly referenced in the ARCADIA tutorials; local datasets and licensing details remain documented within each tutorial.

| **Data category**                               | **Purpose in CRA / tutorials**                                                      | **European open-data sources referenced in tutorials**                                                                                                                                                                                                                                                                                                                       |
| ----------------------------------------------- | ----------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Climate forcing (reanalysis)                    | Baseline and historical climate signals for hazard characterisation and indices.    | [Copernicus ERA5-Land](https://cds.climate.copernicus.eu/datasets/reanalysis-era5-land); [ERA5 extreme precipitation indicators (Europe)](https://cds.climate.copernicus.eu/datasets/sis-ecde-climate-indicators?tab=overview)                                                                                                                                               |
| Climate projections (regional)                  | Future hazard characterisation under scenarios; scenario comparisons.               | [Copernicus EURO-CORDEX](https://cds.climate.copernicus.eu/datasets/projections-cordex-domains-single-levels); [Hydrology-related climate impact indicators (bias-adjusted projections)](https://cds.climate.copernicus.eu/datasets/sis-hydrology-variables-derived-projections?tab=overview)                                                                                |
| Topography / terrain                            | Derivation of drainage, flow paths and terrain-based susceptibility proxies.        | [Copernicus DEM](https://dataspace.copernicus.eu/explore-data/data-collections/copernicus-contributing-missions/collections-description/COP-DEM)                                                                                                                                                                                                                             |
| Land cover / land use / urban form              | Exposure mapping, imperviousness proxies, and spatial context for NbS/BGI planning. | [CORINE Land Cover (Copernicus)](https://land.copernicus.eu/pan-european/corine-land-cover); [Urban Atlas (Copernicus)](https://land.copernicus.eu/local/urban-atlas); [CLCplus Backbone (Copernicus)](https://land.copernicus.eu/en/products/clc-backbone); [High Resolution Layers (Tree Cover / Forests)](https://land.copernicus.eu/pan-european/high-resolution-layers) |
| Hydrography / water bodies                      | River network context for flood screening and BGI connectivity planning.            | [EU-Hydro River Network Database](https://land.copernicus.eu/en/products/eu-hydro)                                                                                                                                                                                                                                                                                           |
| Soils                                           | Soil parameterisation and erosion-related proxies.                                  | [European Soil Database v2.0 (ESDAC)](https://esdac.jrc.ec.europa.eu/content/european-soil-database-v20-vector-and-attribute-data)                                                                                                                                                                                                                                           |
| Protected areas / ecological context            | Context layers for BGI/NbS planning and screening constraints/opportunities.        | [Natura 2000 (EEA)](https://www.eea.europa.eu/data-and-maps/data/natura-2000)                                                                                                                                                                                                                                                                                                |
| Socio-economic exposure / vulnerability proxies | Context indicators for exposed sectors, demographics or land management patterns.   | [Eurostat GISCO](https://ec.europa.eu/eurostat/web/gisco)                                                                                                                                                                                                                                                                                                                    |

Table 2 - European open-data sources referenced in the CRA tutorials (by data category).

The table above provides **a first, intentionally compact synthesis** of the European datasets referenced in the current tutorials. It is not meant to replace the tutorial-specific data documentation: as the Toolkit evolves, **a more structured repository and metadata scheme** (foreseen in follow-up activities) will enable more systematic referencing, traceability and reuse of datasets across regions.