Output data
The principal output is a structured transport-specific threshold database covering road and rail transport systems.
The database consolidates:
- Climate-related risks
- Transport receptors
- Threshold values
- Associated impacts and levels of service disruption
- Traceable information on the source of each threshold
CCRA risk codes are retained, which enables direct linkage between the identified thresholds and the corresponding organisational climate risks.
Traceability is a design goal, not a nicety
Three of the fields below exist purely to record where a threshold came from:
Source Type, Source Link and Year. A fourth, Risk Code in org. CCRA, links
back to the operator's own assessment.
A threshold that cannot be traced to its evidence cannot be defended when a modelling result is challenged, and cannot be reviewed when the underlying standard is updated.
The database fields
For each identified threshold, the database records the following where available.
Identification and classification
| Field | What it records |
|---|---|
| Mode (Road / Rail) | Whether the threshold applies to the road or rail transport system |
| Risk Code in org. CCRA | The corresponding risk identifier from the relevant National Highways or Network Rail CCRA |
| Category | Classification used to group the climate-related risk or threshold |
| Asset / Receptor Type | The transport asset, infrastructure component, operation or user affected by the hazard |
The hazard and its consequence
| Field | What it records |
|---|---|
| Hazard | The weather or climate-related hazard associated with the threshold, such as precipitation, flooding, high temperature or high winds |
| Impact and Risk | Description of the potential consequence of the climate-related hazard for the transport system |
| Level of Service Disruption | The consequence of threshold exceedance for transport-system performance, such as Reduced Service, Temporary Closure, or Asset Damage |
Risk rating, carried over from the CCRA
| Field | What it records |
|---|---|
| Risk Score | The risk score assigned within the relevant organisational CCRA |
| Risk Category | The corresponding CCRA risk classification, such as Major or Severe |
The threshold itself
| Field | What it records |
|---|---|
| Threshold Value | The quantitative value, condition or function at which the identified transport impact or operational response occurs |
| Threshold Type | Classification of the threshold according to its basis, such as Design, Operational, or Observation-based |
Note that Threshold Value accommodates a condition or function, not only a
number. This is where the formula-based thresholds described in
threshold identification
are stored.
Provenance
| Field | What it records |
|---|---|
| Source Type | The type of evidence from which the threshold was derived, such as an industry standard, operational guidance, policy/industry document, or published research |
| Source Link | Link to the original document or evidence source supporting the threshold |
| Year | Publication or issue year of the threshold source |
What the database is for
The resulting database provides a consistent and traceable link across five stages:
- Climate hazards
- CCRA risks
- Transport receptors
- Threshold exceedance
- The resulting service disruption or asset damage
It can be used as an input to subsequent DARe climate-risk assessment, modelling and visualisation activities.
How this feeds the rest of the IMP
The chain above is exactly what the transport simulation needs. Given a hazard map from hazard models and this database, the model can decide which links are disrupted and how badly, which is what performance metrics then quantify.