Dynamic Flood Hazard Assessment Model (DFHAM)
The Dynamic Flood Hazard Assessment Model (DFHAM) is a hydrologically grounded, spatially distributed flood risk assessment model, designed for early warning applications. It constitutes the computational core of the Inachos system, producing spatially distributed risk estimates that are subsequently visualized and delivered through the platform.
Model–system relationship
DFHAM is the model that transforms hydrometeorological inputs and geospatial indicators into a normalized flood risk index. Inachos is the research platform that organizes the data, runs DFHAM simulations, and displays the outputs (e.g. forecast maps and time-based scenarios). This distinction enables independent evolution of the model and the dissemination/visualization infrastructure.
Key features of DFHAM
- Spatial resolution: fixed-resolution grid (typically 500 m).
- Temporal resolution: discrete 1-hour time step (t = 0–72 h for forecasting).
- Area of application: designed for the Greek territory (with the ability to focus on specific regions/case studies).
- Outputs: normalized flood risk index H(t) (0–1) and spatial classification into risk/probability classes.
How it works in brief
DFHAM combines static spatial information describing the inherent susceptibility of an area with dynamic event information capturing the current/recent hydrometeorological conditions. This architecture enables rapid updates per time step and generation of spatial risk estimates in near real time.
- Static component (once per grid): generates topographic and spatial indicators that affect runoff concentration/routing, baseline runoff behavior (e.g. from land cover and soil properties), and spatial vulnerability indicators.
- Dynamic component (every 6 hours): incorporates rainfall and the hydrological “memory” of the soil (e.g. via antecedent wetness indicators), so that the evolution of risk over time is captured.
- Integration into a single index: the information is unified into a normalized flood risk index H(t) (0–1), which is translated into spatial risk/probability classes for map production.
Innovation and added value
The innovation of DFHAM lies in the systematic integration of dynamic hydrometeorological drivers and static spatial indicators in a spatially distributed form, in a way that is computationally lightweight, parameterizable, and suitable for early warning. In contrast to fully hydraulic, high-complexity approaches, it targets rapid production of risk maps with physically interpretable components and the ability to calibrate by area type.
- Cell-level spatial resolution: captures heterogeneity and local risk “hotspots”.
- Temporal consistency: incorporates antecedent wetness/hydrological memory, so risk is not driven solely by instantaneous rainfall.
- Comparative intensity reference: uses reference values/thresholds for consistent assessment of intensity/flow stress.
- Input flexibility: enables the use of different data sources (e.g. rainfall forecasts or analyses).
Information about the Inachos system
The Inachos system is the research platform for disseminating and visualizing DFHAM outputs. It includes a simulation execution mechanism, scenario/version management and a cartographic display interface. Its goal is ease of access.