How this site thinks
One cycle, one ladder, four principles
This is not a loose pile of calculators. Every tool has a place in the flood risk management cycle, a rung on a maturity ladder with explicit gates, and obeys the same working principles.
The cycle — EU Floods Directive vocabulary
Five phases from Directive 2007/60/EC, with the UN four-pillar early-warning framing inside Preparedness. Engineering work belongs to a phase; so does every tool here.
- 1
PreventionYears before the event
“Where is the risk, and how do we keep it from growing?”
Risk assessment and mapping · river morphology analysis · erosion and scour assessment · land-use guidance
Tools in this phase: FluvioMorph · Scour & Erosion Assessor (HEC-18)
- 2
ProtectionStructural works
“What do we build to reduce the hazard where it stands?”
River training · drop structures and chutes · retaining walls · gabions · riprap and bank protection
Tools in this phase: Hydraulic Structures Designer
- 3
PreparednessDays to hours before
“Will we see it coming, and will the warning reach the right hands in time?”
Forecasting and AI models · early-warning systems (the four UN pillars) · dam-break scenario studies · Emergency Action Plans (EAP)
Tools in this phase: Dam-Break Knowledge Base · Oman Cyclone Impact · Dam-Break Hydrograph Calculator
- 4
ResponseDuring the event
“Which decision, where, in the next hour?”
Live decision maps · EAP activation and notification chains · inundation communication
Tools in this phase: Flood a Real River
- 5
RecoveryAfter the event
“What did the flood change, and what did we learn?”
Damage and morphological-change assessment · model validation against the event · hindcasting
Tools in this phase: None yet — an open gap.
The ladder — TRL bands with explicit gates
Maturity is stated in Technology Readiness Levels — the shared language of funders. A tool moves up only through a named gate; nothing is called operational until it has been validated against real data.
Working principles
Every number has a passport.
Each result traces to a published method with its citation and validity domain — see the Methods library.
Validity screening is not optional.
When an input leaves a method’s domain, the tool says so on the output itself — including the arid/wadi verdict.
Your data stays yours.
Calculations run in the browser; project files are never uploaded.
Honest labels.
Historical reconstructions are labelled as such, illustrative graphics are labelled as such, and analysis outputs support — never replace — the judgment of a qualified engineer.
The wadi commitment
Almost every classical river equation was calibrated on perennial temperate rivers. This site’s distinguishing commitment: each method in the library carries an explicit statement of whether it transfers to ephemeral wadis and arid regions — and the tools surface that verdict at the moment of use.
Browse the methods →