Hydrological Early Warning
Hourly rainfall tested against landslide thresholds, now and for the week ahead.
Fetches hourly rainfall for any point, observed and forecast, tests every window from 1 hour to 10 days against published intensity–duration thresholds, tracks antecedent wetness and reads the local slope from a global DEM.
Overview
In forecast mode the tool joins the last 14 days of hourly rain with the 7-day forecast, so a warning reflects both what has fallen and what is coming. In historical mode it replays any period up to a year, which is how thresholds are checked against known landslide dates.
For each hour the exceedance ratio is the largest I / It over durations of 1 to 240 hours. Values above 1 mean the rain has entered the field in which shallow landslides and debris flows have been recorded worldwide. The dominant soil or rock type shapes the written interpretation of how slopes respond.
What you enter · What you get
What you enter
- Site by map click, GPS or coordinates
- Forecast window or historical dates
- Threshold: Caine, Guzzetti or custom
- Dominant soil or rock and API decay constant
What you get
- Daily rain, antecedent index and hourly exceedance ratio
- Log–log intensity–duration plot against thresholds
- Critical durations table and threshold-crossing episodes
- Local slope, aspect and relief from the 30 m Copernicus DEM
- Warning level and geological interpretation
How it works in the field
Method and equations
Intensity–duration thresholds
Lower envelopes of rainfall conditions that triggered shallow landslides and debris flows. I is mean intensity in mm/h over duration D in hours.
Exceedance ratio
Evaluated every hour over eleven durations from 1 to 240 h.
Antecedent precipitation index
Daily running index of soil wetness with decay constant k.
Slope from the DEM
Horn (1981) gradient on a 3 × 3 window of Copernicus GLO-30 elevations (30 m) around the site.
Who uses it
Standards and references
- Caine, N. (1980). The rainfall intensity–duration control of shallow landslides and debris flows. Geografiska Annaler A, 62(1–2), 23–27.
- Guzzetti, F. et al. (2008). The rainfall intensity–duration control of shallow landslides and debris flows: an update. Landslides, 5, 3–17.
- Kohler, M.A. & Linsley, R.K. (1951). Predicting the runoff from storm rainfall. U.S. Weather Bureau Research Paper 34.
- Horn, B.K.P. (1981). Hill shading and the reflectance map. Proceedings of the IEEE, 69(1), 14–47.
- Hersbach, H. et al. (2020). The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, 146, 1999–2049.
- European Centre for Medium-Range Weather Forecasts (ECMWF). Integrated Forecasting System (IFS) documentation.
At a glance
- Category
- Water & rivers
- Runs on
- Phone, tablet and desktop browser
- Export
- Hourly CSV, PNG charts, PDF report
- Access
- Data view free · analysis for subscribers
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