Catchment elevation data are derived from the Centre for Ecology & Hydrology's Integrated Hydrological Digital Terrain Model (IHDTM). The IHDTM is based on a 50m grid interval (i.e. each cell represents a 50m x 50m square) with a 0.1m vertical resolution. It is designed to be hydrologically consistent and is a core component of the Flood Estimation Handbook.
Elevation layer can be displayed on each station details page.
The height (to the nearest metre above Ordnance Datum or, in Northern Ireland, Malin Head Datum) of the Minimum and Maximum levels in the catchment and the level below which 10%, 50% and 90% of the catchment lies.
| Code | Description |
|---|---|
| ZSTD | Standard deviation |
| ZRANGE | Range |
| ZMEAN | Mean |
| P000 | Minimum |
| P002 | 2 percentile |
| P005 | 5 percentile |
| P010 | 10 percentile |
| P025 | 25 percentile |
| P050 | 50 percentile |
| P075 | 75 percentile |
| P090 | 90 percentile |
| P095 | 95 percentile |
| P098 | 98 percentile |
| P100 | Maximum |
