Methodology
| Name | Category | Description |
|---|---|---|
| Regulated Sites | Contaminated Land | Regulated Sites encompasses closed mining areas, end-of-life vehicle treatment sites (operational for 7 years or more), open waste permitted sites, and industrial environmental permitted regulated facilities (permit types A and B only). Mobile sites and sites with no specified address may be excluded. |
| Historic Land Use | Contaminated Land | This dataset provides information on past industrial land use depicted on historic Ordnance Survey maps which could lead to a liability under Part2A of the Environmental Protection Act (1990). |
| Fluvial (undefended) | Flood Risk | This dataset provides modelled information on river flood risk under an undefended scenario, assuming that flood defences may fail. Land is classified as 'medium' or 'high' risk based on the probability of flooding and predicted water depth. Medium risk applies to areas with a 1 in 1,000 probability or 1 in 100 with water depth below 0.2m, while high risk applies to areas with a 1 in 100 probability and depth above 0.2m or a 1 in 10 probability. Since the data is modelled, no physical inspections have been conducted by Martello or GeoSmart. There may be other localised factors such as blocked drains which could also impact flooding. |
| Pluvial | Flood Risk | This dataset provides information on the flood risk from surface water. This dataset provides modelled information on surface water flood risk. Land is classified as 'medium' or 'high' risk based on the probability of flooding and predicted water depth. Medium risk applies to areas with a 1 in 1,000 probability or 1 in 100 with water depth below 0.2m, while high risk applies to areas with a 1 in 100 probability and depth above 0.2m or a 1 in 10 probability. Since the data is modelled, no physical inspections have been conducted by Martello or GeoSmart. There may be other localised factors such as blocked drains which could also impact flooding. |
| Tidal (undefended) | Flood Risk | This dataset provides modelled information on seawater flood risk under an undefended scenario, assuming that flood defences may fail. Land is classified as 'medium' or 'high' risk based on the probability of flooding and predicted water depth. Medium risk applies to areas with a 1 in 1,000 probability or 1 in 100 with water depth below 0.2m, while high risk applies to areas with a 1 in 100 probability and depth above 0.2m or a 1 in 10 probability. Since the data is modelled, no physical inspections have been conducted by Martello or GeoSmart. There may be other localised factors such as blocked drains which could also impact flooding. |
| Groundwater | Flood Risk | This dataset provides modelled information on groundwater flood risk using GeoSmart's GW5 product. Land is classified as 'medium' or 'high' risk based on the probability of flooding and predicted water depth. GW5 incorporates a 5m Digital Terrain Model (DTM) for enhanced resolution at an individual property level revealing the complex relationship between terrain and “ponding” of groundwater. Since the data is modelled, no physical inspections have been conducted by Martello or GeoSmart. |
| Flood Defences and Benefiting Areas | Flood Risk | This dataset shows national flood defence schemes and the areas benefiting from them. Flood defences can be man-made embankments and walls or naturally occurring e.g. shingle ridges and dunes. If the defences were not there, the areas benefiting from them would stand a 1% chance of flooding from rivers, and 0.5% from the sea. Not all benefiting areas are shown. Property level defences to protect individual properties are not included in this dataset. |
| Flood Storage Areas | Flood Risk | This dataset shows areas that act as a balancing reservoir, storage basin or balancing pond. Their purpose is to attenuate an incoming flood peak to a flow level that can be accepted by the downstream channel. It may also delay the timing of a flood peak so that its volume is discharged over a longer time interval. |
| Historical Flood Areas | Flood Risk | This dataset shows the maximum extent of individual Recorded Flood Outlines from river, sea and groundwater springs that meet a set criteria. This excludes flooding from surface water, except in areas where it is impossible to determine whether the source is fluvial or surface water but the dominant source is fluvial. If an area is not covered by the Historic Flood Map it does not mean that the area has never flooded, only that EA or NRW do not currently hold a record of flooding in this area. Additionally, flooding is shown to the land and does not necessarily indicate that properties were flooded internally. |
| Green Belt | Planning Constraints | This dataset shows green belt boundaries. Green belt exists to protect the countryside from urban sprawl and to retain the character of towns and cities. |