Areal rainfall is calculated at a daily timestep for 5 areal units which cover London using the Soil Moisture Model developed and run by the Environment Agency. For each areal unit, the areal rainfall and soil moisture deficits (SMDs) are calculated. Areal rainfall – This is calculated using rainfall data collected at one or more rain...

Number of properties in a floodplain and those with a significant risk of flooding. NAFRA - National Flood Risk Assessment. There are 3 risk categories: (i) low - 0.5% (1 in 200) chance of flooding each year or less. (ii) moderate - 1.3% (1 in 75) chance or less but greater than 0.5% (1 in 200) chance in any year. (iii) significant - greater than...