Flooding: Extreme Weather

The Summer Floods 2007
Have been asked to present a session for the GA's Manchester Branch in September.

There have been several recent additional articles which would be useful for those exploring this.
The first is the announcement that the floods were not due to global warming but in a sense to "the wrong type of rain", which led to huge amounts of saturation excess overland flow.
This comes out from a report by the CEH (Centre for Ecology and Hydrology)
Read the BBC article first.

Then head over to the CEH to read the articles there, and the Hydrological appraisal of the flooding.

This page also has a link where the full report can be downloaded (an 11.5 Mb PDF)

Also check out the NERCs explanation of this flooding type, which is called PLUVIAL flooding (as opposed to fluvial...) (Thanks to Simon Oakes for the tipoff here...)

Pluvial' flooding is defined as flooding that results from rainfall generated overland flow before the runoff enters any watercourse or sewer. It is usually associated with high intensity rainfall events (typically >30mm/h) but can also occur with lower intensity rainfall or melting snow where the ground is saturated, frozen, developed or otherwise has low permeability resulting in overland flow and ponding in depressions in the topography. The focus for this call is on urban pluvial flooding arising from high intensity 'extreme' rainfall events. In such situations urban underground sewerage/drainage systems and surface watercourses may be completely overwhelmed. Examples include the recent June and July 2007 floods in England where pluvial flooding is thought to have been an important element in urban areas. Pluvial flooding may occur alone or be combined with other forms of flooding such as fluvial flooding, flash flooding (from a watercourse) or sewer derived flooding.