This Part of BS 7843 gives guidance on the methods commonly used in the UK for the estimation of areal rainfall. It is applicable to the use of meteorological precipitation data from a raingauge network.

This Part of BS 7843 highlights factors to be considered during the estimation of areal rainfall and presents an outline of methods (full technical details of the methodologies are not provided).

It does not cover methods using precipitation data collected by weather radars. However, discussion of their relevance is included.