abstract = "The problem of accurately determining river flows from
rainfall, evaporation and other factors, occupies an
important place in hydrology. The rainfall-runoff
process is believed to be highly non-linear, time
varying, spatially distributed and not easily described
by simple models. Practitioners in water resources have
embraced data-driven modelling approaches
enthusiastically, as they are perceived to overcome
some of the difficulties associated with physics-based
approaches. Such approaches have proved to be an
effective and efficient way to model the rainfall
runoff process in situations where enough data on
physical characteristics of catchment is not available
or when it is essential to predict the flow in the
shortest possible time to enable sufficient time for
notification and evacuation procedures. In the recent
past, an evolutionary based data driven modelling
approach, genetic programming (GP) has been used for
rainfall-runoff modelling. In this study, GP has been
applied for predicting the runoff from three catchments
-- a small steeply sloped catchment in Hong Kong (Hok
Tau catchment) and two relatively bigger catchments",