Understanding the Dynamic Nature of Catchment Response Time through
Machine Learning Analysis
Abstract
Understanding the hydrologic response to rainfall events is vital for
flood forecasting and design for peak flows. The Time to Peak (Tp) is
used to characterize the speed of catchment response, as the time from
the start of a rainfall event to the time the peak flow is reached in a
stream. Advancing our understanding of a catchment’s temporal response
to rainfall is key to our overall understanding of hydrologic processes.
In this study, more than 1400 storm hydrographs were isolated and
utilized to calculate the Tp value for decades of storms spanning Great
Britain. Previous works into understanding Tp have been static, with no
variability due to storm magnitude or antecedent conditions, providing a
single static value for each catchment. Using this data and machine
learning techniques, dynamic Tp values were predicted for each storm
within the hundreds of catchments, to allow for fuller understanding of
the catchment response. Artificial Neural Networks are utilized in this
study to create models which account for antecedent conditions of the
catchment, and the storm size, to predict the storm-specific, dynamic Tp
value.