I am trying to model rainfall-runoff using TOPMODEL in R. The TOPMODEL needs an input called "cumulative delay function". The R documentation says "Flow is routed through a delay function which represents the time spent in the channel system. The parameter delay is used for this. Delay is a matrix with 2 columns. The first column gives the cumulative relative area. The second column gives the average distance towards the outlet (m). One of the papers (Hydrological modelling with TOPMODEL of Chingaza páramo, Colombia) which used TOPMODEL had this table
Does anyone know how to derive this table either in R or QGIS/GRASS ?