The humid, forested mountain landscape of southwestern British Columbia can be characterised as a debris flow dominated landscape; yet it was not until 1972 that attention was first drawn to the importance of debris flow in this region. The reasons for debris flow dominance over other slope and channel processes include the continuing response of the land to Cordilleran ice retreat, through over-steepened slopes and enhanced sediment supply, the dense rainforest vegetation and the increasing population and land use pressures to which the mountains are subjected.

We can recognise five broad categories of regional controlling variables, namely geologic, morphometric, hydrologic, sediment recharge and anthropogenic factors as follows:
Geologic: Debris flows generated from Quaternary volcanic complexes differ from those in coarse textured plutonic rocks;
Morphometric: Basins from 1-5 km² in area and with channels 25-30o in slope appear to be most active;
Hydrologic: Runoff intensities associated with orographically enhanced frontal disturbances, rapid snowmelt, release from lake storage and log jam bursts are triggering mechanisms.
Sediment Recharge: Basins can be characterised as either weathering- or transport-limited, and factors that are influential in this context are the availability of unconsolidated sediment and the role of organic debris and
Anthropogenic: Widespread urbanisation, intensive recreational use of the mountains and indiscriminate logging have increased debris flow incidence locally and regionally.

Development of terrain and slope stability mapping and new provincial guidelines for forest practice have been the main assessment and mitigation devices implemented.