ABSTRACT
Forecasting flow behaviour requires an understanding of how lava properties, effusion dynamics and environmental factors determine the final dimensions and rate of growth of a flow. This chapter outlines the gross features of historic lava flows and domes, and provides a context for the discussion of flow emplacement. Two complementary approaches are available: one focuses on local lava properties and combines these theoretically to obtain a flow's bulk characteristics; the other starts by monitoring the bulk characteristics, identifies behaviour patterns empirically, and uses these patterns to deduce controls on lava emplacement. Lava accumulates in the channel and may result in overflow, intrusion or breaching of the flow margins. Such cooling-limited flows achieve the greatest lengths possible for a given set of eruption conditions and so it is their behaviour which is of most interest for hazard assessment.
