what defence barriers can you put in to place to help decrease the flow of lava or foam ?

Question: what defence barriers can you put in to place to help decrease the flow of lava or foam ?
- Keywords:
  barrier,
  decrease,
  defence,
  flow,
  foam,
  lava
Asked by chloe96 to David on 18 Mar 2011 in Categories: Your Research.
- David Pyle answered on 18 Mar 2011:
  
  It’s quite easy to divert lava flows, at least on some volcanoes. On Etna, they have done this with earth banks – just using JCBs to put up 10 m high barriers, which the lava will not flow over. In Japan and Indonesia they use concrete to stabilise river channels – this keeps the mudflows in the channel, and reduces damage.

Question: what defence barriers can you put in to place to help decrease the flow of lava or foam ?