Dear Piet van der Poel

Nice to hear from you so quickly. I think no one is sure what really triggered such events. we are proposing  some hypothetical opinion. However to achieved a resonable understanding of such events there is a need to study in greater depth, so far no one has initiated a wholistic study of this castastrophic events that took a large portion of the rice fields in bomdeling. Yes ofcourse the people are smart..infact in whole eastern Bhutan, you will not  much settlement near the river basin.. they are mostly up on the mountainlope. This means that the settlement patterns itself was based on the knowledge of such disastors .  I may not be in a postion to answer wheather a landslides was triggered by heavy rainfall events ( need to check the met data on that year)  and alternately  it may have been long and
unstopable seepage of water  from the melting ice just above the the Baregang Chhu, may have trigerred such events.. we simply dont know at this point in time.  this Baegang chhu is fed by glarciers in its upper catchement.

 

Goodday

Purna