With reports of serious flooding coming from various parts of Thailand e.g. Sukhothai and Chiang Rai, what might happen if heavy rain falls in the the Ping River catchment upstream of Chiang Mai?

These pictures from 2011 give the answer:

Flood Warning - September 2011 - 2014  perhapsFlood Warning - September 2011 - Railway Park

However given similar rains, September 2014 floods could be worse, as levy banks upstream constructed since 2011 will raise water levels, as will this new barrage opposite Chiang Mai’s central market :

Flood Warning - September 2014 Worot Market Barage

Inappropriate construction as reported in July along the Ping River continues.