The chain of geological events that contributed to the disastrous floods that hit the Klang Valley and other parts of the country include prior landslides, said a leading geologist who visited several sites.

The natural disaster this time was so devastating and complex and happened so suddenly that all parties involved were not ready to perform their role, said Prof Ibrahim Komoo, a scholar who specialises in Engineering Geology, Conservation Geology and Sustainability Science.

"Surveys in the Penchala River showed that floods were caused by landslides that blocked the flow of the river.