22 July 2010

The slow-burn rainfall disaster in China, whilst the monsoon in South Asia is weak so far

Posted by Dave Petley

Although it has received scant attention in the west, China is currently undergoing a classic slow-burn weather disaster associated with exceptional rainfall.  The scale is remarkable – Xinhua reports that since 1st July, 273 people have been killed and 218 people are missing, 3 million people have been displaced from their homes and 58 million people have been affected directly.  Economic losses are estimated to be about US$8.6 billion.  This means that over 1,000 people have been lost to floods and landslides so far this year in China.  As of 15th July (i.e. before these most recent storms), economic losses from rainfall-induced disasters in China this year were estimated to be US$17.6 billion. A week earlier than that, on 8th July, the Ministry of Civil Affairs estimated that natural disasters (now including earthquakes) in China  in the first six months of 2010 have left about 4,000 people dead or missing, and caused about US$31.2 billion in direct economic losses.

Unfortunately the situation could deteriorate considerably in the next 24 hours as Typhoon Chantu is just making landfall in southwest China, as this Tropical Storm Risk map shows:

Meanwhile, the monsoon in S. Asia is off to a slow start.  Although the weather system progressed northwards more quickly than is normal, the rainfall totals to date are some way short of normal:

Whilst this is good news from a hazards perspective, S. Asia is dependent upon monsoon rainfall.  Very anomalously low years cause water supply issues.  However, there are now signs that atmospheric conditions that generate monsoon rainfall are developing, so expect to see this situation change soon.  The result will inevitably be an increase in the number of landslides in S. Asia, in line with the normal seasonal pattern.