17 July 2019
The start of the 2019 South Asia monsoon
Last week the summer monsoon arrived in South Asia with a vengeance, with heavy rainfall across the upland areas of Nepal, India, Bhutan, Pakistan and Bangladesh. Reports suggest that losses across these regions have been high, with floods and landslides both causing significant loss of life. As usual I have been trying to keep abreast of those landslides that have caused loss of life.
The graph below shows the cumulative number of fatal landslides that I have recorded in the South Asia region to date in 2019, up to and including 16th July 2019:-
The graph shows the steady accumulation of landslides through the first half of the year, with a jump in late February with a flurry of landslide events in northern Pakistan. From about the end of June the effects of the monsoon started to become apparent as the incidence of landslides increases. However, the impacts of the very heavy monsoon rainfall in the last week is very clear.
By way of comparison, this is the same data plotted for SE. Asia, which does not have a strong monsoon signal:-
The SE. Asia signal tends to be strongly affected by wetter periods around the turn of the year, but in general the landslide rate is relatively constant.
The recent exceptional monsoon rainfall event started to appear in the landslide record on about 11th July 2019. The image below shows the 7 day accumulated rainfall from the NASA GPM mission. The 7 day period ends on 16th July 2019 at 14:30 UTC:-
Interestingly, the rainfall record suggests that there was also a significant rainfall event in northern Burma / Myanmar, but I have seen no reports of impacts there. I suspect that this means that I have some missing data. The S. Asia summer monsoon lasts through to September, so there are many more landslides to come in this region this year.
Froude, M. J. and Petley, D. N. 2018. Global fatal landslide occurrence from 2004 to 2016. Natural Hazards and Earth System Sciences, 18, 2161-2181, https://doi.org/10.5194/nhess-18-2161-2018.
Petley, D.N. 2012. Global patterns of loss of life from landslides. Geology 40 (10), 927-930.