Using VIIRS nightlights to estimate the impact of the 2015 Nepal earthquakes

We use Visible Infrared Imaging Radiometer Suite (VIIRS) nightlight data to model the impact of the 2015 Nepal earthquakes. More specifically, the data—showing nightlight emissions—are used to examine the extent to which there is a difference in nightlight intensity between cells damaged in the earthquake versus undamaged cells based on (1) mean comparisons; and (2) fixed effect regression models akin to the double difference method. The analysis is carried out for the entire country as well as smaller regions in and around the Central area and Kathmandu, which were the hardest hit areas. Overall, the regressions find a significant and negative effect from the initial shock, followed by a positive net effect from aid and relief efforts, which is consistent with what one would expect to find. However, the mean analysis results are inconclusive and there is substantial noise in the nightlight measurements due to how the values are produced and persistent cloud cover over Nepal.