A Study of After-Effects of Kerala Floods Using VIIRS-OLS Nighttime Light Data

Abstract

In August 2018, massive floods occurred in the state of Kerala, India, causing life and property damages amounting to billions of rupees. In this chapter, a methodology is proposed using the Visible Infrared Imaging Radiometer Suite – Day/Night Band (VIIRS-DNB) scan data to estimate the flood-related damage in Kerala in a rapid yet efficient manner. Simple techniques like sum of lights and percent of normal light (PNL) are applied to compare the study region before and after the disaster. It is observed that there is a significant drop in the sum of lights value for several districts of Kerala that are also marked as severely affected districts based on the ground reports. The flood-affected areas are demarcated by using PNL technique. The results demonstrate the effectiveness of the proposed methodology for a rapid yet useful flood damage assessment.