Earth Sciences to the rescue!!

 

Earth Science and the Kerala Floods

Kerala has a timeline with very less major natural disasters. A few small-scale tremors, landslides and a ride in waves. That’s all, but on August 15 2018, a warning for extremely heavy downpour and red alert was issued for all the districts for 16th August. That year, Kerala experienced the worst flood in about a century. It was caused mainly due to unusually high rainfall in the monsoon. 35, out of the 54 dams in the state were opened due to the flooding. Scientists need a better understanding of the interplay between gravity, weather and the form of the oceans to predict storms and their resultant floods better. Consider this as a story where there are two heroes and the sidekick of the first hero (Team Name: Earth Science), working as a team to defeat the villain: The Flood. The story will tell us more about how these heroes help saving the people from the great villain.

First Hero; Meteorology: The deluge that occurred is considered to be a result of our own actions; global warming. A major result of global warming is the warming up of our atmosphere, as the name suggests. As the atmosphere warms up, evaporation and transpiration increase causing excessive rains. We know all this due to the Earth science called Meteorology. The data provided by Indian Meteorology Department helped the State Disaster Management Authority to understand the expected rainfall, its implications and then to take appropriate decisions for dam management, issuing alert to people residing in areas that was going to be affected and so on.  During the flood days the data from Meteorology department helped NDRF, Army, Navy, Fire force and police working under the State Disaster Management Authority to decide on their strategies and priorities in the rescue operation.  Although many lives were lost, people missing and homes destroyed; eventually the state came to normalcy as rains receded. 

The role of Indian Meteorology Department and other organizations like World Meteorology Organization is ever increasing as many areas of the world are predicted to affect by consequences of global warming in different forms.

--Sidekick of Meteorology: Atmospheric Science:  Atmospheric Science is a branch of Meteorology which has a major focus on weather forecasting. Experimental instruments used in Atmospheric science include satellites, radiosondes, weather balloons etc. Many satellites that are put in orbit around the Earth are used to take photos of the Earth which are analysed to predict floods and other natural disasters. Two satellites used by The Indian Meteorology Department are KALPANA-I (Includes a Very High-Resolution Radiometer capable of imaging the Earth in the visible, thermal infrared and water vapor bands.) and INSAT-3A (it carries VHRR, Charged Couple Device (CCD) camera and Data Relay Transponder (DRT)). Data and observations from many other satellites put into orbit by other institutes also share information globally. One such major contributor is NASA with its advanced satellites like TRMM Satellite. It is a passive Multichannel /dual polarized microwave radiometer. Using the observations from these satellites, scientists are given clues to how much moisture is present in the soil; a key factor in how likely a flood will occur. Once the ground is saturated, it acts like a pool and hoards up water in basins, or acts like a concrete drainage ditch, channelling downhill. This causes floods to happen. So, by knowing the amount of moisture in soil, meteorologists can predict when a flood is likely to occur. (This hero just helps to give the right weapons to the other two heroes.)

Final Hero; Oceanology: Oceanology studies the physical and biological aspects of the ocean. It covers a variety of topics including ocean currents and waves. Ocean modelling is a key part in the prediction of floods. It helps understand the processes that happen between gravity, weather and the shape of oceans. So, Oceanology is essential in the prediction and prevention (only possible to a certain extent) of floods.

 

Learning from the lessons of 2018, Kerala has started paying more attention to weather forecast data and taking timely actions. As there is a prediction of the IMD that Kerala may experience high rainfall, The Government of Kerala along with NGOs are taking proactive actions such as removing silt from rivers, preventing further encroachment of river banks, widening canals, etc., to ensure smooth flow of water through its original channels. An aggressive campaign is also being done to increase social forestry and to keep the water bodies clean.