Consider the following statements:

1.    One of the largest flooded areas was those adjacent to the backwaters along the coast. Areas adjoining these wetlands that are normally flood-free were flooded to large extent.

2.    The outlets to the sea, (pozhis/sand banks and spillways), did not have the capacity to evacuate high flood flows the rivers, as they occurred, into the sea and thereby aggravating the floods.

3.    The flood situation in the coastal areas was intensified by the perigean spring tide, during 11-15 August 2018.

4.    Sustained strong onshore winds, resulting in abnormally high sea levels, hampered river outflow into the sea intensifies the flood.

Which among the following statements, listed above, are true with the Kerala floods of August 2018?

The correct answer is Option 1: 1, 2, 3, and 4.

Key Points

• The Kerala floods of August 2018 were one of the worst floods the state has faced in nearly a century.
• All four statements align with the circumstances that exacerbated the floods: backwater flooding, inadequate river outlets, perigean spring tide, and strong onshore winds.
• Backwaters and adjacent areas were heavily affected, flooding even normally safe zones.
• Natural phenomena such as the perigean spring tide (unusually high tides during a full moon) and strong winds worsened the flood situation.

Additional Information

• Backwaters and Flooding: Kerala has an extensive network of backwaters that often act as a natural drainage system. However, during the 2018 floods, these areas saw unprecedented water levels due to heavy rainfall and river overflow.
• Inadequate Outlets to the Sea: Many rivers in Kerala drain into the Arabian Sea through sandbanks (pozhis) or spillways. During the floods, the capacity of these outlets to handle the massive water inflow was insufficient, aggravating the situation.
• Perigean Spring Tide: This is a natural phenomenon where the moon is closest to the Earth (perigee), and its alignment with the Sun causes unusually high tides. This effect coincided with the floods, worsening the inundation of coastal areas.
• Strong Onshore Winds: Sustained winds from the sea pushed water inland, raising sea levels and further hampering the outflow of river water into the sea.