2018 Kerala floods

On 16 August 2018, severe floods affected the south Indian state Kerala, due to unusually heavy rainfall during the monsoon season.^[1][2][3] It was the worst flood in Kerala in nearly a century.^[4] Over 483 people died,^[5] and about one million^[6][7] people were evacuated, mainly from Chengannur,^[8] Pandanad,^[9] Edanad, Aranmula, Kozhencherry, Ayiroor, Ranni, Pandalam, Kuttanad, Malappuram, Aluva, Chalakudy, Thrissur, Thiruvalla, Eraviperoor, Vallamkulam, North Paravur, Chendamangalam, Chellanam, Vypin Island, and Palakkad. All 14 districts of the state were placed on red alert.^[2][10] According to the Kerala government, one-sixth of the total population of Kerala was directly affected by the floods and related incidents.^[11] The Indian government declared it a Level 3 Calamity, or "calamity of a severe nature".^[12][13] It is the worst flood in Kerala after the great flood of '99 that took place in 1924.

Thirty-five^[14] out of the fifty-four^[15] dams within the state were opened for the first time in history. All five overflow gates of the Idukki Dam were opened at the same time, and for the first time in 26 years, five gates of the Malampuzha dam of Palakkad were opened.^[16] Heavy rains in Wayanad and Idukki caused severe landslides and had left the hilly districts isolated.^[17][11] The situation was regularly monitored by the National Crisis Management Committee, which also coordinated the rescue and relief operations. The dam openings disrupted many of those living nearby.^[18]

With the recurrence of flood events in the state in the subsequent years, several studies have attempted to explain the behavior.