KOCHI: It was three days of incessant rain that surpassed the monthly average rainfall that triggered apocalyptic flood in the four districts of North Kerala.
While Wayanad receives an average rainfall of 644 mm in August, Vythiri station recorded 739 mm rainfall from August 8 to 10, which was 114.7 per cent of the monthly average.
The Average rainfall expected in Kozhikode during August is 547 mm, but Vadakara in the district received 806 mm rainfall from August 9 to 11, which accounts to 147.3 per cent of the expected rainfall, reveals the data compiled Kozhikode Centre for Water Resources Development and Management (CWRDM).
The rainfall in Palakkad during the three days was double the monthly average.
While the expected rainfall for the district is 349 mm, Ottappalam received 765.3 mm rainfall from August 9 to 11. The three-day cumulative rainfall in Pattambi was 501 mm.
The rainfall in other stations were Palakkad -443 mm. Alathur - 570 mm, Kollangode 430 mm and Chittoor 364 mm.
The normal rainfall in Malappuram for August is 399 mm but Perinthalmanna in the district received 516 mm rainfall from August 8 to 10, which was 129.3 per cent of the monthly average.
Though other districts like Kannur, Kasargod and Idukki received excessive rainfall during the period, it was these four districts that bore the brunt of the heavy downpour.
“Heavy rainfall in excess of 250 mm during a single day can trigger landslides, while incessant rainfall that continues for days will flood the plains. When it rains excessively, the rate of percolation will be low. The floodwater will not drain to the sea during high tide and it was the wetlands and paddy fields that used to absorb the floodwaters in the past. As we have lost a considerable amount of flood plains, it leads to inundation of the entire area,” said CWRDM Geomatics Division Head V P Dinesan.
Monsoon is now normal
The monsoon, which was 48 per cent deficit in Kerala in June this year has now become normal with the week-long heavy downpour that inundated many places and left a trail of destruction in four districts.
According to the season’s rainfall data, recorded by the Indian Meteorological Department (IMD), the deficit, which stood at 38 per cent on August 1 has reduced to 3 per cent on August 12.