The Hume Centre for Ecology and Wildlife Biology and the Advanced Centre for Atmospheric Radar Research of the Cochin University of Science and Technology (CUSAT) have jointly set up a localized weather forecasting system for Wayanad district, a major landslide prone area in the State.
“While the conventional forecasting systems focus mostly on district wise rainfall, which has limitation in providing regional variation in forecasting, this new model predict rainfall in 25 sq km gridded platform, showing local variation in rainfall”, said S. Abhilash, Meteorologist of CUSAT.
“Everyday forecasting resulted in 70% to 80% accuracy in the spatial distribution as well as the intensity of rainfall. But we have to experiment at least three years to understand the limitations in the modeling system and to further improve the accuracy. The promising results of one year simulation is encouraging and appreciated by various stakeholders and there is also scope for customization of the forecast products for various stakeholders” Dr. Abhilash, said.
Western Ghats mountain ranges in the south western side of the hill district often attract huge clouds during monsoon and receive heavy orographic rainfall. While the western side receives 4,000 to 5,000 mm rainfall annually, the eastern side, which is a rain shadow region, receives only 1,500 mm rainfall.
Though the district was showing a declining trend in annual rainfall during the decade ending 2017, suddenly an upsurge of extreme rainfall experienced in 2018 and 2019 resulting in a series of landslide and floods in Wayanad, due to climate change.
Extreme rainfall ranging from 300 to 800 mm in twenty four hours duration has been recorded during the last three years, many of that intensity resulted in major landslides, he added.
'One of the major objective of this initiative is to provide day to day information about rainfall in different region of Wayanad through a localized prediction system as well as wide spread rainfall collection system in a citizen science mode', C.K. Vishnudas, director, Hume, said.
The district has divided in 107 grids of 25 sq km for the purpose and a rain gauge and thermometer has been installed in each of the grids except forest areas. Currently rainfall data is being collected from 93 locations of Wayanad and this pooled into a centralized system for synthesis, Mr. Vishnudas said . This system supported to provide localized warning to people living in mountains slopes about possible landslide when rainfall exceeds the threshold during monsoon, he said.
Hume Centre has already mapped all the landslide prone areas of the district with a Panchayath wise landslide susceptibility map. So the new tool of rainfall mapping will enhance districts capacity to combat disasters in future, he added. The information generated from the system is pooled to the district disaster management authority for better decision making, he added.
