KOZHIKODE: The landslide atlas of Kerala, prepared by the University of Kerala, has identified Wayanad district as the most landslide-prone area in Malabar region . As per the atlas, Wayanad is the second most landslide prone area in Kerala after Idukki district. Kozhikode figures third and Kannur fourth in the atlas. “More than 25 per cent of the land mass in Wayanad is prone to landslide, the report said. According to the atlas, 20 percent of the land area in Kozhikode district and 10 per cent of the land in Kannur district are prone to landslide. Idukki is the landslide hazard zone inKerala with over 60 per cent of the land mass prone to landslides,” said Sajin Kumar K S, assistant professor at the Department of Geology, University of Kerala.
“Although heavy rainfall is the prime factor triggering landslides in Kerala, the thickness of the veneer cover soil, the steepness of the slope, as well as the anthropogenic activities control the spatial distribution of landslides,” he said. Every year land slips and landslides are reported in Kerala during monsoon season. Landslides in the state include rock fall, rock slip and debris flows. However, the most disastrous type of landslide in Kerala is the debris flow characterised by the swift and sudden flow of water carrying soil particles to boulders destroying everything in its path.
Wayanad district stands on the southern tip of the Deccan plateau and the areas bordering Kozhikode and Kannur districts are the most affected. These boundaries are parts of Western Ghats.
According to Sajin, mining of red stone in the high ranges of Kozhikode is one of the reasons triggering landslides in the area. “The soil in Kozhikode district is rich in iron. Tipu Sultan had extracted iron from the region and made arsenals. While extracting iron ore, trenches were created inside the hills and water filling the trenches are causing landslides in the region,” he said. In Kannur district,Iritty region is a landslide prone area. Here the soil is young compared to the rocks. The water easily percolate through the soil and fill the space between the soil and the rock. This causes landslides.
The atlas was prepared with the help of the Geological Survey of India (GSI), the nodal agency for landslide studies in India. The susceptibility map was derived using the Geographic Information System (GIS) Tool for Infinite Slope Stability Analysis (TISSA). Digital Elevation Model (DEM) was obtained from Shuttle Radar Topography Mission (SRTM) data, whereas the vegetation map was prepared using Landsat satellite imagery, both having a spatial resolution of 30 m.
Wayanad district hazard analyst Asha Kiran said the disaster management cell has identified Western Ghats region in the Wayanad district as the most landslide prone region. “The district administration has imposed restrictions on construction in these areas. We are planning to form a task force by including members from local self governments, revenue department and people at the village level. This task force will monitor further developmental activities in the region,” she said.The district disaster management cells in Kozhikode and Kannur have prepared action plan to reduce the risk of landslides.
What’s landslide?
Landslides in the state include rock fall, rock slip and debris flow. However, the most disastrous type of landslide in Kerala is the debris flow characterised by the swift and sudden flow of water carrying soil particles to boulders destroying everything in its path
The looming threat
Mining of red stone itriggering landslides in Kozhikode district
In Kannur district,Iritty region is a landslide-prone area. Here the soil is young. The water easily percolate through the soil and fill the space between the soil and the rock
The disaster management cell has identified Western Ghats region in the Wayanad district as the most landslide prone region