THIRUVANANTHAPURAM: The expert committee which conducted an inspection in the landslide-hit areas in the northern districts has cited unscientific land use as the reason for the natural calamities.
The committee, comprising scientists G.Sankar of CESS, Thiruvananthapuram, S.Sankar,KFRI, Peechi, R.Gopakumar, CWRDM, Kozhikode, Xavier K.Jacob, KAU, Vellayani and Suresh Francis, KSREC, Thiruvananthapuram, came to the conclusion that exceptionally high South-West Monsoon rains received during this year in the districts of Wayanad, Malappuram and Kozhikode had caused land disturbances such as landslides, in the form of debris flow (urulpottal), rockfalls, rotational landslides and subsidence due to piping.
The committee also found that the natural drains and topographic hollows (ill-defined drainage canals) could not conduct the voluminous storm runoff properly resulting in debris flow. Most of the natural drains were either blocked or modified by agricultural practice, the report said.
The rainwater infiltration pits (mazhakuzhi) for rainwater harvesting were observed at high slopping areas (slopes more than 20 degrees). This practice will further destabilise the slope which is already saturated with water. Roads had been constructed without considering cross drainage of the area into account.
The report said that in places such as Kunnamangalam-Chembra peak area in the Meppadi panchayat in Wayanad, proper drains were lacking to conduct storm water. This area receives very high rainfall and all rainwater is filtered into the soil causing rotational type slide movement and piping.
In Vellamunda, there are quarries located very close to the multiple slide locality. The vibration due to blasting during monsoon also could be a reason for landslip.