KERI: Instability of hill slopes due to erosion and sudden down movement of rain water containing debris material are among the causes of the recent massive landslide at Satre in Sattari taluka, experts say.
The landslide occurred in the Mhadei wildlife sanctuary, on the left of the Chandsurya Ghat, going from Satre to Parwad. The landslide started from the top of the hill and a part of the loose material, along with huge boulders and pebbles moved away, forming a channel.
Though the area where the landslides took place is far from human settlement, forest clearance undertaken in the past for slash and burn agriculture in Satre as well as in Chikhale and Parwad of Karnataka have intensified landslide instances.
A wildlifer who visited the area recently, Vitthal Shelke, told TOI, “ Due to torrential rain, the huge boulders lying on the hill slopes have undergone chemical weathering, thereby accounting for movement of slurry soil and loose rocks down the slope.”
Keri resident Gajanan Shetye said that due to the landslide a large quantum of sediment, along with rainwater, is moving into the Kalasa nullah, which eventually empties in to the Mhadei river at Uste.
Apart from this, there is also the immense ecological damage. “The landslide has been responsible for uprooting a large number of trees as well as vegetation thereby causing environmental loss,” Vithoba Gawde said.
Nandkumar Kamat, a scientist associated with the Goa State Biodiversity Board said, “Full aerial surveillance and mapping using drones as well as ground truthing by a joint team of officials from the forest department and the water resources department (WRD), using the help of local stakeholders must be undertaken.”
He said there is also a need for full mapping of the mud flow. “The forest department must undertake contour binding, slope stabilisation measures and tree plantation to stabilise eroded hill slope while WRD must build temporary check dams and sediment traps to stop mud flow entering the main river channel.”
Further, he said that officials must also investigate the matter on the Karnataka side, above Satrem village, to ascertain the extent of deforestation, soil erosion and sediment flow in Goa through streams.
