THIRUVANANTHAPURAM: The entire project alignment of SilverLine falls in Seismic Zone III. The risks include earthquake, tsunami, floods and landslides, reveals the DPR. While the risk probability of earthquake and tsunami are low, there is medium probability for floods, water inundation, landslides, cyclone, storm surges and heavy rain.
One of the serious observations is health hazard due to exposure to infections like Covid and toxic substances. There is medium to high probability for risk of epidemic - viral, bacterial, parasitic, fungal, or prion infections, in addition to insect infestations.
The section ‘General Risk Identification and Management’ says that even though alignment lies in a seismic zone, Kerala continues to be the most earthquake-free zone, compared to other southern states and hence there is low probability for the same. There is a medium risk of heavy rainfall in a short time, creating flooding conditions within minutes or a few hours during or after the rainfall.
Some permanent impacts of the project include change in land use pattern, local topography, loss of fertile top soil and agricultural produce. In addition, there will be temporary impacts like deposition of spilled construction material on soil, spillage/spread/deposition of debris and conversion of land into waste land.
“During construction of embankment, loose soil for embankment preparation could result in silt run-offs, if exposed to wind or rain and if appropriate compaction or stabilisation measures are not adopted immediately. Loss of productive soil may also result from uncontrolled opening up of borrow pits. Loosening of top soil and loss of vegetative cover due to excavation, land-cut and back-filling could lead to soil erosion,” says the report.
It further points out that during construction, there could be an impact on water bodies too. Scarcity of water for users is also mentioned as a possibility. The report has suggested a slew of mitigation measures to address these issues.