Suggestions on heavy rain events remain on paper

Panel mooted slope stabilisation, tree planting to avoid landslips

Most of the recommendations of an expert committee constituted two years ago to examine the causes of repeated extreme heavy rainfall events and to recommend appropriate policy responses remain on paper even as the State is reeling under fresh rounds of flooding and landslips.

The panel headed by K.P. Sudheer, executive vice-president, Kerala State Council for Science, Technology and Environment, submitted its report to the Kerala State Planning Board in December 2019. The committee, which had experts drawn from various scientific disciplines, had also submitted action plans to be implemented in six months, besides short-, medium- and long-term ones for various sectors.

Human activities

The panel had put the blame of the devastating landslips in the State during 2018 and 2019 on the instability of the slopes caused due to various anthropogenic activities, though it noted that the landslips were primarily initiated by the extreme rainfall events.

Besides slope stabilisation, remedial measures like providing vegetation cover to the degraded slope by either promoting natural vegetation growth or by planting suitable species were suggested. In areas where clear-felling of trees was done, the deep taproots should be removed and refilled with earth to avoid oversaturation and decay of the taproot system, which will lead to soil piping and landslips, it suggested.

Use of machinery

The panel was against the unscientific use of machinery for pit formation for farming as it feared that the ‘process might lead to increased disturbance of the land and cause additional water-holding, resulting in oversaturation.’

The cutting and levelling of ground for construction of houses on the toe region of slopes having more than 25% inclination and a slope length exceeding 100 m shall be avoided. It had also recommended against the blocking of stream channels in the upper slopes, especially above settlements.

The panel suggested modification of unstable slopes by regrading, geotextile mats, vegetation, bioengineering and geotechnical measures such as soil nailing. Anthropogenic activities that cause saturation of the soil should be strictly regulated in critical/prone areas, it recommended.