Early Warning System for landslides set up

The frequent occurrences of natural disasters which beset the country recently demanded the need of improving disaster management and early warning systems for various disasters such as tsunamis, earthquakes and landslides. Apart from the catastrophic tsunami of 2004, recent landslides which occurred in the country caused heavy damage to public property and resulted in several fatalities.

This emphasized the importance of having an early warning system for landslides, which could give an indication of the imminent disaster without any delay. Thus the setting up of an early warning system to minimise the effect of landslides was initiated by the National Building Research Organisation (NBRO), Department of Meteorology, Disaster Management Centre (DMC) and the Industrial Technology Institute (ITI) contributed significantly towards the setting up of such a system.

Experts from these organisations have joined hands together with the government of Sri Lanka and the United Nations Development Program (UNDP) to implement a landslide early warning system and are successfully carrying out their first ever pilot project in the Ratnapura district.

Past records show that in Sri Lanka landslides are triggered by heavy rainfall. The attention of the experts was thus focused on drawing a logical relationship between landslides and the rainfall.

Individual institutions took the responsibility of various parts of the project and ITI played the role of the technical partner.

The Landslides Studies and Services Division of the NBRO, after a long and laborious process has prepared the Landslide Hazard Zonation Map (LHZM) for the entire country.

The process was based on six key factors; i.e. geology, hydrology, slope, landform, land use and soil thickness and early landslides in an area.

Using the LHZM the degree of the landslide hazard has been evaluated and the whole land area of the country has been categorised as High, Medium and Low hazard areas.

The map could be effectively used for planning purposes, such as at the outset of a construction project. From the map the vulnerability of the area to landslide could be predicted and this information can be effectively used for decision-making.