Ulu Klang has a dubious reputation, suffering 12 major landslides since the infamous Higland Tower collapse in December 1993. And it for this reason that the PWD has chosen this area to begin mapping landslide-prone areas in the country, writes ELIZABETH JOHN

A STUDY of slopes in Ulu Klang has found over a hundred landslide scars, with most left unattended and having the potential of becoming fatal slope failures.

The one-year pilot study undertaken by a multi-agency team of experts also found that slopes in this area had been stabilised with ground anchors that were not maintained.

Major failures were related to rock falls and these occurred in ex-quarry areas that were developed without proper scaling or protection of loose rocks.

The study identified regular maintenance and repair works as a critical issue in the Ampang area.

The study to assess and map hazards in landslide-prone Ulu Klang was commissioned by the Public Works Department's Slope Engineering branch, ahead of the National Slope Masterplan that will be ready next month.

It covered an area of about 100 square kilometres from Cheras to the north of Taman Melawati.

The data from this study will be used to formulate measures and put in place an effective inspection and monitoring policy for the Ulu Klang Kelang area which has seen a number a number of fatal landslide disasters over the years.

It will serve as a template for future hazard assessment and mapping projects to be carried out in other landslide prone areas.

Malaysia has more than 19,000 slopes including 1,200 major ones and in the 50 years since 1961, records show that 455 landslide incidents have been reported.

Among the major factors causing slope failures in the Ulu Klang area was poor maintenance of drainage systems for slopes, said the study findings that were presented at the recent International Conference on Slopes 2008.

There were areas with no drainage systems that could prevent surface runoff, the formation of ponds or water infiltration, said the experts in a paper titled Slope Field Mapping and Findings at Ulu Klang Area, Malaysia.

Its aim was to identify the various factors that caused landslides in the area which the experts did taking into account the landform, rainfall intensity and duration, geological factors and human activities among others.

Detailed field studies were carried out in 564 locations, covering 45 residential areas in the Ampang area.

An optical remote sensing technology was also used to map out the terrain and produce a contour map of the study area.

Defects and problem areas were individually referenced according to housing estate and street name and GPS location to allow local authorities to conduct rectification work with ease.

Mapping teams identified many sites with soggy soil, potential rock fall areas, rock overhang and where there was seepage and cracks in walls and floors that needed attention.