ENGINEERS are examining hi-tech monitoring systems in an attempt to prevent landslips such as the one at Kwun Lung Lau, Kennedy Town, which killed five people last summer. Seismic techniques, involving the use of radar, could show up soil movements or gaps formed under surfaces that might pose potential dangers, said chief geotechnical engineer John Massey of the Civil Engineering Department. After the Kwun Lung Lau disaster, the Canadian consultant who headed the official inquiry, Professor Norbert Morgenstern, recommended that the Government consider such techniques. Other methods being considered include magnetic and electrical monitoring techniques, he said. Mr Massey's comments follow the demonstration of ground-penetrating radar at a slope in Kennedy Town a few streets away from Kwun Lung Lau, at the junction of Pokfield and Smithfield roads. The company had also shown the technique to Civil Engineering Department inspectors last week, Mr Massey said. But he warned such methods were only as good as the skills of the people reading the results, since the reflections of the seismic waves did not produce simple pictures. 'It's a matter of skilled interpretation as to what the waves tell you,' he said. 'To an unskilled person . . . it looks like a meaningless jumble, and even a skilled person has to make some inspired guesses sometimes.' Sandra Mak of China Light and Power said the company used radar techniques to search for pipes and cables under roads before drilling. Engineers also found it difficult to interpret the results, she said. Radiodetection engineer Wong King agreed that experience was 'a key point, but we are developing software so that someone without any background can understand it'. After a 21/2-hour inspection of a slope, he said: 'We can see if the density of soil is not high enough, how deep the rock is and where the weakest point is in the different layers.'