Danger: landslide zone

Geologists say that seismic movements are constantly taking place in the Himalayas. On an average, nearly 200 earthquakes of smaller magnitudes occur every year in the Uttarakhand region alone see graph. Most of them are undetected by the local communities. Says Dr V.C. Thakur,director of the Dehra Dun-based Wadia Institute of Himalayan Geology, 8220;Thousands of landslides of medium to large dimensions have been occurring in the Himalayas every year. This time they have become more noticeable because of the large-scale death and destruction caused.8221;

The heavy rains this time contributed to the tragedy. A major part of the Himalayas in Uttarakhand usually receive heavy monsoon showers during the summer months and some rains in winter. This time the region was visited by incessant rain that continued for more than a week at a stretch. According to Thakur, the uncontrolled, downhill flow of water after heavy rains, particularly along barren slopes, was an important causative factor in these landslides.

Says Thakur, 8220;Apart from geological reasons, changes in the land use pattern in the mountains has also led to the increase in the frequency and magnitude of landslides. The most obvious of these changes is, of course, the rapid destruction of forests which has left large tracts inthe entire Himalayan region with denuded slopes.8221;

The destruction of forests and the vegetative cover that binds the top soil has been going on at an ever-increasing pace because of the various developmental activity in the region, including the expansion of the road network; the establishment of new townships and the expansion of existing ones; and the conversion of forest land into agricultural and horticultural holdings.

The Himalayas are a notoriously poverty-stricken region. In a desperate bid to get better returns from the land, local communities have taken recourse to creating more and more terraced agricultural fields in a bid to grow cash crops like paddy 8212; a switch-over that has made the area more ecologically fragile. Scientists feel that changes in the cropping pattern has also increased the seepage of water into the rocky surface of the mountains. This could, in the long run, break up the inter-locking ecosystem which binds the mountains.

Then take an activity like road construction. Theuse of explosives to blast the surfaces of the mountains while making roads has wrought its own brand of havoc. A study conducted in 1984 on the relationship between the building of the Mussoorie-Tehri road and landslides occurring in the region, revealed that landslides caused more devastation in deforested rather than forested areas. The study found that 148 landslides took place on slopes where the tree cover was less than 40 per cent and 118 took place where the tree cover was more than 60 per cent. It was found that the landslide debris in afforested area was only 12 cubic metres as compared to 26 cubic metres of debris in deforested areas.

Similarly, 30,000 to 40,000 cubic metres of soil is excavated in carving out one kilometre of road in the Himalayas 8212; a figure that eloquently reveals the extent of damage that even relatively 8220;harmless8221; activity like road construction does to the local ecology. To make matters worse, most roads are constructed without proper surveys. Such roads invariably causenew landslides or reactivate old ones.

Laments Dhan Singh Rawat, a geologist working with a non-government organisation in the Garhwal Himalayas, 8220;Although a geologist is appointed in each hill district, no holistic approach has been evolved to measure the geological fall-out of developmental and construction activities in the mountains.8221;

Unbridled urbanisation has also done its bit in making the region more unstable. Dr J.S. Samra, director, Central Soil and Water Conservation Research and Training Institute, feels that the change in the architecture of the houses in the hills, the increasing use of brick and concrete 8212; instead of the traditional mud and wood 8212; has resulted in higher casualty figures when disasters strike. Urbanisation also brings the severe problem of garbage and sewage disposal. The discharge of sewerage and the choking of gullies, which function as natural drains, leads to dangerous seepage, making mountain surfaces that much weaker.

According to Samra, this country still lacksa separate institution dealing with mountain hazards in general and landslides in particular. 8220;Look at China,8221; says Samra. 8220;More than 60 per cent of its total area is mountainous and it has taken a lead in studying and taking remedial steps to prevent and rehabilitate landslides.8221; According to him, the Institute of Mountain Hazards and Environment at Chengdu, China, set up as early as 1965, has done excellent work in this field.

N.S. Virdi of the Wadia Institute of Himalayan Geology emphasises that a proper geological and geotechnical survey is vital before launching any developmental project in the hills, including the preparation of landslides hazard zonation maps, so that prior knowledge about the status of the area to be undertaken for development is available. This way, efforts could be made to take measures to minimise and even prevent the ensuing damage to the local ecology.

True, landslides can occur anywhere at any time, but unlike earthquakes, their occurrence can be predicted and plannedfor. The tragedy is that despite a wealth of data and numerous experts in the field, there is very little planning going on. The tragedy is that it is the construction lobbyists and the mafias dealing in Himalayan timber and stone, working in league with the politician and the administrator, who finally get to set the agenda for development in this region. Meanwhile, the forgotten people of the region continue to die as their land slips from under them and their houses collapse over them.