In the early hours of July 30, tragedy hit three villages located in the foothills of the Western Ghats in Wayanad. A humungous volume of runoff that flowed down the hills caused a horrific landslide.

While there is no denying that Wayanad region had witnessed increased ecological disturbances during the past couple of decades mostly associated with tourism, quarrying and road building, the billion dollar question is whether this great tragedy had been caused by such activities.

There are no empirical studies from around the world to show that the activities such as those mentioned above can always cause landslides of such magnitude. In this case, the two hills with thick vegetation that came crushing did not witness any infrastructure development.

The second controversy is about the availability of hazard maps for western Ghat region. Much hype had already been created about the report prepared by the Western Ghats Ecology Expert Panel (WGEEP) in 2012. The panel had argued that no infrastructure development should be allowed in around 35 per cent of the Ghat region, which according to the report is ecologically most sensitive.

But the point is that there is no scientific data that links the occurrence of landslides to construction activities, sand mining and quarrying. Even the claims about increasing intensity of rainfall in the WG region, often cited by some ecologists as the cause of increasing landslides in the region, need to be verified. So let us now focus on a hazard mapping of the entire region, considering the rainfall, its intensity, soil characteristics, slopes, geological structures and land cover, the factors that actually influence the occurrence of landslides.

The third controversy is about the effectiveness of the early warning system. Some argued that the IMD’s rain forecast was too vague. When the IMD issued ‘orange’ alert (indicating a rainfall of 100-206mm during 24 hours), the actual rainfall that the tragedy spot witnessed was much higher, around 532mm in 48 hours, warranting a ‘red alert’. But what we often ignore is that for a region which receives 3,500 mm rainfall on an average in a year, an ‘orange’ alert will not create much anxiety among the local people.

Probably what would have made a difference is a warning issued on the basis of the ‘cumulative rainfall’ that the area received over a period of say, one week or so. So there is a need to work on the criteria for issuing warnings.

Accurate forecast

That said, is there a scope for improving the accuracy of weather forecasts? The western Ghat region witnesses wide variation in rainfall within a short distance (in the east-west direction) given the sharp differences in altitude. Therefore, predicting the rainfall with some degree of accuracy becomes extremely complex.

Many talk about real-time monitoring of weather and wider dissemination of the data. But this data needs to be processed along with several other datasets — land use, slopes, sil characteristics and moisture conditions, to say something about the runoff and the kinetic energy of the flowing water. Even when all these are done, the local people should be able to relate to the highly technical data.

While law-enforcing agencies should act against illegal sand mining and quarrying, putting the blame of such weather-induced disasters on cutting of trees and mining, based on half-baked knowledge, is not correct. Even the knowledge of the extent to which trees can stabilise hill slopes is often insufficient. When the slopes become unstable with several days of continuous rains, thousands of trees that the soils hold were washed away.

So let us evolve a pragmatic approach for protecting the Western Ghats based on scientific knowledge.

Kumar is Executive Director of the Institute for Resource Analysis and Policy (IRAP), Hyderabad. Narayanamoorthy is former full-time Member (Official), CACP. Views expressed are personal