Wayanad disaster highlights need for multi-hazard early warning systems

The death toll in the landslides that occurred in Kerala’s Wayanad during the early hours of July 30 has crossed 300 and it is expected to be higher as many are still missing.

The disaster has evoked varied responses on what could have been done to avert or to minimise human deaths. One perspective centres on the inappropriate development paradigm that is being followed in a fragile Western Ghat ecosystem. Others have pointed to a lack of or failure of early warning systems (EWS) that could have saved many of these lives. There is a contesting view as to whether an early warning was issued or was not found useful or adequate in spite of being issued. However, what merits further attention is a sharp variation in rainfall patterns induced by climate change that is being observed on a continual basis. It thus shifts the focus beyond the availability of a hazard warning service to the necessity of a Multi-hazard Early Warning System (MHEWS).

The district of Wayanad receives an average annual rainfall of 3,000 mm, three quarters of which is reported during the monsoon period. A whopping 572 mm rainfall was reportedly recorded in just 48 hours, triggering the massive landslides. Even then, as of August 2, the district’s accumulated rainfall since June 1 this year is 15 per cent less than the normal rainfall for the same period. The challenge resulting from such large variation in rainfall distribution is recognised by the district administration. For example, the district’s disaster management plan clearly highlights this aspect while discussing a landslide incident in the Mundakkai area in August 2019 (DDMA, 2021, 117). Rainfall variation of this range is not limited to Wayanad or Kerala but observed at a much wider scale attributed to climate change. For instance, the country as a whole received nine per cent more rainfall in July while the central region received as much as 33 per cent excess rainfall. Thus, what was required in case of Wayanad was not just accurate rainfall forecast but also real time analysis of its consequences such as landslide and floods. Further, such analysis had to be validated with ground level field data and acted upon with help from local administration and community volunteers. In this respect, it differs from the conventional intensity threshold-based approach to one that moves up the value chain, keeping the interest of the vulnerable population at the center of the EWS design.  

The Wayanad landslides and the loss of lives should be a wakeup call to move further towards Impact-based Forecasts and Warnings (IbFW) in a MHEWS. What this framework entails is that the early warnings are not oriented towards hazards like heavy rainfall, landslide, and earthquake per se but focused on providing advisories on cumulative impacts including magnitude of phenomena, their destructive potential, and overall consequences from a people’s perspective. This framework is endorsed by the World Meteorological Organization (WMO) and is already being followed by most National Hydrological and Meteorological Services (NHMS) including India Meteorological Department (IMD).

However, its focus remains largely on hydro-meteorological warning services. Barring a few exceptions, the approach is yet to be extended to include geological hazards such as landslides. It does not mean though that the agencies warning of landslides are not informed of meteorological forecasts such as heavy rain. The requirement, however, is to work together towards a common objective rather than striving coordination while working in one’s own respective domain. The challenge involved in integrating a number of agencies to work together in this kind of framework is indeed huge and it has made this goal such a daunting task. In addition, bringing operational change in existing early warning mechanisms involves uncertainty that can be ill-afforded. It thus requires a strong political and institutional commitment over a period of time to move away from a conventional hazard-based EWS to an integrated risk-based system. However, given the stakes for a large country such as India, efforts must be made in the wake of this particular disaster.

Three challenges

There are three immediate challenges that require to be confronted by different stakeholders as far as early warning lessons from the Wayanad landslide are concerned. Is meteorological science and its models up to the task in terms of capturing sharp monsoon rainfall variation in the Indian subcontinent and able to provide forecasts with a reasonable degree of confidence? The colour codes of IMD representing the level of risk are at best qualitative, while the requirement is entirely different.

Second, how far can extreme rainfall forecasts be successfully overlaid with geological and terrain features to generate a landslide warning at a local level? To note, such warning formulation requires involvement of several other agencies and rainfall forecasts can lead to several other consequences as well. For example, flash floods, crop damage, waterlogging, etc.

Thirdly, how to distribute early warnings? For whom are they intended? And importantly, how to ensure that vulnerable populations who receive them act upon them?

The last in particular is an extremely worrying feature of many other hazards for which EWS are operating. To assume that availability of an early warning is an end in itself has been proven to be erroneous.

Biswanath Dash is with the Department of Humanities and Social Sciences, BITS Pilani Hyderabad Campus

Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth