Focus on Migration: Better river flooding predictions needed

Flooding in India
Copyright: Oxfam

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  • A new report may shed light on the causes of a disastrous Indian flood
  • Better river behaviour forecasts would also aid the region’s routine migrants
  • Yet interstate sharing of data on the river and climate is impeded by politics

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A commission in India has finally submitted its report on the cause of a massive flood in the Kosi river valley in the north of the country that happened more than five years ago. [1]
The Kosi river breached its flood defences in Nepal close to the Indian border during heavy rains in August 2008 and changed its course. It devastated about 1,000 villages in Bihar state, involving about three million people. [2]
The exact content of the commission’s report has not been made public, but according to media speculation, it will explain how a breach in a defensive embankment led to such a major disaster.
It will obviously be useful if the report provides lessons on how to avoid a repeat of the disaster. But the region plays host to many migrants — including seasonal and economic migrants — and often the river flow patterns influence their movements, for example by flooding fields and villages, by creating fertile soil or even new tracts of land by depositing silt and destroying areas of land.
So the region’s authorities don't just need a one-off report on a flooding disaster. They need a wholly more accurate understanding of the river's behaviour — because if this was communicated to migrants, it could help them predict where is safe to live and when to move on.
Two measures are key: improved state-state collaboration for flood warnings, and a re-examination of flood defence systems. Further, these measures need to be underpinned by a better understanding of the nature of climatic events, their changing trends and the uncertainties involved in responding to them.
In terms of interstate collaboration, governments in the region should understand that elements such as rain, snow and river water do not respect state boundaries. Changes in rainfall or snowmelt can have dramatic impacts downstream, so weather and flood forecasts must include upstream activities and changes in environmental and climatic patterns.
Yet poor political relations and security concerns among nation states in the region often impede the free sharing of data — even among scientists.
Making this data available would be a first step to better forecasts. Getting these communicated to migrants is a separate issue, which needs consideration. But first a more effective and collaborative cross-border data sharing, planning and response mechanism is desperately needed.
In terms of flood defences, historical attempts to ‘tame’ Himalayan rivers by regulating their flow have been questioned by scientists. For instance, while embankments can save riverside villages, they can worsen floods by preventing natural drainage and changing silt flow patterns. Often the villagers’ disaster response measures — including migration patterns — are based merely on local knowledge and experience. Giving them better river predictions could would help them make more resilient plans.
The commission's report might help us prevent future flooding disasters in the Himalayan foothills. But in planning new flood prevention measures, governments in the region should not forget their many migrants who also stand to benefit from a better understanding of rivers.
Max Martin is a doctoral candidate at the University of Sussex, United Kingdom, researching on climate-related migration. The views expressed are his own.