Writing in The Conversation, Dr Himalayan floods are natural, but poor planning turns rain into disaster. Reading the land could save lives.
On August 5, a cloudburst near the Kheer Ganga river triggered a flash flood that tore through Dharali, a village in the Indian Himalayas. Within minutes, the river swelled with water, mud and debris, sweeping away homes, roads and lives.
Every monsoon season, the Himalayas see similar tragedies – flash floods caused by cloudbursts or glacial lake outbursts. The first explanation we often hear is climate change. Extreme rainfall and melting glaciers are part of our warming world, but that is only half the story. The other half lies in where and how we build.
A cloudburst is an extreme, sudden downpour – often more than 100mm of rain in just an hour, falling over a small area. It’s like the sky suddenly emptying a huge bucket of water over the mountainside.
A glacial lake outburst flood happens when a lake formed by melting glaciers bursts through its natural dam of ice or loose rock, releasing a sudden torrent downstream.
Both cloudbursts and glacial lake outbursts send huge volumes of water rushing down steep valleys. On their way, they pick up mud, rocks and trees, turning into debris-laden flash floods that sweep away whatever lies in their path.
These are natural events in higher mountainous regions, such as the Himalayas. They cannot be stopped. What makes them disasters is when towns, hotels and roads are built directly where these floods predictably flow.
Where we build matters
To understand why the damage is so severe, we need to look at the land itself. Geomorphology is the study of how Earth’s surface is shaped. It shows us how rivers, slopes and valleys have been formed and modified over time by floods, landslides and debris flows.
In the Himalayas, many safe-looking places are anything but. Take the alluvial fan, which is a cone-shaped pile of sand, gravel and silt that forms where a steep stream slows and drops the debris it carries. Over time, repeated floods build up this fan. It looks flat and inviting – perfect for a settlement, hotel, or car park – but when the next flash flood happens, the water and debris flow straight back down, burying whatever is built there.
This is not theory but history repeating itself. Dharali, which is built around the ancient Kalp Kedar Hindu temple, has faced flash floods before. Records show the temple has been buried multiple times, most recently in 2013. This also highlights our short memory span.
Climate change and poor planning
Rising temperatures can lead to more intense and erratic rainfall, and this does raise the likelihood of cloudbursts and glacial lake outbursts. But focusing only on climate change makes disasters sound unavoidable.
In reality, much of the destruction is preventable. Poor planning and reckless construction have put people in harm’s way. Roads, hotels, even entire towns, are expanding into zones geomorphology tells us are flood prone.
When disaster follows, we blame the climate. But the harder truth is that our own decisions magnify the risks.
Ignoring geomorphology has serious consequences. For governments, it means billions spent on disaster relief and rebuilding after every monsoon. For developers, it means investments washed away in a single night. For tourists, it means the risk of being caught in floods during what should be a holiday. And for mountain communities, it means living in constant danger.
What is needed is geomorphic literacy. Planners, policymakers, developers and citizens need to read the land and respect its signals. The land itself tells us where floods have happened before, and where they will happen again. Listening to it can save lives.
Flash floods due to cloudbursts and glacial lake outbursts are a natural part of the Himalayan monsoon. They cannot be prevented, and climate change may make them more frequent. But the devastation they cause is not inevitable – it is shaped by where and how we build.
Geomorphology is nature’s diary, showing where water and debris have flowed for centuries. Learning to read it can keep people safe.
The Dharali disaster is a painful reminder that the real danger is not only in the sky, but in our failure to understand and respect the land beneath our feet. Unless we take that lesson seriously and build geomorphic awareness into planning, policy making and public understanding, tragedies like Dharali will keep happening, year after year.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
