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Why One State Floods While Another Runs Dry: An IIT Professor Explains India's Weather

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yesterday

Imagine checking the weather and seeing two different faces of India at once.

In one part, people are wading through flooded streets as rivers rise and homes take in water. In another, farmers are looking at dry fields and waiting for rain that still has not arrived.

This is already playing out during the same monsoon. Assam and Gujarat have seen intense rain and flooding, while parts of Andhra Pradesh have faced prolonged dry spells.

So how can one country have too much rain and too little rain at the same time?

The answer lies in how unevenly rain is falling across India. Some places are getting intense downpours, while others are seeing longer gaps without rain.

To understand why, The Better India spoke to Prof. Rajib Maity of IIT Kharagpur, an expert in hydrology, water resources and climate variability. We also referred to his latest research on changing rainfall patterns and hydroclimatic extremes in India to better understand the science behind this growing monsoon paradox.

Here's what he had to say about what this shift means for our farms, cities and water security.

Q1. How is it possible that one part of India is battling devastating floods while another is experiencing drought at the very same time? What is happening scientifically?

One of the biggest changes we're seeing today is that rainfall is no longer spread evenly across India. Instead, we're getting shorter bursts of very heavy rain in some places, while other regions are going through long dry spells at exactly the same time.

A warming climate has intensified what's known as the hydrological cycle. In simple terms, a warmer atmosphere can hold more moisture. This is changing how much rain falls, where it falls, how intensely it falls and how long the gaps between rain spells last. 

As a result, we're seeing more hydroclimatic extremes, including floods, flash floods, droughts and flash droughts.

What's particularly striking is that wet and dry extremes are now happening simultaneously. For example, while many parts of peninsular India have recorded a significant increase in extreme rainfall events, studies also show that dry spells during the monsoon have become more frequent across the country. 

For farmers, these prolonged dry periods can quickly become a serious problem. They reduce moisture in the soil, put crops under stress and, when combined with rising temperatures, can dry the land out even faster. 

Research also shows that around 20% of India's land area has become increasingly dry, especially parts of the northeast, eastern and central India. At the same time, around 23% of the country has become wetter, including parts of Telangana, Andhra Pradesh, Maharashtra, Punjab, Rajasthan, Ladakh and Jammu & Kashmir.

So the larger story is about how rain is being distributed. India may receive plenty of rain overall, but where it falls, how heavily it falls and how long the gaps between rain spells last are becoming increasingly important. 

Q2. Is climate change the only reason?

Climate change is a major driver, but several other forces also shape India’s rainfall.

Climate change has intensified the hydrological cycle, leading to more frequent and severe floods and droughts. Rising temperatures have also increased the amount of moisture the atmosphere can hold. That creates greater potential for intense rainfall.

But rainfall is also influenced by large weather systems, changes in wind and atmospheric circulation, urbanisation, land-use changes and local weather conditions.

These factors interact with one another, which is why rainfall can vary so sharply across different parts of the country.

Q3. Could you explain how the Indian monsoon actually works? Why doesn't rainfall spread evenly across the country?

India receives rainfall from two different monsoon systems.

The Southwest Monsoon, which runs from June to September, brings most of the country's annual rainfall. The Northeast Monsoon, from October to December, mainly affects the southeastern parts of peninsular India.

Even under normal conditions, rainfall has never been distributed evenly across the country because India's geography plays a huge role.

Peninsular India is surrounded by the Arabian Sea, the Bay of Bengal and the Indian Ocean. The interaction between these water bodies, the monsoon winds and mountain ranges creates major regional differences in rainfall.

That's why the Western........

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