Climate Change Manifestations on Kerala's Fragile Landscape During Heavy Monsoons: Causes, Impacts and Remedies JOHN KURIEN

Climate Change Manifestations on Kerala's Fragile Landscape During Heavy Monsoons: Causes, Impacts and Remedies 

John Kurien 
Earth Scientist 
3/08/2026

Introduction 

Kerala, occupying barely 1.2% of India's geographical area, is one of the country's most ecologically diverse and environmentally fragile states. Stretching between the Arabian Sea and the Western Ghats, it is characterized by steep mountain slopes, undulating midlands and narrow coastal plains. This unique physiography, coupled with intense monsoon rainfall, makes Kerala highly vulnerable to climate change. In recent decades, the State has witnessed a sharp increase in extreme rainfall events, devastating floods, landslides, coastal erosion and ecological degradation. These disasters are not merely natural phenomena but the outcome of a changing climate interacting with fragile geology and increasing human interference.

Climate Change and Changing Monsoon Behaviour. 

Scientific observations indicate that the Arabian Sea has warmed significantly over the past few decades. A warmer sea surface increases evaporation, resulting in greater atmospheric moisture. During the southwest monsoon, this excess moisture often forms deep convective cloud systems such as towering cumulonimbus clouds instead of the widespread stratiform rain clouds associated with normal monsoon conditions.

These vertically developed clouds contain enormous quantities of water vapour and produce intense rainfall over short durations, commonly referred to as cloudbursts or extreme precipitation events. Consequently, rainfall that would normally occur over several days may now fall within a few hours, overwhelming river basins, reservoirs and drainage systems.

Climate change has therefore altered not only the quantity of rainfall but also its temporal and spatial distribution. Long dry spells are frequently interrupted by short periods of exceptionally heavy rainfall.

Kerala's Physiographic Fragility 

Kerala consists of three distinct physiographic regions:

The Western Ghats (highlands), rising to over 2,600 metres.

The undulating midlands.

The low-lying coastal plains.

Nearly forty-four west-flowing rivers originate in the Western Ghats and descend rapidly to the Arabian Sea. Because these rivers are generally short and steep, they carry enormous volumes of runoff during heavy rainfall. Their limited length provides little opportunity for floodwaters to spread gradually, resulting in flash floods downstream.

The State also contains extensive backwaters, lakes, reservoirs and numerous dams, which together form an intricate water management network. However, extreme rainfall frequently exceeds their storage and discharge capacities.

Geological and Ecological Factors 

The Western Ghats are composed predominantly of ancient crystalline rocks such as charnockites and gneisses. Over millions of years these rocks have undergone deep weathering, producing thick layers of soil and weathered overburden on hill slopes.

Under normal conditions, vegetation stabilizes these slopes through extensive root systems. However, when rainfall exceeds the soil's storage capacity, water infiltrates into the weathered mantle, increasing pore-water pressure and reducing slope stability. The weakened soil mass may then slide over the underlying bedrock, causing landslides.

Large-scale conversion of natural forests into monoculture plantations such as rubber, tea, coffee and cardamom has further reduced slope stability. Road construction, quarrying, unscientific hill cutting and expanding settlements have accelerated environmental degradation.

Climate Change and Extreme Rainfall 

Recent decades have witnessed an increasing frequency of high-intensity rainfall events in Kerala. Atmospheric disturbances over the Arabian Sea, low-pressure systems and occasional cyclonic circulations further intensify moisture transport towards the Western Ghats.

When these moisture-laden air masses encounter the mountain barrier, rapid uplift results in intense orographic rainfall. Climate change is amplifying this process by increasing atmospheric moisture content and atmospheric instability.

Consequently, many landslides now occur after only a few hours of exceptionally heavy rainfall rather than prolonged seasonal rainfall.

Ecological Sensitivity 

Several districts, particularly Wayanad, Idukki, Pathanamthitta, Kottayam, Kozhikode and Malappuram, contain highly fragile slopes susceptible to landslides. Ecologically sensitive landscapes require scientific land-use planning based on geology, slope gradient, drainage characteristics and vegetation cover.

Modern remote sensing, GIS mapping and satellite monitoring can identify vulnerable zones well before disasters occur.

Disaster Preparedness 

Kerala has significantly strengthened its disaster management framework following the devastating floods of 2018. Early warning systems, weather forecasting, reservoir management, landslide monitoring and community awareness programmes have improved considerably.

Meteorological agencies now issue district-level rainfall warnings, while disaster management authorities coordinate evacuation, emergency response and relief operations. Nevertheless, greater public compliance with evacuation orders and stronger coordination among departments remain essential.

Sustainable Remedies 

Reducing disaster risk requires both climate adaptation and ecological conservation.

Major priorities include:

Protection and restoration of natural forests in the Western Ghats.

Strict regulation of quarrying and hill cutting.

Scientific land-use planning based on ecological sensitivity.

Improved drainage and watershed management.

Stabilization of vulnerable slopes through bioengineering and afforestation.

Continuous monitoring of rainfall, soil moisture and slope movement.

Reservoir operation based on scientific flood forecasting.

Climate-resilient agriculture with diversified cropping systems.

Strengthening community-based disaster preparedness and early warning dissemination.

At the national and global levels, reducing greenhouse gas emissions remains essential to limit further warming of the Arabian Sea and the increasing frequency of extreme weather events.

Conclusion 

Kerala's remarkable natural beauty is inseparable from its ecological fragility. Climate change is transforming the southwest monsoon by increasing the frequency of short-duration, high-intensity rainfall events that trigger floods and landslides. These hazards are intensified by deforestation, inappropriate land use, quarrying and unplanned development on vulnerable slopes.

The future resilience of Kerala depends upon integrating climate science, geological understanding, ecosystem conservation and responsible governance. Protecting the Western Ghats, restoring degraded landscapes, strengthening disaster preparedness and promoting sustainable development are no longer optional—they are essential for safeguarding lives, livelihoods and the State's unique natural heritage. Climate change cannot be completely prevented at the State level, but its impacts can be substantially reduced through science-based planning, ecological stewardship and collective public responsibility.
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19 years ago John Kurien had retired from NABARD. He was CGM at that time. We have been good friends for the past 15 years. To me , he has appeared a 'no nonsense' man. 

This morning he forwarded to me this excellent article with a comment

'News paper did not come today at 5 am.So this'

I was stunned when I read it. The statments, arguments and the clarity in expression were pulsating. He didn't stop there. He has outlined how to overcome the  ecological disaster which is imminent.

I rang him up and asked, "Whether it was his own creation or a consolidation of downloads."

He response was, "I hope you are aware that I worked for 13 yrs in Govt.of India as an earth scientist and hydrogeologist with GSI and CGWB,Min.of Earth Science and Water Resources and thereafter 24 yrs as a development banker from the inception of NABARD

So basic education in earth science and it's practical application in Project Financing and Rural Infrastructure will always linger on

That's why I respond to ecological concerns when natural resources management goes  to hazards   through human intervention too."

I advised him, "You must ask the newspaper man to deliver it late by two hours minimum everyday."