Lonar Lake, History, Physical & Geographical Features
Lonar Lake in Maharashtra is India’s only meteorite-formed basaltic crater lake and a 2020-declared Ramsar Site. Formed 35,000–52,000 years ago, it features saline-alkaline water, rare microbes, and diverse birdlife. Lonar Lake holds UPSC relevance for geography and environment topics.
Shruti Kumari1 Aug, 2025
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Lonar Lake is one of the unique geographical formations, which is located in the Buldhana district of Maharashtra. This is one of the naturally occurring crater lakes is the only hyper-velocity impact crater formed in basaltic rock in India and among the few such formations in the world.
For aspirants who are preparing for the UPSC examination, understanding the Lonar Lake provides them with key insights. Candidates can get a greater understanding of India’s geological diversity, ecological importance, and environmental governance under international conservation protocols. Questions related to Lonar Lakes have been asked in the geography and environment-related sections of the UPSC syllabus.
Why is Lonar Lake Important for UPSC?
The inclusion of Lonar Lake in the examination is not just by chance. Rather, it covers various subjects like physical geography, ecology, environmental governance, and cultural studies.
Candidates must be aware that questions related to Lonar Lake are frequently asked in prelims and mains under the Ramsar site. The space has a unique geological structure and conservation efforts, which make it UPSC's favourite. Therefore, to help the aspirants, here are some of the ecological significances of the Lonar Crater Lake. This will help them in building conceptual clarity for both the static and dynamic portions of the exam.
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The question related to Lonar Lake may appear in GS Paper 1 (Geography) and GS Paper 3 (Environment).
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Linked with India’s Ramsar wetlands and National Geo-heritage Sites.
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Useful for topics like crater lakes, meteorite impacts, and wetland conservation.
Lonar Lake History and Formation
Now, let’s delve into understanding the origin of the Lonar Lake, which offers a deep insight into the Earth’s geological past. So, the history of the lake begins with a meteorite that struck the Deccan Plateau roughly between 35,000 and 52,000 years ago. The impact of this meteorite led to the creation of a nearly circular crater approximately 1.2 kilometers in diameter and 150 meters deep.
Initially, it was believed that it was going to be volcanic in nature. But then it was later discovered that the meteorite impact site, due to the presence of rare minerals like maskelynite, formed under extreme pressure and heat.
Physical and Geographical Features of Lonar Lake
Lonar Lake is located at the heart of the Lonar Wildlife Sanctuary in Maharashtra. There is no outlet around this basin, thereby resulting in the high saline and alkaline nature. This lonar lake collects water from the rain and minor streams but has no natural drainage.
The Lonar Lakes' unique chemical composition includes high concentrations of sodium, potassium, and carbonates. All of these make it uninhabitable for most aquatic organisms. These aspects of the lake are particularly relevant to UPSC when studying an endorheic basin, saline water bodies, and their unique freshwater-saltwater transition zone.
| Physical and Geographical Features of Lonar Lake | |
| Feature | Description |
| Location | Buldhana, Maharashtra |
| Shape | Circular Crater |
| Diameter | Approx. 1.2 km |
| Depth | Approx. 150 m |
| Water Type | Saline and Alkaline |
| Origin | Meteorite Impact |
Biodiversity and Ecological Significance of Lonar Lake
Despite its harsh environment, Lonar Crater Lake hosts a variety of life forms. From halophilic microbes to rare bird species, the lake represents a functioning yet extreme ecosystem. The surrounding sanctuary is home to mammals, reptiles, and over 160 bird species, including migratory birds that visit during winter.
This biodiversity is significant in UPSC environment and ecology questions, particularly under India’s wetland ecosystems and biospheres.
| Biodiversity and Ecological Significance of Lonar Lake | |
| Category | Examples |
| Microorganisms | Halophiles, Cyanobacteria, Methylotrophs |
| Birds | Common Pochard, Asian Woollyneck, Flamingos |
| Mammals | Langur, Mongoose, Wild Boars |
| Reptiles | Monitor Lizards, Cobras, Vipers |
Ramsar Site Designation Declaration to Lonar Lake
It was in the year 2020, Lonar Lake was designated as a Ramsar Site. After this designation, the site placed a major emphasis on the ecological importance. Because the Ramasar designation helps in the wetland conservation under international law. Thereby offering legal protection to this unique ecosystem.
Hence, the lake met the multiple Ramasar criteria, including its ecological uniqueness and presence of the threatened species. UPSC often asks about recently declared Ramsar sites, their significance, and the criteria. Lonar Lake fits well in these questions.
| Ramsar Site Designation Declaration to Lonar Lake | |
| Attribute | Details |
| Ramsar Site Code | 2441 |
| Year of Designation | 2020 |
| Wetland Type | Inland Saline/Alkaline Crater Lake |
| Conservation Status | Protected under Ramsar Convention |
Environmental Threats and Conservation Efforts
Although the lake has protected status, it confronts multiple environmental issues. Wastewater from the adjacent town, plastic waste from visitors, and nutrient runoff causing eutrophication are harming the lake’s distinctive ecosystem.
Poor management and insufficient sustainable tourism methods present enduring threats. These environmental challenges are vital in GS Paper 3, particularly in responses concerning biodiversity conservation, pollution, and assessments of environmental impact.
| Environmental Threats and Conservation Efforts | |
| Threat | Conservation Response |
| Sewage/wastewater pollution | Ban bathing, regulate streams, plan proper sewage diversion |
| Nutrient/pesticide runoff | Biodiversity monitoring + Geopark model to promote eco-agriculture and reduce external inputs |
| Marine solid waste/plastic | Visitor infrastructure, signage, regulated pathways, and waste disposal |
| Encroachment/degradation around temples | Clear encroachments, restore buffer areas, and upgrade road access in coordination with ASI |
| Unregulated tourism growth | ₹91 Cr master plan for tourism infrastructure aligned with sustainable principles |
Looking for guidance in UPSC preparation? Explore Physics Wallah’s UPSC courses!
Lonar Lake FAQs
What is Lonar Lake and how was it formed?
Why is Lonar Lake important for UPSC aspirants?
When was Lonar Lake declared a Ramsar Site?
What kind of biodiversity is found in Lonar Crater Lake?
What environmental threats does Lonar Lake face?
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