Lakes of India: Natural and Artificial Explained for UPSC SSC

Introduction to Indian Lakes

India boasts a diverse range of lakes, both natural and artificial, spread across its varied topography. These water bodies are formed through different geological processes or human intervention. Natural lakes are typically found in mountainous regions, river floodplains, and coastal areas, shaped by tectonic activity, glacial erosion, or river meandering. Artificial lakes, also known as reservoirs, are created by constructing dams across rivers for purposes like irrigation, hydroelectric power generation, drinking water supply, and flood control. The study of Indian lakes is important for understanding regional geography, water resources, and environmental conservation efforts.

Lakes play a significant role in maintaining ecological balance. They support diverse aquatic flora and fauna, act as habitats for migratory birds, and influence local climate. Economically, lakes contribute to fisheries, tourism, and provide water for agriculture and industries. Culturally, many lakes hold religious significance and are associated with local traditions and festivals. The conservation and sustainable management of these water bodies are critical, especially given the challenges of pollution, encroachment, and climate change affecting their health and longevity.

Types of Natural Lakes

Natural lakes in India can be classified based on their formation. Tectonic lakes are formed by the Earth's crustal movements, creating depressions that fill with water. Wular Lake in Jammu and Kashmir, the largest freshwater lake in India, is an example of a tectonic lake. Glacial lakes are formed by the erosional and depositional activities of glaciers. High-altitude lakes like Pangong Tso and Tso Moriri in Ladakh are prime examples of glacial or high-altitude endorheic lakes. Oxbow lakes are crescent-shaped lakes formed when a meander of a river is cut off from the main channel, often found in the Gangetic plains. Kanwar Taal in Bihar is a notable oxbow lake.

Crater lakes are formed in the depressions of volcanic craters, such as Lonar Lake in Maharashtra, which is a unique saline soda lake believed to be formed by a meteorite impact. Lagoon lakes or backwater lakes are formed along the coast when seawater is trapped by sandbars or spits. Chilika Lake in Odisha, India's largest brackish water lagoon, and Vembanad Lake in Kerala, the longest lake in India, are prominent examples. These natural formations highlight the geological diversity of the Indian subcontinent.

Artificial Lakes and Reservoirs

Artificial lakes, or reservoirs, are human-made water bodies created by damming rivers. These are crucial for India's water security and economic development. The Govind Ballabh Pant Sagar, formed by the Rihand Dam on the Rihand River in Uttar Pradesh, is the largest artificial lake in India by volume. Other significant artificial lakes include the Hirakud Reservoir in Odisha, formed by the Hirakud Dam on the Mahanadi River, which is one of the longest earthen dams in the world. The Nagarjuna Sagar Dam on the Krishna River in Telangana and Andhra Pradesh also creates a vast reservoir.

These reservoirs serve multiple purposes. They store water for irrigation, supporting agricultural productivity in vast regions. They are also vital for generating hydroelectric power, contributing significantly to the national grid. Furthermore, they provide drinking water to urban and rural populations, help in flood control by regulating river flow, and support inland fisheries. The construction of these large-scale projects often involves significant environmental and social considerations, including displacement of communities and impact on ecosystems, which are important aspects of development studies.

Key Lakes and Their Significance

India is home to several iconic lakes, each with unique characteristics and importance. Wular Lake in Jammu and Kashmir is a Ramsar site and a crucial wetland. Dal Lake, also in Kashmir, is famous for its houseboats and scenic beauty, contributing significantly to tourism. Loktak Lake in Manipur is known for its 'phumdis' (floating islands) and is the only floating national park in the world, Keibul Lamjao National Park, home to the endangered Sangai deer. This lake is also a Ramsar site.

Chilika Lake in Odisha is the largest brackish water lagoon in Asia and a major wintering ground for migratory birds, making it a significant biodiversity hotspot and a Ramsar site. Vembanad Lake in Kerala is part of the backwater system and is important for transportation, fisheries, and tourism, hosting the Nehru Trophy Boat Race. Sambhar Lake in Rajasthan is India's largest inland salt lake, a major source of salt production, and a Ramsar site. These lakes are not just geographical features but also integral to the cultural, economic, and ecological fabric of their respective regions.

Important Keywords Explained

Ramsar Siteconcept

A wetland site designated to be of international importance under the Ramsar Convention, an intergovernmental environmental treaty established in 1971 in Ramsar, Iran. The convention aims to conserve and sustainably use wetlands. India has numerous Ramsar sites, including Chilika Lake, Wular Lake, and Loktak Lake, highlighting their ecological significance.

Oxbow Lakeconcept

A U-shaped lake or pool formed when a wide meander of a river is cut off, creating a free-standing body of water. This process typically occurs in flat, low-lying river valleys. The Ganga plains in India have several oxbow lakes, which are remnants of old river courses and are important for local ecosystems.

Brackish Waterconcept

Water that has more salinity than freshwater, but not as much as seawater. It often occurs where freshwater and seawater mix, such as in estuaries, lagoons, and some coastal lakes. Chilika Lake is a prime example of a brackish water lagoon in India, supporting unique biodiversity adapted to this salinity level.

Additional Facts & Context

• India has over 75 Ramsar sites as of 2023.
• The total area covered by lakes and reservoirs in India is approximately 2.25% of its geographical area.
• The average depth of Wular Lake is about 5.8 meters.
• Chilika Lake spans over 1,100 square kilometers during the monsoon season.
• Lonar Lake is approximately 52,000 years old.