Eastern Coastal Plains in the context of "Krishna River"

Tamil Nadu is the southernmost state of India. The tenth largest Indian state by area and the sixth largest by population, Tamil Nadu is the home of the Tamil people, who speak the Tamil language—the state's official language and the first to be recognised as a classical language in India. The capital and largest city is Chennai.

Located on the south-eastern coast of the Indian peninsula, Tamil Nadu is straddled by the Western Ghats and Deccan Plateau in the west, the Eastern Ghats in the north, the Eastern Coastal Plains lining the Bay of Bengal in the east, the Gulf of Mannar and the Palk Strait to the south-east, the Laccadive Sea at the southern cape of the peninsula, with the river Kaveri bisecting the state. Politically, Tamil Nadu is bound by the Indian states of Kerala, Karnataka, and Andhra Pradesh, and encloses a part of the union territory of Puducherry. It shares an international maritime border with the Northern Province of Sri Lanka at Pamban Island.

The Deccan Plateau (/ˈdɛkən/ DEK-ən ) is a geographic formation that extends over an area of 422,000 km (163,000 sq mi) on the southern part of the Indian peninsula. It stretches from the Satpura and Vindhya Ranges in the north to the northern fringes of Tamil Nadu in the south. It is bound by the mountain ranges of the Western Ghats and the Eastern Ghats on the sides, which separate the region from the Western and Eastern Coastal Plains respectively. It covers most of the Indian States of Maharashtra, Karnataka, Telangana and Andhra Pradesh excluding the coastal regions, and minor portions of Tamil Nadu and Kerala.

The plateau is marked by rocky terrain with an average elevation of about 600 m (2,000 ft). It is subdivided into Maharashtra Plateau, Karnataka Plateau, and Rayalaseema and Telangana Plateau. The Deccan Traps in the northwest were formed by multiple layers of igneous rock deposited by basaltic lava flows following a massive volcanic eruption occurred at the end of the Cretaceous period (66 mya). The underlying bed consists of granite and sedimentary rocks formed during the Precambrian era and the formation of Gondwana.

India is a union consisting of 28 states and 8 union territories. As of 2024, with an estimated population of 1.484 billion, India is the world's most populous country. India occupies 2.4% of the world's area and is home to 17.5% of the world's population. The Indo-Gangetic Plain has one of the world's biggest stretches of fertile not-deep alluvium and are among the most densely populated areas of the world. The eastern and western coastal regions of Deccan Plateau are also densely populated regions of India. The Thar Desert in western Rajasthan is one of the most densely populated deserts in the world. The northern and north-eastern states along the Himalayas contain cold arid deserts with fertile valleys. These states have relatively low population density due to indomitable physical barriers.

The Western Coastal Plains is a narrow stretch of landmass lying between the western part of the Deccan Plateau and the Arabian Sea in India. The plains stretch from the Kutch region in the Western India to Kaniyakumari at the southern tip of the Indian peninsula, with the Western Ghats forming its eastern boundary. It traverses the states of Gujarat, Maharashtra, Goa, Karnataka, and Kerala.

The plains are broadly divided into six subdivisions–Kutch and Kathiawar along with the Gujarat Plains in the north, Konkan Coast and Canara in the center, and Malabar in the south. Due to the presence of Western Ghats, which blocks the rain-bearing winds, the region from the south of Gujarat experiences heavy rainfall during the monsoons. Unlike the Eastern Coastal Plains, very few rivers cut across the region due to the steeper gradient of the Indian peninsula moving from east to west and the major rivers include Narmada and Tapti.

Chilika Lake is the largest brackish water lagoon with estuarine character that sprawls along the east coast of Indian sub-continent in Asia and second largest coastal lagoon in the world, covering an area of over 1,100 square kilometres (420 sq mi). It is spread over the Puri, Khordha and Ganjam districts of Odisha state on the east coast of India, at the mouth of the Daya River, flowing into the Bay of Bengal.

It has been listed as a tentative UNESCO World Heritage site. Its salinity varies by region, from freshwater where rivers flow in, to oceanic salinity levels due to tidal influx.