Exploring Odisha's Geographical Tapestry

Summary

Sources

en.m.wikipedia.org

Nestled in the eastern part of India, Odisha is a land where geography narrates the story of time. Its topographical canvas stretches from the latitude of seventeen point three one degrees north to twenty-two point three one degrees north, and from the longitude of eighty-one point three one degrees east to eighty-seven point two nine degrees east. This expansive territory of Odisha unfolds into five distinct physiographic divisions, each with its unique geological personality. The coastal belt, known as the Utkal Plains, is a sedimentary region that whispers tales from the Paleogene and Neogene eras, dating back approximately sixty-five to two point six million years ago. These plains are the offspring of the deltas of six significant rivers: the Mahanadi, the Brahmani, the Budhabalanga, the Subarnarekha, the Baitarani, and the Rushikulya. Hence, the area is often referred to as the "Gift of Six Rivers" or the "Hexadeltaic region." It is a region that stretches along the Bay of Bengal, with the Mahanadi Delta carving out the broadest swath, known as the Middle Coastal Plain. The Northern Coastal Plain, or the Baleshwar District, is marked by the deltas of the Budhabalanga and the Subarnarekha. In contrast, the Southern Coastal Plain, or the Ganjam District, is significantly narrower and characterized by the Rushikulya River delta and the lacustrine plain of Chilika Lake. The Middle Coastal Plain, the most expansive, is a confluence of the deltas of the Mahanadi, Brahmani, and Baitarani rivers. This region is not only a geographic marvel but also an ecological haven, with numerous lakes and evidence of past 'back bays.' Ascending from the plains, one encounters the middle mountainous and highlands region, which covers about three-fourths of the state. This region is a testament to ancient geological formations, being a part of the Eastern Ghats, where the hills and mountains rise steeply in the east and gently slope to the eroded plateaus in the west. This part of Odisha has deep ties to the ancient supercontinent of Gondwanaland. The Garhjat Hills, as they are known locally, are dissected by river valleys and flood plains, with the highest peak, Deomali, standing at about nine hundred meters above sea level. The central plateaus are an extension of the Western slopes of the Eastern Ghats. These eroded plateaus have elevations ranging from three hundred and five to six hundred and ten meters, divided into two main plateaus: the Panposh-Keonjhar Pallahara plateau in the north and the Nabrangpur-Jeypore plateau in the south. Transitioning to the western rolling uplands, one finds a landscape with elevations between one hundred and fifty-three meters to three hundred and five meters. These uplands are geographically distinct, with regions such as the Rairangpur rolling upland in the north part of Mayurbhanj district, the Keonjhar rolling upland in Kendujhar district, and the Rourkela rolling upland in Sundergarh district, among others. Additionally, Odisha's geology is accentuated by its major flood plains, which are formed by the rivers coursing through highlands, uplands, and plateaus. These flood plains, with heights varying from seventy-five to one hundred fifty-three meters, include the Baripada, Anandapur, Talcher, Bhuban, Sonepur, Athagarh, Aska, Rayagada, and Malkangiri flood plains. The state's geological complexity extends to some of the oldest rock formations on the planet, with rocks in the Kendujhar district dating back an astounding four point two billion years. Odisha is part of two cratonic blocks: the North Orissa Craton and the West Orissa Craton, as well as the Eastern Ghats Granulite Belt, which showcases the Khondalite formations, charnockites, granites, migmatites, and pegmatites. This region's geological kinship with Eastern Antarctica is evident through lithological similarities and rift features like the Mahanadi Rift. The Gondwana basins, found in regions like the Ib River valley and Talcher, hold vast coal deposits, marking Odisha's significance in the energy landscape. The East Coast of Odisha, predominantly made up of deltaic sediments and Quaternary formations, reflects changes shaped by river growth and glacial movements. Forests envelop about one-third of Odisha, with types ranging from very dense with a canopy density over seventy percent, to open forests with a canopy density between ten to forty percent. This green blanket covers most of southern and western Odisha, shaping the state's rich biodiversity. The narrative of Odisha's geography would be incomplete without its rivers, springs, waterfalls, and lakes. Springs like the Chandikhole and Barunei, hot springs such as Taptapani, and waterfalls like the Khandadhar, which cascades from a height of eight hundred one feet, add to the state's allure. The Chilika Lake, Asia's largest brackish water lagoon, is a crown jewel among Odisha's lakes, hosting a symphony of migratory and local birds, while fresh water lakes like Anshupa and Sara embellish the landscape. The Hirakud, Indravati, and Kolab dams stand as artificial reservoirs, with the Hirakud Dam being the largest in Asia, further enriching the state's hydrographic diversity. Each of these elements weaves together to form the intricate tapestry of Odisha's geography, a land of unparalleled natural beauty and geological wonder. Building upon the geological framework, the Odisha Coastal Plains, or the Utkal Plains, reveal a fascinating chapter in the state's geographical narrative. These plains are a testament to the geological processes of the Paleogene and Neogene ages, a period marking significant shifts in the Earth's climatic and biological systems. The sedimentary layers that compose these plains house secrets from a time when the world was undergoing profound transformations, approximately sixty-five to two point six million years ago. The formation of the Utkal Plains is an extraordinary geological phenomenon that began with the convergence of six mighty rivers: the Mahanadi, the Brahmani, the Budhabalanga, the Subarnarekha, the Baitarani, and the Rushikulya. These rivers, with their origins in the Eastern Ghats, journeyed across the landscape, carrying with them vast amounts of sediment. Over millennia, these sediments settled at the river mouths, giving birth to extensive deltas that eventually coalesced to form the fertile coastal plains of Odisha, a region befittingly nicknamed the "Gift of Six Rivers" or the "Hexadeltaic region." The ecological significance of the Utkal Plains cannot be overstated. This region, with its rich alluvial soil, has become a cradle of biodiversity. The interplay of fresh river waters and the saline sea has created a unique environment that supports a diverse range of flora and fauna. The deltas, with their intricate network of tributaries and distributaries, serve as vital habitats for numerous aquatic species, including fish, crustaceans, and mollusks. These waterways also provide essential breeding and feeding grounds for migratory birds, making the region an ornithologist's paradise. The lush vegetation that thrives on the plains acts as a natural barrier against erosion and storm surges, protecting inland areas from the ravages of cyclones and floods that are not uncommon in this part of the country. The mangrove forests that dot the coastal belt play a crucial role in maintaining the ecological balance, sequestering carbon, and offering refuge to a myriad of species, including the endangered Olive Ridley turtles that nest along the shores. Furthermore, the plains are central to the livelihoods of millions of people in Odisha. Agriculture, a mainstay of the state's economy, flourishes here, with the fertile soil and abundant water resources enabling the cultivation of rice, pulses, and a variety of other crops. The rivers are also a source of sustenance for the fisherfolk communities, who depend on them for their daily catch. In essence, the Odisha Coastal Plains are more than just a geological marvel; they are a vibrant ecosystem teeming with life and an indispensable asset for the people of Odisha. The preservation and sustainable management of this region are vital not only for the state but also for the global community, as it represents a key link in the intricate web of Earth's biodiversity. Venturing away from the fertile Utkal Plains, the landscape of Odisha undergoes a dramatic elevation to form the middle mountainous and highlands region. This vast area is the largest geographic expanse within the state and serves as the backbone of the Eastern Ghats. These hills and mountains are not mere geological structures but are steeped in the history of the Earth's formation, offering a window into the past. The Eastern Ghats, characterized by their rugged terrain and steep slopes, are a continuation of the ancient landmass known as Gondwanaland. This supercontinent, which existed more than two hundred million years ago, was part of a world much different from what is known today. The Gondwana fragmentation led to the drifting of the Indian Plate, which eventually collided with the Eurasian Plate, giving rise to the Himalayas and, as a consequence, shaping the Eastern Ghats. This region's very existence is a chronicle of tectonic shifts and monumental geological events that have occurred over aeons. These mountainous highlands, also known as the Garhjat Hills, are marked by numerous watersheds and river valleys that have been carved into the Eastern Ghats. The average elevation of this region is about nine hundred meters above sea level, with Deomali claiming the title of the highest peak. The terrain here is rugged, with deep valleys and high ridges that together create a diverse and complex topography. Moving westward, the highlands gradually transition into central plateaus. These include the Panposh-Keonjhar Pallahara plateau in the north and the Nabrangpur-Jeypore plateau in the south. These plateaus are essentially eroded landscapes with elevations that range from three hundred and five to six hundred and ten meters above sea level. They are the remnants of ancient erosional processes that have shaped the land over countless centuries, leaving behind flat-topped uplands that are interspersed with rolling hills. The western rolling uplands form another intriguing aspect of Odisha's geography. With heights varying from one hundred and fifty-three meters to three hundred and five meters, these uplands include distinct geographical entities such as the Rairangpur, Keonjhar, Rourkela, Bolangir-Bargarh-Rairkhol, Aska, Rayagada, and Malkangiri rolling uplands. Each of these areas hosts its own unique ecosystems, supported by the diverse climatic conditions and varying altitudes. These ecosystems are not just visually stunning but also ecologically significant. They harbor a rich array of flora and fauna, some of which are endemic to the region. The forests that cloak these plateaus and uplands are home to species such as the Indian bison, sambar deer, and a variety of birdlife. The dense forests also play a crucial role in soil conservation, water cycle regulation, and climate moderation. Moreover, the plateaus and uplands are not just natural treasures but also cultural landscapes, as they are home to numerous indigenous communities. These communities have lived in harmony with the environment for generations, developing a deep understanding and respect for the natural resources that sustain them. The knowledge and practices of these communities in agriculture, forest management, and conservation are invaluable and contribute to the sustainable stewardship of these regions. In summary, the highlands and plateaus of Odisha are more than physical features. They are the custodians of history, the guardians of biodiversity, and the sustainers of cultures. The geological history, coupled with the unique ecosystems they support, make these regions vital for the ecological health and cultural heritage of Odisha. They stand as a testament to the state's commitment to preserving the natural environment while also respecting the lives and traditions of its people.