Orissa is divided into five natural regions
Orissa is divided into five natural regions
the coastal plains, the river valleys and flood plains, the rolling uplands, the plateaus and the hills and mountains. a) The coastal plains (upto 75m in elevation) are formed by the alluvial deposits of the six major rivers Mahanadi, Subarnarekha, Burhabalanga, Brahmani, Baitarani, Rushikulya and their tributaries and distributaries. The long stretch of land, from the Subarnarekha in the north to the Rushikulya in the south, adjoining the 480 km long coastline, covers the undivided districts of Balasore, Cuttack, Puri and a part of Ganjam. The plains are narrow; in the north, wide in the middle, the narrowest on the Chilika lake coast and again broad in the south.
They constitute a perennially green belt of fertile land watered by the rivers and canals and are known as the ‘granary’ of Orissa. b) The river valleys and flood plains are also the creations of the major rivers, mainly the Mahanadi, the Brahmani and the Vamsadhara, They are differntiated from the coastal plains by their slightly higher elevation (75-150m) as well as their process of formation.
While the coastal plains have been reclaimed from the sea shore by the process of uplift through deposits of silt, the river valleys and flooded plains have been carved out of the high land by the opposite process of erosiop through fluvial action – and subsequently rendered fertile by fluvialite deposits. Unlike the coastal belt, these valleys and plains are not continuous but scattered along the courses of different rivers. They are also thickly populated and agriculturally prosperous. Such natural regions occur mostly in the undivided districts of Dhenkanal, Sambalpur and Bolangir. c) The rolling uplands have an undulating topography with their elevation varying between 100m. and 300m.
Situated in the submountainous zones, they have a bedrock of hard soil and patches of forest growth to cover them partially. They also offer good opportunity for paddy cultivation in the wet areas. The rolling uplands of Orissa comprise Rairangpur, ajgangpurPanposh, Jharsuguda, Baragarh, Bhawanipatna, Bolangir-PatnagarhTitlagarh and Malkangiri areas. d) The plateaus including the subdued ones are the old peninsular table lands located in the hilly regions, with their elevation varying between 305 and 610 metres. The topography is flat, but its monotony is relieved by the interruption of river valleys.
Though insignificant from the point of agriculture, the plateaus are of considerable importance in respect of mineral and forest resources.
