Sonbhadra or Sonebhadra (Hindi: सोनभद्र ज़िला, Urdu: سون بھدر ضلع) is the 2nd largest district of Uttar Pradesh, India. The district has an area of 6788 km² and a population of 1,463,468 (2001 census), with a population density of 216 persons per km². It lies in the extreme southeast of the state, and is bounded by Mirzapur District to the northwest, Chandoli District to the north, Kaimur and Rohtas districts of Bihar state to the northeast, Garhwa district of Jharkhand state to the east, Koriya and Surguja districts of Chhattisgarh state to the south, and Singrauli district of Madhya Pradesh state to the west. The district headquarters is in the town of Robertsganj. It is the only district in India which borders four states namely Madhya Pradesh, Chhattisgarh, Jharkhand, and Bihar. It is currently a part of the Red Corridor.
The Sone River flows through the district from east to west and its tributary the Rihand River, which rises to the south in the highlands of Surguja district of Chhattisgarh, flows north to join the Son in the center of the district. Sonbhadra is located in the south-eastern ranges of the Vindhyachal mountain.The Govind Ballabh Pant Sagar, a reservoir on the Rihand, lies partly in the district and partly in Madhya Pradesh. The district has historic, cultural, and ecological affinities with the Bagelkhand region. Obra and NTPC Rihand are the power projects located in this city. Robertsganj is the main town. Almost 100 km from Varanasi, the cultural centre of Indian epitome of Vedic civilsation, holds a prime importance as the district headquarter.
Sonbhadra has a relatively subtropical climate with high variation between summer and winter temperatures. The average temperature is 32°C–42°C in the summer and 2°C–15°C in the winter. The weather is pleasant in rainy season from July to October.
The southern region of Sonbhadra District is referred as the "Energy Capital of India"; this region has many electrical power stations around Govind Ballabh Pant Sagar. NTPC (a leading power generation company in India) has three coal-based thermal power plants at Shaktinagar (India's first NTPC), Vindhyanagar (largest capacity in India, 3260 MW) and Bijpur (Rihandnagar). Other power stations are Anpara (UPRVUNL), Obra (UPRVUNL), Renusagar (Hindalco Pipri-Hydro(UPRVUNL). NCL (a branch of Coal India Ltd.) has its headquarters and many coal mines in this region. Hindalco has a major aluminium plant at Renukut.
This region became an industrial heaven from an area of forest and hills. Some of the hills were having limestone and lot of them were having coal. There were some small rivers running through the area and the major was the Son.
Owing to the limestone hills, initially one cement factory was established at Churk in 1956. Later another cement factory started at Dala in 1971 and ancillary unit of Dala got started at Chunar in 1980. The cement factories became the foundation on which other industries were built. A big dam constructed at Pipri in 1961, named Rihand Dam. The dam produced 300 MW of electricity. Another small dam was constructed at Obra in 1968, 40 km from Rihand dam which generated 99 MW of electricity.
The Birla group then set up an aluminum plant at Renukut, which is one of the biggest aluminum plant of Hindalco. Later, the Birla group set up its own power plant at Renusagar in 1967. This plant has the current capacity of 887.2 MW and supplies the power to Hindalco. The Birlas also started a company in Renukut called HiTech Carbon. Another industrial group initiated a company in Renukut named Kanoria Chemicals, which produces chemicals and later it started own power plant at Renukoot in 1998 which generates 50 MW of electricity.
A big thermal power plant construction was started at Obra in 1967 with support from Russian engineers and was successfully completed in 1971. This had a capacity to produce 1550 MW of electricity.Another power plant was initiated at Anpara in 1980. It produces 1630 MW of electricity and has proposed to extend the capacity to 2630 MW. The thermal power plant that NTPC started in Shaktinagar, generates 2000 MW. The plant at Bijpur generates 2000 MW.
Three cement factories, one of the biggest aluminum plants, a carbon plant, a chemical factory and an energy hub to India, which generates 11000 MW with plans to reach 20000 MW. The whole country is benefiting from this region, which was once full of forests and hills, which seemed like infertile land. Last but not least, Geological Survey of India
In 2006 the Ministry of Panchayati Raj named Sonbhadra one of the country's 250 most backward districts (out of a total of 640). It is one of the 34 districts in Uttar Pradesh currently receiving funds from the Backward Regions Grant Fund Programme (BRGF).
Robertsganj,Headquarter of Sonbhadra is located about 90 km from the city of Varanasi, which is also the nearest airport. Flights are available to all major Indian cities including Delhi, Mumbai, Kolkata, Lucknow, Agra, Bangalore, Chennai, Patna, Khajuraho, Hyderabad, Gaya etc.International connections are Bangkok, Colombo, Hong Kong, Macca and Kathmandu. Robertsganj is well connected to Lucknow, Allahabad, Varanasi and Mirzapur by road. Buses are available at all hours of the day from Varanasi and it normally takes 2½ hours to cover the distance. The city is connected by rail to Delhi, Allahabad, Ranchi and Patna. Some notable trains passing through the town are Muri express (Jammu Tawi - Delhi - Tata Nagar), Jharkhand Swarna Jayanti Express/12873(Hatia - Kanpur - Delhi), Triveni Express (Bareilly - Lucknow - Shaktinagar) and Shaktipunj Express/11448(Howrah-Bokaro - Chopan- jabalpur).Intercity Express (shaktinagar - Chopan-Varanasi). The highway connecting Varanasi and Waidhan passes through the city. Though this is not a national highway it is a very busy road because of the towns Renukot, Anpara, Shaktinagar which are sufficiently commercialized areas. National Thermal Power corporation is in Shaktinagar and also National Coalfield different projects like Singrauli, khadia, Jayant, Dudhichua, amlori, Kakri etc. These areas have several major coal mines which cater a big part of the coal need of the state.churk a nearby town is situated around 10 km, where jaypee group is establishing a thermal power project. One of the main reasons this road is always busy is due to daily transport of around 1000 trucks of grits and sand.
According to the 2011 census Sonbhadra district has a population of 1,862,612 , roughly equal to the nation of Kosovoor the US state of West Virginia. This gives it a ranking of 254th in India (out of a total of 640). The district has a population density of 274 inhabitants per square kilometre (710 /sq mi) . Its population growth rate over the decade 2001-2011 was 27.27 %. Sonbhadra has a sex ratio of 913 females for every 1000 males, and a literacy rate of 66.18 %.