The Ganges is a trans-boundary river of Asia which flows through India and Bangladesh. The 2,525 km (1,569 mi) river rises in the western Himalayas in the Indian state of Uttarakhand. It flows south and east through the Gangetic plain of North India, receiving the right-bank tributary, the Yamuna, which also rises in the western Indian Himalayas, and several left-bank tributaries from Nepal that account for the bulk of its flow. In West Bengal state, India, a feeder canal taking off from its right bank diverts 50% of its flow southwards, artificially connecting it to the Hooghly River. The Ganges continues into Bangladesh, its name changing to the Padma. It is then joined by the Jamuna, the lower stream of the Brahmaputra, and eventually the Meghna, forming the major estuary of the Ganges Delta, and emptying into the Bay of Bengal. The Ganges–Brahmaputra–Meghna system is the second-largest river on earth by discharge.
India is situated north of the equator between 8°4' north to 37°6' north latitude and 68°7' east to 97°25' east longitude. It is the seventh-largest country in the world, with a total area of 3,287,263 square kilometres (1,269,219 sq mi). India measures 3,214 km (1,997 mi) from north to south and 2,933 km (1,822 mi) from east to west. It has a land frontier of 15,200 km (9,445 mi) and a coastline of 7,516.6 km (4,671 mi).
Nepal measures about 880 kilometers (547 mi) along its Himalayan axis by 150 to 250 kilometers across. It has an area of 147,516 km2 (56,956 sq mi).
The Brahmaputra is a trans-boundary river which flows through Tibet (China), Northeastern India, and Bangladesh. It is known as Brahmaputra or Luit in Assamese, Yarlung Tsangpo in Tibetan, the Siang/Dihang River in Arunachali, and Jamuna River in Bengali. It is the 9th largest river in the world by discharge, and the 15th longest.
The Indo-Gangetic Plain, also known as the North Indian River Plain, is a 700-thousand km2 (172-million-acre) fertile plain encompassing northern regions of the Indian subcontinent, including most of modern-day northern and eastern India, most of eastern-Pakistan, virtually all of Bangladesh and southern plains of Nepal. Also known as the Indus–Ganga Plain, the region is named after the Indus and the Ganges rivers and encompasses a number of large urban areas. The plain is bounded on the north by the Himalayas, which feed its numerous rivers and are the source of the fertile alluvium deposited across the region by the two river systems. The southern edge of the plain is marked by the Deccan Plateau. On the west rises the Iranian Plateau. Many developed cities like Delhi, Dhaka, Kolkata, Lahore, Islamabad and Karachi are located in the Indo-Gangetic Plain.
The Karnali River, called Ghaghara River in India, Mapcha Tsangpo in Tibet, and the lower Ghaghara in Awadh called Sarayu River, is a perennial trans-boundary river that originates in the northern slopes of the Himalayas in the Tibetan Plateau, cuts through the Himalayas in Nepal and joins the Sharda River at Brahmaghat in India. Together they form the Ghaghara River, a major left-bank tributary of the Ganges. With a length of 507 km (315 mi), it is the longest river in Nepal. The total length of the Ghaghara up to its confluence with the Ganges at Revelganj in Bihar is 1,080 km (670 mi). It is the largest tributary of the Ganges by volume and the second largest by length after Yamuna.
The Gandaki River, also known as the Narayani and Gandak, is one of the major rivers in Nepal and a left-bank tributary of the Ganges in India. Its total catchment area is 46,300 km2 (17,900 sq mi), most of it in Nepal. In the Nepal Himalayas, the Gandaki is notable for its deep canyon. The basin also contains three mountains over 8,000 m (26,000 ft), namely Dhaulagiri, Manaslu and Annapurna Massif. Dhaulagiri is the highest point of the Gandaki basin.
The Terai–Duar savanna and grasslands is a narrow lowland ecoregion at the base of the Himalayas, about 25 km (16 mi) wide, and a continuation of the Indo-Gangetic Plain in India, Nepal and Bhutan. It is colloquially called Terai in the Ganges Basin east to Nepal, then Dooars in West Bengal, Bhutan and Assam east to the Brahmaputra River. It harbours the world's tallest grasslands, which are the most threatened and rare worldwide.
The Kosi or Koshi is a transboundary river which flows through China, Nepal and India. It drains the northern slopes of the Himalayas in Tibet and the southern slopes in Nepal. From a major confluence of tributaries north of the Chatra Gorge onwards, the Kosi River is also known as the Saptakoshi for its seven upper tributaries. These include the Tamur River originating from the Kanchenjunga area in the east and Arun River and the Sun Kosi from Tibet. The Sun Koshi's tributaries from east to west are the Dudh Koshi, Likhu Khola, Tamakoshi River, Bhote Koshi and Indravati. The Saptakoshi crosses into northern Bihar, India where it branches into distributaries before joining the Ganges near Kursela in Katihar district. The Kosi is the third-largest tributary of the Ganges by water discharge after the Ghaghara and the Yamuna.
The Upper Gangetic Plains moist deciduous forests is a tropical and subtropical moist broadleaf forests ecoregion of northern India.
The Lower Gangetic Plains moist deciduous forests is a tropical and subtropical moist broadleaf forests ecoregion of Bangladesh and India. The ecoregion covers an area of 254,100 square kilometres (98,100 sq mi), comprising most of Bangladesh and the Indian states of West Bengal, Bihar and Tripura, and extending into adjacent states of Odisha, Uttar Pradesh and a tiny part of Assam, as well as adjacent western Myanmar.
Uttar Pradesh is India's fourth largest state by land area, and most populous state, located in the north-central part of the country. It spreads over a large area, and the plains of the state are quite distinctly different from the high mountains in the north. The climate of this state can also vary widely - primarily due to it being far from the moderating effect of the sea and the occasional cold air arising due to western disturbances.
The 2008 Indian floods were a series of floods in various states of India during the 2008 monsoon season. The floods mostly affected the western regions of Maharashtra state and Andhra Pradesh as well as northern Bihar. In India, the monsoon season generally lasts from June to September.
The 2008 Bihar flood was one of the most disastrous floods in the history of Bihar, an impoverished and densely populated state in India. The Koshi embankment near the Indo-Nepal border broke on 18 August 2008. The river changed course and flooded areas which had not been flooded in many decades. The flood affected over 2.3 million people in the northern part of Bihar.
Bihar is located in the eastern region of India, between latitudes 24°20'10"N and 27°31'15"N and longitudes 83°19'50"E and 88°17'40"E. It is an entirely land–locked state, in a subtropical region of the temperate zone. Bihar lies between the humid West Bengal in the east and the sub humid Uttar Pradesh in the west, which provides it with a transitional position in respect of climate, economy and culture. It is bounded by Nepal in the north and by Jharkhand in the south. Bihar plain is divided into two unequal halves by the river Ganges which flows through the middle from west to east. Bihar's land has average elevation above sea level of 173 feet.
Bihar is India's most flood-prone state, with 76% of the population of North Bihar living under the recurring threat of devastating flooding. Bihar makes up 16.5% of India's flood-affected area and contains 22.1% of India's flood-affected population. About 73.06% of Bihar's geographical area, 68,800 square kilometres (26,600 sq mi) out of 94,160 square kilometres (36,360 sq mi), is affected. Each year, floods kill many and damage livestock and other assets worth millions. In total, floods have claimed 9,500 lives since the government started publishing figures in 1979. North Bihar districts are vulnerable to at least five major flood-causing rivers during monsoon – the Mahananda, Koshi, Bagmati, Burhi Gandak, and Gandak rivers – which originate in Nepal. Some South Bihar districts have also become vulnerable to floods, from the Son, Punpun, and Phalgu rivers. The 2013 flood affected over 5.9 million people in 3,768 villages in 20 districts in the state. The 2017 flood affected 19 districts in North Bihar, killing 514 people and affecting over 17 million.
The Sunkoshi, also spelt Sunkosi, is a river that is part of the Koshi or Saptkoshi River system in Nepal. Sunkoshi has two source streams, one that arises within Nepal in Choukati, and the other more significant stream that flows in from Nyalam County in the Tibet region of China. The latter is called Bhote Koshi in Nepal and Matsang Tsangpo in Tibet. Due to the significant flows from Bhote Koshi, the Sun Koshi river basin is often regarded as a trans-border river basin.
The ecology of the Himalayas varies with climate, rainfall, altitude, and soils. The climate ranges from tropical at the base of the mountains to permanent ice and snow at the highest elevations. The amount of yearly rainfall increases from west to east along the southern front of the range. This diversity of climate, altitude, rainfall and soil conditions supports a variety of distinct plant and animal species, such as the Nepal gray langur
Located in the eastern India, Bihar is the twelfth-largest Indian state with an area of 94,163 km2 and an average elevation of about 150 meters above mean sea level. The landlocked Bihar shares boundary with Nepal to the north, the states of West Bengal to the east, Jharkhand to the south and Uttar Pradesh to the west. Bihar has three parts on basis of physical and structural conditions- Southern Plateau Region, Bihar Plain, and Shivalik Region. Third, Shivalik Region in sub-Himalayan foothills of Shivalik range's shadows the state from Northern part of West Champaran over an area 32 km long and 6–8 km wide. West Champaran district are clad in a belt of moist deciduous forest. As well as trees, this consists of scrub, grass and reeds.
