When people built the town and planted crops before the flood occurred thousands of years ago, the river formed a continent by cutting a deep canyon. These rivers are often overflowing from the banks of the river, causing floods in the surrounding areas and depositing minerals-rich silt and soil in the surrounding plains and valleys. As the flood enriched the soil, some of the first cities were built along the river. The most important are growth along the Indus River in Pakistan, the Nile River in Egypt, the Yellow River in China, the Tigris River in the Middle East and the Euphrates River.
Floods are common to all countries. Floods occur every year in some parts of India. In Bangladesh, severe flooding occurred in 1913. It is known as the Damodar flood. A wide area of Burdwan, Hooghly, Midnapur was flooded. The flood of North Bengal in 1922 also caused a great loss of life and property. In 1931, North Bengal and East Bengal suffered a bad flood. In 1934, a bad flood brought about a lot of loss to Assam people. Their condition became extremely tragic. People from other parts of India came forward to help victims. In recent years, flooding has suffered serious damage in Assam, North Bengal, Bihar. In the southern part of India there are also bad folds due to the rising water of Cauvery and other rivers. In 1987, flooding occurred in Assam State, North Bengal State, North Bihar State, Uttar Pradesh State in the eastern part. It also brings significant losses to the lives and property of humans, crops and livestock.
In India, a part of Assam, Bihar, Ganges Uttar Pradesh tends to flood during the rainy season (Figure 18.3). The Ganges and Brahmaputra rivers and their tributaries are the most vulnerable to floods. However, in Gujarat, Maharashtra, Karnataka and Tamil Nadu, occasional floods are occurring due to heavy rain. In India, floods are a big problem. Usually between July and September some or part of the area will be affected by the flood. Floods bring infinite suffering to affected areas in the form of large losses of lives and wealth. Agriculture and livestock are seriously damaged. The affected areas of the flood are facing serious lack of food and drinking water. In addition, the flood can cause many waterborne diseases such as diarrhea, gastroenteritis, jaundice, malaria.