question no.. (1) The embankments are breached and the flood water enters into villages
Answers
Answer:
Explanation:
Floods in Bihar is an annual phenomenon and in the past few decades, there isn’t a single year when the state did not experience floods. It witnessed some of the major floods in the last six decades that caused unprecedented damage and loss of lives. In 1954, a major flood struck north Bihar affecting an area of 2.46 million hectares and a population of 7.61 million.
Map showing flood zones in Bihar (Source: NIDM, 2007)
Map showing flood zones in Bihar (Source: NIDM, 2007)
Yet again, in 1974 another major flood hit the state, which was not restricted to just the northern part of the state but was also felt in the southern districts, affecting 16.39 million people. In 1987, the worst recorded flood of the twentieth century battered the state; it came in five spells and killed 1373 people.
The year 2004 and 2007 also witnessed major floods and in August 2008, the massive Kosi river flood hit the state. The flood that engulfed half the state and is considered to have caused the highest damage in five decades of flood history in Bihar, was the result of an embankment breach in Nepal.
Post bifurcation, Bihar has become the most flood-prone area in the country in terms of percentage of land susceptible to flooding. Total flood-prone area of the state is 68.80 lakh hectares which accounts for 73.06 percent of its total geographical area and 17.2 percent of the total flood-prone area in the country. Bihar falls under the flood zone of the Ganga-Brahmaputra basin and its location coupled with hydrometeorology, hydrology, geomorphology and topography makes it one of the worst flood-affected regions in the world.
Ganga river enters the state from the west and flows towards the east. A large number of rivers-- Ghagra, Gandak, Burhi Gandak, Bagmati, Adhwara group of rivers, Kamla, Kosi (also known as ‘the sorrow of Bihar’) and Mahananda joins the Ganga. These rivers are notorious for changing their course, forming a delta and affecting the deposition of sediment. Most of these rivers enter northern plains of Bihar from Nepal where their bed slopes are very sharp. Because of a sudden drop in bed slope, silt brought by the flow of these rivers get deposited at their base and become the major cause of recurring floods in the Bihar plains. Moreover, floods in North Bihar are not an independent physical event. Instead, these are a cycle of interdependent natural events and processes such as year-round rain wash of mountains resulting into the spread of sediments in the lower reaches by river spills, groundwater situation, storages in water bodies, surface detentions, waterlogging, drainage, deforestation, concentrated rainfall etc.