Ganges delta
The Ganges Delta (also called Ganges-Brahmaputra Delta or Bengal Delta ) is the world's largest river delta and is located in the South Asian region of Bengal . Its catchment area extends over India , the People's Republic of China , Bhutan , Nepal , Myanmar (Burma) and Bangladesh .
Rivers etc.
The Ganges delta is created by the confluence of the main rivers Brahmaputra , Ganges and Meghna and consists of around 240 rivers - more or less constant in their course. The Brahmaputra, called Jamuna in its lower course , brings in the largest amount of water of the three main rivers (the Himalayas) and together with the Ganges forms the Padma river arm , which in turn flows into the Meghna. This flows into the Bay of Bengal . The Ganges delta has the triangular shape typical of river deltas. In total, it covers an area of approx. 140,000 km² (110,000 km² permanently) and is therefore about twice the size of the Mississippi Delta .
Landforms and geology
The Ganges Delta is divided into an eastern (active) and a western (less active) part. The Sundarbans , the world's largest mangrove forest , deep green on satellite images, is the southernmost part of the Ganges Delta. In the north there are islands and peninsulas where agriculture is practiced. Due to the current, bank erosion occurs again and again, the material of which, however, is deposited again in another place; Fields and entire villages are disappearing and are being rebuilt elsewhere.
The landscape is to a certain extent comparable to the German North Sea coast or the Rhine delta: The area is extremely flat and characterized by the absence of any hill up to the horizon. Large areas are below sea level, or at least below high water level. The residents build dykes to protect their rice fields and houses from salt water (there is a mean tidal range of 2.6 m to 6 m). Due to the slow current, very fine sediments are deposited in the delta, some of which the rivers from the Himalayas have carried with them as glacial milk since the source. Therefore, there is mainly loamy to silty soil in the delta.
Infrastructure
The delta consists of a maze of waterways, swamps, lakes and alluvial islands (chars). The many small river arms in particular make the area somewhat impassable. Some islands can only be reached by ferry and some of them are not yet connected to the public grid, so many residents use photovoltaics . Roads and paths have to be paved with bricks, and even these do not offer absolute protection against erosion. However, the construction of asphalt roads and bridges is being promoted in India.
population
The islands are inhabited north of the Sundarbans . The islanders mostly live from agriculture, grow rice and keep cattle. Traditionally, houses are built from the ubiquitous clay with wood reinforcement.
The simple dykes made of clay are usually not able to cope with storm surges (cyclones), so that dyke breaks often occur. The Indian areas will therefore be cleared with the help of the army if the weather forecast is appropriate. Despite the risks posed by floods and cyclones , over 143 million people live in the Ganges Delta. In 1987 and 1998, monsoons claimed 2,550 and 3,000 lives, respectively. Between 1961 and 1991, as many as 700,000 people were killed as a result of 15 cyclones.
Web links
- NASA (Johnson Space Center): Ganges-Brahmaputra River Delta
- The Golden Fiber Trade Center: Ganges Delta: Most Fertile Land for Growing Raw Jute
- Banglapedia: Ganges-Padma River System
Individual evidence
- ↑ http://www2.klett.de/sixcms/media.php/229/beitrag_3a.pdf "Delta growth despite sea level rise - all-clear for Bangladesh?" - Terrace - 1st half of 2011.
- ↑ http://www.goruma.de/Laender/Asien/Bangladesch/Landkarte/geografie.html