The stunning blood vessels of our planet: How river deltas change our world - and the lives of the 500million people who live on their shores




Deltas are the unsung heroes of our planet, fertilising hundreds of thousands of miles across our planet as they distribute sediment from rivers to the shorelines.

One in 15 of the world's population lives, breathes and works on one of the 40 or so major deltas on planet Earth, relying on their inexhaustible power to keep the area stable.

From space, these vast areas look like branching blood vessels, crossing entire continents until they reach the sea.

In fact, only when viewed from above is it possible to appreciate their scale and the impact they have on shaping our land - and how beautiful they are.



A dash of Van Gogh: This is the delta in Bijagos archipelago, West Africa, where just 20 of 80 islands are inhabited - and doesn't it look like a Van Gogh painting?

The Gulf of Papua, Papua New Guinea: The 400-kilometer-wide region holds a sea area of approximately 35,000km squared, with the coasts surrounded by coastal mangrove forests

Like the tree of life: The Lena Delta in Russia covers 61,000 square kilometres of land ,with the delta about 30,000 square kilometres - one of the largest in the world

Criss cross: The delta in Ganges River, Bangladesh is the most sacred river in the world to Hindus, for a variety of religious and historical reasons

A river runs through it: the Mississippi Delta in Louisiana, United States, showing odd bits of vegetation escaping the water

From so far away it's impossible imagine the 500 million people who live around the banks, or of the natural disasters that can take place.

Deltas are accumulations of sediment at river mouths. The term 'delta' is derived from the greek letter 'delta', which in its capital form is triangular, a common shape of river deltas, such as the Nile.

Dr. Helene Burningham, 39, a Lecturer in Physical Geography at University College London, said: 'The photos show a variety of forms associated with river deltas.

'Deltas offer a wide range of environments, including valuable wetlands that provide significant ecosystems.

'The Ganges-Brahmaputra delta covers a large area of southern Bangladesh and east India, and is one of the most densely populated areas in the world.

'It is an excellent example of the importance of deltas in providing many resources for human populations, including fertile land for agriculture and access to fishing.'

Shanghai, China: A satellite image shows the important sea port in the Shanghai and the Yangtze river estuary

The Khatanga River delta in Siberia, Russia, looks almost like a cloud as it winds through the area

This satellite image shows a Delta in Bombetoka Bay, Madagascar: It is hard to imagine that 500 million people live around the banks of deltas like these

Rivers from Hell? Nope - this is the Betsiboka estuary in Madagascar, which carries lots of reddish silt down to the sea - natural erosion is causing a lot of damage to the area The delta in Ganges River, Bangladesh, with false colours serving as a contrast between land and water But there can be dangers of living around deltas.



Dr Burningham added: 'Deltas are inherently low-lying and can be easily eroded. They are vulnerable to sea level rise, which may result in increased flooding. 'Deposition of more sediment also adds weight to the delta, which can often result in sinking of the delta landform, thereby increasing the likelihood of flooding.' There are many causes of change to delta systems over time, and they often occur in cycles. Dr Burningham added: 'Causes are both natural and human-induced. 'Sea level rise associated with global warming is probably the most important impact of global warming on river deltas.'

The delta carves through Cairo in Egypt, bringing much-needed water to the area. The delta itself takes up 240km of the Mediterranean coastline

Psychedelic: Another image of the Lena delta in Russia, with false-colours highlighting different sediments

The Volga Delta in Russia: Due to changes in water level in the Caspian Sea, this delta has grown from 3,000 square kilometres to more than 25,000 over 130 years