The Amazon River snakes around for at least 6,400 kilometers (3,977 miles), yet it is not crossed by a single bridge (at least officially). Given humankind’s strong tendency to reshape natural landscapes and traverse the seemingly impossible, this anomaly begs the question – why?
One of the main reasons is that there isn’t much demand for an Amazon river crossing. The depths of the rainforests are sparsely populated with relatively little infrastructure and roads, making bridges unnecessary, unlike the bustling crossings over the Thames in London.
“There is no sufficiently pressing need for a bridge across the Amazon,” Walter Kaufmann, chair of Structural Engineering (Concrete Structures and Bridge Design) at the Swiss Federal Institute of Technology in Zurich, told Live Science in 2022.
“Of course, there are also technical and logistical difficulties,” added Kaufmann.
It’s undeniably challenging to build infrastructure in the dense rainforest, hence why there are very few human settlements of significant size in the Amazon. The ground is soft and unpredictable, plus it’s extremely easy for any human-made structures to be consumed by the rainforest’s relentless vegetation and harsh conditions, like intense rainfall.
Any attempt to build a bridge, unless perfectly planned, would likely end in crumbling foundations and caked in unforgiving greenery.
Map of the Amazon River drainage basin.
Image credit: Rainer Lesniewski/Shutterstock.com
You can barely tell by looking at the landscape, but the Amazon is scattered with the long-lost remains of human settlements that have become lost to nature over the centuries.
New imaging technologies are revealing that there are likely to be more than 10,000 pre-Columbian archaeological sites hidden throughout the Amazon basin. Unlike archaeological remains from ancient cultures in temperate parts of the world, the Amazonian structures have become swamped, swallowed by plant growth, and buried.
If you need a modern example, look no further than the notorious BR-319 highway, an 870-kilometer (541-mile) long road that runs through a pristine part of the Amazon rainforest from Manaus to Porto Velho. The highway was built in the early 1970s under Brazil’s military dictatorship, but it was ultimately abandoned by 1988 because it was uneconomical to maintain and required constant repairs due to rapid deterioration.
Some might argue that it’s better that bridges don’t ever start crossing the Amazon River, either. The Amazon is an incredibly rich and unique hive of biodiversity and human culture that’s already under immense pressure from logging and mining.
The construction of roads, highways, and bridges could open it up for more exploitation. Research has highlighted that the overwhelming majority (95 percent) of deforestation occurs within 5.5 kilometers (3.4 miles) of a road because it provides access to loggers, vehicles, and heavy machinery.
A 2022 study used AI to identify rural (often unofficial and illegal) roads in the Brazilian Amazon from satellite imagery, identifying 3.46 million kilometers (2.15 million miles) of roads. The researchers then used these findings to see how the new roads were impacting deforestation, forest fires, and landscape fragmentation.
“These are arteries of destruction. The roads are opened to extract wood, and the ramifications spread from the main line, where the trucks and heavy machinery are,” study co-author Carlos Souza Jr., an associate researcher at Imazon who runs their Amazon monitoring program, told Mongabay.
Source Link: The Amazon River Doesn't Have Any Bridges – And For Good Reason