Despite the Amazon River stretching from the Andes Mountains to the Atlantic Ocean across multiple South American countries, what makes this river particularly memorable is the absence of any bridges crossing it.
The Amazon River is the largest river in the world by discharge, with an average flow rate of about 219,000 m3/s. It is also the river with the largest drainage area and the most tributaries in the world, only slightly shorter than the Nile, making it the second-longest river globally.
The Amazon contains more freshwater than any other river and is home to the largest river dolphins in the world, as well as a diverse array of flora and fauna.
The absence of bridges over the Amazon River has posed significant challenges for explorers and anyone wishing to cross from one bank to the other. This is quite unusual, as even smaller rivers typically have bridges.
For instance, the world’s longest river, the Nile, has nine bridges just in the section flowing through Cairo, Egypt, while the Danube in Europe, which is only one-third the length of the Amazon, boasts 133 bridges.
So what are the reasons behind the lack of any bridges over the Amazon? What fundamental challenges exist when constructing bridges in the tropical rainforest, vast wetland areas, and deep, dense vegetation? Are there financial barriers?
For a long time, humans have known how to utilize river water; however, it is strange that the Amazon River resembles a wild beast that is hard to tame, causing disturbances every few years. As a result, humans have yet to build a bridge over the Amazon. So what is happening?
Located in South America, the Amazon River is one of the longest rivers in the world. (Photo: Sohu)
The Amazon River is situated in a tropical rainforest climate, characterized by high temperatures and year-round rainfall, with annual precipitation exceeding 2000mm.
Not only does it receive abundant rainfall, but the Amazon also has 15,000 tributaries, which continuously pump water into the river. However, these tributaries do not only bring river water; they also carry substantial sediment. When sediment is swept along during floods, it can cause the Amazon River to become uncontrollable, leading to rising water levels, widening of the river, and sometimes even changes in its course.
For the people living on both banks of the Amazon, flooding and river shifts occur frequently, profoundly impacting their agriculture. Flooded rivers bring nutrient-rich sediment, and when the waters recede, locals plant crops in the sediment, which acts as a natural fertilizer, resulting in higher yields.
The shifting of the river forces residents to relocate regularly. To cope with the frequent changes in the Amazon, locals build a special type of housing: elevating their homes on long wooden stilts, allowing them to live above the floodwaters.
The frequent shifting and flooding of the Amazon River not only affects the livelihoods of local people but also makes it impossible to build bridges here. Once the river changes course, any bridge would become ineffective. Such situations have occurred in Honduras.
Choluteca Bridge.
Honduras once invested heavily in the construction of the Choluteca Bridge, designed as a marvel of technology. It withstood the assault of Hurricane Mitch in 1998. However, the hurricane rendered it the most useless bridge in the world. Hurricane Mitch altered the flow of the Choluteca River, causing the river to no longer flow beneath the bridge as it once did. Since then, the bridge has become isolated, with no access roads and failing to cross the river it was intended to span.
One can imagine that if a bridge like this were built over the Amazon, it would suffer the same fate as the Choluteca Bridge.
In fact, it is not only the Amazon that is prone to flooding disasters and course changes; many rivers worldwide experience similar issues. For example, the Yellow River in China has undergone numerous course changes, significantly impacting the residents on either side.
While other rivers have been “tamed” by humans, the Amazon remains a wild beast due to its extremely high discharge, with a flow rate of 219,000 cubic meters per second, vastly exceeding any other river in the world.
Along with the flat topography of the Amazon, it is challenging to construct large reservoirs to block flood peaks. Therefore, once local rainfall becomes excessive, the waters of the Amazon will overflow uncontrollably downstream.
The Amazon River is the largest river in the world.
Moreover, there are few people living along the banks of the Amazon, and the environment is still relatively undeveloped, so their mobility relies more on boats, making bridge construction less beneficial. Furthermore, the Amazon Basin is densely covered with small tributaries, and a single bridge cannot resolve the transportation issues.
More importantly, the local economy is not robust enough to support large-scale infrastructure projects, resulting in the reality that despite the Amazon’s vast energy resources, local residents struggle to utilize them.
The banks of the Amazon River are rich in biodiversity and unique cultural resources, attracting numerous explorers from around the world. However, there is a saying along the Amazon: “Every animal here wants to kill you, and they all have the capability to do so.” Due to the abundant waters of the Amazon and the low river levels, ferocious aquatic creatures can lurk within the waters, and if one inadvertently enters their territory, they may be attacked.
The Amazon region is dotted with remnants of settlements that have been reclaimed by nature over centuries. New archaeological imaging technology suggests that there may be over 10,000 pre-Columbian archaeological sites hidden within the Amazon Basin. Unlike remnants from ancient cultures in temperate regions globally, the structures in the Amazon are covered and buried by dense vegetation.
A prime example is the BR-319 highway, an 870 km road that runs through the pristine rainforest of the Amazon from Manaus to Porto Velho. This highway was built in the early 1970s but was ultimately abandoned in 1988 due to insufficient maintenance funds and the frequent repairs required due to rapid deterioration.
The Amazon is an area of extreme biodiversity and rich, unique culture. This region is under enormous pressure from deforestation and mining activities. The construction of roads and bridges could lead to heavier exploitation. Research shows that 95% of deforestation occurs within 5.5 km of a road, providing access for loggers, vehicles, and machinery. Roads opened for logging have many branches spreading from the main path, according to Carlos Souza Jr., a researcher in the Imazon program.
