The threats and challenges surrounding sedimentary environments involve how the river may affect our activities and in turn how our activities influence sedimentary environments. Many organisms rely on the stability of their habitats to thrive, and we are dependent on many of these organisms as well. As covered before, changes in river flow and sediment supply can have dire consequences for life in the waters.

Due to the complexity of rivers and sedimentary basins, we won’t cover all challenges associated with these systems. But some challenges are more widespread or urgent than others. 

Here are some:

Weathering and erosion can increase if the climate brings more intense rain or storms or if too much vegetation is removed. Plant roots help hold sediments in place, so that they don’t get washed away easily. After a night of heavy storms, a river can gain destructive power, as seen during summer thunderstorms along the Danube River. If we remove too much vegetation around rivers, it might result in increased sediment supply which may affect habitats and river flow.

While rivers can bring disastrous and deadly flooding after severe rain events, they also remove excess water all the time. Rivers are, in a sense, flood control systems, but sometimes they get more water than they can carry within their channel. This is when we get floods.

More sediments accumulated on the riverbed means that the river can carry less water, showing how closely connected river flow and sedimentation are.

Hydropower is a promising source of renewable energy and can help reduce fossil fuel use. But hydropower plants can have intense effects on several of the issues covered earlier.

Dams and hydropower plants may disrupt and or reduce essential supplies of sediment along a river, disproportionately accumulating sediments upstream. Downstream the river may receive too little sediment, which can have dire effects on ecosystems and the shape of the river and floodplains.

In many countries, there is growing momentum to remove old or unused barriers where the environmental and social costs are greater than the benefits. This generally applies to smaller or obsolete structures.

Large hydropower plants on major rivers like the Danube, however, provide significant electricity and cannot simply be removed, so other sediment solutions are needed.

At times, we need to step in to shift the balance manually a bit. This can involve removing, adding or displacing sediments directly, or changing how we manage rivers.

The importance of sedimentary processes can’t be understated. Before we humans started influencing rivers and basins, there was a long-established natural balance between erosion and deposition. Even with dramatic changes from earthquakes, rain events or landslides, rivers could gain a new equilibrium.

However, human activities are often quick, repeated, or on the opposite constant, which prevents this important rebalancing from taking place. By understanding a river basin better, we can work toward achieving a new, functional balance – and then managing it carefully so it remains stable as conditions change.

Besides manual sediment management, there are many solutions being researched and tested to improve the quality of our river systems and the sedimentary processes in them. Again, finding such solutions are not only vital for the ecosystems in them – it also supports our livelihoods.

Local activism and engagement from people who rely on rivers for their daily activities and well-being is key. We need more to learn about the consequences of our activities and how they can shift a long-established natural balance.