Final answer:
Too much river discharge can cause flooding, leading to the destruction of infrastructure such as bridges. An example is the I-35W Mississippi River bridge collapse, though not directly due to flooding. Human alterations to the environment can exacerbate these risks.
Step-by-step explanation:
When there is too much discharge from a river, it can lead to flooding. The excessive water flow, often due to heavy rainfall or snowmelt, can exceed the capacity of the river channel and overflow onto the surrounding land. Flooding can cause significant damage to infrastructure, including bridges. An example of a river causing flooding that destroyed a bridge is the collapse of the I-35W Mississippi River bridge in Minneapolis in 2007, although this was primarily due to structural deficiencies rather than flooding.
Oversaturation of slope materials with water can result in debris flows, which may obstruct rivers, damaging bridges and causing floods in the process. The excess water can also lead to soil erosion, transportation of sediments, and disruption of aquatic and terrestrial ecosystems. Human activities, such as deforestation and urbanization, can exacerbate the flooding risks by reducing the land's natural ability to absorb and slowly release water.