Final answer:
Climate, dams, tectonism, and geology are conditions that affect the flow of river systems over time. Dams change the ecology and physical characteristics of rivers, and climate influences seasonal patterns and long-term water levels. Tectonism alters river paths, while geology shapes land slope and soil types, affecting river flow.
Step-by-step explanation:
Select conditions that have an effect on the flow of river systems over time include climate, dams, oil spills, runoff, tectonism, and geology.
Dams can significantly alter the ecology and physical characteristics of river systems by changing water temperatures, chemistry, flow characteristics, and silt loads. This leads to changes both upstream and downstream of the dam and can have negative impacts on native species and habitats.
Climate change can lead to short-term effects like unseasonal rainfall and changes in the life cycles of various organisms, while long-term effects may include the melting of glaciers and a rise in sea levels, which can alter river flows and ecosystems.
Tectonism, which refers to the movement and deformation of the Earth's crust, can also have a profound impact on river systems by reshaping the landscape and thus the path and flow of rivers over time. Similarly, the underlying geology of an area determines soil types, permeability, and features like the slope of the land, which all influence how a river flows and changes over time.