Final answer:
The question pertains to the dynamic environmental factors that influence river behavior and streamflow, such as changes in the river's slope, water supply, and sediment load. As a river flows from its source to its mouth, the channel widens, current slows, and sedimentation generally increases. Human interventions, like damming, can also significantly change the riverine ecology and the physical river characteristics.
Step-by-step explanation:
The riverine system and its dynamics represent a key element of physical geography. As a river progresses from its source to its mouth, various environmental factors contribute to changes in its behavior and characteristics. Abiotic features of rivers, such as temperature, nutrient levels, and water clarity, vary along the course of the river. At the source, the water is typically cold, low in nutrients, and clear, with a narrow channel and fast current.
The slope of the river course affects streamflow, with steeper slopes contributing to faster moving water, which can lead to increased erosion. Changes in the river's base level, slopes, or sources of water and sediment supply can result in alterations to its course and functionality. Over time, these changes influence sedimentation patterns, river width, and current speed, especially as tributaries join and the gradient decreases, leading to a wider channel and a slower flow downstream, often resulting in more sediment deposition.
Hydrological processes like evaporation, sublimation, condensation, precipitation, subsurface water flow, surface runoff, and snowmelt contribute to the river's water budget and impact its flow characteristics. Additionally, human factors such as reservoirs and dam operations can significantly alter a river's ecology and physical properties by changing water temperatures, chemistry, flow characteristics, and silt loads.