Read the following statements and choose the CORRECT answer. I. The suspended sediment concentration in rivers is supply-limited rather than hydraulically-limited, when II. Much suspended material is contributed by overland flow from hillslope erosion III. Suspended material is entirely derived by turbulent diffusion from the channel bed
Sediment Concentration: Supply vs. Hydraulic Limits
Understanding the factors controlling suspended sediment concentration is key. A concentration can be:
- Supply-limited: The amount of sediment available from the surrounding environment limits the concentration in the water.
- Hydraulically-limited: The river's flow characteristics (velocity, turbulence) determine the maximum amount of sediment it can carry, regardless of availability.
Statement II Analysis: Hillslope erosion, particularly when intensified by overland flow (surface runoff), is a major source of sediment supplied to the river system from the adjacent land. This external contribution directly increases the potential sediment supply.
Connecting Statement II to Statement I: When a significant portion of the suspended material originates from processes like hillslope erosion and overland flow (as described in Statement II), the river's sediment load is primarily governed by how much material is delivered to it. In such cases, the concentration is dictated by the available supply rather than the river's inherent capacity to transport sediment (hydraulic capacity). Therefore, Statement II serves as a valid explanation for why Statement I might be true.
Statement III Evaluation: This statement proposes that suspended material comes *entirely* from turbulent diffusion from the channel bed. While channel bed processes contribute, this statement is restrictive (using "entirely") and presents a different primary mechanism. Statement II provides a more direct reason for the concentration being supply-limited in a broader river system context.
Important Questions from Hydrology And Water Resources
- A river with $2\text{ km}$ wide flood plain and $10\text{ m}$ channel depth flows with a velocity of $2\text{ ms}^{-1}$. What will be flow condition in the river?
- With reference to water in the hydrologic cycle, its residence time is the maximum in
Match the basin types A, B and C with the hydrograph patterns P, Q and R
Basin types Hydrograph pattern A. 
P. 
B. 
Q. 
C. 
R. 
Hydraulic gradient beneath A and B during rainy and dry seasons will
Identify the correct sequence of freshwate abundance on the Earth.(GP = Glaciers and Polar ice; A = Atmosphere; LR = Lakes and Rivers; UW = Underground Water)
