In: Civil Engineering
what is a runoff coefficient in hydrology and what is hydrologic abstraction?
what is their use and why do they matter in the engineering world?
What are the primary strengths or weaknesses of the concept?
What would have made it easier for you to understand the method or concept?
Runoff Coefficient is a coefficient which has no dimension and is used to determine the runoff from the amount of precipitation is received. Runoff coefficient value is higher for low infiltration value areas and runoff is high for pavement and steep gradient. Value is lower for permeable areas like forest.
Hydrologic abstraction is referred to the precepitation which are not runoff or when rainfall is intercepted by something, that rainfall doesnot reach to ground .
Q= (P-0.2S)²/(P+0.8S)
Q= runoff volume
P= precipitation
S= soil water retention parameter
0.2 in is called abstraction coefficient.
✓✓ Runoff coefficient is used to determine the amount of runoff of preceipitation from the catchment area and in the engineering world from the runoff coefficient value we can determine the soil types, its permeability and moisture content.
Hydraulic abstraction is used to determine the amount of rainfall is collected by the canopy of plant or the amount of rainfall go back to the atmosphere (i.e interception) and in the engineering world to determine rainfall intensity, amount of Evapotranspiration, surface depression.