What is SCS curve number method?
The SCS curve number method is a simiple, widely used and efficient method for determining the approxient amount of runoff from a rainfall even in a particular area. Although the method is designed for a single storm event, it can be scaled to find average annual runoff values.
What is SCS CN method of runoff estimation?
Soil Conservation Service – Curve Number (SCS – CN) method is employed to estimate the runoff. It is one of the physical based and spatially distributed hydrological models. In this model, the curve number is a primary factor used for runoff calculation.
What do you think are the advantages of using NRCS curve number method in determining the peak discharge?
The advantages of the method are: (1) its simplicity; (2) its predictability; (3) its stability; (4) its reliance on only one parameter; and (5) its responsiveness to major runoff-producing watershed properties.
What are curve numbers used for?
Curve Numbers are determined according to the ground cover and soil type, and are used to approximate the varying infiltration, interception and storage capacities of different land covers.
How is curve number related to potential maximum retention?
Equation 4.5 is the rainfall-runoff relationship used in the Curve Number Method. It allows the runoff depth to be estimated from rainfall depth, given the value of the potential maximum retention S. This potential maximum retention mainly represents infiltration occurring after runoff has started.
How do you calculate a weighted curve number?
The weighted CN is calculated by taking the sum of each CN value multiplied by its fraction of the total subcatchment area. The sum is (usually) rounded to the nearest whole number, as described below. The rounded result is used for all calculations and reports.
What does a curve number represent and what does it mean to have a high curve number?
The runoff curve number, , is then related. has a range from 30 to 100; lower numbers indicate low runoff potential while larger numbers are for increasing runoff potential. The lower the curve number, the more permeable the soil is.
What does a higher curve number mean?
has a range from 30 to 100; lower numbers indicate low runoff potential while larger numbers are for increasing runoff potential. The lower the curve number, the more permeable the soil is. As can be seen in the curve number equation, runoff cannot begin until the initial abstraction has been met.
What does a high curve number mean?