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The runoff curve number (also called a curve number or simply CN) is an empirical parameter used in hydrology for predicting direct runoff or infiltration from rainfall excess. [1] The curve number method was developed by the USDA Natural Resources Conservation Service , which was formerly called the Soil Conservation Service or SCS — the ...
A runoff models or rainfall-runoff model describes how rainfall is converted into runoff in a drainage basin (catchment area or watershed). More precisely, it produces a surface runoff hydrograph in response to a rainfall event, represented by and input as a hyetograph. Rainfall-runoff models need to be calibrated before they can be used.
[8] The runoff coefficients for different surface types on a site can be multiplied with the area for each surface along with the annual precipitation to generate a rough runoff footprint. If the runoff coefficient and areas of proposed stormwater green solutions like rain gardens and bioswales for the site are known, the reduction in overall ...
Other external programs that aid in the generation of data for the EPA SWMM 5 model include: SUSTAIN, [22] BASINS, [23] SSOAP, [24] and the EPA’s National Stormwater Calculator (SWC) [17] which is a desktop application that estimates the annual amount of rainwater and frequency of runoff from a specific site anywhere in the United States ...
The Kling–Gupta efficiency (KGE) is a goodness-of-fit indicator widely used in the hydrologic sciences for comparing simulations to observations. It was created by hydrologic scientists Harald Kling and Hoshin Vijai Gupta. [1]
The Nash–Sutcliffe coefficient masks important behaviors that if re-cast can aid in the interpretation of the different sources of model behavior in terms of bias, random, and other components. [11] The alternate Kling–Gupta efficiency is intended to improve upon NSE by incorporating bias and variance terms. [12]
The linear-reservoir model (or Nash model) is widely used for rainfall-runoff analysis. The model uses a cascade of linear reservoirs along with a constant first-order storage coefficient, K, to predict the outflow from each reservoir (which is then used as the input to the next in the series).
[1] [13] [30] [31] Structural BMPs are defined as the components of the drainage pathway between the source of runoff and a stormwater discharge location that affect the volume, timing, or quality of runoff. SELDM uses a simple stochastic statistical model of BMP performance to develop planning-level estimates of runoff-event characteristics.