Nash–Sutcliffe model efficiency coefficient

The Nash–Sutcliffe model efficiency coefficient (NSE) is used to assess the predictive skill of hydrological models. It is defined as: NSE = 1 − ∑ t = 1 T ( Q o t − Q m t ) 2 ∑ t = 1 T ( Q o t − Q ¯ o ) 2 {\displaystyle {\text{NSE}}=1-{\frac {\sum _{t=1}^{T}\left(Q_{o}^{t}-Q_{m}^{t}\right)^{2}}{\sum _{t=1}^{T}\left(Q_{o}^{t}-{\overline {Q}}_{o}\right)^{2}}}} where Q ¯ o {\textstyle {\overline {Q}}_{o}} is the mean of observed discharges available, Q m t {\textstyle Q_{m}^{t}} is modeled discharge at time t, and Q o t {\textstyle Q_{o}^{t}} is observed discharge at time t.

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