leakyExpStore.sim {hydromad} | R Documentation |

An exponential store (linear transfer function) which has a loss term, produces no flow when the store drops below a level, and can therefore model longer-term disconnection of a store from streamflow.

leakyExpStore.sim(x, tau, loss, thres, init = 0, return_components = FALSE)

`x` |
input time series. |

`tau` |
Time constant for flow from exponential store. |

`loss` |
Constant loss that occurs while the value of the store is greater
than |

`thres` |
Trigger level to turn off loss, which can be interpreted as a store capacity. |

`init` |
Initial value of exponential store |

`return_components` |
whether to return store value (G) as well as flow (Q) |

Storage is increased by effective rainfall and decreased by flow and losses.

*G[k] = G[k-1] + U[k] - Q[k] - L[k]*

Flow is proportional to storage

*Q[k] = a G[k], G[k]>0*

*Q[k] = 0, otherwise*

Loss switches off at some threshold, as a piece-wise continuous function.

*L[k] = L, G[k]>T+L (with T<=0)*

*L[k] = G[k] - T, T+L > G[k] > T*

*L[k] = 0, G[k]<T*

the flow time series with the same dimensions and time windows as the
input `x`

.
If `return_components = TRUE`

, it will have multiple
columns named `G`

and `Q`

.

Joseph Guillaume joseph.guillaume@anu.edu.au with advice from Barry Croke

U <- ts(c(1, rep(0, 10),1,rep(0, 20))) ## Without a loss, equivalent to expuh ## Loss threshold has no effect all.equal(leakyExpStore.sim(U,5,loss=0,thres=0),expuh.sim(U, tau_s = 5)) ## With losses stopping when flow stops, equivalent to expuh with a loss all.equal(leakyExpStore.sim(U,5,loss=0.1,thres=0), expuh.sim(U, tau_s = 5,loss=0.1)) ## Plot of unit hydrographs xyplot(cbind("U"=U, "loss=0"=expuh.sim(U,tau_s=5), "loss=0.1 & thres=0"=expuh.sim(U,tau_s=5,loss=0.1), "loss=0.1 & thres=-0.3"=leakyExpStore.sim(U,5,loss=0.1,thres=-0.3), "loss=0.1 & thres=-Inf"=leakyExpStore.sim(U,5,loss=0.1,thres=-Inf) ),superpose=TRUE) ## Time series plot of value of store xyplot(cbind( "thres=0"=leakyExpStore.sim(U,5,loss=0.1,thres=0, return_components=TRUE)[,"G"], "thres=-0.3"=leakyExpStore.sim(U,5,loss=0.1,thres=-0.3, return_components=TRUE)[,"G"], "thres=-Inf"=leakyExpStore.sim(U,5,loss=0.1,thres=-Inf, return_components=TRUE)[,"G"] ),superpose=TRUE) ## Time series of loss xyplot(cbind( "thres=0"=leakyExpStore.sim(U,5,loss=0.1,thres=0, return_components=TRUE)[,"L"], "thres=-0.3"=leakyExpStore.sim(U,5,loss=0.1,thres=-0.3, return_components=TRUE)[,"L"], "thres=-Inf"=leakyExpStore.sim(U,5,loss=0.1,thres=-Inf, return_components=TRUE)[,"L"] ),superpose=TRUE)

[Package *hydromad* version 0.9-18 Index]