SCOC: A Sediment Model of Oxygen Consumption

Description

A model that describes oxygen consumption in a marine sediment

One state variable:

sedimentary organic carbon,

Organic carbon settles on the sediment surface (forcing function Flux) and decays at a constant rate.

The equation is simple: $$\frac{dC}{dt}=Flux-k C$$

This model is written in FORTRAN.

Usage

SCOC(times, y=NULL, parms, Flux, ...)

Arguments

times

time sequence for which output is wanted; the first value of times must be the initial time,

the initial value of the state variable; if NULL it will be estimated based on Flux and parms,

parms

the model parameter, k,

Flux

a data set with the organic carbon deposition rates,

...

any other parameters passed to the integrator ode (which solves the model).

Details

The model is implemented primarily to demonstrate the linking of FORTRAN with R-code.

The source can be found in the dynload subdirectory of the package.

References

Soetaert, K. and P.M.J. Herman, 2009. A Practical Guide to Ecological Modelling. Using Ras a Simulation Platform. Springer, 372 pp.

Examples

Run this code

# Forcing function data
Flux <- matrix(ncol=2,byrow=TRUE,data=c(
  1, 0.654, 11, 0.167,   21, 0.060, 41, 0.070, 73,0.277, 83,0.186,
  93,0.140,103, 0.255,  113, 0.231,123, 0.309,133,1.127,143,1.923,
  153,1.091,163,1.001,  173, 1.691,183, 1.404,194,1.226,204,0.767,
  214, 0.893,224,0.737, 234,0.772,244, 0.726,254,0.624,264,0.439,
  274,0.168,284 ,0.280, 294,0.202,304, 0.193,315,0.286,325,0.599,
  335, 1.889,345, 0.996,355,0.681,365,1.135))

parms <- c(k=0.01)

times <- 1:365
out<- SCOC(times,parms=parms,Flux=Flux)

plot(out$time,out$Depo,type="l",col="red")
lines(out$time,out$Mineralisation,col="blue")

# Constant interpolation of forcing function - left side of interval
fcontrol<-list(method="constant")

out2 <- SCOC(times,parms=parms,Flux=Flux, fcontrol=fcontrol)

plot(out2$time,out2$Depo,type="l",col="red")
lines(out2$time,out2$Mineralisation,col="blue")