allow {lulcc}

Implement decision rules for land use change

Description

Identify legitimate transitions based on land use history and specific transition rules.

Usage

allow(x, categories, cd, rules, hist = NULL, ...)

Arguments

x

numeric vector containing the land use pattern for the current timestep

categories

numeric vector containing land use categories in the study region

cd

numeric vector indicating the direction of change for each land use category. A value of 1 means demand is increasing (i.e. the number of cells belonging to the category must increase), -1 means decreasing demand and 0 means demand is static

rules

matrix. See details

hist

numeric vector containing land use history (values represent the number of timesteps the cell has contained the current land use category). Only required for rules 2 and 3

...

additional arguments (none)

Details

Decision rules are based on those described by Verburg et al. (2002). The rules input argument is a square matrix with dimensions equal to the number of land use categories in the study region where rows represent the current land use and columns represent future transitions. The value of each element should represent a rule from the following list:

1. rule == 0 | rule == 1: this rule concerns specific land use transitions that are allowed (1) or not (0)

2. rule > 100 & rule < 1000: this rule imposes a time limit (rule - 100) on land use transitions, after which land use change is not allowed. Time is taken from hist

3. rule > 1000: this rule imposes a minimum period of time (rule-1000) before land use is allowed to change

allow should be called from allocate methods. The output is a matrix with the same dimensions as the matrix used internally by allocation functions to store land use suitability. Thus, by multiplying the two matrices together, disallowed transitions are removed from the allocation procedure.

Value

A matrix.

References

Verburg, P.H., Soepboer, W., Veldkamp, A., Limpiada, R., Espaldon, V., Mastura, S.S. (2002). Modeling the spatial dynamics of regional land use: the CLUE-S model. Environmental management, 30(3):391-405.

See Also

allowNeighb

Examples

## Plum Island Ecosystems

## load observed land use data
obs <- ObsLulcRasterStack(x=pie,
                   pattern="lu",
                   categories=c(1,2,3),
                   labels=c("forest","built","other"),
                   t=c(0,6,14))

## get land use values
x <- getValues(obs[[1]])
x <- x[!is.na(x)]

## create vector of arbitrary land use history values
hist <- sample(1:10, length(x), replace=TRUE)

## calculate demand and get change direction for first timestep
dmd <- approxExtrapDemand(obs=obs, tout=0:14)
cd <- dmd[2,] - dmd[1,]
 
## create rules matrix, only allowing forest to change if the cell has
## belonged to forest for more than 8 years
rules <- matrix(data=c(1,1008,1008,
                        1,1,1,
                        1,1,1), nrow=3, ncol=3, byrow=TRUE)

allow <- allow(x=x,
               hist=hist,
               categories=obs@categories,
               cd=cd,
               rules=rules)

## create raster showing cells that are allowed to change from forest to built
r <- obs[[1]]
r[!is.na(r)] <- allow[,2]
r[obs[[1]] != 1] <- NA
plot(r)

## NB output is only useful when used within allocation routine