Linear trend is useful for mapping forest degradation, land degradation, etc. This algorithm is capable of obtaining the slope of an ordinary least-squares linear regression and its reliability (p-value).
linearTrend(x, type = "lm", ...)
| x | RasterStack, RasterBrick or Matrix (row*col, n_images) |
|---|---|
| type | There are two options: "lm" for a linear regression and "glm" for Generalized Linear Models |
| ... | For "lm" and "glm": arguments to be used to form the default control argument if it is not supplied directly. See lm and glm. |
Linear regression is widely used to analyze forest degradation or land degradation. Specifically, the slope and its reliability are used as main parameters and they can be obtained with this function. On the other hand, logistic regression allows obtaining a degradation risk map, in other words, it is a probability map. Please see the references or see Tarazona and Maria-Miyasiro (2020).
Tarazona, Y., Maria, Miyasiro-Lopez. (2020). Monitoring tropical forest degradation using remote sensing. Challenges and opportunities in the Madre de Dios region, Peru. Remote Sensing Applications: Society and Environment, 19, 100337.
Wilkinson, G.N., Rogers, C.E., 1973. Symbolic descriptions of factorial models for analysis of variance. Appl. Stat. 22, 392-399.
Chambers, J.M., 1992. Statistical Models in S. CRS Press.
library(ForesToolboxRS) library(raster) data(serie_pv) e <- extent(350420.9, 352028.8, -1417869, -1416288) imgs <- crop(serie_pv, e) trend <- linearTrend(x = imgs) plot(trend[[1]]) # raster of slope plot(trend[[2]]) # raster of p-value