variogrammodel
In geostatistics, a variogram model (variogrammodel) is a parametric function that describes how the spatial dependence of a regionalized variable changes with separation distance. It provides the theoretical variogram γ(h) used in kriging and related methods. The empirical variogram is estimated from sample data and then fitted with a chosen model to obtain a smooth, usable representation of spatial structure.
Common models include spherical, exponential, Gaussian, and Matérn. All share parameters such as the nugget, sill,
Model fitting is typically done by adjusting parameters to minimize the difference between the empirical and
Applications include ordinary, simple, and universal kriging, as well as cokriging and stochastic simulation. Variogram models
Limitations include assumptions of second-order stationarity and isotropy (unless explicitly modeled). Poorly estimated models can bias