A fitted semivariogram can be dissected into three possible elements: nugget, range, and sill polati (Figure 15.19). The nugget is the semivariance at the distance of 0, representing measurement error, or microscale variation, or both. The range is the distance at which the semivariance starts to level off. In other words, the range corresponds to the spatially correlated portion of the semivariogram. Beyond the range, the semivariance becomes a relatively constant value. The semivariance at which and the leveling takes place is called the sill. The sill