where z is a datum at a particular location, h is the distance between ordered data, and n(h) is the number of paired data at a distance of h. The semivariance is half the variance of the increments z ( x i + h ) − z ( x i ) {\displaystyle z(x_{i}+h)-z(x_{i})} , but the whole variance of z-values at given separation distance h (Bachmaier and Backes, 2008).