Mean and Variance Relationships for Soil Moisture at Multiple Scales

Hydrologic studies of the land surface have revealed that observable relationships exist between the mean and variance of soil moisture fields. In these investigations uncertain trends occur where sometimes a decreasing soil moisture mean produces an increase in soil moisture variance; other times a directly proportional relationship exists. Recent studies to model and explain these paradoxical trends have focused on moisture thresholds that depend on physical properties of the soil itself. These examinations have used sparse point location data to model vertical transport processes only. In this work we pursue a continuum approach using digital spatial soil data to examine the trends between the mean and variance of soil moisture fields. We account for the additional effects of lateral dispersion on moisture movement as we investigate the mean and variance relationships of soil moisture at multiple scales.