Heterogeneity in geology refers to the variation in physical and chemical properties within geological materials, such as rocks or soils. This variation can influence fluid flow, mechanical behavior, and geochemical reactions, and is significant in fields such as hydrogeology, petroleum geology, and environmental science.
Reference: Pine, W. J., & Park, C. F. (2004). Geological Heterogeneity and Its Implications for Fluid Flow. Hydrogeology Journal, 12(1), 26-39.