Evidence Based Estimation of Macrodispersivity for Groundwater Transport Applications

Understanding contaminant transport in groundwater systems requires accurate estimation of dispersion parameters. Prior research has shown that macrodispersivity values often exceed pore-scale dispersivity measurements. However, field data for these coefficients remain limited. Practitioners frequently adopt arbitrary dispersivity values due to insufficient site-specific data. This uncertainty motivates the need for evidence-based dispersivity ranges. Existing literature lacks consensus on transverse dispersivity estimates. The gap in reliable field-derived dispersivity values drives the need for systematic analysis. No prior work had resolved dispersivity ranges across aquifer heterogeneity classes. This study addresses the lack of standardized dispersivity recommendations.

The authors aimed to establish dispersivity ranges based on field data analysis. They sought to classify aquifers by heterogeneity levels. The study focused on quantifying macrodispersivity values. The goal was to provide practical dispersivity estimates for modeling. They intended to reduce reliance on arbitrary dispersivity assumptions. The work targeted contaminant transport modeling applications. They aimed to distinguish between longitudinal and transverse dispersivity. The study sought to improve prediction of plume characteristics.

The researchers analyzed tens of field experiments for dispersivity data. They categorized aquifers into heterogeneity classes. Statistical moments of hydraulic conductivity were considered. Geostatistical analysis informed dispersivity estimates. Field measurements provided dispersivity ranges. The study compared longitudinal and transverse dispersivity. They evaluated spatial moment predictions from transport models. Field-derived dispersivity values were synthesized for each class.

The study identified dispersivity ranges for three aquifer classes. Weak heterogeneity aquifers showed lower dispersivity values. Medium heterogeneity systems exhibited moderate dispersivity. High heterogeneity aquifers had the largest dispersivity values. Transverse dispersivity remained significantly smaller. Field data supported recommended dispersivity ranges. Transport models using these values predicted plume moments. Breakthrough curves aligned with field observations.

The authors propose dispersivity ranges based on field data analysis. They suggest classifying aquifers by heterogeneity for dispersivity selection. Longitudinal dispersivity values exceed transverse estimates. The study confirms macrodispersivity's role in plume prediction. Field-derived dispersivity values improve model accuracy. The work supports robust contaminant transport modeling. Dispersivity recommendations reduce reliance on arbitrary assumptions. The findings align with stochastic transport theory principles.