Simulating contaminant transport in unsaturated and saturated groundwater zones

Abstract

The demand for clean and adequate water is rising rapidly with increasing population. This growing demand for water necessitates the measurement of the quantity and quality of water. Simulation modeling has become increasingly popular in the last two decades largely because of their predictive ability. This paper reviews the approaches for simulation modeling in groundwater resources management, focusing on models that have been used to simulate contaminant transport through the aquifer system. Recent research papers that have integrated the models for unsaturated and saturated zones have also been studied and described. Integrated models require assessment of the complex interactions between the groundwater zones and the movement of water and solute through them. Due to this, integrated models provide a more accurate modeling approach than models that have been independently developed for saturated and unsaturated zones. Application of such models is encouraged at the regional level to arrive at the best groundwater management decisions. © 2021 Water Environment Federation • Practitioner points• In the past few decades, modeling of contaminant transport in groundwater systems has seen tremendous applications. • A number of models exist that independently simulate flow and solute transport in unsaturated and saturated zones. • Recently, focus has been given on developing advanced coupled modeling approaches that require less inputs and run times.

Accumulation of Na+ in cotton field under mulched drip irrigation of brackish water in arid areas

“…(2) Na + accumulation and soil water and salt dynamics in cotton elds Salt ows with water, and water removes salt (Arbat, 2020;Sarma, 2021). Soil water and salt changes under drip irrigation under lm also follow this basic law (Momii,2021).…”

Assessing the effect of urbanization on regional-scale surface water-groundwater interaction and nitrate transport

“…However, these values are not easy to measure and are rarely available for watershed-scale studies, usually assumed based on commonly used values from the literature. In this study area, related studies are unavailable, and therefore, we have referred to worldwide literature, e.g., 15 , 16 , 64 – 66 , and considered 0.05/day and 10 g/m 3 for the first-order denitrification and Monod half-saturation constant. The surface and subsurface hydrological processes, models, and scenario simulations were conceptualized by modifying the schematic diagram from previous studies 13 , 16 , 44 .…”

“…Process-based coupled surface water-groundwater models appear to be plausible for simulating complex physical processes, such as urbanized and highly irrigated regions 12 , 26 , 27 . Moreover, integrated models provide a more accurate modeling approach, compared to separate saturated and unsaturated zones focused models, for best water resources management decisions 28 . Studies on nitrate loading into urban rivers by considering river-aquifer connection usually focus on small reach or experimental catchment, e.g., 29 .…”

Navigating the Depths: A Comprehensive Review of Numerical Groundwater Models – Objectives, Advantages & Challenges

“…[30] Expanding to 2D groundwater numerical models broadens the scope of applications, allowing for the simulation of lateral groundwater flow, groundwater-surface water interactions, and contaminant transport across a two-dimensional plane. These models are instrumental in studying regional groundwater flow dynamics, assessing the impacts of land-use changes on groundwater resources, and predicting the migration of pollutants from various sources [31]. Furthermore, 2D models play a crucial role in watershed-scale hydrological studies, aiding in understanding groundwater flow within river basins and predicting aquifer responses to hydrological changes and climate variability.…”

“…Figure 2. Schematic procedure of the integrated model with landscape unit-based conceptual models and FEFLOW[31] …”