Monitoring and modeling infiltration-recharge dynamics of managed aquifer recharge with desalinated seawater

Abstract

Abstract. We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors and observation wells. During a month (January 2015) of continuous intensive MAR (2.45 · 106 m3 discharged to a 10.7 hectare area), groundwater level has risen by 17 m attaining full connection with the pond, while average infiltration rates declined by almost 2 orders of magnitude (from ~ 11 to ~ 0.4 m d−1). This reduction can be explained solely by the lithology of the unsaturated zone that includes relatively low-permeability sediments, whereas clogging processes at pond-surface – abundant in many MAR operations – are negated by the high-quality desalinated seawater or negligible compared to the low-permeability layers. Recharge during infiltration was estimated reasonably well by simple analytical models, whereas a numerical model was used for estimating groundwater recharge after the end of infiltration. It was found that a calibrated numerical model with a one-dimensional representative sediment profile is able to capture MAR dynamics, including temporal reduction of infiltration rates, drainage and groundwater recharge. Measured infiltration rates of an independent MAR event (January 2016) fitted well to those calculated by the calibrated numerical model, showing the model validity. The successful quantification methodologies of the temporal groundwater recharge are useful for MAR practitioners and can serve as an input for groundwater flow models.

Effect of multilayered groundwater mounds on water dynamics beneath a recharge basin: Numerical simulation and assessment of surface injection

“…According to the simulation results, the fluctuations of the water mounding height and width were both asymmetrical with a slow rising phase and quick falling phase, and this asymmetry could be enhanced by increasing the injection rates or prolonging the injection durations (Figures 8 and 11). However, such phenomenon is inconsistent with previous studies on the dynamics of perched water mound (Ganot et al, 2017; Nimmer et al, 2010), in which the rising phase is quicker and the falling phase is impeded and slower. This difference could be related to (1) the designed scenarios in our study were all conducted with a constant and continuous injection strategy, which indirectly extend the rising phase of groundwater mounding; (2) The soil layers in this model were assumed at an isotropic condition, the undiminished vertical hydraulic conductivity in layers accelerated the downward flux, leading to a quick falling phase when the injection process is completed.…”

Hydraulic Issues Concerning Injection of Harvested Rainwater to the Subsurface Through Drywells: Insight From Numerical Simulations of Flow in a Realistic Combined Vadose Zone‐Groundwater Flow System

“…This result is significantly different from the results of previous investigations considering the presence of a clayey layer in an infiltration system. There is a general consent that under infiltration basins, clayey layers decreases infiltration and recharge rates (D'Aniello, Cimorelli, & Cozzolino, 2019; Ganot et al., 2017; Sasidharan et al., 2019). There is also no debate on the advantage of a deep drywell which can go through the clayey layer and be screened under it (Sasidharan et al., 2021).…”

Exploring Predictive Uncertainty at a Double‐Source Managed Aquifer Recharge Site via Stochastic Modeling

“…(IV) Annual volumes of runoff and DSW recharge were temporally distributed over each single year with reoccurring typical tendencies of recharge fluxes (according to the infiltration‐recharge calibrated model of Ganot et al. (2017)). (e) Direct precipitation is applied uniformly on the entire model domain with reoccurring monthly rates (i.e., means of historic monthly data with a 0.4 recharge coefficient, which is a realistic coefficient for sparsely vegetated, sandy soil in the Mediterranean climate, used in similar regions to the studied aquifer) $$$\left\{\left.\begin{array}{c}\hfill {V}_{sp.i}={V}_{T,i}\hfill \\ \hfill {V}_{1,i}={V}_{2,i}=0\,\hfill \\ \hfill \,{V}_{sp,i}=3\hfill \\ {V}_{1,i}=0.6\left({V}_{T,i}-3\right)\hfill \\ {V}_{2,i}=0.4\left({V}_{T,i}-3\right)\hfill \end{array}\right\vert \begin{array}{l}{V}_{T,i}< 3\,\hfill \\ \,\hfill \\ {V}_{T,i}\ge 3\hfill \\ \,\hfill \\ \,\hfill \end{array}\right\}$$$ …”

“…Whether an MAR site is initially designed, or redesignated to operate as a double source, later, during operation years, there is a need to understand the affect it will have on the system in terms of mixing of the two types of water in the aquifer. In the case of Menashe, this need is emphasized by public health concerns caused by the lack of Mg 2+ in recharged DSW (Avni et al., 2013; Rosen et al., 2018) and its potential remineralization due to mixing with naturally fresh mineral rich groundwater (Ganot et al., 2017; Ganot, Holtzman, Weisbrod, Russak, et al., 2018; Ronen‐Eliraz et al., 2017).…”