Interactions of artificial lakes with groundwater applying an integrated MODFLOW solution

Abstract

Artificial lakes (reservoirs) are regulated water bodies with large stage fluctuations and different interactions with groundwater compared with natural lakes. A novel modelling study characterizing the dynamics of these interactions is presented for artificial Lake Turawa, Poland. The integrated surface-water/groundwater MODFLOW-NWT transient model, applying SFR7, UZF1 and LAK7 packages to account for variably-saturated flow and temporally variable lake area extent and volume, was calibrated throughout 5 years (1-year warm-up, 4-year simulation), applying daily lake stages, heads and discharges as control variables. The water budget results showed that, in contrast to natural lakes, the reservoir interactions with groundwater were primarily dependent on the balance between lake inflow and regulated outflow, while influences of precipitation and evapotranspiration played secondary roles. Also, the spatio-temporal lakebed-seepage pattern was different compared with natural lakes. The large and fast-changing stages had large influence on lakebed-seepage and water table depth and also influenced groundwater evapotranspiration and groundwater exfiltration, as their maxima coincided not with rainfall peaks but with highest stages. The mean lakebed-seepage ranged from~0.6 mm day −1 during lowest stages (lake-water gain) to~1.0 mm day −1 during highest stages (lake-water loss) with largest losses up to 4.6 mm day −1 in the peripheral zone. The lakebed-seepage of this study was generally low because of low lakebed leakance (0.0007-0.0015 day −1 ) and prevailing upward regional groundwater flow moderating it. This study discloses the complexity of artificial lake interactions with groundwater, while the proposed front-line modelling methodology can be applied to any reservoir, and also to natural lake interactions with groundwater.

Hydrological Modeling to Assess the Efficiency of Groundwater Replenishment through Natural Reservoirs in the Hungarian Drava River Floodplain

“…Water 2020, 12, x FOR PEER REVIEW 3 of 21 more realistically in the latest update LAK7 package [49]. The experience gathered from the MODFLOW lake packages is utilized in the modeling of water balance for the reservoir planned in the Drava floodplain.…”

“…Isotope-balance approaches [44] using δ 2 H or δ 18 O measurements of water were used in several hydrological studies to assess groundwater inflow to lakes, with varying degrees of success [40,[45][46][47][48]. Hydrological models are the most reliable tools for the assessment of lake water/groundwater interactions [49]. A Modular Three-Dimensional Finite-Difference Ground-Water Flow Model (MODFLOW) [50] is applied widely to assess this interaction from different approaches.…”

“…The main advantage of the lake package is that it allows the fluctuation of lake stage. Also, the exchange of volumetric water between the lake and the aquifer is determined [49]. The LAK2 package is capable of simulating more than one lake simultaneously.…”

“…The advantages and disadvantages of three approaches for simulating lake-groundwater interactions (namely, fixed lake stages, high-K nodes, and LAK3 package) were compared by Hunt [59]. Water balance is simulated more realistically in the latest update LAK7 package [49]. The experience gathered from the MODFLOW lake packages is utilized in the modeling of water balance for the reservoir planned in the Drava floodplain.…”

Application of MODFLOW with Boundary Conditions Analyses Based on Limited Available Observations: A Case Study of Birjand Plain in East Iran

“…In this study, a three-dimensional, block-centered (cell-centered), steady-state, finite difference model, MODFLOW (McDonald and Harbaugh [12]) is employed to quantify groundwater in Birjand plain, South Khorasan, Iran. In recent years, GMS: MODFLOW model (Groundwater Modeling System) has been successfully developed and published in a large number of groundwater quantitative and qualitative studies because of its simple methods, modular program structure, and separate packages to resolve special hydrogeological problems [10,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. This model, with a graphical user interface (GUI), can be integrated with geographic information system (GIS) to provide an appropriate visual environment for groundwater resources evaluation and management [15].…”