Coupling of groundwater and surface water at Lake Willersinnweiher: Groundwater modeling and tracer studies

Abstract

Coupling between groundwater and surface water at Lake Willersinnweiher, a gravel pit lake in the Upper Rhine Graben without any surface in-or outfl ow, was investigated using both a groundwater model and the tracers 18 O and SF 6 . Based on groundwater modeling, recharge and discharge areas around the lake as well as the residence time of the lake water were determined in a regional context. The uncertainty of the simulated fl ow fi eld was assessed by sensitivity analysis. The tracers 18 O and SF 6 were measured in several observation wells and piezometers around the lake as well as in the lake's water column. They were used to verify groundwater fl ow directions found in the modeling. We found that the groundwater-lake interaction model had a large uncertainty even though relatively detailed information on input data was available. Independent information obtained from the environmental tracers allowed us to improve and verify the model.

Tracing and quantifying groundwater inflow into lakes using a simple method for radon-222 analysis

“…In this part of the Rhine Valley precipitation and to H7 for the transverse transect from South to North. The groundwater wells are GWM B and GWM C. Groundwater enters mainly on the southern lake shore, especially in the southwestern part, and leaves the lake on the northeastern shore (Wollschläger et al, 2007). Fig.…”

“…The sampling points in the lake are numbered from L1 to L5 in case of the SE to NW longitudinal transect and from H1 to H7 for the transverse transect from South to North. The groundwater wells are GWM B and GWM C. Groundwater enters mainly on the southern lake shore, especially in the south-western part, and leaves the lake on the northeastern shore (Wollschläger et al, 2007). evaporation are in the same range averaged over one year. We therefore neglect their influence on the water balance.…”

“…Using this method leads to large uncertainties due to unknown flow paths and small scale changes in the hydraulic conductivity (Wollschläger et al, 2007). Furthermore, low hydraulic head gradients as in our study area may make it difficult to obtain sufficient precision.…”

The Environmental Risk Assessment for Decision Support System for Water Management in the Vicinity of Open Cast Mines (Ds Wmvoc) / Rizikos Aplinkai Vertinimas Naudojant Netoli Atvirųjų Kasyklų Esančių Vandens Išteklių Valdymo Sprendimų Paramos Sistemą

“…Due to the strong connection between the aquifers and the lakes within the modelled area, the lakes were implemented in the groundwater model since their water surface is expected to reflect the dynamics of the upper groundwater head. This approach to modelling lake levels was used successfully by Wollschläger et al (2007). The calibrated groundwater model can be run in predictive, steady state or transient mode, for hypothetical dewatering scenarios.…”

Investigating Groundwater‐Lake Interactions by Hydraulic Heads and a Water Balance

“…The quality of the obtained results depends on factors like sediment disturbance during installation (Rosenberry et al 2010) as well as the properties of the plastic bags used for the measurements and external forces (e.g., waves) acting on them (Cable et al 2006). Stable isotope analyses have also been used in the quantification of LGD (Wollschläger et al 2007;Kidmose et al 2011).…”