scholarly journals Influence of surface water level fluctuation and riverbed sediment deposits on groundwater regime

2014 ◽  
Vol 62 (3) ◽  
pp. 177-185 ◽  
Author(s):  
Márta Koczka Bara ◽  
Yvetta Velísková ◽  
Renáta Dulovičová ◽  
Radoslav Schügerl
Keyword(s):  
Surface Water ◽  
Hydraulic Conductivity ◽  
Water Level ◽  
Flow Direction ◽  
Level Fluctuation ◽  
Spatial And Temporal Patterns ◽  
Channel Network ◽  
Erosion Processes ◽  
Riverbed Sediments ◽  
Two Parameters

Abstract The spatial and temporal patterns of surface water (SW) - groundwater (GW) exchange are significantly affected by riverbed silting, clogging or erosion processes, by altering the thickness and hydraulic conductivity of riverbed sediments. The duration of SW-GW exchange is controlled by the drainage and infiltration resistance of river bottom sediments (e.g. Andrássy et al., 2012). Generally, these two parameters primarily depend on the hydraulic conductivity and on the thickness of clogged layer. In this study the flow processes between GW and SW were modeled by model TRIWACO for different infiltration resistance and drainage resistance of riverbed sediments. The model area is situated on the Rye Island, which is a lowland area with very low slope. In this area a channel network was built up, where the flow conditions are controlled by water-gates. Because of the low slope and the system of water gates built on the channels, the riverbeds are influenced by intensive clogging processes. First, the applicability of model TRIWACO in the study area was tested by modelling the response of GW on SW level fluctuation. It was simulated, how the regulation of water level and flow direction in the channels influence the GW level, especially in extreme hydrological conditions (drought/flood), and if the GW flow direction and GW level change as it was expected. Next, the influence of channel network silting up on GW-SW interaction was modeled. The thickness of riverbed sediments was measured and their hydraulic conductivity from disturbed sediment samples was evaluated. The assessed hydraulic conductivity was used to calculate the infiltration resistance and the drainage resistance of riverbed sediments in the study area. Then, the GW level and flow direction was simulated for different infiltration resistance and drainage resistance of sediments.

scholarly journals The influence of channel network silting up at Žitný Ostrov to range of interaction between surface and groundwater

2020 ◽  
pp. 23-31
Author(s):  
Renáta Dulovičová ◽  
Yvetta Velísková
Keyword(s):  
Surface Water ◽  
Hydraulic Conductivity ◽  
Field Measurements ◽  
Saturated Hydraulic Conductivity ◽  
Water Levels ◽  
Channel Network ◽  
Undisturbed Samples ◽  
The Impact ◽  
Surface And Groundwater

The movement of water resources, especially the possibilities of their regulation by interaction between surface and groundwaters are the subject matter of attention particularly during the occurrence of extreme hydrologic situation. This work presents the overview of knowledge and results which were achieved at IH SAS in this question. It can show the ways how to optimize the adjudicated processes which emerge during the requirement of emergency intervention. The solution of this task was located at the Žitný Ostrov area because this territory with their existence of channel network is suitable for studying the surface and groundwater interaction. The channel network at Žitný Ostrov was built up for drainage and also to safeguard irrigation water. The water level in the whole channel network system has an effect on groundwater level on the Žitný Ostrov and vice versa. It was been necessary to judge the impact of the channel network silting up by bed silts on the interaction between channel network and groundwater on the Žitný Ostrov. The aim was to evaluate the changes of bed silt state of Žitný Ostrov channel network and consecutively their influence on interaction processes between groundwater and surface water along the channels in the period from 1993 to present. The measurements of bed silt thickness in Žitný ostrov channel network had been started from1993, later they continued at selected profiles of three main channels – channel Gabčíkovo-Topoľníky, Chotárny channel and Komárňanský channel (for checking of the silting up variability). From 2008 the detailed field measurements of cross-section profiles aggradations along these selected three channels have been started. The objective of detailed field measurements was the determination of the silt permeability which is expressed by parameter of saturated hydraulic conductivity. This parameter was determined by two ways – as the saturated hydraulic conductivity obtained from disturbed samples of silt Kp and as the saturated hydraulic conductivity obtained from undisturbed samples of silt Kn. In the first case the granularity of silts was determined as a first step and then was computed their Kp from the empirical formulas according Bayer-Schweiger and Spacek. From undisturbed samples of silts which were extracted along the channels from top, middle and bottom layer of silts, were determined the values Kn by the laboratory falling head method. The valid values Kp on channel Gabčíkovo-Topoľníky ranged from 4,33 10-7 to 4,46.10-5 m s-1, on Chotárny channel from 5.98 10-5 to 2.14 10-6 m s-1 and on Komárňanský channel fluctuated from 1.93 10-6 – 6.09 10-5 m s-1. The valid values Kn on on channel Gabčíkovo-Topoľníky ranged from 5.21 10-8 – 4.18 10-3 m s-1 , on Chotárny channel ranged from 8.54 10-8 – 2.70 10-4 m s-1 and on Komárňanský channel fluctuated from 4.72 10-7 – 1.26 10-5 m s-1. The remarkable results were noticed by comparison of values of saturated hydraulic conductivity from disturbed and undisturbed samples Kp and Kn. On Chotárny channel the values of silt saturated hydraulic conductivity from undisturbed samples Kn approximately hundredfold decreased (from 10-6 to 10-8 m s-1). On Komárňanský channel the comparison of values Kp and Kn shown that the values Kn from undisturbed samples approximately tenfold descended against Kp. Simultaneously, the bed silts‘ impact on the groundwater recharge (saturated hydraulic conductivity of silt) was also examined. Determination of the total recharge amount was done by numerical simulation (model SKOKY) and by the so-called method of interaction formulas. These two approaches were applied at the Žitný Ostrov channel network. There were field measurements performed in monitored three main channels and adjacent to obtain correct input data. These characteristics were used for simulation and computation of total recharge along the channels. The total recharge amount was calculated for four alternatives of the surface water levels in the channel and the surroundings groundwater respectively. We chose four simplified variants with the same geological conditions in surroundings area of channels, only water levels of groundwater and in channels were modified. The results of the simulations seem to show greater impact of the silt in the case of outflow from the channels to the surroundings than the inflow into the channel from the surroundings.  

scholarly journals Effect of Surface Water Level Fluctuations on the Performance of Near-Bank Managed Aquifer Recharge from Injection Wells

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3013
Author(s):  
Peipeng Wu ◽  
Jean-Christophe Comte ◽  
Lijuan Zhang ◽  
Shuhong Wang ◽  
Bin Chang
Keyword(s):  
Surface Water ◽  
Water Level ◽  
Penetration Depth ◽  
Managed Aquifer Recharge ◽  
Groundwater Table ◽  
Water Level Fluctuation ◽  
Water Level Fluctuations ◽  
Level Fluctuation ◽  
Aquifer Recharge ◽  
Average Travel Time

Managed aquifer recharge operations are often conducted in near-bank areas to regulate water resources or reduce seawater intrusion. Yet little is known about the influence of surface water level fluctuations at different temporal scales on MAR performance. A generalized conceptual model was developed based on an investigation site in Western China as a basis to simulate the response surface water level fluctuations on the water table, artificially recharged water lens (formed by the artificially recharged water), groundwater flow paths and average travel times (which is an important control on how quickly contaminants are flushed out of aquifers), and the discharge of the artificially recharged aquifer during the surface water level fluctuation. The results showed a fluctuating groundwater table in the artificially recharged near-bank aquifer under the influence of surface water level fluctuations. The peak values of the increment of the groundwater table induced by artificial recharge decreased with the increase of the period and amplitude of surface water level fluctuation, but the trough values of the increment of water table increases with that. The penetration depth of surface water into the aquifer with a fluctuating surface water level leads to a decreasing increment of the groundwater table which follows a power law. The fluctuating surface water level leads to dynamic changes of artificially recharged water lens morphology and a thinner artificially recharged water lens. A mixing zone of recharged water and ambient water could be found in the artificially recharged near-bank area, which is expected to lead to modifications in the geochemical conditions in the artificially recharged near-bank aquifer. A longer period of surface water level fluctuation leads to a longer average travel time, but the larger penetration depth of surface water and amplitude lead to a shorter average travel time. The peak discharge of the near-bank aquifer was found to decrease with the period of surface water level fluctuation, but it increases with penetration depth and amplitude. This study is important in providing insights into the performance of near-bank managed aquifer recharge with respect to surface water level fluctuation.

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