scholarly journals Lateral groundwater flow and pond interactions during dry and wet years

SURG Journal ◽  
2017 ◽  
Vol 9 (1) ◽  
pp. 27-39
Author(s):  
Andrew Wicke ◽  
Thair Patros ◽  
Gary Parkin
Keyword(s):  
Surface Water ◽  
Groundwater Flow ◽  
Flow Direction ◽  
Unconfined Aquifer ◽  
Hydrologic Cycle ◽  
Future Climate Change ◽  
Visual Modflow ◽  
Evaporative Demand ◽  
Monitoring Wells ◽  
Tightly Coupled

Groundwater and surface water are tightly coupled elements of the hydrologic cycle that have often been treated as separate entities. Future climate change modelling has predicted that hydrologic cycle changes, namely increasing drought frequency and flood-type events, are likely to occur. These events may directly impact the quality and quantity of both groundwater and surface water. Future water management policies must therefore be based on an understanding of how interactions between groundwater and surface water will change with a warming climate. The aim of this study was to model and analyze the lateral flow of groundwater and its interactions with a nearby pond in a shallow, unconsolidated, unconfined aquifer. Data were collected as part of a larger and ongoing study during the year 2012, a comparatively dry year, and 2013, a comparatively wet year. We first used ArcGIS and Visual MODFLOW Flex to create a conceptual model of the system, its soil layers, monitoring wells, and potential flow patterns. We then analyzed hydraulic head data, and calculated groundwater flow volumes using the Dupuit equation. We found that the groundwater flow direction reversed in the summer of 2012 and continued until the spring of 2013. Additonally, flow rate was greater in 2013 than 2012. The flow reversal was likely caused by higher evaporative demand during the summer months of 2012, drawing substantially more water from the pond than from the soil. The two-year timeframe was not long enough to determine whether this was a typical, yearly pattern, or was primarily due to the fact that 2012 was a particularly dry year.

Innovative real-time sensing of flow dynamics in groundwater and sediments to map contaminant spreading

2021 ◽  
Author(s):  
Goedele Verreydt ◽  
Niels Van Putte ◽  
Timothy De Kleyn ◽  
Joris Cool ◽  
Bino Maiheu
Keyword(s):  
Surface Water ◽  
Groundwater Flow ◽  
Real Time ◽  
Flow Direction ◽  
Flow Dynamics ◽  
Sensor Data ◽  
Time Data ◽  
Mass Fluxes ◽  
First Case

<p>Groundwater dynamics play a crucial role in the spreading of a soil and groundwater contamination. However, there is still a big gap in the understanding of the groundwater flow dynamics. Heterogeneities and dynamics are often underestimated and therefore not taken into account. They are of crucial input for successful management and remediation measures. The bulk of the mass of mass often is transported through only a small layer or section within the aquifer and is in cases of seepage into surface water very dependent to rainfall and occurring tidal effects.</p><p> </p><p>This study contains the use of novel real-time iFLUX sensors to map the groundwater flow dynamics over time. The sensors provide real-time data on groundwater flow rate and flow direction. The sensor probes consist of multiple bidirectional flow sensors that are superimposed. The probes can be installed directly in the subsoil, riverbed or monitoring well. The measurement setup is unique as it can perform measurements every second, ideal to map rapid changing flow conditions. The measurement range is between 0,5 and 500 cm per day.</p><p> </p><p>We will present the measurement principles and technical aspects of the sensor, together with two case studies.</p><p> </p><p>The first case study comprises the installation of iFLUX sensors in 4 different monitoring wells in a chlorinated solvent plume to map on the one hand the flow patterns in the plume, and on the other hand the flow dynamics that are influenced by the nearby popular trees. The foreseen remediation concept here is phytoremediation. The sensors were installed for a period of in total 4 weeks. Measurement frequency was 5 minutes. The flow profiles and time series will be presented together with the determined mass fluxes.</p><p> </p><p>A second case study was performed on behalf of the remediation of a canal riverbed. Due to industrial production of tar and carbon black in the past, the soil and groundwater next to the small canal ‘De Lieve’ in Ghent, Belgium, got contaminated with aliphatic and (poly)aromatic hydrocarbons. The groundwater contaminants migrate to the canal, impact the surface water quality and cause an ecological risk. The seepage flow and mass fluxes of contaminants into the surface water were measured with the novel iFLUX streambed sensors, installed directly in the river sediment. A site conceptual model was drawn and dimensioned based on the sensor data. The remediation concept to tackle the inflowing pollution: a hydraulic conductive reactive mat on the riverbed that makes use of the natural draining function of the waterbody, the adsorption capacity of a natural or secondary adsorbent and a future habitat for micro-organisms that biodegrade contaminants. The reactive mats were successfully installed and based on the mass flux calculations a lifespan of at least 10 years is expected for the adsorption material.  </p>

scholarly journals Impacts of groundwater extraction on groundwater flow and arsenic distribution in the western Hetao Basin, Inner Mongolia, China

2019 ◽  
Vol 98 ◽  
pp. 09037
Author(s):  
Zhuo Zhang ◽  
Huaming Guo ◽  
Weiguang Zhao ◽  
Haicheng Weng
Keyword(s):  
Surface Water ◽  
Groundwater Flow ◽  
Flow Direction ◽  
Temporal Variations ◽  
Water Levels ◽  
Labile Organic Matter ◽  
Near Surface ◽  
Groundwater Levels ◽  
Arsenic Distribution ◽  
Geochemical Parameters

Temporal variations in water levels are crucial for understanding As behaviour in groundwater systems. Groundwater levels were recorded in irrigation wells in non-irrigation and irrigation seasons. Groundwater samples were collected yearly in irrigation wells from 2014 to 2016 and in a multilevel well from 2015 to 2016 for analysing geochemical parameters. Results showed that groundwater flow direction was reversed due to groundwater pumping. The change of groundwater flow led to the surface water, as a new groundwater recharge source, which flushed the near-surface sediments enriched in soluble components and increased groundwater TDS. The labile organic matter introduced by the surface water recharge fueled dissimilatory reduction of Fe(III) oxides and further increased groundwater As concentration.

scholarly journals Solutions for groundwater flow with sloping stream boundary: analytical, numerical and experimental models

2017 ◽  
Vol 49 (4) ◽  
pp. 1120-1130 ◽  
Author(s):  
Uğur Boyraz ◽  
Cevza Melek Kazezyılmaz-Alhan
Keyword(s):  
Surface Water ◽  
Groundwater Flow ◽  
Laboratory Experiments ◽  
Groundwater Resources ◽  
Experimental Models ◽  
Flow Equation ◽  
Visual Modflow ◽  
Aquifer System ◽  
Aquifer Characteristics ◽  
Made In

Abstract Protecting groundwater resources plays an important role in watershed management. For this purpose, studies on groundwater flow dynamics incorporating surface water–groundwater interactions have been conducted including analytical, numerical, and experimental models. In this research, a stream–aquifer system was considered to understand the physical behavior of surface water–groundwater interactions. Interactions in a stream–aquifer system were incorporated into the mathematical modeling by defining the stream head as a boundary condition for the groundwater flow equation. This boundary was chosen as a sloping stream boundary, which is an approach in representing the natural conditions of the stream and may be used to define continuous interactions between stream and aquifer. A semi-analytical solution for transient 2D groundwater flow was developed for the considered problem. Isotropic, homogeneous, and finite aquifer assumptions were made in order to define the aquifer characteristics. Then, a series of laboratory experiments was conducted to simulate this stream–aquifer system. Finally, a numerical model was developed by using Visual MODFLOW to verify analytical and experimental results. Numerical results matched with both analytical solutions and the experimental observations.

scholarly journals DELINEATION OF AQUIFEROUS ZONES USING GEOPHYSICAL METHODS AND CONTAMINANT FLOW DIRECTION -A case study of dumpsite at Cassidy, Okokomaiko, LASU-Badagry Expressway, Lagos State, Nigeria

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Rafiu Adegbola ◽  
Olanike Abidoye ◽  
Ibrahim Adaranijo
Keyword(s):  
Electrical Resistivity ◽  
Groundwater Flow ◽  
Flow Direction ◽  
Geophysical Methods ◽  
Electrode Array ◽  
Unconfined Aquifer ◽  
Near Surface ◽  
The North ◽  
Lagos State ◽  
Groundwater Flow Direction

Introduction: Cassidy area, of Okokomaiko, Ojo, Lagos State, is a rapidly developing area with attendant growing population arising from the presence of University, financial institutions and popularly known Alaba market. Unfortunately, water supply by the water corporation is not readily available. The inhabitants only rely on the surface water and groundwater extracted from hand dug wells and boreholes. Aims: The study is to map the aquiferous zone and establish the groundwater flow direction, with a view to averting subsurface contamination emanated from dumpsite within the area. Materials and Methods: Twenty five (25) Vertical Electrical Sounding (VES) using Schlumberger electrode array, four (4) Electrical Resistivity imaging using Wenner Electrode Array were acquired at four different traverses. Manual groundwater flow direction was also conducted. Results: The identified unconfined aquifer was sand/sandy clay which is overlain by peat/clay soil that is loose and may allow downward migration of the contaminant plumes to deep groundwater. However, the confined aquifer observed to occur approximately at depth 18 m. The electrical resistivity distribution observed decreases upward, south and north. This implies increase in conductivity in such directions and as such indicating the contaminant could be more concentrated near-surface, north and south. Conclusion: The implication of the results obtained with respect to vulnerability to groundwater pollution is that the southern section of the aquifer is more susceptible to receive transported contaminants from the northern part of the study area. The study suggests the potential borehole should be sited in the north-eastern direction with the aid of geophysical survey.

Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

2018 ◽  
Vol 7 (4) ◽  
pp. 191
Author(s):  
Sherwan Sh. Qurtas
Keyword(s):  
Unconfined Aquifer ◽  
Middle Part ◽  
Water Levels ◽  
Specific Yield ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Water Table Fluctuation Method ◽  
Recharge Estimation ◽  
Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

scholarly journals Groundwater Depletion Signals in the Beqaa Plain, Lebanon: Evidence from GRACE and Sentinel-1 Data

2021 ◽  
Vol 13 (5) ◽  
pp. 915
Author(s):  
Elias C. Massoud ◽  
Zhen Liu ◽  
Amin Shaban ◽  
Mhamad Hage
Keyword(s):  
Snow Water Equivalent ◽  
Water Storage ◽  
Hydrologic Cycle ◽  
Groundwater Depletion ◽  
Satellite Mission ◽  
Groundwater Storage ◽  
Significant Drop ◽  
Monitoring Wells ◽  
High Productivity ◽  
Soil Moisture Storage

Regions with high productivity of agriculture, such as the Beqaa Plain, Lebanon, often rely on groundwater supplies for irrigation demand. Recent reports have indicated that groundwater consumption in this region has been unsustainable, and quantifying rates of groundwater depletion has remained a challenge. Here, we utilize 15 years of data (June 2002–April 2017) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission to show Total Water Storage (TWS) changes in Lebanon’s Beqaa Plain. We then obtain complimentary information on various hydrologic cycle variables, such as soil moisture storage, snow water equivalent, and canopy water storage from the Global Land Data Assimilation System (GLDAS) model, and surface water data from the largest body of water in this region, the Qaraaoun Reservoir, to disentangle the TWS signal and calculate groundwater storage changes. After combining the information from the remaining hydrologic cycle variables, we determine that the majority of the losses in TWS are due to groundwater depletion in the Beqaa Plain. Results show that the rate of groundwater storage change in the West Beqaa is nearly +0.08 cm/year, in the Rashaya District is −0.01 cm/year, and in the Zahle District the level of depletion is roughly −1.10 cm/year. Results are confirmed using Sentinel-1 interferometric synthetic aperture radar (InSAR) data, which provide high-precision measurements of land subsidence changes caused by intense groundwater usage. Furthermore, data from local monitoring wells are utilized to further showcase the significant drop in groundwater level that is occurring through much of the region. For monitoring groundwater storage changes, our recommendation is to combine various data sources, and in areas where groundwater measurements are lacking, we especially recommend the use of data from remote sensing.

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