Geostatistical screening of flood events in the groundwater levels of the diverted inner delta of the Danube River: implications for river bed clogging

2018 ◽  
Vol 10 (1) ◽  
pp. 64-78 ◽  
Author(s):  
Balázs Trásy ◽  
Tamás Garamhegyi ◽  
Péter Laczkó-Dobos ◽  
József Kovács ◽  
István Gábor Hatvani
Keyword(s):  
Spatial Autocorrelation ◽  
Groundwater Monitoring ◽  
Shallow Groundwater ◽  
Monitoring Network ◽  
Danube River ◽  
Monitoring Networks ◽  
Flood Events ◽  
Raw Data ◽  
Monitoring Wells ◽  
Autocorrelation Structure

Abstract The efficient operation of shallow groundwater (SGW) monitoring networks is crucial to water supply, in-land water protection, agriculture and nature conservation. In the present study, the spatial representativity of such a monitoring network in an area that has been thoroughly impacted by anthropogenic activity (river diversion/damming) is assessed, namely the Szigetköz adjacent to the River Danube. The main aims were to assess the spatial representativity of the SGW monitoring network in different discharge scenarios, and investigate the directional characteristics of this representativity, i.e. establish whether geostatistical anisotropy is present, and investigate how this changes with flooding. After the subtraction of a spatial trend from the time series of 85 shallow groundwater monitoring wells tracking flood events from 2006, 2009 and 2013, variography was conducted on the residuals, and the degree of anisotropy was assessed to explore the spatial autocorrelation structure of the network. Since the raw data proved to be insufficient, an interpolated grid was derived, and the final results were scaled to be representative of the original raw data. It was found that during floods the main direction of the spatial variance of the shallow groundwater monitoring wells alters, from perpendicular to the river to parallel with it for over a period of about two week. However, witht the passing of the flood, this returns to its original orientation in ~2 months. It is likely that this process is related first to the fast removal of clogged riverbed strata by the flood, then to their slower replacement. In addition, the study highlights the importance of assessing the direction of the spatial autocorrelation structure of shallow groundwater monitoring networks, especially if the aim is to derive interpolated maps for the further investigation or modeling of flow.

Pesticides in groundwater and drinking water wells: overview of the situation in the Netherlands

2008 ◽  
Vol 57 (8) ◽  
pp. 1277-1286 ◽  
Author(s):  
P. N. M. Schipper ◽  
M. J. M. Vissers ◽  
A. M. A van der Linden
Keyword(s):  
Drinking Water ◽  
The Netherlands ◽  
Groundwater Resources ◽  
Shallow Groundwater ◽  
Monitoring Network ◽  
Fresh Groundwater ◽  
Water Abstraction ◽  
Pesticides Residues ◽  
Monitoring Wells ◽  
Water Wells

In the Netherlands, many of the fresh groundwater resources are vulnerable to pollution. Owing to high population densities and intensive farming practices, pesticide residues are found in groundwater at many places. Hence a number of drinking water abstraction wells contain pesticides residues, causing considerable costs for purification. The Water Framework Directive (WFD) requires countries to assess the chemical status of groundwater bodies and set up monitoring plans for groundwater quality, including pesticides. 771 groundwater samples were taken from monitoring wells in 2006 and analysed for a broad list of pesticides in order to fulfil these requirements. Pesticide were detected in 27% of samples, while in 11% the WFD limit of 0.1 μg/l was exceeded. In this paper, these and earlier measurements are evaluated further, considering also measurements in drinking water wells, information about the origin of measured pesticides and calculated trends in use and emissions. The measurements in the monitoring wells showed that where pesticides are used, 15–55% (minimal and maximal estimation) of the wells in shallow groundwater (1 to 20m below soil surface) contain pesticides residues at concentrations above 0.1 μg/l. When the metabolites BAM and AMPA are excluded (as not relevant in human toxicological terms), the estimation range is 7–37%. These patterns observed in shallow groundwater are reflected by the occurrence of pesticides in vulnerable abstraction wells that are used for the production of drinking water. The WFD requires the determination of both status and trends. The design of current monitoring network is evaluated from this perspective. Several recommendations are made for more adequate and efficient monitoring.

scholarly journals Multi-objective optimization of groundwater monitoring network using a probability Pareto genetic algorithm and entropy method (case study: Silakhor plain)

2020 ◽  
Author(s):  
Mehdi Komasi ◽  
Hesam Goudarzi
Keyword(s):  
Genetic Algorithm ◽  
Groundwater Monitoring ◽  
Monitoring Network ◽  
Entropy Theory ◽  
Monitoring Networks ◽  
Nsga Ii ◽  
Potential Wells ◽  
Optimal Monitoring ◽  
Observation Wells ◽  
Optimal Monitoring Network

Abstract Optimal groundwater monitoring networks have an important role in water resources management. For this purpose, two scenarios were presented. The first scenario designs a monitoring network and the second scenario chooses optimal wells from the existing ones in the study area of the monitoring network. At the first step, a database including groundwater elevation in potential wells was produced using the Kriging method. The optimal monitoring network in the first scenario was determined by preset conventions and found by the non-dominated sorting genetic algorithm (NSGA-II). In the second scenario, the optimal monitoring network was determined by entropy theory through calculating entropy for each of the 29 observation wells. Finally, the first scenario obtained a network with 12 observation stations showing root mean square error (RMSE) value given as 0.61 m. Comparison between entropy of rainfall and groundwater level time series in the first scenario had the same variation. The optimal monitoring network in the first scenario has been able to reduce the number of monitoring stations by 60% in comparison with the existing observation network. The second scenario used entropy theory and calculated the energy of each of the 29 observation wells which obtained a monitoring network with 11 stations.

scholarly journals Measuring the unseen: mobilizing citizen scientists to monitor groundwater in Nepal

2021 ◽  
Vol 193 (9) ◽  
Author(s):  
Rajaram Prajapati ◽  
Rocky Talchabhadel ◽  
Bhesh Raj Thapa ◽  
Surabhi Upadhyay ◽  
Amber Bahadur Thapa ◽  
...  
Keyword(s):  
Groundwater Level ◽  
Groundwater Monitoring ◽  
Monsoon Season ◽  
Land Use Changes ◽  
Ground Surface ◽  
Shallow Groundwater ◽  
Monitoring Network ◽  
Essential Information ◽  
Groundwater Levels ◽  
Personal Connections

AbstractGroundwater-level monitoring provides crucial information on the nature and status of aquifers and their response to stressors like climate change, groundwater extraction, and land use changes. Therefore, the development of a spatially distributed long-term monitoring network is indispensable for sustainable groundwater resource management. Despite being one of our greatest unseen resources, groundwater systems are too often poorly understood, ineffectively managed, and unsustainably used. This study investigates the feasibility of establishing a groundwater monitoring network mobilizing citizen scientists. We established a network of 45 shallow monitoring wells in the Kathmandu Valley using existing wells. We recruited 75% of the citizen scientists through personal connections and the rest through outreach programs at academic institutes and site visits. We used various methods to encourage citizen scientists to complete regular measurements and solicited feedback from them based on their experiences. Citizen scientists were more consistent during the monsoon season (June through September) than non-monsoon seasons. The depth-to-water below the ground surface varied from − 0.11 m (negative sign represents a groundwater level higher than the ground surface) to 11.5 m, with a mean of 4.07 m and standard deviation of 2.63 m. Groundwater levels began to rise abruptly with the onset of monsoon season and the shallowest and the deepest groundwater levels were recorded in peak rainfall months and dry months respectively. Citizen science-based groundwater monitoring using existing wells would be an economic and sustainable approach for groundwater monitoring. Improved groundwater-level data will provide essential information for understanding the shallow groundwater system of the valley, which will assist concerned authorities in planning and formulating evidence-based policy on sustainable groundwater management.

scholarly journals Optimal design of groundwater-level monitoring networks

2017 ◽  
Vol 19 (6) ◽  
pp. 920-929 ◽  
Author(s):  
Fahimeh Mirzaie-Nodoushan ◽  
Omid Bozorg-Haddad ◽  
Hugo A. Loáiciga
Keyword(s):  
Groundwater Level ◽  
Groundwater Monitoring ◽  
Design Method ◽  
Monitoring Network ◽  
Optimization Method ◽  
Monitoring Networks ◽  
Nsga Ii ◽  
Design Data ◽  
Groundwater Levels ◽  
Level Monitoring

Abstract Groundwater monitoring plays a significant role in groundwater management. This study presents an optimization method for designing groundwater-level monitoring networks. The proposed design method was used in the Eshtehard aquifer, in central Iran. Three scenarios were considered to optimize the locations of the observation wells: (1) designing new monitoring networks, (2) redesigning existing monitoring networks, and (3) expanding existing monitoring networks. The kriging method was utilized to determine groundwater levels at non-monitoring locations for preparing the design data base. The optimization of the groundwater monitoring network had the objectives of (1) minimizing the root mean square error and (2) minimizing the number of wells. The non-dominated sorting genetic algorithm (NSGA-II) was applied to optimize the network. Inverse distance weighting interpolation was used in NSGA-II to estimate the groundwater levels while optimizing network design. Results of the study indicate that the proposed method successfully optimizes the design of groundwater monitoring networks that achieve accuracy and cost-effectiveness.

scholarly journals Are Groundwater Monitoring Networks Economical? Cost-Benefit Analysis on the Long-Term Groundwater Supply Project of South Korea

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 753 ◽  
Author(s):  
Sun G. Kim ◽  
Gyoo-Bum Kim
Keyword(s):  
South Korea ◽  
Groundwater Monitoring ◽  
Cost Benefit Analysis ◽  
Monitoring Network ◽  
Pairwise Comparison ◽  
Cost Benefit ◽  
Monitoring Networks ◽  
Benefit Analysis ◽  
Groundwater Supply ◽  
Economic Background

Analyses of the relative economic efficiencies of surface-water and groundwater are important for policy-makers in many water-stressed countries. Groundwater is becoming an increasingly attractive and viable option as a supplementary water source, but its economic background must be understood before implementation. Employing the basic frameworks of the British and US Geological Surveys, we examined the economic viability of groundwater monitoring networks in South Korea, based on an analytic hierarchy process (AHP), pairwise comparison, and cost–benefit analysis. The total cost including installation, maintenance and servicing over the next 50 years is estimated to be US$ 0.79 billion, while the benefits are valued at US$ 2.31 billion. The monitoring network should provide benefits worth 292% of the costs, with the monitoring project thus clearly being economically viable. A sensitivity analysis indicates that the monitoring project is still economical, even if the network installation schedule is delayed slightly. As this study combines both economic and scientific perspectives, it might provide a concrete economic background for implementing groundwater utilization projects elsewhere.

scholarly journals Shallow groundwater quality in Latvia and Denmark

2007 ◽  
Vol 13 ◽  
pp. 65-68 ◽  
Author(s):  
Edmund Gosk ◽  
Igors Levins ◽  
Lisbeth Flindt Jørgensen
Keyword(s):  
Groundwater Quality ◽  
Environmental Protection Agency ◽  
Groundwater Monitoring ◽  
Shallow Groundwater ◽  
Monitoring Network ◽  
Monitoring Programme ◽  
Geological Survey ◽  
Detailed Knowledge ◽  
Comprehensive Overview ◽  
Few Data

Experience and results from the Danish groundwater monitoring programme that has been carried out systematically since 1990, have been used in a co-operative project between Latvia and Denmark. The main objective of the project was to obtain more detailed knowledge of the shallow Latvian groundwater, to optimise the Latvian groundwater monitoring programme and to support the implementation of Euro pean legislation such as the Water Framework Directive, the Nitrate Directive and the Groundwater Directive in Latvia. Comprehensive summaries describing the methodology of groundwater quality monitoring as well as the major results from the Danish groundwater monitoring network can be found in GEUS (2005) and Stockmarr (2005). Until recently only few data on Latvian groundwater quality were available, but in a project running from 2003 to 2006, 800 samples from groundwater, springs and drains have been analysed for a large number of components resulting in a comprehensive overview of the status of Latvian groundwater (Fig. 1; Gosk et al. 2006). The project Agricultural influence on groundwater in Latvia was carried out by the State Geological Survey of Latvia and the Geological Survey of Denmark and Greenland (GEUS) and was supported by the Danish Environmental Protection Agency within the framework of the DANCEE programme (Danish Co-operation for Environment in Eastern Europe). As a spin-off of the project this paper compares groundwater quality in the two countries.

scholarly journals Pilot-Scale Groundwater Monitoring Network for Earthquake Surveillance and Forecasting Research in Korea

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2448
Author(s):  
Hyun A Lee ◽  
Se-Yeong Hamm ◽  
Nam C. Woo
Keyword(s):  
Groundwater Monitoring ◽  
Continuous Monitoring ◽  
Monitoring Network ◽  
Pilot Scale ◽  
Water Levels ◽  
Monitoring Networks ◽  
The Public ◽  
High Potentials ◽  
Groundwater Monitoring Network ◽  
Precursory Change

Although there is skepticism about the likelihood of predictive success, research on the prediction of an earthquake through precursory changes in natural parameters, including groundwater, has continued for decades. One of the promising precursors is the changes in groundwater, i.e., the level and composition of groundwater, and the monitoring networks are currently operated to observe earthquake-related changes in several countries situated at the seismically active zone. In Korea, the seismic hazards had not been significantly considered for decades since the seismic activity was relatively low; however, the public demands on the management and prediction of earthquakes were raised by two moderate-size earthquakes which occurred in 2016 and 2017. Since then, a number of studies that were initiated in Korea, including this study to establish a pilot-scale groundwater-monitoring network, consisted of seven stations. The network is aimed at studying earthquake-related groundwater changes in the areas with relatively high potentials for earthquakes. Our study identified a potential precursory change in water levels at one particular station between 2018 and 2019. The observed data showed that most monitoring stations are sufficiently isolated from the diurnal natural/artificial activities and a potential precursory change of water level was observed at one station in 2018. However, to relate these abnormal changes to the earthquake, continuous monitoring and analysis are required as well as the aid of other precursors including seismicity and geodetic data.

Effect of Distance to Orthogonal Buffer Zone Boundary on Contaminant Detection Well Layout at Solid Waste Impoundment

2021 ◽  
Vol 47 (1) ◽  
pp. 131-136
Author(s):  
Paul F. Hudak
Keyword(s):  
Groundwater Monitoring ◽  
Buffer Zone ◽  
Point Sources ◽  
Monitoring Networks ◽  
Zone Boundary ◽  
Monitoring Wells ◽  
Contaminant Detection ◽  
Rate Of Increase ◽  
Minimum Number ◽  
Small Point

A modeling investigation examined the effect of nearby buffer zone (property) boundaries on passive groundwater monitoring networks at a hypothetical landfill. Network designs considered the unknown location of a small point source in the landfill's liner, contaminant concentrations simulated in groundwater, and the need to detect a contaminant before its concentration at a buffer zone boundary reached a certain threshold. Several buffer zone boundaries were considered, ranging from 6 m to 51 m downgradient of the landfill's downgradient corner. Monitoring wells in each network were located 5 m downgradient of the landfill's downgradient boundaries. Both the minimum number of wells, and the rate of increase in number of wells, increased with proximity of the landfill's downgradient corner to the buffer zone boundary. Based on out-comes of this study, landfill designers should consider a possible need for many closely-spaced detection wells for small potential point sources and close buffer zone boundaries.

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