Mineralogical analysis of a long-term groundwater system in Tono and Horonobe area, Japan

2010 ◽  
pp. 97-108 ◽  
Keyword(s):  
Mineralogical Analysis ◽  
Groundwater System

scholarly journals Assessing the long-term sustainability of the groundwater resources in the Bacchiglione basin (Veneto, Italy) with the Mann–Kendall test: suggestions for higher reliability

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Mara Meggiorin ◽  
Giulia Passadore ◽  
Silvia Bertoldo ◽  
Andrea Sottani ◽  
Andrea Rinaldo
Keyword(s):  
Groundwater Level ◽  
Water Cycle ◽  
Groundwater Resources ◽  
Sustainable Use ◽  
Kendall Test ◽  
Groundwater System ◽  
Aquifer System ◽  
Mann Kendall Test ◽  
Status Assessment

The social, economic, and ecological importance of the aquifer system within the Bacchiglione basin (Veneto, IT) is noteworthy, and there is considerable disagreement among previous studies over its sustainable use. Investigating the long-term quantitative sustainability of the groundwater system, this study presents a statistical methodology that can be applied to similar cases. Using a combination of robust and widely used techniques, we apply the seasonal Mann–Kendall test and the Sen’s slope estimator to the recorded groundwater level timeseries. The analysis is carried out on a large and heterogeneous proprietary dataset gathering hourly groundwater level timeseries at 79 control points, acquired during the period 2005–2019. The test identifies significant decreasing trends for most of the available records, unlike previous studies on the quantitative status of the same resource which covered the domain investigated here for a slightly different period: 2000–2014. The present study questions the reason for such diverging results by focusing on the method’s accuracy. After carrying out a Fourier analysis on the longest available timeseries, for studies of groundwater status assessment this work suggests applying the Mann–Kendall test to timeseries longer than 20 years (because otherwise the analysis would be affected by interannual periodicities of the water cycle). A further analysis of two 60-year-long monthly timeseries between 1960 and 2020 supports the actual sustainable use of the groundwater resource, the past deployment of the groundwater resources notwithstanding. Results thus prove more reliable, and meaningful inferences on the longterm sustainability of the groundwater system are possible.

Long-term monitoring of coastal saltwater intrusion using the geoelectrical monitoring system SAMOS

2021 ◽  
Author(s):  
Michael Grinat ◽  
Mathias Ronczka ◽  
Thomas Günther ◽  
Dieter Epping ◽  
Vitali Kipke ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Monitoring System ◽  
North Sea ◽  
Early Warning ◽  
Groundwater System ◽  
Transition Zones ◽  
The North ◽  
The North Sea ◽  
Local Water

<p>Efficient groundwater management is the key to a sustainable use of freshwater aquifers. In the coastal areas worldwide, saltwater intrusions caused by sea-level rise, overuse of freshwater resources and changing groundwater recharge is a major threat to the availability of freshwater. A reduced groundwater recharge combined with an increased extraction can lead to vertical upconing or lateral movement of the freshwater-saltwater transition zones, therefore reducing the local freshwater resources. Long-term and continuous observation of the freshwater-saltwater transition zones is crucial to implement early warning procedures, yields more detailed insight into the groundwater system and therefore enables early adjustment and adaptation of extraction rates if needed.</p><p>The SAltwater MOnitoring System (SAMOS) consists of two main parts: a vertical electrode chain of steel ring electrodes permanently installed in a backfilled borehole and a measuring system at the surface. The number of electrodes (commonly about 80) and distance between adjacent electrodes (commonly about 25 cm) is generally flexible. The chain of electrodes is connected to a lightweight and small resistivity meter (LGM, 4-Point light 10W). Thanks to the maximum output current of 100 mA and a voltage of 380 V a low power consumption is achieved and long-term and autonomous monitoring is enabled by solar panel based power supply. Furthermore, the system is designed to run predefined measurement protocols and transfers the data to a remote server immediately after a measurement is performed. SAMOS is commonly installed in the transition zone between fresh- and saltwater allowing the detection of very slight resistivity changes (less than 1 Ohmmeter). While first systems were completely manufactured by LIAG, the latest subsurface systems were built by Solexperts which allowed us to include temperature sensors.</p><p>We present data from four SAMOS systems currently running at different locations. Two of them are installed in the central part of the freshwater lense of the North Sea island Borkum (in cooperation with Stadtwerke Borkum) in depths between 44 m and 65 m below the surface, close to freshwater wells of the local water supplier, thus monitoring the overall groundwater system and delivering data since 2009. Even though measurements immediately after the installation are disturbed by the drilling process and an adjustment to undisturbed natural conditions is observed, adapted inversion schemes allow to use all data. While in most cases only slight resistivity changes are observed up to now, at some depths larger seasonal resistivity changes occur at one Borkum site that can mostly be explained by changes of the groundwater recharge rate and changing pumping activities in a water catchment area. Two further systems have been installed in 2018 and 2020. One is located behind the dune line at the edge of the freshwater lense on the North Sea island Spiekeroog. In cooperation with the local water supply company OOWV (Oldenburg-Ostfriesischer Wasserverband) another system for their groundwater extraction fields is installed near Jever several kilometers from the coast-line used for early warning.</p>

National scale climate change impact assessment – investigating long-term variations in the climate change signal for groundwater levels across geologies and aquifers

2020 ◽  
Author(s):  
Ida Bjørnholt Karlsson ◽  
Luc Taliesin Eisenbruchner ◽  
Jacob Kidmose ◽  
Anker Lajer Højberg
Keyword(s):  
Climate Change ◽  
Hydrological Model ◽  
Climate Model ◽  
Climate Change Signal ◽  
Special Focus ◽  
Groundwater System ◽  
Phreatic Surface ◽  
Near Surface ◽  
Marine Sand

<p>The effect of climate change on groundwater system is still not extensively understood. Studies often focuses on changes in recharge to the groundwater system but rarely investigate the resulting impacts on hydraulic head levels especially the spatial distribution of the change across larger domains.</p><p>Only few countries in the world have access to a detailed national hydrological model, and fewer still have done nationwide climate change assessments. This study applies a combination of the newest updated national hydrological model for the entire Denmark (the DK-model 2019, http://dk.vandmodel.dk/in-english/) and 20 climate model projections from the Euro-Cordex project (Jacob et al., 2014) for the RCP4.5 and the RCP8.5 emission scenario (4 and 16 runs respectively). The climate dataset are bias-corrected for the Danish area using double Gamma distribution-based scaling for temperature and precipitation (Pasten-Zapata et al., 2019).</p><p>This large dataset is used to evaluate the distribution of the magnitude and direction of changes with special focus on the phreatic surface and the main water-bearing groundwater layers for drinking water consumption in Denmark. The spatial variations in the near-surface impact signal across the entire country is also analyzed, as different Quaternary geology is represented from sandy layers in the west to moraine clay tills in the east and marine sand and clay to the north. The climate dataset is a successive time series from 1970ties to the end of the century and thus also enables an analysis of long-term changes in the state of the groundwater system and aquifers. </p><p> </p><p> </p><p>Jacob, D., Petersen, J., Eggert, B., Alias, A., Christensen, O. B., Bouwer, L. M., Braun, A., Colette, A., Déqué, M., Georgievski, G., Georgopoulou, E., Gobiet, A., Menut, L., Nikulin, G., Haensler, A., Hempelmann, N., Jones, C., Keuler, K., Kovats, S., Kröner, N., Kotlarski, S., Kriegsmann, A., Martin, E., van Meijgaard, E., Moseley, C., Pfeifer, S., Preuschmann, S., Radermacher, C., Radtke, K., Rechid, D., Rounsevell, M., Samuelsson, P., Somot, S., Soussana, J.-F., Teichmann, C., Valentini, R., Vautard, R., Weber, B., and Yiou, P.: EURO-CORDEX: new high-resolution climate change projections for European impact research, Regional Environmental Change, 14, 563-578, 10.1007/s10113-013-0499-2, 2014.</p><p>Pasten-Zapata, E., Sonnenborg, T. O., and Refsgaard, J. C.: Climate change: Sources of uncertainty in precipitation and temperature projections for Denmark, Geological Survey of Denmark and Greenland Bulletin 43, e2019430102-2019430101-e2019430102-2019430106, https://doi.org/10.34194/GEUSB-201943-01-02 2019.</p><p> </p>

Laboratory Investigation into Applicability of Red Sand-Bitumen Mixture as Landfill Liner

2012 ◽  
Vol 178-181 ◽  
pp. 1022-1025
Author(s):  
Stephen K. Kariuki ◽  
Mohamed A. Shahin
Keyword(s):  
Hydraulic Conductivity ◽  
Environmental Impact ◽  
Contaminant Transport ◽  
Laboratory Investigation ◽  
Cost Effective ◽  
Groundwater System ◽  
Landfill Liner ◽  
Barrier Materials ◽  
Limit Value

Liners play an important role in control of contaminant transport to ensure negligible long-term environmental impact. Fill liners have therefore been designed with the requirement to perform as barriers that separate leachate from the groundwater system. Liners have been traditionally designed using clay or geo-membranes and geo-synthetics. However, these traditional methods are becoming increasingly uneconomical and out of reach of most undeveloped countries. Development of innovative barriers and barrier materials is thus essential to provide more sustainable and cost effective solutions. The aim of this paper is to investigate the feasibility of using a new mixture of red sand-bitumen, as a landfill liner. The results indicate that the mixture meets the limit value of hydraulic conductivity for waste landfills of 1 × 10−9 m/s and that the mixture has a high potential to be used in landfill applications.

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