Exploring the hydrogeological functioning and microbial habitats of the deep hillslope aeration zone in limestone-mudrock alternations

2020 ◽  
Author(s):  
Robert Lehmann ◽  
Cassandre Sara Lazar ◽  
Kirsten Küsel ◽  
Kai Uwe Totsche
Keyword(s):  
Groundwater Quality ◽  
Environmental Changes ◽  
Earth Science ◽  
Groundwater Resources ◽  
Archaeal Community ◽  
Critical Zone ◽  
Aeration Zone ◽  
Monitoring Wells ◽  
Rock Fragments ◽  
Directional Flow

<p>The aeration zone beneath topographic groundwater recharge areas, comprising variably water-saturated soil, regolith and bedrock is a typically large but hardly explored compartment of the Critical Zone. Fluid and matter exchange within the deep hillslope aeration zone, the dynamics of its diverse microbial dwellers and their contribution for subsurface matter cycling and groundwater quality are widely unknown. In the Hainich Critical Zone Exploratory (Collaborative Research Center AquaDiva, Küsel et al., 2016), we accessed the aeration zone and groundwater resources in fractured limestone-mudstone alternations by exploratory drillings and hillslope monitoring wells. Multi-year groundwater sampling, environmental monitoring, drill core and petrological analyses revealed a multi-storey architecture of the aeration zone, covering perched water bodies and multi-directional flow phenomena (Lehmann and Totsche 2020). In a ~50 m deep well that underwent pronounced seasonal head fluctuation up to 25 m of oligotrophic groundwater, we incubated bedrock fragments that mimicked large fracture habitats and monitored the dynamic environmental conditions in the fractured mixed carbonate-/siliciclastic alternations as well. During groundwater-saturated colonization, successional exposure to seasonal de-saturation and re-saturation, we analyzed the bacterial and archaeal 16S rRNA diversity and found a diverse bacterial, and less diverse archaeal community, both including persistent genera that withstood the harsh environmental changes. In accordance with mature fracture-surfaces (drill cores), the colonized rock fragments were dominated by Gammaproteobacteria. General compositional differences to communities within the phreatic zone (i.e. groundwater and rock matrices), and shallow sources in soil, suggest a distinct subsurface microbiome that is hardly represented by ecological surveys that utilize groundwater or rock samples.</p><p> </p><p>References:</p><p>Küsel, K., Totsche, K. U., Trumbore, S. E., Lehmann, R., Steinhäuser, C., Herrmann, M. (2016). How deep can surface signals be traced in the critical zone? Merging biodiversity with biogeochemistry research in a central German Muschelkalk landscape. Frontiers in Earth Science 4 (32). https://doi.org/10.3389/feart.2016.00032</p><p>Lehmann, R., Totsche, K. U. (2020). Multi-directional flow dynamics shape groundwater quality in sloping bedrock strata. Journal of Hydrology 580. https://doi.org/10.1016/j.jhydrol.2019.124291</p>

scholarly journals Susceptibility Prediction of Groundwater Hardness Using Ensemble Machine Learning Models

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2770
Author(s):  
Amirhosein Mosavi ◽  
Farzaneh Sajedi Hosseini ◽  
Bahram Choubin ◽  
Mahsa Abdolshahnejad ◽  
Hamidreza Gharechaee ◽  
...  
Keyword(s):  
Machine Learning ◽  
Groundwater Quality ◽  
Groundwater Resources ◽  
Boosted Regression Trees ◽  
Susceptibility Map ◽  
Monitoring Wells ◽  
Modeling Process ◽  
Ensemble Machine Learning ◽  
Long Time ◽  
Groundwater Quality Monitoring

Groundwater resources, unlike surface water, are more vulnerable to disturbances and contaminations, as they take a very long time and significant cost to recover. So, predictive modeling and prevention strategies can empower policymakers for efficient groundwater governance through informed decisions and recommendations. Due to the importance of groundwater quality modeling, the hardness susceptibility mapping using machine learning (ML) models has not been explored. For the first time, the current research aimed to predict groundwater hardness susceptibility using the ML models. The performance of two ensemble models of boosted regression trees (BRT) and random forest (RF) is investigated through the arrangement of a comparative study with multivariate discriminant analysis (MDA). According to the hardness values in 135 groundwater quality monitoring wells, the hard and soft water are determined; then, 11 predictor variables including distance from the sea (DFS), land use, elevation, distance from the river (DFR), depth to groundwater (DTGW), pH, precipitation (PCP), evaporation (E), groundwater level (GWL), curvature, and lithology are used for predicting the groundwater hardness susceptibility map. Results indicated that the variables of DFR, DTGW, elevation, and DFS had a higher contribution to the modeling process. So, the high harness areas are mostly related to low elevations, low DTGW, and proximity to river and sea, which facilitate the percolation conditions for minerals containing calcium or magnesium into groundwater.

scholarly journals Seismically induced changes in groundwater levels and temperatures following the ML5.8 (ML5.1) Gyeongju earthquake in South Korea

2021 ◽  
Author(s):  
Soo-Hyoung Lee ◽  
Jae Min Lee ◽  
Sang-Ho Moon ◽  
Kyoochul Ha ◽  
Yongcheol Kim ◽  
...  
Keyword(s):  
South Korea ◽  
Groundwater Level ◽  
Seismic Waves ◽  
Groundwater Resources ◽  
Fluid Pressure ◽  
Water Levels ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Gyeongju Earthquake

AbstractHydrogeological responses to earthquakes such as changes in groundwater level, temperature, and chemistry, have been observed for several decades. This study examines behavior associated with ML 5.8 and ML 5.1 earthquakes that occurred on 12 September 2016 near Gyeongju, a city located on the southeast coast of the Korean peninsula. The ML 5.8 event stands as the largest recorded earthquake in South Korea since the advent of modern recording systems. There was considerable damage associated with the earthquakes and many aftershocks. Records from monitoring wells located about 135 km west of the epicenter displayed various patterns of change in both water level and temperature. There were transient-type, step-like-type (up and down), and persistent-type (rise and fall) changes in water levels. The water temperature changes were of transient, shift-change, and tendency-change types. Transient changes in the groundwater level and temperature were particularly well developed in monitoring wells installed along a major boundary fault that bisected the study area. These changes were interpreted as representing an aquifer system deformed by seismic waves. The various patterns in groundwater level and temperature, therefore, suggested that seismic waves impacted the fractured units through the reactivation of fractures, joints, and microcracks, which resulted from a pulse in fluid pressure. This study points to the value of long-term monitoring efforts, which in this case were able to provide detailed information needed to manage the groundwater resources in areas potentially affected by further earthquakes.

Archaeal community in a human-disturbed watershed in southeast China: diversity, distribution, and responses to environmental changes

2016 ◽  
Vol 100 (10) ◽  
pp. 4685-4698 ◽  
Author(s):  
Anyi Hu ◽  
Hongjie Wang ◽  
Jiangwei Li ◽  
Jing Liu ◽  
Nengwang Chen ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Archaeal Community ◽  
Southeast China

scholarly journals Groundwater management based on monitoring of land subsidence and groundwater levels in the Kanto Groundwater Basin, Central Japan

2015 ◽  
Vol 372 ◽  
pp. 53-57 ◽  
Author(s):  
K. Furuno ◽  
A. Kagawa ◽  
O. Kazaoka ◽  
T. Kusuda ◽  
H. Nirei
Keyword(s):  
Sea Level ◽  
Groundwater Resources ◽  
Sustainable Use ◽  
Ground Subsidence ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Chiba Prefecture ◽  
Groundwater Basin ◽  
Term Monitoring

Abstract. Over 40 million people live on and exploit the groundwater resources of the Kanto Plain. The Plain encompasses metropolitan Tokyo and much of Chiba Prefecture. Useable groundwater extends to the base of the Kanto Plain, some 2500 to 3000 m below sea level. Much of the Kanto Plain surface is at sea level. By the early 1970s, with increasing urbanization and industrial expansion, local overdraft of groundwater resources caused major ground subsidence and damage to commercial and residential structures as well as to local and regional infrastructure. Parts of the lowlands around Tokyo subsided to 4.0 m below sea level; particularly affected were the suburbs of Funabashi and Gyotoku in western Chiba. In the southern Kanto Plain, regulations, mainly by local government and later by regional agencies, led to installation of about 500 monitoring wells and almost 5000 bench marks by the 1990's. Many of them are still working with new monitoring system. Long-term monitoring is important. The monitoring systems are costly, but the resulting data provide continuous measurement of the "health" of the Kanto Groundwater Basin, and thus permit sustainable use of the groundwater resource.

A GIS-based assessment of spatial groundwater quality for drinking purposes in Asmara City, Eritrea

2021 ◽  
Author(s):  
Kabral Mogos Asghede ◽  
Dawit Berhane Hagos
Keyword(s):  
Groundwater Quality ◽  
Potable Water ◽  
Critical Level ◽  
Groundwater Resources ◽  
Total Dissolved Solids ◽  
Total Hardness ◽  
Analysis Framework ◽  
Alternative Source ◽  
Drinking Purposes ◽  
Supply Problem

<p><strong>Abstract</strong>: Presently the water-supply problem in the Asmara area has reached to a critical level. Using a GIS-based method this study identifies the spatial variability of the groundwater quality in the Asmara Area which could be an alternative source. The results show that, the Total Dissolved Solids (TDS), Total Hardness (TH), Chloride (Cl<sup>-</sup>), Nitrates (NO<sub>3</sub><sup>-</sup>), Calcium (Ca), Magnesium (Mg), Sulphate (SO<sub>4</sub>) and pH are 791.71, 569.12, 124.41, 64.46, 155.60, 46.64, 159.26 and 7.72 mg/L, respectively. Moreover, the zone map of the developed groundwater quality shows that the potable water without treatment covers about 35%, and the potable water in the absence of better alternate sources covers about 58% of the total area. The remaining, 7.04% of the total, falls under non-potable groundwater quality. The verification of the spatialanalysis demonstrates that the framework is the first one in Eritrea and could be used as a potential prediction for the assessment of the spatial groundwater quality in the countries with further verification results. Hence, the delineation of groundwater quality zones and establishment of a GIS-based database will easily help the decision makersto monitor and plan the utilization of the groundwater resources in the study area.</p><p><strong>Keywords: </strong>Groundwater quality; physicochemical parameters; GIS spatial analysis; framework</p>

Data Analysis Protocol for Using Resistivity Array as an Early-Warning Wastewater Pond Leak Detector

2018 ◽  
Vol 23 (2) ◽  
pp. 251-260
Author(s):  
Bryan L. Woodbury ◽  
Roger A. Eigenberg ◽  
H. Gordon Minns ◽  
Pius M. Ndegwa
Keyword(s):  
Groundwater Quality ◽  
Calibration Method ◽  
Detection Sensitivity ◽  
Concentrated Animal Feeding Operations ◽  
Organic Salts ◽  
Animal Feeding Operations ◽  
Monitoring Wells ◽  
Potential Problems ◽  
A Site ◽  
Automated Software

Mineral and organic salts from beef manure in runoff alter the resistivity properties of soil and water. Typically, holding ponds are used to control runoff from concentrated animal feeding operations. The integrity of these holding ponds has come under increased scrutiny since subsurface leakage has the potential to affect soil and groundwater quality. Traditionally, leaks from holding ponds are detected by installing a series of monitoring wells at strategic locations near the pond to intercept any contaminants that reach groundwater. Monitoring wells are expensive to install, costly to sample, generate information that is difficult to interpret and can only warn of a leak after contamination of groundwater has already occurred. A method was developed to continually measure the soil quality around the perimeter of holding ponds. When a change is detected, a message can be sent to facility managers to alert them of potential problems. However, the analysis of the data generated by this new method can be difficult to interpret. A protocol was developed that has 1) a site-calibration method to tailor analysis for most geologic and geographic settings, 2) establishes statistical-based thresholds for detecting changes in soil and groundwater quality, 3) allows for detection sensitivity to be scaled, 4) provides a filter for reducing false-positive leak detections and 5) provides a consistent framework for regulatory reporting. The protocol is designed to be incorporated into automated software that can immediately notify pond managers of potential problems using currently available telecommunication technology.

Applications of ANN for Agriculture Using Remote Sensed Data

2022 ◽  
pp. 1008-1030
Author(s):  
Geetha M. ◽  
Asha Gowda Karegowda ◽  
Nandeesha Rudrappa ◽  
Devika G.
Keyword(s):  
Remote Sensing ◽  
Food Security ◽  
Environmental Changes ◽  
Earth Science ◽  
Yield Estimation ◽  
Government Organizations ◽  
Security Issues ◽  
Time Availability ◽  
Efficient Information ◽  
Indispensable Tool

Ever since the advent of modern geo information systems, tracking environmental changes due to natural and/or manmade causes with the aid of remote sensing applications has been an indispensable tool in numerous fields of geography, most of the earth science disciplines, defense, intelligence, commerce, economics, and administrative planning. Remote sensing is used in science and technology, and through it, an object can be identified, measured, and analyzed without physical presence for interpretation. In India remote sensing has been using since 1970s. One among these applications is the crop classification and yield estimation. Using remote sensing in agriculture for crop mapping, and yield estimation provides efficient information, which is mainly used in many government organizations and the private sector. The pivotal sector for ensuring food security is a major concern of interest in these days. In time, availability of information on agricultural crops is vital for making well-versed decisions on food security issues.

Spatial distribution of physico-chemical parameters for groundwater quality evaluation in a part of Satluj River Basin, India

2019 ◽  
Vol 19 (5) ◽  
pp. 1480-1490 ◽  
Author(s):  
Akshay Kumar Chaudhry ◽  
Kamal Kumar ◽  
Mohammad Afaq Alam
Keyword(s):  
Spatial Distribution ◽  
Groundwater Quality ◽  
Spatial Dependence ◽  
Groundwater Resources ◽  
Quality Parameters ◽  
Northern Region ◽  
Total Hardness ◽  
Data Set ◽  
Distribution Maps ◽  
Physico Chemical

Abstract The rising population, contamination and mismanagement of groundwater worldwide require sustainable management techniques and strategies to prevent misuse of groundwater resources especially in the semi-arid regions of the world. The aim of the present study is to assess the distribution of contaminants in groundwater at a spatial level by using a geostatistical method, namely ordinary kriging. For this, a physico-chemical parameter data set at 14 sampling locations for a period over 25 years was assessed. Three semi-variogram models, namely exponential, Gaussian and spherical, fitted well for the data set and were cross-validated using predictive statistics. Based on nugget/sill ratio, which characterizes the overall spatial dependence of water quality parameters, it was observed that, apart from nitrate, all the other parameters showed moderate to weak spatial dependence (i.e. total hardness), indicating significant influence of urbanization, fertilization and industrialization. Spatial distribution maps of all the parameters were generated. Concentration of most of the parameters reported high values in the northern region, while silicon dioxide and potassium recorded high values in the southern and central regions of the study area respectively. The study highlighted the depleting groundwater resources in various regions of the study area, indicating that the groundwater quality is in a declining state.

scholarly journals Contribution to the hydrogeology of Six Hills sandstone aquifer in East El-Oweinat area, south Western desert, Egypt

2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Saad Younes Ghoubachi
Keyword(s):  
Cross Sections ◽  
Land Reclamation ◽  
Groundwater Resources ◽  
Western Desert ◽  
Pumping Rate ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Sandstone Aquifer ◽  
Domestic Livestock ◽  
The Impact

El-Oweinat area is located in southwestern Egypt and is considered to be one of the new land reclamation projects in the Western Desert. The Nubian Sandstone aquifer has high potentiality and good groundwater quality. The results of geologic and hydrogeologic studies reveal that the Six Hills sandstone aquifer represents the sole groundwater resource used for all purposes (agriculture, drinking, domestic, livestock and poultry) in East El-Oweinat area. The Six Hills sandstone aquifer overlies directly the Precambrian basement rocks. The concerned aquifer exists under unconfined conditions as it is exposed on the surface. The hydrogeological cross sections show that the fully saturated thickness of the Six Hills sandstone aquifer ranges between 150.2 m and 651 m and increases towards the west. The groundwater generally flows towards the northeast direction with an average hydraulic gradient of 0.6 ‰. The calculated groundwater volume of the Six Hills sandstone aquifer in East El-Oweinat area (4,340 km2) reaches 350 bcm of fresh water. The comparison of the depth to water in the same monitoring wells during 14 years (2003 and 2016) reveals that the head decline rate in groundwater depths were ranging between 5 cm/year and 80 cm/year. The pumping rate increased from 600,000 m3/day in year 2003 to 3,600,000 m3/day in 2016. The average transmissivity attains 2,060 m2/day reflecting the high potential of the Six Hills sandstone aquifer in East El-Oweinat area. The groundwater flow model (MODFLOW) has been used to investigate the impact of groundwater withdrawal on groundwater levels for sustainable groundwater management. Four scenarios were applied to predict the probable head changes in the Six Hills sandstone aquifer and their impact on the availability of groundwater. The fourth scenario is recommended in order to sustain the groundwater resources in the study area and keep the drawdown rates in the range of 0.66 m/year through reducing the present discharging rates (10,000 m3/day/well) by about 40%.

scholarly journals Hydrogeochemical Characteristics and Groundwater Quality Evaluation Based on Multivariate Statistical Analysis

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2792
Author(s):  
Yunxu Chai ◽  
Changlai Xiao ◽  
Mingqian Li ◽  
Xiujuan Liang
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
Quality Evaluation ◽  
Control Mechanism ◽  
Groundwater Resources ◽  
Fuzzy Comprehensive Evaluation ◽  
Multivariate Statistical ◽  
Rock Interaction ◽  
Geological Conditions ◽  
Development And Management

Hydrogeochemical research and water quality evaluation are an important part of groundwater development and management projects in Dehui City, Jilin Province, China. We collected 217 groundwater samples in the study area and used two multivariate statistical methods, hierarchical cluster analysis and principal component analysis to classify groundwater; combined graphical method, piper diagram, and Gibbs diagram to characterize groundwater chemical types and distinguish the water chemical control mechanism; and fuzzy comprehensive evaluation method to evaluate groundwater quality. Three major categories have been identified. Most of the groundwater in the study area is Ca-HCO3 type water. The water chemistry control mechanism is determined to be based on water-rock interaction and less evaporation. From east to west in the study area, the total dissolved solids (TDS) gradually increased, and water quality gradually deteriorated. In the whole region, 79.26% of the groundwater is suitable for drinking. With Yinma River at the boundary, the water quality in the eastern part is excellent, while that in the southwest is poor. After appropriate treatment, it can be used in industry and agriculture. The excess NO3− is mainly affected by human activities. The unique geological conditions of the Songnen Plain result in an excess amount of Fe3+ and Mn2+ in some areas. This study determined the chemical characteristics of groundwater in the study area and distinguished water quality levels. The results will be helpful for the development and management of groundwater resources.

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