Numerical classification of saline groundwater chemistry in the Murrumbidgee irrigation area

Soil Research ◽  
1987 ◽  
Vol 25 (4) ◽  
pp. 337 ◽  
Author(s):  
BG Williams ◽  
JK Ward ◽  
L Belbin
Keyword(s):  
Chemical Composition ◽  
Geographical Distribution ◽  
Shallow Groundwater ◽  
Numerical Classification ◽  
Saturation Indices ◽  
Saline Groundwater ◽  
Irrigation Area ◽  
Groundwater Samples ◽  
Total Soluble Salt

Numerical classification techniques were used to examine the chemical composition of 169 shallow groundwater samples in relation to their geographical distribution within the Murrumbidgee Irrigation Area. The ionic proportions are very similar throughout the whole area, but the total soluble salt concentrations are very variable. The classification was more coherent when primary variables were used rather than derived variables such as Saturation Indices.

scholarly journals Elevated levels of diesel range organic compounds in groundwater near Marcellus gas operations are derived from surface activities

2015 ◽  
Vol 112 (43) ◽  
pp. 13184-13189 ◽  
Author(s):  
Brian D. Drollette ◽  
Kathrin Hoelzer ◽  
Nathaniel R. Warner ◽  
Thomas H. Darrah ◽  
Osman Karatum ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Noble Gas ◽  
Marcellus Shale ◽  
Health And Safety ◽  
Shallow Groundwater ◽  
High Volume ◽  
Gas Extraction ◽  
Environmental Health And Safety ◽  
Saline Groundwater ◽  
Groundwater Samples

Hundreds of organic chemicals are used during natural gas extraction via high-volume hydraulic fracturing (HVHF). However, it is unclear whether these chemicals, injected into deep shale horizons, reach shallow groundwater aquifers and affect local water quality, either from those deep HVHF injection sites or from the surface or shallow subsurface. Here, we report detectable levels of organic compounds in shallow groundwater samples from private residential wells overlying the Marcellus Shale in northeastern Pennsylvania. Analyses of purgeable and extractable organic compounds from 64 groundwater samples revealed trace levels of volatile organic compounds, well below the Environmental Protection Agency’s maximum contaminant levels, and low levels of both gasoline range (0–8 ppb) and diesel range organic compounds (DRO; 0–157 ppb). A compound-specific analysis revealed the presence of bis(2-ethylhexyl) phthalate, which is a disclosed HVHF additive, that was notably absent in a representative geogenic water sample and field blanks. Pairing these analyses with (i) inorganic chemical fingerprinting of deep saline groundwater, (ii) characteristic noble gas isotopes, and (iii) spatial relationships between active shale gas extraction wells and wells with disclosed environmental health and safety violations, we differentiate between a chemical signature associated with naturally occurring saline groundwater and one associated with alternative anthropogenic routes from the surface (e.g., accidental spills or leaks). The data support a transport mechanism of DRO to groundwater via accidental release of fracturing fluid chemicals derived from the surface rather than subsurface flow of these fluids from the underlying shale formation.

An Investigation of the Quantity, Quality and Sources of Groundwater Seepage into the St. Clair River near Sarnia, Ontario, Canada

1986 ◽  
Vol 21 (3) ◽  
pp. 351-367 ◽  
Author(s):  
Michael Sklash ◽  
Sharon Mason ◽  
Suzanne Scott ◽  
Chris Pugsley
Keyword(s):  
Electrical Conductivity ◽  
River Water ◽  
Organic Contaminants ◽  
Shallow Groundwater ◽  
Seepage Rate ◽  
Groundwater Seepage ◽  
Seepage Meters ◽  
Groundwater Samples ◽  
Hydraulic Gradients ◽  
Unidentified Source

Abstract We used seepage meters and minipiezometers to survey a 100 m by 7 km band of streambed of the St. Clair River near Sarnia, Ontario, Canada, to determine the quantity, quality, and sources of groundwater seepage into the river. The average observed seepage rate, 1.4 x 10−8 m3/s/m2, suggests higher than expected hydraulic conductivities and/or hydraulic gradients in the streambed. We found detectable levels of some organic contaminants in streambed groundwater samples from 1.0 and 1.5 m depths, however , concentrations did not exceed drinking water guidelines. Our isotopic and electrical conductivity data indicate that: (l) the streambed groundwater is not just river water, (2) groundwater from the “freshwater aquifer” at the base of the overburden Is not a significant component of the streambed groundwater, (3) some of the streambed groundwater is partially derived from a shallow groundwater flow system, and (4) an unidentified source of water with low tritium, river water-like δ18O, and very high electrical conductivity, contributes to the streambed groundwater.

Numerical classification of French vegetation of Carici caryophylleae – Genistetea lobelii J.-C. Klein 1972

2021 ◽  
Vol 42 ◽  
pp. e68062
Author(s):  
Pauline Delbosc ◽  
Mathieu Le Dez ◽  
Jean-Bernard Bouzillé ◽  
Kevin Cianfaglione ◽  
Frédéric Bioret
Keyword(s):  
Expert System ◽  
Dominant Species ◽  
Numerical Classification ◽  
Distribution Map ◽  
Diagnostic Species ◽  
Plant Associations ◽  
Formal Definitions ◽  
Twinspan Classification ◽  
New Association

Carici-Genistetea lobelii Klein 1972 corresponds to cyrno-sardinian oromediterranean cushion scrub and related grasslands. In France, this class is only present in Corsica and the syntaxonomic scheme is debated among phytosociologists. The aim of this paper is to highlight the main plant associations of Carici-Genistetea lobelii Klein 1972 and to define the diagnostic species for each phytosociological unit. We compiled 519 vegetation plots and we applied EuropeanVegetationChecklist expert system for the classes of European vegetation to retain only vegetation plots belonging to Carici-Genistetea lobelii. We obtained a dataset with 189 vegetation plots and we classified them with Modified TWINSPAN classification. Our analyses recognized 6 plant associations and 3 sub-associations already described in the literature; and to describe a new alliance corresponding to the supra-mediterranean vegetations (Genistion salzmannii), a new association (Brimeuro fastigiatae-Juniperetum nanae) and its sub-association (alnetosum suaveolentis). For each of them, we identified diagnostic, constant and dominant species and produced their distribution map. Formal definitions were then written for each phytosociological unit (from subassociation to class) and grouped in an expert system to automatically classify the vegetations of Carici-Genistetea lobelii.

Numerical Classification of Thermus Isolates from Globally Distributed Hot Springs

1989 ◽  
Vol 11 (3) ◽  
pp. 250-256 ◽  
Author(s):  
J. Andrew Hudson ◽  
Hugh W. Morgan ◽  
Roy M. Daniel
Keyword(s):  
Hot Springs ◽  
Numerical Classification ◽  
Globally Distributed

scholarly journals Chemical composition of groundwaters in the Hornsund region, southern Spitsbergen

2012 ◽  
Vol 44 (1) ◽  
pp. 117-130 ◽  
Author(s):  
Tomasz Olichwer ◽  
Robert Tarka ◽  
Magdalena Modelska
Keyword(s):  
Chemical Composition ◽  
Ion Exchange ◽  
Shallow Groundwater ◽  
Mineralogical Composition ◽  
Deep Groundwater ◽  
Exchange Processes ◽  
Groundwater Circulation ◽  
Initial Chemical Composition ◽  
The University ◽  
Intermediate System

Chemical composition of groundwaters was investigated in the region of the Hornsund fjord (southern Spitsbergen). The investigations were conducted during polar expeditions organized by the University of Wroclaw in two summer seasons of 2003 and 2006. Three zones of groundwater circulation: suprapermafrost, intrapermafrost and subpermafrost, were identified in areas of perennial permafrost in the region of Hornsund. The zone of shallow circulation occurs in non-glaciated (suprapermafrost) and subglacial areas. In this zone, the chemical composition of groundwater originates from initial chemical composition of precipitation, mineralogical composition of bedrock, oxidation of sulphides and dissolution of carbonates. The intermediate system of circulation is connected with water flow inside and below perennial permafrost (intrapermafrost and subpermafrost). In this zone, the chemical composition of groundwater is mainly controlled by dissolution of carbonates, ion exchange processes involving Ca2+ substitution by Na+, and oxidation of sulphides under oxygen-depleted conditions. The subpermafrost zone (deep groundwater circulation) occurs in deep-tectonic fractures, which are likely conduits for the descent of shallow groundwater to deeper depths. In this zone, the groundwater shows lower mineralization comparing to intrapermafrost zone and has a multi-ion nature Cl–HCO3–Na-Ca–Mg.

scholarly journals Irrigation Salinity Risk Assessment and Mapping in Arid Oasis, Northwest China

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 966 ◽  
Author(s):  
Jumeniyaz Seydehmet ◽  
Guang-Hui Lv ◽  
Abdugheni Abliz ◽  
Qing-Dong Shi ◽  
Abdulla Abliz ◽  
...  
Keyword(s):  
Risk Index ◽  
Shallow Groundwater ◽  
Northwest China ◽  
High Elevation ◽  
Analytic Hierarchy ◽  
Environmental Threat ◽  
Total Soluble Salt ◽  
Composite Risk ◽  
Risk Parameters ◽  
Grey Relational

Irrigation salinity is a common environmental threat for sustainable development in the Keriya Oasis, arid Northwest China. It is mainly caused by unreasonable land management and excessive irrigation. The aim of this study was to assess and map the salinity risk distribution by developing a composite risk index (CRI) for seventeen risk parameters from traditional and scientific fields, based on maximizing deviation method and analytic hierarchy process, the grey relational analysis and the Pressure-State-Response (PSR) sustainability framework. The results demonstrated that the northern part of the Shewol and Yeghebagh village has a very high salinity risk, which might be caused by flat and low terrain, high subsoil total soluble salt, high groundwater salinity and shallow groundwater depth. In contrast, the southern part of the Oasis has a low risk of salinity because of high elevation, proper drainage conditions and a suitable groundwater table. This achievement has shown that southern parts of the Oasis are suitable for irrigation agriculture; for the northern area, there is no economically feasible solution but other areas at higher risk can be restored by artificial measures. Therefore, this study provides policy makers with baseline data for restoring the soil salinity within the Oasis.

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