scholarly journals Karst Spring Recharge Areas and Discharge Relationship by Oxygen-18 and Deuterium Isotopes Analyses: A Case Study in Southern Latium Region, Italy

2020 ◽  
Vol 10 (5) ◽  
pp. 1882 ◽  
Author(s):  
Silvia Iacurto ◽  
Gerardo Grelle ◽  
Francesco Maria De Filippi ◽  
Giuseppe Sappa
Keyword(s):  
Probability Function ◽  
Isotope Composition ◽  
Groundwater Resources ◽  
Karst Aquifer ◽  
Cumulative Probability ◽  
Aquifer Recharge ◽  
Groundwater Samples ◽  
Simulated Distribution ◽  
Deuterium Isotopes

Karst aquifer recharge areas are usually difficult to identify because of the complexity of these aquifers’ characteristics. On the other hand, their identification is very important in the aim of protecting the groundwater resources that these aquifers host. Regarding this topic, this paper presents an approach aimed at identifying karst aquifer recharge areas by the application of oxygen-18 and deuterium isotopes composition of groundwater coupled with hydrological features. Oxygen-18 and deuterium isotope composition of Capodacqua di Spigno Spring, in the South of the Latium Region, has been applied with rainfall and discharge values related to the feeding aquifer of this spring. As δ18O and δ2H values of groundwater samples are natural tracers of the recharge area’s elevation, we propose a model, based on the distribution of the basin surfaces involved as recharge areas, in relation to elevations. The model estimates, for any discharge value, the percentage of the topographic area involved in the aquifer recharge. The setting up of this simulated distribution is supported by a Weibull cumulative probability function. The results show that the measured discharges increase as larger areas with lower elevations are involved in the recharge process.

scholarly journals Hydrochemical and multivariate analysis of groundwater quality in the northwest of Sinai, Egypt

2017 ◽  
Vol 15 (4) ◽  
pp. 644-657 ◽  
Author(s):  
M. F. El-Shahat ◽  
M. A. Sadek ◽  
W. M. Salem ◽  
A. A. Embaby ◽  
F. A. Mohamed
Keyword(s):  
Groundwater Quality ◽  
Groundwater Resources ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Human Consumption ◽  
Development Programs ◽  
Aquifer Recharge ◽  
Economic Activities ◽  
Groundwater Samples ◽  
Principal Factors

The northwestern coast of Sinai is home to many economic activities and development programs, thus evaluation of the potentiality and vulnerability of water resources is important. The present work has been conducted on the groundwater resources of this area for describing the major features of groundwater quality and the principal factors that control salinity evolution. The major ionic content of 39 groundwater samples collected from the Quaternary aquifer shows high coefficients of variation reflecting asymmetry of aquifer recharge. The groundwater samples have been classified into four clusters (using hierarchical cluster analysis), these match the variety of total dissolvable solids, water types and ionic orders. The principal component analysis combined the ionic parameters of the studied groundwater samples into two principal components. The first represents about 56% of the whole sample variance reflecting a salinization due to evaporation, leaching, dissolution of marine salts and/or seawater intrusion. The second represents about 15.8% reflecting dilution with rain water and the El-Salam Canal. Most groundwater samples were not suitable for human consumption and about 41% are suitable for irrigation. However, all groundwater samples are suitable for cattle, about 69% and 15% are suitable for horses and poultry, respectively.

scholarly journals The groundwater quality of Aruba, Bonaire and Curaçao: a hydrogeochemical study

2000 ◽  
Vol 79 (4) ◽  
pp. 459-466 ◽  
Author(s):  
M.H.G. van Sambeek ◽  
H.G.M. Eggenkamp ◽  
M.J.M. Vissers
Keyword(s):  
Groundwater Quality ◽  
Urban Areas ◽  
Isotope Composition ◽  
Groundwater Resources ◽  
Agricultural Waste ◽  
Poor Quality ◽  
Anthropogenic Influences ◽  
Calcite Dissolution ◽  
Caribbean Islands ◽  
Groundwater Samples

AbstractThe Groundwater resources on the Caribbean Islands of Aruba, Bonaire and Curaçao are limited and of poor quality. The groundwater of the islands is brackish, due to both seawater mixing and the semi-arid climate of the islands. Two hundred and thirty water samples were collected to relate chemical variations in the groundwater of the three islands to the underlying differences in geology, and to define the natural versus anthropogenic influences. Both the chemical and isotopic (δ180, δD, and δ37Cl) compositions of samples were determined.Several geochemical processes are recognised in the chemistry of the groundwater samples. The most important processes are calcite dissolution, cation exchange, silicate weathering and potassium fixation. In (sub)urban areas anthropogenic influences affect the groundwater quality: high nitrate concentrations were measured. Infiltrating domestic and agricultural (waste)water replenishes the aquifer, and has a desalinization effect on the groundwater quality. This phenomenon is primarily seen on Curaçao, the most populated island.Oxygen and hydrogen isotopie compositions of groundwaters from Curaçao and Bonaire show that the samples are either meteoric water, or are affected by evaporation or seawater mixing. No distinction could be made between the last two processes. Only a few samples were measured for the Cl-isotope composition; all showed that no physical processes have taken place.

Monte Carlo Simulation in Sampling Techniques of Traffic Data Collection

2002 ◽  
Vol 1804 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Derek G. Williamson ◽  
Maosheng Yao ◽  
John McFadden
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Probability Function ◽  
Time Frame ◽  
Cumulative Probability ◽  
Sampling Techniques ◽  
Traffic Data ◽  
Traffic Data Collection ◽  
Traffic Volumes

Traffic volume counts are used in transportation planning, design, operation, and safety analyses. A new methodology establishes a statistical basis for comparing traffic volumes generated from different samples. Monte Carlo simulation was used to generate a cumulative probability function (CPF) of traffic volumes based on the fit-of-Weibull probability distribution to a particular traffic sample. A 90% confidence interval of the traffic volumes from a given traffic sample was obtained from the CPF and was used to compare different traffic samples. A case study was performed by using this methodology to determine if shorter time-frame data may be used to represent longer-time traffic. Results from the case study show that traffic at 20-min intervals may be used to represent 1-h traffic when moderate to high traffic volumes are considered. It was observed that subsamples failed to represent the 1-h traffic data for lower traffic volumes of selected vehicle types.

scholarly journals Marble Slurry’s Impact on Groundwater: The Case Study of the Apuan Alps Karst Aquifers

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2462 ◽  
Author(s):  
Leonardo Piccini ◽  
Tiziana Di Lorenzo ◽  
Pilario Costagliola ◽  
Diana Maria Paola Galassi
Keyword(s):  
Groundwater Resources ◽  
Karst Aquifer ◽  
Economic Damage ◽  
Karst Aquifers ◽  
Runoff Water ◽  
Karst Springs ◽  
Ornamental Stones ◽  
The Impact ◽  
Apuan Alps

Modern sawing techniques employed in ornamental stones’ exploitation produce large amounts of slurry that can be potentially diffused into the environment by runoff water. Slurry produced by limestone and marble quarrying can impact local karst aquifers, negatively affecting the groundwater quality and generating a remarkable environmental and economic damage. A very representative case-study is that of the Apuan Alps (north-western Tuscany, Italy) because of the intensive marble quarrying activity. The Apuan Alps region extends over about 650 km2; it hosts several quarries, known all over the world for the quality of the marble extracted, and a karst aquifer producing about 70,000 m3/day of high-quality water used directly for domestic purposes almost without treatments. In addition, Apuan Alps are an extraordinary area of natural and cultural heritage hosting many caves (about 1200), karst springs and geosites of international and national interest. During intense rain events, carbonate slurry systematically reaches the karst springs, making them temporarily unsuitable for domestic uses. In addition, the deterioration of the water quality threatens all the hypogean fauna living in the caves. This paper provides preliminary insights of the hydrological and biological indicators that can offer information about the impact of the marble quarrying activities on groundwater resources, karst habitats and their biodiversity.

IMPACT OF THE SOUTH-TO-NORTH WATER DIVERSION PROJECT ON GROUNDWATER RESOURCES: A CASE STUDY IN PINGGU BASIN, BEIJING, CHINA

2013 ◽  
Vol 12 (11) ◽  
pp. 2239-2247 ◽  
Author(s):  
Guomin Li ◽  
Haizhen Xu ◽  
Ming Li ◽  
Shouquan Zhang ◽  
Yanhui Dong ◽  
...  
Keyword(s):  
Groundwater Resources ◽  
Water Diversion ◽  
The South ◽  
Water Diversion Project ◽  
North Water ◽  
Beijing China

scholarly journals Investigation into the Cause of Iron-Related Clogging of Groundwater Bores Used for Viticulture in the Limestone Coast, South Australia

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 683
Author(s):  
Birte Moser ◽  
Meruyert Beknazarova ◽  
Harriet Whiley ◽  
Thilini Piushani Keerthirathne ◽  
Nikki Harrington ◽  
...  
Keyword(s):  
Groundwater Resources ◽  
South Australia ◽  
Water Levels ◽  
Clear Correlation ◽  
Problem Analysis ◽  
Persistent Problem ◽  
Root Cause ◽  
Complex Interactions ◽  
Iron Manganese

Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem for irrigators worldwide. The primary cause of iron-related clogging is still debated. Previous studies have described complex interactions between biological clogging and inorganic iron/manganese oxide precipitation. This case study examined groundwater bores used for viticulture irrigation in the Limestone Coast region, a highly productive wine growing area in the SE of South Australia. Iron clogging of bore screens, pumps and dripper systems has been a persistent problem in the region and the issue is perceived to be growing, with irrigators suggesting the widespread introduction of iron-related bacteria (IRB) through drilling equipment to be the root cause of the problem. Analysis of the groundwater microbiology and inorganic chemistry found no apparent correlation between the presence of IRB and the clogging status of wells. In fact, IRB proved to be widespread throughout the limestone aquifer. However, a clear correlation could be found between clogging affected bores and the redox potential of the groundwater with the most severely affected bores strongly oversaturated in respect to iron oxide minerals. Elevated dissolved concentrations of Fe(II) thereby tended to be found in deeper bores, which also were generally more recently drilled. Following decades of less than average rainfall, a tendency to deepen bores in response to widespread declines in water levels has been documented for the SE of South Australia. The gradually widening clogging problem in the region is postulated to be related to the changes in climate in the region, with irrigators increasingly driven to rely on deeper, anoxic iron-rich groundwater resources.

scholarly journals Modeling Insights into Precipitation Deuterium Excess as an Indicator of Raindrop Evaporation in Lanzhou, China

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 193
Author(s):  
Fenli Chen ◽  
Mingjun Zhang ◽  
Athanassios A. Argiriou ◽  
Shengjie Wang ◽  
Qian Ma ◽  
...  
Keyword(s):  
Arid Region ◽  
Quantitative Methods ◽  
Isotope Composition ◽  
Sampling Site ◽  
Western China ◽  
Cloud Base ◽  
Deuterium Excess ◽  
Semi Arid Region ◽  
Semi Arid

The deuterium excess in precipitation is an effective indicator to assess the existence of sub-cloud evaporation of raindrops. Based on the synchronous measurements of stable isotopes of hydrogen and oxygen (δ2H and δ18O) in precipitation for several sites in Lanzhou, western China, spanning for approximately four years, the variations of deuterium excess between the ground and the cloud base are evaluated by using a one-box Stewart model. The deuterium excess difference below the cloud base during summer (−17.82‰ in Anning, −11.76‰ in Yuzhong, −21.18‰ in Gaolan and −12.41‰ in Yongdeng) is greater than that in other seasons, and difference in winter is weak due to the low temperature. The variations of deuterium excess in precipitation due to below-cloud evaporation are examined for each sampling site and year. The results are useful to understand the modification of raindrop isotope composition below the cloud base at a city scale, and the quantitative methods provide a case study for a semi-arid region at the monsoon margin.

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