scholarly journals The use of pilot points method on groundwater modelling for a degraded aquifer with limited field data: the case of Lake Karla aquifer

2021 ◽  
Author(s):  
G. Tziatzios ◽  
P. Sidiropoulos ◽  
L. Vasiliades ◽  
A. Lyra ◽  
N. Mylopoulos ◽  
...  
Keyword(s):  
Process Analysis ◽  
Anthropogenic Activities ◽  
Groundwater Resources ◽  
Flow Simulation ◽  
Groundwater Modelling ◽  
Water Levels ◽  
Balance Model ◽  
Groundwater Depletion ◽  
Pilot Points ◽  
Lake Karla

Abstract Groundwater depletion poses a major threat to global groundwater resources with increasing trends due to natural and anthropogenic activities. This study presents a surface-groundwater framework for water resources modelling of ill-posed problems in hydrogeologically data-scarce areas. The proposed framework is based on the application of a conceptual water balance model and composed of surface hydrological (UTHBAL) and groundwater flow simulation with the integration of a Newton formulation of the MODFLOW-2005 code (MODFLOW-NWT) and PEST suite modules. The groundwater simulation includes a pre-processor tool for automated calibration and a post-processor tool for automated validation. The methodology was applied to a rural region of Central Greece, Lake Karla Basin, which is degraded due to groundwater resources overexploitation to cover irrigation water demands. The aquifer is modelled focusing on precise simulation – validation procedure of the conceptual model. The groundwater model was calibrated with the calibration pre-processor tool for spatially distributed hydraulic conductivity with the pilot points method. The calibration process achieved satisfactory results as validated by the post-process analysis of observed and simulated water levels. The findings for the groundwater budget indicate that the groundwater system is still under intense pressure even though farming activity in recent years has turned to less water-intensive crops. HIGHLIGHT My research deals with the Pilot Points Method on Groundwater Modelling in area with scarce hydro-geologic data.

scholarly journals Hydrological processes and water resources management in a dryland environment IV: Long-term groundwater level fluctuations due to variation in rainfall

1999 ◽  
Vol 3 (3) ◽  
pp. 353-361 ◽  
Author(s):  
J. A. Butterworth ◽  
R. E. Schulze ◽  
L. P. Simmonds ◽  
P. Moriarty ◽  
F. Mugabe
Keyword(s):  
Groundwater Resources ◽  
Water Levels ◽  
Shallow Aquifer ◽  
Balance Model ◽  
Specific Yield ◽  
Evaporative Demand ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Modelling Methods

Abstract. To evaluate the effects of variations in rainfall on groundwater, long-term rainfall records were used to simulate groundwater levels over the period 1953-96 at an experimental catchment in south-east Zimbabwe. Two different modelling methods were adopted. Firstly, a soil water balance model (ACRU) simulated drainage from daily rainfall and evaporative demand; groundwater levels were predicted as a function of drainage, specific yield and water table height. Secondly, the cumulative rainfall departure method was used to model groundwater levels from monthly rainfall. Both methods simulated observed groundwater levels over the period 1992-96 successfully, and long-term simulated trends in historical levels were comparable. Results suggest that large perturbations in groundwater levels area a normal feature of the response of a shallow aquifer to variations in rainfall. Long-term trends in groundwater levels are apparent and reflect the effect of cycles in rainfall. Average end of dry season water levels were simulated to be almost 3 m higher in the late 1970s compared to those of the early 1990s. The simulated effect of prolonged low rainfall on groundwater levels was particularly severe during the period 1981-92 with a series of low recharge years unprecedented in the earlier record. More recently, above average rainfall has resulted in generally higher groundwater levels. The modelling methods described may be applied in the development of guidelines for groundwater schemes to help ensure safe long-term yields and to predict future stress on groundwater resources in low rainfall periods; they are being developed to evaluate the effects of land use and management change on groundwater resources.

Environmental issues of groundwater in Korea: implications for sustainable use

2011 ◽  
Vol 38 (1) ◽  
pp. 64-74 ◽  
Author(s):  
J.Y. LEE
Keyword(s):  
Petroleum Hydrocarbons ◽  
Groundwater Resources ◽  
Sustainable Use ◽  
Chlorinated Solvents ◽  
Environmental Issues ◽  
Water Source ◽  
Water Levels ◽  
Military Bases ◽  
Groundwater Depletion ◽  
Monitoring Wells

SUMMARYGroundwater has been extensively exploited worldwide but is now confronted by a variety of problems, including groundwater depletion and contamination, that threaten its sustainable use as a clean water source. Groundwater is one of the major sources of water for domestic, agricultural and industrial uses, and provides 13% of the total annual water supply in Korea. Annual groundwater use has continuously increased from 2.57 billion m3 in 1994 to 3.72 billion m3 in 2007, of which 48.1% was consumed for domestic purposes. However, due to imprudent groundwater development and inappropriate management, Korea has confronted some critical groundwater problems, including extensive water level decline and quality deterioration caused by petroleum hydrocarbons and chlorinated solvents. Among 193 national groundwater deep-monitoring wells nationwide, 62% showed decreasing water levels over the period 2004–2008. Soil and groundwater contamination by petroleum hydrocarbons was detected at a great number of military bases and public facilities, which drew national attention and complaints. The presence of high levels of radionuclides such as uranium and radon in groundwater has awakened controversy on their health effects. Increasing outbreaks of massive gastroenteritis were attributed to noroviruses in contaminated groundwater, and raised public health concerns. In addition, chlorinated solvents, especially trichloroethylene (TCE), have been frequently found in urban and industrial groundwaters, further adding to the burdens of environmental authorities. Consequently, these groundwater-related environmental issues have forced the Korean government and relevant authorities to urgently devise mitigation plans to secure a sustainable future use of groundwater resources. This paper provides details of the groundwater issues and implications for appropriate development and management.

Influence of Anthropogenic Pressures on Groundwater Quality from a Rural Area

2017 ◽  
Vol 68 (8) ◽  
pp. 1744-1748
Author(s):  
Catalina Stoica ◽  
Gabriela Geanina Vasile ◽  
Alina Banciu ◽  
Daniela Niculescu ◽  
Irina Lucaciu ◽  
...  
Keyword(s):  
Water Quality ◽  
Anthropogenic Activities ◽  
Groundwater Resources ◽  
Bacterial Load ◽  
Animal Husbandry ◽  
Anthropogenic Factors ◽  
Contamination Level ◽  
Anthropogenic Pressures ◽  
Limit Values ◽  
Physico Chemical

During the past few decades, the anthropogenic activities induced worldwide changes in the ecological systems, including the aquatic systems. This work analysed the contamination level of groundwater resources from a rural agglomeration (Central-Western part of Prahova County) by biological and physico-chemical approaches. The study was performed during the autumn of 2016 on several sampling sites (four drilling wells, depth higher than 100 m supplying three villages; two wells lower than 10 m depth and one spring). The water quality was evaluated by comparison with the limit values of the drinking water quality legislation (Law no.458/2002) and the Order 621/2014 (applicable to all groundwater bodies of Romania). The results showed that phenols and metals (iron and manganese) exceeded the threshold values in all sampling sites. Moreover, the anthropogenic factors including agriculture, use of fertilizers, manures, animal husbandry led to an increase of the bacterial load, particularly at wells sites.

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 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.

scholarly journals Study Relating to the Spatial Distribution of Ground Water Quality for Different Elements using Legacy Data of RWS&S, Andhra Pradesh, India

2014 ◽  
Vol XL-8 ◽  
pp. 383-390
Author(s):  
P. Prakash ◽  
A. Kumar Das ◽  
C. V. S. Sandilya
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Spatial Distribution ◽  
Ground Water ◽  
Andhra Pradesh ◽  
Chemical Elements ◽  
Groundwater Resources ◽  
Water Levels ◽  
Contamination Level ◽  
Ground Water Quality

The state of Andhra Pradesh, India falls in water stress<sup>4</sup> area. The primary objective of this study is to examine the spatial distribution of different chemical elements with respect to its contamination level. About 70 % of drinking water needs in rural areas and 40 % drinking water needs in urban areas are met from groundwater resources. In the last decades, rapid population growth coupled with agricultural expansion due to subsidized power to agriculture has significantly increased demand on groundwater resources. Combined to this, the effect of Global warming has put stress on ground water which is resulting in declines in water levels and deterioration of ground water quality. This may be evidenced by the fact that the phreatic aquifer which was in use two decades ago, is existing no more now in some of the parts of the study area and the water is being drawn from deeper aquifers beyond phreatic aquifers. The study has been carried out for which one or more elements are contaminated and to study its spatial distribution.

scholarly journals Optimizing Reduction of Groundwater Discharge to Control Land Subsidence (Case study: Nadjafabad Aquifer)

2021 ◽  
Author(s):  
hamid Kardan moghaddam ◽  
Zahra Rahimzadeh kivi ◽  
Fatemeh Javadi ◽  
Mohammad Heydari
Keyword(s):  
Land Subsidence ◽  
Groundwater Resources ◽  
Treatment Strategies ◽  
Flow Simulation ◽  
Maximum Amount ◽  
Water Withdrawal ◽  
Ground Subsidence ◽  
Risk Zoning ◽  
Dry Conditions ◽  
The Impact

Abstract This study evaluates and predicts the ground subsidence that happens due to the haphazard operation of groundwater resources. Also, several strategies have been developed to control this unpleasant phenomenon. For this purpose, groundwater flow simulation has been conducted using MODFLOW numerical model, and subsidence simulation in Najafabad plain has been done using SUB package under three climatic scenarios for future periods. Examination of the simulation results shows that the amount of land subsidence will increase with the aquifer operation's continuation. The maximum amount of subsidence for 6 years in drought conditions will be 23 cm at the aquifer's outlet. According to the land subsidence results at the aquifer, risk zoning of the aquifer operation was done to develop a solution to reduce the withdrawal of groundwater resources to control subsidence. Therefore, risk zoning was performed using land use and the extent of operation of groundwater resources. The results showed that the north-eastern part of the aquifer has the maximum risk of subsidence. According to the obtained results from subsidence risk zoning, scenarios of reduced water withdrawal from the aquifer in its outlet were developed. The treatment strategies results showed that the maximum amount of subsidence in wet, normal and dry conditions will be 10, 14 and 18 cm, respectively. These results indicate a 14% improvement in the quantitative condition of the aquifer in wet conditions, 10% in normal conditions and 7% in dry conditions in the total aquifer of Najafabad. Improvement of conditions by simulation shows the impact of the importance of optimal utilization of groundwater resources.

scholarly journals A partially-coupled hydro-mechanical analysis of the Bengal Aquifer System under hydrological loading

2018 ◽  
Author(s):  
Nicholas D. Woodman ◽  
William G. Burgess ◽  
Kazi Matin Ahmed ◽  
Anwar Zahid
Keyword(s):  
Mechanical Load ◽  
Groundwater Resources ◽  
Ground Surface ◽  
Coupled Model ◽  
Hydraulic Head ◽  
Water Levels ◽  
Elastic Model ◽  
Surface Boundary ◽  
Aquifer System ◽  
Terrestrial Water

Abstract. The coupled poro-mechanical behaviour of geologic-fluid systems is fundamental to numerous processes in structural geology, seismology and geotechnics but is frequently overlooked in hydrogeology. Substantial poro-mechanical influences on groundwater head have recently been highlighted in the Bengal Aquifer System, however, driven by terrestrial water loading across the Ganges-Brahmaputra-Meghna floodplains. Groundwater management in this strategically important fluvio-deltaic aquifer, the largest in south Asia, requires a coupled hydro-mechanical approach which acknowledges poro-elasticity. We present a simple partially-coupled, one-dimensional poro-elastic model of the Bengal Aquifer System, and explore the poro-mechanical responses of the aquifer to surface boundary conditions representing hydraulic head and mechanical load under three modes of terrestrial water variation. The characteristic responses, shown as amplitude and phase of hydraulic head in depth profile and of ground surface deflection, demonstrate (i) the limits to using water levels in piezometers to indicate groundwater recharge, as conventionally applied in groundwater resources management; (ii) the conditions under which piezometer water levels respond primarily to changes in the mass of terrestrial water storage, as applied in geological weighing lysimetry; (iii) the relationship of ground surface vertical deflection to changes in groundwater storage; and (iv) errors of attribution that could result from ignoring the poroelastic behaviour of the aquifer. These concepts are illustrated through application of the partially-coupled model to interpret multi-level piezometer data at two sites in southern Bangladesh. There is a need for further research into the coupled responses of the aquifer due to more complex forms of surface loading, particularly from rivers.

scholarly journals Spatial Distribution of Fluoride in Drinking Water in Dhamar City, Yemen

2021 ◽  
Vol 10 (1) ◽  
pp. 49-63
Author(s):  
Hefdhallah Al Aizari ◽  
Rachida Fegrouche ◽  
Ali Al Aizari ◽  
Saeed S. Albaseer
Keyword(s):  
Drinking Water ◽  
Anthropogenic Activities ◽  
Groundwater Resources ◽  
Principal Component ◽  
World Health ◽  
Residential Areas ◽  
Central Plateau ◽  
The World ◽  
Pca Method ◽  
Health Organization

The fact that groundwater is the only source of drinking water in Yemen mandates strict monitoring of its quality. The aim of this study was to measure the levels of fluoride in the groundwater resources of Dhamar city. Dhamar city is the capital of Dhamar governorate located in the central plateau of Yemen. For this purpose, fluoride content in the groundwater from 16 wells located around Dhamar city was measured. The results showed that 75% of the investigated wells contain fluoride at or below the permissible level set by the World Health Organization (0.5 – 1.5 mg/L), whereas 25% of the wells have relatively higher fluoride concentrations (1.59 – 184 mg/L). The high levels of fluoride have been attributed to the anthropogenic activities in the residential areas near the contaminated wells. Interestingly, some wells contain very low fluoride concentrations (0.30 – 0.50 mg/L).  Data were statistically treated using the principal component analysis (PCA) method to investigate any possible correlations between various factors. PCA shows a high correlation between well depth and its content of fluoride. On the other hand, health problems dominating in the study area necessitate further studies to investigate any correlation with imbalanced fluoride intake.

scholarly journals A review of seawater intrusion in the Nile Delta groundwater system – the basis for assessing impacts due to climate changes and water resources development

2013 ◽  
Vol 10 (8) ◽  
pp. 10873-10911 ◽  
Author(s):  
M. B. Mabrouk ◽  
A. Jonoski ◽  
D. Solomatine ◽  
S. Uhlenbrook
Keyword(s):  
Climate Change ◽  
Nile Delta ◽  
Groundwater Resources ◽  
Scientific Evidence ◽  
Three Dimensional ◽  
Water Levels ◽  
Population Increase ◽  
Regional Process ◽  
Environmentally Sound ◽  
Resources Development

Abstract. Serious environmental problems are emerging in the River Nile basin and its groundwater resources. Recent years have brought scientific evidence of climate change and development-induced environmental impacts globally as well as over Egypt. Some impacts are subtle, like decline of the Nile River water levels, others are dramatic like the salinization of all coastal land in the Nile Delta – the agricultural engine of Egypt. These consequences have become a striking reality causing a set of interconnected groundwater management problems. Massive population increase that overwhelmed the Nile Delta region has amplified the problem. Many researchers have studied these problems from different perspectives using different methodologies, following different objectives and, consequently, arrived at different findings. However, they all confirmed that significant groundwater salinization has affected the Nile Delta and this is likely to become worse rapidly in the future. This article presents, categorizes and critically analyses and synthesizes the most relevant research regarding climate change and development challenges in relation to groundwater resources in the Nile Delta. It is shown that there is a gap in studies that focus on sustainable groundwater resources development and environmentally sound protection as an integrated regional process in Nile Delta. Moreover, there is also a knowledge gap related to the deterioration of groundwater quality. The article recommends further research that covers the groundwater resources and salinization in the whole Nile Delta based on integrated three-dimensional groundwater modelling of the Nile delta aquifer.

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