scholarly journals Variability of Intrinsic Groundwater Vulnerability to Pollution in River Valley due to Groundwater Depth and Recharge Changes

2019 ◽  
Vol 9 (6) ◽  
pp. 1133 ◽  
Author(s):  
Ewa Krogulec ◽  
Sebastian Zabłocki ◽  
Danuta Zadrożna

Groundwater management can be effectively implemented by assessment of groundwater vulnerability to pollution. The research was carried out in the Vistula River valley (Poland) in an area of shallow groundwater occurrence, defined as a Groundwater-Dependent Ecosystem area. The goal of this study was to identify the average, maximum, and minimum depths of the groundwater table for variant assessment of groundwater vulnerability to contamination. The variants correspond to the average vulnerability, the vulnerability during hydrogeological drought, and the vulnerability during the flood risk period. Theoretical and effective weights of vulnerability parameters were calculated using the DRASTIC method. Vulnerability maps constructed for the various vulnerability variants and by using different parameter weights show the spatial variability of the individual vulnerability classes. Due to the specifics of this protected area, the expected dependency between vulnerability index and chloride concentrations in the monitoring points was not found. Comparison showed strong dependency of water chemistry and the value of recharge, lithology of aquifer, and unsaturated zone. The research results confirm the need for variant vulnerability assessment to protect against floods or predict the effects of climate change.

2021 ◽  
Vol 930 (1) ◽  
pp. 012012
Author(s):  
T Widodo ◽  
W Wilopo ◽  
A Setianto

Abstract Groundwater is a water resource that is still a mainstay for humans. The need for groundwater increases with the growth of population and the development of the industrial and agricultural sectors. The residents of Kediri City still use wells from shallow aquifers to fulfill their water needs. Shallow aquifers are prone to pollution due to the influence of shallow groundwater depths and human activities. The purpose of this study is to determine the vulnerability of groundwater pollution in Kediri City. Groundwater vulnerability was conducted by the GOD method (Groundwater Occurrence, Overlaying Lithology, and Depth of Groundwater) that consists of 3 parameters, namely the groundwater confinement, the type of overlying strata, and the depth of the groundwater level. The analysis results show that the level of groundwater vulnerability according to the GOD method in Kediri City consists of moderate and high classes. The western and the eastern part of Kediri City is classified as a high level of vulnerability. In contrast, in the middle of Kediri City, it tends to experience a moderate level of vulnerability.


2016 ◽  
Vol 48 (4) ◽  
pp. 1088-1099 ◽  
Author(s):  
Ewa Krogulec ◽  
Joanna Trzeciak

Assessment of groundwater vulnerability to pollution was conducted by the DRASTIC method in central Poland, in the Vistula River valley. The results of this study have shown that 68.18% of the study area has a low pollution potential and 31.2% has a medium pollution potential. Single-parameter and map removal sensitivity analyses were conducted to evaluate the relative importance of the parameters for aquifer vulnerability. Both analyses showed that by far the most significant parameter of the DRASTIC vulnerability index in the study area is the depth to the water table. Although the water table in more than 90% of the study area is shallow, less than 3 m below ground level, the assessment shows that this does not lead to a high groundwater vulnerability.


2021 ◽  
pp. 1-16 ◽  
Author(s):  
Grzegorz Wierzbicki ◽  
Piotr Ostrowski ◽  
Piotr Bartold ◽  
Filip Bujakowski ◽  
Tomasz Falkowski ◽  
...  
Keyword(s):  

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Ratha Phok ◽  
Nandalal Kosgallana Duwage Wasantha ◽  
Weerakoon Sumana Bandara ◽  
Pitawala Herath Mudiyanselage Thalapitiye Ge ◽  
Dharmagunawardhane Hingure Arachchilage

AbstractGroundwater vulnerability assessment has become a crucial step in successfully protecting groundwater against pollution. An attempt of this study has been made to evaluate groundwater contamination risk using intrinsic vulnerability and land-uses in Vanathavillu, Kalpitiya and Katana area in Sri Lanka, using coupled DRASTIC with GIS as feasible methodology. The findings reveal that the groundwater in the areas under study falls under very low to high contamination risk. The higher risk of contamination has been identified in most of the Kalpitiya (about 82%) with the moderate along the beach in the west and next to Puttalam lagoon in the northeast and southeast. This is mainly due to pollution risk inherent with intense vegetable cultivation, over pumping, shallow groundwater tables and permeable sandy soil. Vanathavillu is under very low to moderate contamination risk, in which the moderate risk (about 13%) has especially been found the center, central southwest and west of the area. The relative less deep groundwater tables, possible seepage from the underlying limestone aquifer and less permeable red earth soil could be cause for the moderate risk in the area. Furthermore, results show that the Katana has low to moderately high groundwater contamination risk. Nitrate has a good agreement with the different pollution risk classes and that nitrate can be used as an indicator of aquifer degradation inherent with land-use activities in the coastal areas. Groundwater quality monitoring network should be set up to minimize the anthropogenic acts, particularly in high and moderate contamination risk zones.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1288
Author(s):  
Husam Musa Baalousha ◽  
Bassam Tawabini ◽  
Thomas D. Seers

Vulnerability maps are useful for groundwater protection, water resources development, and land use management. The literature contains various approaches for intrinsic vulnerability assessment, and they mainly depend on hydrogeological settings and anthropogenic impacts. Most methods assign certain ratings and weights to each contributing factor to groundwater vulnerability. Fuzzy logic (FL) is an alternative artificial intelligence tool for overlay analysis, where spatial properties are fuzzified. Unlike the specific rating used in the weighted overlay-based vulnerability mapping methods, FL allows more flexibility through assigning a degree of contribution without specific boundaries for various classes. This study compares the results of DRASTIC vulnerability approach with the FL approach, applying both on Qatar aquifers. The comparison was checked and validated against a numerical model developed for the same study area, and the actual anthropogenic contamination load. Results show some similarities and differences between both approaches. While the coastal areas fall in the same category of high vulnerability in both cases, the FL approach shows greater variability than the DRASTIC approach and better matches with model results and contamination load. FL is probably better suited for vulnerability assessment than the weighted overlay methods.


2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Nyakno Jimmy George

AbstractAVI (Aquifer vulnerability index), GOD (groundwater occurrence, overlying lithology and depth to the aquifer), GLSI (geo-electric layer susceptibility indexing) and S (longitudinal unit conductance) models were used to assess economically exploitable groundwater resource in the coastal environment of Akwa Ibom State, southern Nigeria. The models were employed in order to delineate groundwater into its category of vulnerability to contamination sources using the first- and second-order geo-electric indices as well as hydrogeological inputs. Vertical electrical sounding technique employing Schlumberger electrode configuration was carried out in 16 locations, close to logged boreholes with known aquifer core samples. Primary or first-order geo-electric indices (resistivity, thickness and depth) measured were used to determine S. The estimated aquifer hydraulic conductivity, K, calculated from grain size diameter and water resistivity values were used to calculate hydraulic resistance (C) used to estimate AVI. With the indices assigned to geo-electric parameters on the basis of their influences, GOD and FSLI were calculated using appropriate equations. The geologic sequence in the study area consists of geo-electric layers ranging from motley topsoil, argillites (clayey to fine sands) and arenites (medium to gravelly sands). Geo-electric parametric indices of aquifer overlying layers across the survey area were utilized to weigh the vulnerability of the underlying water-bearing resource to the contaminations from surface and near-surface, using vulnerability maps created. Geo-electrically derived model maps reflecting AVI, BOD, FLSI and S were compared to assess their conformity to the degree of predictability of groundwater vulnerability. The AVI model map shows range of values of log C ( −3.46—0.07) generally less than unity and hence indicating high vulnerability. GOD model tomographic map displays a range of 0.1–0.3, indicating that the aquifer with depth range of 20.5 to 113.1 m or mean depth of 72. 3 m is lowly susceptible to surface and near-surface impurities. Again, the FLSI map displays a range of FLSI index of 1.25 to 2.75, alluding that the aquifer underlying the protective layer has a low to moderate vulnerability. The S model has values ranging from 0.013 to 0.991S. As the map indicates, a fractional portion of the aquifer at the western (Ikot Abasi) part of the study area has moderate to good protection (moderate vulnerability) while weak to poor aquifer protection (high vulnerability) has poor protection. The S model in this analysis seems to overstate the degree of susceptibility to contamination than the AVI, GOD and GLSI models. From the models, the categorization of severity of aquifer vulnerability to contaminations is relatively location-dependent and can be assessed through the model tomographic maps generated.


Author(s):  
Stefania Stevenazzi ◽  
Marco Masetti ◽  
Giovanni Pietro Beretta

Groundwater is among the most important freshwater resources. Worldwide, aquifers are experiencing an increasing threat of pollution from urbanization, industrial development, agricultural activities and mining enterprise. Thus, practical actions, strategies and solutions to protect groundwater from these anthropogenic sources are widely required. The most efficient tool, which helps supporting land use planning, while protecting groundwater from contamination, is represented by groundwater vulnerability assessment. Over the years, several methods assessing groundwater vulnerability have been developed: overlay and index methods, statistical and process-based methods. All methods are means to synthesize complex hydrogeological information into a unique document, which is a groundwater vulnerability map, useable by planners, decision and policy makers, geoscientists and the public. Although it is not possible to identify an approach which could be the best one for all situations, the final product should always be scientific defensible, meaningful and reliable. Nevertheless, various methods may produce very different results at any given site. Thus, reasons for similarities and differences need to be deeply investigated. This study demonstrates the reliability and flexibility of a spatial statistical method to assess groundwater vulnerability to contamination at a regional scale. The Lombardy Plain case study is particularly interesting for its long history of groundwater monitoring (quality and quantity), availability of hydrogeological data, and combined presence of various anthropogenic sources of contamination. Recent updates of the regional water protection plan have raised the necessity of realizing more flexible, reliable and accurate groundwater vulnerability maps. A comparison of groundwater vulnerability maps obtained through different approaches and developed in a time span of several years has demonstrated the relevance of the continuous scientific progress, recognizing strengths and weaknesses of each research.


Author(s):  
Gillian Hughes

Much good therapeutic work is done with individual separated young people seeking asylum to help them overcome the effects of trauma and abuse and to reconstruct their identities in unfamiliar settings. This chapter highlights the dangers to many of the individual trauma focused interventions where young people can become defined by their vulnerabilities, stuck in relationships which position them as damaged, vulnerable and needing help. It outlines a Narrative Liberation framework to enable practitioners to reflect on what they are doing in their care of separated young people, and to help guard against isolating and unhelpful therapeutic practices. This includes a recognition of past events, but also highlighting personal accounts of survival and resistance. A key element is connections with other unaccompanied young migrants and the facilitation of collective practices where people are able to connect with life affirming aspects of their cultural and social histories.


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