scholarly journals Groundwater Protection Model at Niagara Using GIS Tools

Author(s):  
Mafruha Ahmed

Groundwater is the safest and most reliable source of available freshwater. Although traditionally groundwater has been assumed to be free from contamination, numerous discoveries, in recent years of toxic chemicals in well water have proven this assumption to be false. Groundwater contamination from chemical dump sites tends to attract the greatest public attention, but contamination from other sources such as septic systems, pesticides, and underground storage tanks also can be significant. Intensive agriculture in areas of high soil permeability and high water tables also causes groundwater contamination from the percolation of chemicals and nutrients through the soil profile. Protecting groundwater resources from pollution is therefore essential for its proper management and preventing probable hazards. Groundwater vulnerablility assessment is an issue of spatial distribution and therefore typically carried out using geographic information systems (GIS). Even when using a simple qualitative method, the complex processing of spatial information is completed faster using GIS Models are tools to simulate the behavior of physical systems. They can predict the future evolution of the systems, they can be used as interpretative tools in order to study system dynamics and they can give hints for data collection and design of experiments. Models are sometimes used to examine the evolution of generic natural systems, without a specific application to a definite site or population. ArcGis 9 provides new tolls to build protection model to study grounwater contamination isues of various watersheds that performs multiple geoprocessing operations. The study articulates the most vulnerable locations of Niagara for groundwater contamination, what geospatial data are needed to support these resource assessment activities, and how GIS tools are required to facilitate the generation of a best optimized model.

2021 ◽  
Author(s):  
Mafruha Ahmed

Groundwater is the safest and most reliable source of available freshwater. Although traditionally groundwater has been assumed to be free from contamination, numerous discoveries, in recent years of toxic chemicals in well water have proven this assumption to be false. Groundwater contamination from chemical dump sites tends to attract the greatest public attention, but contamination from other sources such as septic systems, pesticides, and underground storage tanks also can be significant. Intensive agriculture in areas of high soil permeability and high water tables also causes groundwater contamination from the percolation of chemicals and nutrients through the soil profile. Protecting groundwater resources from pollution is therefore essential for its proper management and preventing probable hazards. Groundwater vulnerablility assessment is an issue of spatial distribution and therefore typically carried out using geographic information systems (GIS). Even when using a simple qualitative method, the complex processing of spatial information is completed faster using GIS Models are tools to simulate the behavior of physical systems. They can predict the future evolution of the systems, they can be used as interpretative tools in order to study system dynamics and they can give hints for data collection and design of experiments. Models are sometimes used to examine the evolution of generic natural systems, without a specific application to a definite site or population. ArcGis 9 provides new tolls to build protection model to study grounwater contamination isues of various watersheds that performs multiple geoprocessing operations. The study articulates the most vulnerable locations of Niagara for groundwater contamination, what geospatial data are needed to support these resource assessment activities, and how GIS tools are required to facilitate the generation of a best optimized model.


2020 ◽  
Vol 28 (8) ◽  
pp. 2635-2656
Author(s):  
Samson Oiro ◽  
Jean-Christophe Comte ◽  
Chris Soulsby ◽  
Alan MacDonald ◽  
Canute Mwakamba

AbstractThe Nairobi volcano-sedimentary regional aquifer system (NAS) of Kenya hosts >6 M people, including 4.7 M people in the city of Nairobi. This work combines analysis of multi-decadal in-situ water-level data with numerical groundwater modelling to provide an assessment of the past and likely future evolution of Nairobi’s groundwater resources. Since the mid-1970s, groundwater abstraction has increased 10-fold at a rate similar to urban population growth, groundwater levels have declined at a median rate of 6 m/decade underneath Nairobi since 1950, whilst built-up areas have increased by 70% since 2000. Despite the absence of significant trends in climatic data since the 1970s, more recently, drought conditions have resulted in increased applications for borehole licences. Based on a new conceptual understanding of the NAS (including insights from geophysics and stable isotopes), numerical simulations provide further quantitative estimates of the accelerating negative impact of abstraction and capture the historical groundwater levels quite well. Analysis suggests a groundwater-level decline of 4 m on average over the entire aquifer area and up to 46 m below Nairobi, net groundwater storage loss of 1.5 billion m3 and 9% river baseflow reduction since 1950. Given current practices and trajectories, these figures are predicted to increase six-fold by 2120. Modelled future management scenarios suggest that future groundwater abstraction required to meet Nairobi projected water demand is unsustainable and that the regional anthropogenically-driven depletion trend can be partially mitigated through conjunctive water use. The presented approach can inform groundwater assessment for other major African cities undergoing similar rapid groundwater development.


2014 ◽  
Vol 955-959 ◽  
pp. 3225-3230
Author(s):  
Yu Jie Liu ◽  
Hui Cao ◽  
Qiang An ◽  
De Chang Xie ◽  
Ning Qiu Huang

Given the increasing groundwater exploitation, an attempt is enforced to establish the hydro geological conceptual model of this area. This carries on the numerical simulation of groundwater flow by using the IGW, which is known as the international standard software. The mathematical model established in this paper has reflected the local practical hydro geological conditions and can be used to predict and manage groundwater resources.


2015 ◽  
Vol 01 (02) ◽  
pp. 1550002
Author(s):  
Deepa Pradhan ◽  
Ram Ranjan

Crop choices made by farmers can make important contributions toward the sustainable management of groundwater resources in drought prone regions. However, farmers who would tend to maximize profits under normal circumstances face a trade-off between the choices of risky but more profitable high water intensive (HWI) crops on one hand and the low risk but less profitable low water intensive (LWI) and drought resistant (DR) crops on the other. In drought-hit regions of South India, institutional programs, such as crop water budgeting and farmer schools, have been promoted to provide support and information to the farmers in helping them make judicious crop choices. A multivariate probit (MVP) analysis reveals that crop water budget exercise and farmer field school participation, in fact, are positively associated with HWI crop choices, whereas participation in soil moisture conservation efforts is positively associated with growing LWI and DR crops. Our findings indicate that the objective of groundwater augmentation through institutional interventions that are solely based on educating and training farmers have been ineffective and have even been providing perverse incentives, and that there is a need for adding water extraction compliance components to such support programs in order for them to be efficacious.


Author(s):  
K. O. Nkem ◽  
C. L. Eze ◽  
I. U. Ini

The investigation of groundwater contamination from septic tank siting was done in Umungasi/Abayi, Abia State. The aim of this study was to investigate the effect of siting septic systems on the quality of groundwater in Umungasi, Abayi, Aba. Twenty (20) water samples were randomly collected from boreholes located less than 30 m away from septic systems in Umungasi, Abayi Aba, Nigeria to determine their physico-chemical and heavy metals characteristics. While three (3) water samples at distances ranging from 60 m from the nearest septic system were sampled for analyses as controls. Standard analytical techniques were employed in the investigation. The result showed that most of the physicochemical parameters analysed in the borehole water samples were within the WHO/SON/NAFDAC recommended limits except for pH in BH4 and BH7 which had values of 6.3 respectively and were not within the WHO/SON/NAFDAC standard limit of 6.5-8.5. Some of the heavy metals analysed during the period of study were within the permissible limits except for iron in BH5 (0.443 mg/L), BH7 (0.367 mg/L), BH8 (0.511 mg/L), BH9 (0.31 mg/L), BH15 (0.41 mg/L), BH16 (0.327 mg/L), BH17 (0.337 mg/L) and BH18 (0.315 mg/L) that were above the permissible limits of WHO standards of 0.3 mg/l. There was no influence of septic tank siting to the boreholes on groundwater quality during the period of study even though the distance of septic tanks from boreholes in the areas investigated did not conform with that recommended by WHO of 30 – 40 m. The contamination is from the general unhygienic condition of the environment.


Author(s):  
I. H. Thakuria ◽  
P. P. Hazarika ◽  
K. Deka ◽  
B. K. Medhi ◽  
N. Rahman ◽  
...  

Groundwater is an essential resource for sustainable development all over the world. To understand the use of water resources, the fundamental characteristics and recharge of the groundwater need to be analyzed. GIS is considered as an effective and powerful tool for collecting, storing, transforming the spatial information for the need-based site-specific decision-making process. Thus, GIS tools have opened new paths in land and water resource studies. In the present study, GIS-based mapping of the groundwater in the central Brahmaputra Valley Zone is done with a view to observing the various quality characters. The results of this investigation could be used by decision-makers for the sustainable management of groundwater resources. The groundwater pH of the district was found to be within the desirable limit as recommended by WHO but 67.30% sample covering 79% of the total geographical area of the district was slightly alkaline in nature. Groundwater quality parameters that surpassed the desirable limit recommended by WHO, were electrical conductivity and nitrate which accounted for 41.22% and 0.79% of the total samples. Total Dissolved Solids, calcium, magnesium, carbonate, bicarbonate and nitrate in groundwater were recorded within the desirable limit of WHO and thus could be considered as safe. Spatial autocorrelation run for all the quality parameters with respect to their positions and values over the entire district envisaged the possibilities of forming different pattern namely CLUSTER for pH, EC, As, F, Fe, Al, Mn,HCO3, RANDOM for Mg, Ca, CO3, NO3, SO4 and DISPERSED for TDS. GIS-aided mapping of groundwater quality parameters embracing their category wise spatial distribution, area, maximum and minimum values, surface autocorrelation of observed values could give a better idea to opt for suitable need-based management strategy for the entire district.


2012 ◽  
Vol 1 (33) ◽  
pp. 64 ◽  
Author(s):  
Isabel Moreno ◽  
Irene Del Barrio ◽  
Ana Lloret ◽  
Ainhoa Pérez-Puyol

In 2008, the European Community adopted the Marine Strategy Framework Directive, aiming to achieve or maintain good environmental status in the European marine environment by 2020, applying an ecosystem-based approach to the management of human activities. Spatial information of the distribution of the human activities and their related pressures is essential to accomplish this task successfully. After compiling the available data from official sources, the spatial extent of the land-based and ocean-based human activities that could have an impact on the Spanish marine waters were estimated and mapped using GIS tools. In addition, a series of indexes were created in order to develop a cumulative analysis, taking into account the different relevance of pressures and that single pressures have different intensities. The identification of areas with an accumulation of pressures revealed that it is in coastal waters around big cities where the greater part of the pressures concentrates for each of the five Spanish marine districts. Human impacts emanating from the identified pressures could not be evaluated and this task is proposed to be accomplished in further projects. Nonetheless, the resulting information is considered very useful for managers and technical staff to support not only marine management but also other planning and decision making in Spain.


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2492 ◽  
Author(s):  
Tien-Duc Vu ◽  
Chuen-Fa Ni ◽  
Wei-Ci Li ◽  
Minh-Hoang Truong

The groundwater vulnerability (GV) assessment for contamination is an effective technique for the planning, policy, and decision-making, as well as for sustainable groundwater resource protection and management. The GV depends strongly on local hydrogeological settings and land-use conditions that may vary in response to the activities of agricultural development. In this study, a modified DRASTIC model, which employs an additional factor of land use coupled with the analytic hierarchy process (AHP) theory, was used to quantify the spatial and temporal variation of GV and groundwater contamination risk in the Pingtung groundwater basin. The results show that the GV slightly decreased due to the decrease in agricultural areas under the change of land use over two decades (1995–2017). The yearly changes or a shorter period of observations incorporated with the accurate land-use map in DRASTIC parameters could improve GV maps to obtain a better representation of site-specific conditions. Meanwhile, the maps of yearly contamination risk indicated that the counties of Jiuru and Ligang are at high risk of nitrate pollution since 2016. In other agriculture-dominated regions such as Yanpu, Changzhi, and Gaoshu in the Pingtung groundwater basin, the climate conditions influence less the temporal variations of groundwater contamination risk. The results of this study are expected to support policy-makers to adopt the strategies of sustainable development for groundwater resources in local areas.


2021 ◽  
Author(s):  
Tamara Leins ◽  
Isabella Serena Liso ◽  
Mario Parise ◽  
Andreas Hartmann

<p>Vora Bosco Cave is located in the Salento karst peninsula (Apulia, S Italy), surrounded by the Ionian and Adriatic Seas. In this part of Apulia, due to climate change, the typical Mediterranean climate is moving towards arid and semi-arid, with scarce or absent surface runoff. The Salento groundwater is a freshwater lens fluctuating on seawater, entering inland because of intrusion phenomena. The freshwater volume stored in the lens is subjected to both sea level rise and an increasing pressure caused by the high water demand, especially in summer time, for touristic purposes. Therefore, developing an understanding of the hydrogeological dynamics of the karst aquifer can be a useful tool for planning better protection and management actions on Apulian groundwater resources.</p><p>Vora Bosco cave was instrumented with a multi-parameter probe for groundwater level measurements from November 2017 to July 2018. Thereby, the system behaviour within the cave recharge area can be explored. To characterise and quantify the natural recharge and discharge behaviour of the system, a simple reservoir model was developed and calibrated with the measured data. The model consists of 4 reservoirs, which are filled and emptied using simple discharge equations. The model considers evapotranspiration from the soil, slow flow in the unsaturated and saturated zone, as well as fast flow in the karstic conduits. Daily data of precipitation and potential evapotranspiration are used as model inputs. The model simulates the water level at Vora Bosco and is calibrated by comparison of simulated and measured water level, using the Kling-Gupta-Efficiency as an objective function. Our results reveal that the model simulations show acceptable performance in reflecting the dynamics of the observed water level data. The calibration achieves reasonable results for the model parameters. In addition to the water level simulations, quantifying predictions uncertainty by Monte Carlo approach, it is shown that there is still potential to produce more reliable estimates of future groundwater dynamics, in order to better manage the precious regional groundwater resources.</p>


2021 ◽  
Vol 11 (6) ◽  
pp. 307
Author(s):  
Bertha Santos ◽  
Jorge Gonçalves ◽  
Ana M. Martins ◽  
Maria T. Pérez-Cano ◽  
Eduardo Mosquera-Adell ◽  
...  

Geographical Information Systems (GISs) in architecture were initially limited to regional and urban development applications. Over recent years its potential has been recognized and its use has evolved to address urban planning and architectural heritage management subjects. Nevertheless, evidence shows that its use in architecture teaching is scarce and uneven. Directive 2007/2/EC, establishing the infrastructure for spatial information in the European Community (EU), is, in this way, an opportunity to develop a greater knowledge and application of GIS in the framework of higher education. In architecture, this can be achieved by problem solving based on real case scenarios, which can benefit from GIS-based techniques and analysis capabilities. In this paper, the authors aim to present a review of the use of GIS in teaching and research in architecture to assess its level in different European programmes. Experiences from three European universities (University of Seville, Spain, University of Beira Interior, Portugal, and Technical University of Crete, Greece), which are among the few in their respective countries that promote the inclusion of GIS in architectural education, particularly in the fields of urban and regional planning and architectural heritage, are compared and framed within the European scenario. The paper concludes with a reflection on the three universities’ practice compared to the leading European architecture programmes listed in the main international university rankings. Main trends of future evolution on the use of GIS in architecture teaching are also presented.


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