scholarly journals A system for modelling groundwater contamination in water supply areas: chloride contamination from road de-icing as an example

2006 ◽  
Vol 37 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Riitta Lindström
Keyword(s):  
Water Supply ◽  
Groundwater Contamination ◽  
Management Strategies ◽  
Chloride Concentration ◽  
Geographical Information ◽  
Transport Models ◽  
The Road ◽  
Potential Groundwater ◽  
Pumping Rates ◽  
Different Parts

A system for modelling groundwater contamination in water supply areas is presented, consisting of the flow and transport models, MACRO for the unsaturated zone and MOC for the groundwater zone, coupled to the geographical information system, IDRISI. A graphical user interface links the different parts of the system. The system was applied to a water supply area located close to a major road south of Stockholm. Chloride was used as an indicator in determining the risk for groundwater contamination from the road. The future chloride concentration in the aquifer was predicted and the effects of different pumping rates on the chemistry of the water supply well were tested. Modelling results showed that the chloride concentration in the aquifer will increase substantially due to road de-icing and that it will take decades to lower the chloride concentration down to the original background values after an end to the use of de-icing salt. The system may serve as a valuable tool in a planning context. Potential groundwater contamination scenarios can be simulated, and alternative groundwater management strategies can be evaluated.

Assessment of hydrogeochemical processes and geogenic mercury pollution in coastal karstic aquifers in semi-arid environments

2020 ◽  
Author(s):  
Christos Pouliaris ◽  
Alexandra Spyropoulou ◽  
Ioannis Sarris ◽  
Chrysi Laspidou ◽  
Andreas Kallioras
Keyword(s):  
Water Supply ◽  
Water Demand ◽  
Tap Water ◽  
Chloride Concentration ◽  
Distribution Networks ◽  
Mercury Contamination ◽  
Arid Environments ◽  
Aquifer Salinization ◽  
Pumping Rates ◽  
The Town

<p>Water resources management in coastal where the freshwater availability is limited has often led to rising concerns about the capability of local resources to cover the increased water needs. This condition is especially amplified in areas whereextra stress is added to the water sources from overexploitation and/or quality degradation.</p><p>The present study is located in the island of Skiathos, which is one of the Greek islands that are most popular to tourists. Throughout the long touristic period the population of the island is steeply increased resulting to an increase in water demand compared to the remaining months.The island is dealing with serious water supply issues since groundwaterquality is deteriorated due to aquifer salinization and Hg contamination, making the tap water not safe for drinking and other household uses for more than a decade.</p><p>Mercury concentration in water for domestic usage is monitored systematically, with values up to 6 μg/L (maximum permitted European limit for total mercury in the drinking water is 1 μg/L).The local water utility company, in order to cover the increased water demand, intensifies the pumping from the main well resulting to sea intrusion in the aquifer. Mercury is present in the rocks of Skiathos with the form of the mineral cinnabar (HgS) and although it is practically insoluble, the increase of chloride concentration due to aquifer salinization, shifts the reaction equilibrium towards mercury solubilization by complexation with chloride. Thus, mercury is released from the rocks to the groundwater entering later on the water supply network.</p><p>In order to face the twofold problem of groundwater salinization and mercury contamination the present study aims at defining a threshold for thevolume that is abstracted from the aquifer on a daily basis. The investigation involves the development of a groundwater flow model covering an area of approximately 13.3 km<sup>2</sup> that is exploited for supplying the town of Skiathos with tap water. Information about the general hydrogeological conceptual model is derived from previous investigations in the area. The groundwater model achieves an optimizationof the groundwater pumping rates that prevent seawater from entering the aquifer and deteriorating the groundwater quality. Results show that a reduction of 27.2 % in the pumping rates, in combination with the already planned upgrade in the distribution networks, would prevent seawater from entering the aquifer and affecting groundwater reserves, while, at the same time, the need for tap water in the town of Skiathos is met.</p>

scholarly journals A New Heuristic Method for Transportation Network and Land Use Problem

2016 ◽  
Vol 8 (3) ◽  
pp. 94 ◽  
Author(s):  
Mouhamadou A.M.T. Bald ◽  
Babacar M. Ndiaye
Keyword(s):  
Land Use ◽  
Transportation Network ◽  
Heuristic Method ◽  
Optimization Techniques ◽  
Geographical Information ◽  
Mixed Integer ◽  
Individual Agent ◽  
The Road ◽  
Agent Simulation ◽  
Network Costs

Our paper deals with the Transportation Network and Land Use (TNLU) problem.  It consists in finding, simultaneously, the best location of urban area activities, as well as of the road network design that may minimize the moving cost in the network, and the network costs. We propose a new mixed integer programming formulation of the problem, and a new heuristic method for the resolution of TNLU. Then, we give a methodology to find locations or relocations of some Dakar region amenities (home, shop, work and leisure places), that may reduce travel time or travel distance. The proposed methodology mixes multi-agent simulation with combinatorial optimization techniques; that is individual agent strategies versus global optimization using Geographical Information System. Numerical results which show the effectiveness of the method,  and simulations based on the scenario of Dakar city are given.

Taking the road less taken: reorienting the state for periurban water security

2017 ◽  
Vol 18 (4) ◽  
pp. 528-545 ◽  
Author(s):  
Vishal Narain ◽  
Pranay Ranjan ◽  
Sumit Vij ◽  
Aman Dewan
Keyword(s):  
Action Research ◽  
Water Supply ◽  
Service Providers ◽  
Intervention Strategy ◽  
Water Security ◽  
Research Process ◽  
The State ◽  
The Road ◽  
Water Users ◽  
Building Community

This paper describes the intervention strategy to improve water security in Sultanpur, a village in periurban Gurgaon, India. Most approaches to improving natural resource management in periurban contexts focus on mobilising the community; little attention is paid to reorienting the state or strengthening the user-bureaucracy interface. This paper describes the action research process that was followed to reorient civic agencies engaged in the provisioning of water and to break from a situation of distrust and prisoners' dilemma between water users and service providers. The paper argues that the creation and provision of a platform for direct engagement between water users and service providers can be a key tool for improving periurban water security. These platforms can provide support in building community resilience to face challenges such as climate variability and urbanisation, both of which threaten periurban water security. The action research emphasises on building the community's capacity to ask for improved water supply and to negotiate with state service providers, rather than augmenting water supply physically.

Feasibility Study of Traffic Signals at Intersections in Peshawar, Pakistan

2012 ◽  
Vol 253-255 ◽  
pp. 1645-1649
Author(s):  
Rawid Khan ◽  
Ghulam Dastagir ◽  
Omar Shahid ◽  
Zeeshan Ahmed ◽  
Bashir Alam
Keyword(s):  
Traffic Management ◽  
Management Strategies ◽  
Traffic Signals ◽  
Level Of Service ◽  
Signal Timing ◽  
Traffic Data ◽  
Ongoing Research ◽  
The Road ◽  
Micro Simulation ◽  
Signal Time

The paper is part of an ongoing research project on traffic management strategies for Peshawar Pakistan. Traffic data collected and warrant tests checked at selected intersections. Peak hour vehicular volume warrant test selected and performed at intersections. Signal timing capacity and delay analysis performed and level of service determined for selected intersection. It was found that “for the same width of the road” the delay and level of service is different at different locations and the corresponding signal time is also different. Some data also analysed in 3D micro simulation.

scholarly journals GIS-Based Urban Road Network Accessibility Modeling Using MLR, ANN and ANFIS Methods

2021 ◽  
Vol 22 (1) ◽  
pp. 15-28
Author(s):  
K. Sai Sahitya ◽  
Csrk Prasad
Keyword(s):  
Network Structure ◽  
Road Network ◽  
Structural Parameters ◽  
Transportation Network ◽  
Sustainable Transportation ◽  
Geographical Information ◽  
Urban Road Network ◽  
Inference System ◽  
Urban Road ◽  
The Road

Abstract A sustainable transportation system is possible only through an efficient evaluation of transportation network performance. The efficiency of the transport network structure is analyzed in terms of its connectivity, accessibility, network development, and spatial pattern. This study primarily aims to propose a methodology for modeling the accessibility based on the structural parameters of the urban road network. Accessibility depends on the arrangement of the urban road network structure. The influence of the structural parameters on the accessibility is modeled using Multiple Linear Regression (MLR) analysis. The study attempts to introduce two methods of Artificial Intelligence (AI) namely Artificial Neural Networks (ANN) and Adaptive network-based neuro-fuzzy inference system (ANFIS) in modeling the urban road network accessibility. The study also focuses on comparing the results obtained from MLR, ANN and ANFIS modeling techniques in predicting the accessibility. The results of the study present that the structural parameters of the road network have a considerable impact on accessibility. ANFIS method has shown the best performance in modeling the road network accessibility with a MAPE value of 0.287%. The present study adopted Geographical Information Systems (GIS) to quantify, extract and analyze different features of the urban transportation network structure. The combination of GIS, ANN, and ANFIS help in improved decision-making. The results of the study may be used by transportation planning authorities to implement better planning practices in order to improve accessibility.

scholarly journals APPROACH ON DETECTION OF SITUATION OF POTENTIAL RISK TO HEALTH, RELATED TO WATER QUALITY: AN EXAMPLE

2018 ◽  
Vol 15 (29) ◽  
pp. 123-135
Author(s):  
S. DOVIDAUSKAS ◽  
I. A. OKADA ◽  
M. H. IHA ◽  
Á G. CAVALLINI ◽  
M. A. DE OLIVEIRA
Keyword(s):  
Water Supply ◽  
Groundwater Contamination ◽  
Potential Risk ◽  
Nitrate Contamination ◽  
Nitrate Group ◽  
Human Consumption ◽  
Public Water Supply ◽  
Microbiological Parameters ◽  
Confirmatory Tests ◽  
Health Related

This work describes the approach of a situation of potential risk to health due to nitrate contamination in water intended for human consumption, found in a study conducted in 88 municipalities in the Northeast region of the State of São Paulo (Brazil). 4,347 public water supply samples were analysed for 21 physico-chemical and 2 microbiological parameters. A municipality was distinguished from the others with regard to higher nitrate levels, while the principal components analysis showed that it belonged to a group of 14 municipalities (nitrate group). The Sanitary Surveillance Group was then contacted and, after confirmatory tests in new public water supply samples, analyses were performed on water samples from 16 wells in the county. The groundwater contamination was found, and technical meetings were held. One of the deliberations was the repetition of water analyses of the 16 wells. Consolidated results showed that the 5 wells had nitrate levels above the maximum value permitted by legislation. To mitigate nitrate groundwater contamination of that municipality actions are being taken as a result of 3 technical meetings already held. The other municipalities of the nitrate group are being monitored.

scholarly journals APPLICATION OF MLS DATA TO THE ASSESSMENT OF SAFETY-RELATED FEATURES IN THE SURROUNDING AREA OF AUTOMATICALLY DETECTED PEDESTRIAN CROSSINGS

2018 ◽  
Vol XLII-2 ◽  
pp. 1067-1074 ◽  
Author(s):  
M. Soilán ◽  
B. Riveiro ◽  
A. Sánchez-Rodríguez ◽  
L. M. González-deSantos
Keyword(s):  
Laser Scanning ◽  
Geographical Information ◽  
Mobile Mapping ◽  
Cloud Data ◽  
Traffic Lights ◽  
The Road ◽  
Processing Module ◽  
Pedestrian Crossing ◽  
Mobile Mapping Systems ◽  
Mapping Systems

During the last few years, there has been a huge methodological development regarding the automatic processing of 3D point cloud data acquired by both terrestrial and aerial mobile mapping systems, motivated by the improvement of surveying technologies and hardware performance. This paper presents a methodology that, in a first place, extracts geometric and semantic information regarding the road markings within the surveyed area from Mobile Laser Scanning (MLS) data, and then employs it to isolate street areas where pedestrian crossings are found and, therefore, pedestrians are more likely to cross the road. Then, different safety-related features can be extracted in order to offer information about the adequacy of the pedestrian crossing regarding its safety, which can be displayed in a Geographical Information System (GIS) layer. These features are defined in four different processing modules: Accessibility analysis, traffic lights classification, traffic signs classification, and visibility analysis. The validation of the proposed methodology has been carried out in two different cities in the northwest of Spain, obtaining both quantitative and qualitative results for pedestrian crossing classification and for each processing module of the safety assessment on pedestrian crossing environments.

scholarly journals Well Water Site Selection at Local Scale Using Geographical Information System for Flood Victim in Malaysia

2018 ◽  
Vol 50 (2) ◽  
pp. 205
Author(s):  
Koh Liew See ◽  
Nayan Nasir ◽  
Saleh Yazid ◽  
Hashim Mohmadisa ◽  
Mahat Hanifah ◽  
...  
Keyword(s):  
Water Supply ◽  
Spatial Data ◽  
Water Sources ◽  
Geographical Information ◽  
Well Water ◽  
Clean Water ◽  
Flood Events ◽  
Field Methods ◽  
The Impact ◽  
Area Data

Clean water supply is a major problem among flood victims during flood events. This article aims to determine the sites of well water sources that can be utilised during floods in the District of Kuala Krai, Kelantan. Field methods and Geographic Information Systems (GIS) were applied in the process of selecting flood victim evacuation centres and wells. The data used were spatial data obtained primarily, namely the well data, evacuation centre data and flood area data. The well and evacuation centre data were obtained by field methods conducted to determine the position of wells using global positioning system tools, and the same for the location of the evacuation centres. Information related to evacuation centres was obtained secondarily from multiple agencies and gathered into GIS as an evacuation centre attribute. The flood area data was also obtained via secondary data and was digitised using the ArcGIS software. The data processing was divided into two stages, namely the first stage of determining the flood victim evacuation centres to be used in this research in a structural manner based on two main criteria which were the extent to which an evacuation centre was affected by the flood and the highest capacity of victims for each district with the greatest impact to the flood affected population. The second stage was to determine the location of wells based on three criteria, namely i) not affected by flood, ii) the closest distance to the selected flood victim evacuation centre and iii) located at different locations. Among the main GIS analyses used were locational analysis, overlay analysis, and proximity analysis. The results showed that four (4) flood evacuation centres had been chosen and matched the criteria set, namely SMK Sultan Yahya Petra 2, SMK Manek Urai Lama, SMK Laloh and SK Kuala Gris. While six (6) wells had been selected as water sources that could be consumed by the flood victims at 4 evacuation centres in helping to provide clean water supply, namely Kg. Keroh 16 (T1), Kg. Batu Mengkebang 10 (T2), Lepan Meranti (T3), Kg. Budi (T4), Kg. Jelawang Tengah 2 (T5) and Kg. Durian Hijau 1 (T6). With the presence of the well water sources that can be used during flood events, clean water supply can be distributed to flood victims at the evacuation centres. Indirectly, this research can reduce the impact of floods in the future, especially in terms of clean water supply even during the hit of a major flood.

scholarly journals Air quality trends in Europe over the past decade: a first multi-model assessment

2011 ◽  
Vol 11 (7) ◽  
pp. 19029-19087 ◽  
Author(s):  
A. Colette ◽  
C. Granier ◽  
Ø. Hodnebrog ◽  
H. Jakobs ◽  
A. Maurizi ◽  
...  
Keyword(s):  
Air Quality ◽  
Management Strategies ◽  
Anthropogenic Emissions ◽  
Model Assessment ◽  
Transport Models ◽  
The Past ◽  
Current State ◽  
Primary Compounds ◽  
Long Term Trend

Abstract. We discuss the capability of current state-of-the-art chemistry and transport models to reproduce air quality trends and inter annual variability. Documenting these strengths and weaknesses on the basis of historical simulations is essential before the models are used to investigate future air quality projections. To achieve this, a coordinated modelling exercise was performed in the framework of the CityZEN European Project. It involved six regional and global chemistry-transport models (Bolchem, Chimere, Emep, Eurad, OsloCTM2 and Mozart) simulating air quality over the past decade in the Western European anthropogenic emissions hotspots. Comparisons between models and observations allow assessing the skills of the models to capture the trends in basic atmospheric constituents (NO2, O3, and PM10). We find that the trends of primary constituents are well reproduced (except in some countries – owing to their sensitivity to the emission inventory) although capturing the more moderate trends of secondary species such as O3 is more challenging. Apart from the long term trend, the modelled monthly variability is consistent with the observations but the year-to-year variability is generally underestimated. A comparison of simulations where anthropogenic emissions are kept constant is also investigated. We find that the magnitude of the emission-driven trend exceeds the natural variability for primary compounds. We can thus conclude that emission management strategies have had a significant impact over the past 10 yr, hence supporting further emission reductions strategies.

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