scholarly journals Characterization of Stormwater Runoff Based on Microbial Source Tracking Methods

2021 ◽  
Vol 12 ◽  
Author(s):  
Silvia Monteiro ◽  
Gaspar Queiroz ◽  
Filipa Ferreira ◽  
Ricardo Santos
Keyword(s):  
Urban Areas ◽  
Water Reuse ◽  
Stormwater Runoff ◽  
Fecal Contamination ◽  
Geographical Information ◽  
Rain Event ◽  
High Concentration ◽  
Environmental Waters ◽  
Fecal Matter ◽  
Source Markers

Rainfall and associated urban runoff have been linked to an increased deterioration of environmental waters, carrying several pollutants including pathogenic microorganisms. Such happens because fecal matter is washed into storm drainage pipes that are afterward released into environmental waters. Stormwater has not been extensively characterized as it is, because most studies are performed either on drainage pipes that are often impacted by sewage leakage or directly in environmental waters following a rain event. In this study, stormwater collected directly from the streets, was monitored for the presence of fecal indicator bacteria (FIB) and three potential important sources of fecal contamination in urban environments (human, cats, and dogs) in three distinct basins in Lisbon, Portugal. Stormwater was collected in sterilized plastic boxes inserted in the storm drains, therefore collecting only runoff. High concentration of fecal contamination was detected with a high percentage of the samples displayed at least one source of contamination. A strong relationship was found between the number of detected sources and the precipitation levels. Although no statistical correlation was found between the locations and the presence of FIB or source markers, the results show a trend in geographical information on the type of urban use in each basin. To the best of our knowledge, this is the first study analyzing the runoff collected directly from the streets. This study suggests that, in urban areas, stormwater runoff is highly impacted by fecal matter, not only from domestic animals but also from human origin, before any cross-contamination in the drainage system and may, by itself, pose a high risk to human health and the environment, particularly if water reuse of this water without further disinfection treatment is the final goal.

scholarly journals Accesibility to Basic Urban Services in Mbour City (Senegal): An Approach Based on Geographical Information System

2015 ◽  
Vol 9 (1) ◽  
pp. 47-62 ◽  
Author(s):  
Sokhna Thiam ◽  
Lucian Roșu ◽  
Ousmane Faye ◽  
Aminata Diène Niang ◽  
Ionel Muntele
Keyword(s):  
Urban Areas ◽  
Urban System ◽  
Spatial Accessibility ◽  
Geographical Information ◽  
High Concentration ◽  
Transportation Services ◽  
Urban Services ◽  
Basic Services ◽  
Spatial Analysis Method ◽  
The City

Abstract The uneven spatial distribution of basic facilities within urban areas is a major problem for developing countries like Senegal due to the emphasis of accessibility disparities and the use of this services. The efforts to quantify the problem and its consequences on people are constrained by the lack of satisfactory data and methods. The study seeks to examine the spatial accessibility to basic services (access to water, health, education, economic infrastructure and transportation services) in a very heterogeneous urban system and to highlight inequalities in access for improving the geographical accessibility and to ensure equity. The article explore the use of spatial analysis method (Closest Facility) to measure the potential accessibility to services and facilities in the city of Mbour. The analyses uses all the inhabited houses of the city as the potential demand. Results emphasis unequal access to basic urban services in the city and a center-periphery model with a high concentration of services around the city. The study demonstrates the utility of this method for the identification of disadvantaged areas, decision making and planning of basic services. It also provides paths for improving accessibility in urban areas with a high density of population.

scholarly journals Groundwater-Sewer Interaction in Urban Coastal Areas

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1774 ◽  
Author(s):  
Ting Liu ◽  
Xin Su ◽  
Valentina Prigiobbe
Keyword(s):  
Surface Water ◽  
Water Table ◽  
Urban Areas ◽  
Weather Conditions ◽  
Rain Event ◽  
Combined Sewer Overflows ◽  
High Concentration ◽  
Sewer Pipes ◽  
Model Combining ◽  
One Year

In this paper, a study of the potential causes of the occurrence of high concentration of Enterococcus Faecalis in surface water within urban areas in dry-weather conditions (DWCs) is presented. Two hypotheses were formulated: (1) undersized sewer system; and (2) groundwater infiltration into damaged sewer pipes. In both cases, more frequent combined sewer overflows (CSOs) may occur discharging untreated sewage into surface water. To evaluate the first hypothesis, a hydraulic model of a sewer was developed assuming a water-tight system. The simulation results show that CSOs never occur in DWCs but a rain event of intensity equal to 1/3 of one-year return period may trigger them. To evaluate the second hypothesis, a model combining sewer failure with groundwater level was developed to identify the sections of damaged sewer below the water table and, therefore, potentially affected by infiltration. The risk of infiltration exceeds 50% in almost half of the entire network even at the lowest calculated water table. Considering 50% of infiltration distributed throughout that part of the network, CSOs can occur also in DWCs.

scholarly journals Analysis of Stormwater Management Systems: Sustainable Approaches for Wuhan, China

2016 ◽  
Vol 9 (1) ◽  
pp. 89 ◽  
Author(s):  
Rong Sheng ◽  
Nawari O. Nawari
Keyword(s):  
Water Management ◽  
Water Reuse ◽  
System Analysis ◽  
Central City ◽  
Geographical Information ◽  
Storm Water ◽  
Wetland Protection ◽  
Land Form ◽  
Storm Water Management ◽  
Inland Inundation

<p>With the rapid pace of urbanization and drastic transformation of economic form, Wuhan, a central city of China is facing serious inland inundation problems in recent decades. This study intends to alleviate Wuhan’s storm water management problems in a sustainable way and give suggestions as to the improvement of residential area storm water management and lakeside wetland protection. Based on the data provided by Geographical Information System, analysis is done to the land form of the whole city and the change of its lake areas, which evidently demonstrates the influences of economic development on the natural environment of the city and reveals the causes of the inundation problems. Taking the population growth, land use and climate change into consideration, this research argues that strategies such as green roof fostering, neighbor-hood water reuse and wetland conservation can make a difference in stormwater drainage and prevention of inland inundation in Wuhan.</p>

Contextual Density and US Automotive CO2 Emissions across the Rural–Urban Continuum

2015 ◽  
Vol 40 (6) ◽  
pp. 590-615 ◽  
Author(s):  
Andrew Perumal ◽  
David Timmons
Keyword(s):  
Urban Areas ◽  
Methodological Approach ◽  
Fuel Efficiency ◽  
Geographical Information ◽  
Population Densities ◽  
Spatial Differences ◽  
Using Data ◽  
Household Travel ◽  
Vehicle Fuel Efficiency ◽  
National Household Travel Survey

Using data from the 2009 National Household Travel Survey, we quantify the effects of settlement patterns on individual driving habits and the resulting automotive carbon dioxide (CO2) emissions. We employ CO2 emissions to capture this impact accurately, as it reflects both vehicle miles traveled and any spatial differences in vehicle fuel efficiency choices. While previous studies have compared automotive travel in urban and suburban areas, our approach characterizes emissions across the entire US rural–urban gradient, focusing on the effects of population density. Rather than using categorical measures of contextual density (city, suburb, town, etc.), we use a geographical information system to calculate continuous measures of contextual density, that is, density at different proximities to households. These measures of contextual density allow us to model travel effects induced by the gravitational pull of the population densities of urban cores. Further, our methodological approach frames location choice as an endogenous treatment effect; that is, residential locations are not randomly assigned across our sample and significantly alter driving behavior. We find that individuals living in urban cores generate the lowest per capita automotive CO2 emissions, due to close proximities of population concentrations. Rather than attracting individuals who would likely have low CO2 emissions anyway, urban location apparently mitigates the emissions of people who would otherwise tend to have high automotive CO2 emissions. We find larger elasticities with respect to density than previous studies and also find that the attractive forces of population densities affect driving patterns at distances up to sixty-one kilometers outside of urban areas.

scholarly journals Measuring COVID-19 Vaccination Coverage to Support Healthcare Equity Decision-Making in Urban Areas

2021 ◽  
Author(s):  
Alireza Mohammadi ◽  
Abolfazl Mollalo ◽  
Robert Bergquist ◽  
Behzad Kiani
Keyword(s):  
Vaccination Coverage ◽  
Urban Areas ◽  
Geographical Information Systems ◽  
Public Hospitals ◽  
Geographical Information ◽  
Public Healthcare ◽  
Special Importance ◽  
Decision Matrix ◽  
Spatial Access ◽  
Public Health Decision

Abstract Background: Limited studies have been conducted on access to COVID-19 vaccines and identifying the most appropriate health centres for performing vaccination in metropolitan areas. This study aimed to measure potential spatial access to COVID-19 vaccination centres in Mashhad, the second-most populous city in Iran.Methods: The age structure of the urban census tracts was integrated into the enhanced two-step floating catchment area model to improve accuracy. The model was developed based on three different scenarios: only public hospitals, only public healthcare centres, and the top 20% healthcare centres were employed as potential vaccination facilities. The weighted decision-matrix and analytic hierarchy process based on four criteria (i.e. service area, accessibility index, capacity of vaccination centres, and distance to main roads) were used to choose potential vaccination centres with the highest suitability for residents.Results: Our findings indicate that including the both public hospitals and public healthcare centres can provide high accessibility to vaccination in central parts of the urban areas. However, using only public healthcare centres for vaccination can provide higher accessibility to vaccination sites in the eastern and north-eastern parts of the study area. Therefore, a combination of public hospitals and public healthcare centres is recommended for efficient vaccination coverage.Conclusions: Measuring spatial access to COVID-19 vaccination centres can provide valuable insights for urban public health decision-makers. Our model, coupled with geographical information systems (GIS), provides more efficient vaccination coverage by identifying the most suitable healthcare centres, which is of special importance when only few centres are available.

scholarly journals Modeling in Water Resources Management in East Nile Delta: Review

2020 ◽  
Vol 17 (2) ◽  
pp. 41-46
Author(s):  
Heba F. Abdelwahab ◽  
Elsayed M. Ramadan ◽  
Abdelazim M. Negm
Keyword(s):  
Water Resources ◽  
Water Supply ◽  
Water Reuse ◽  
Geographical Information Systems ◽  
Nile Delta ◽  
Mathematical Optimization ◽  
Water Shortage ◽  
Optimal Operation ◽  
Geographical Information ◽  
Modelling Studies

AbstractIt is acknowledged that providing a safe water supply for all countries is one of the major challenges of the twenty-first century. Egypt is one of the greatest countries affected in Africa and Middle East. The Nile is facing a major water shortage due to the limited water resources and the the demand is growing as a result high population growth and development in industrial and agricultural sectors. This paper has been motivated by the fact that there is no up-to-date literature review of the optimal operation of Water Resources. The analysis of the reviewed literature is structured along five broad branches: (1) Mathematical Optimization Modelling Studies, (2) Numerical Simulation Modelling Studies, (3) Geographical Information Systems “GIS” based Studies, (4) Ecological Studies, (5) Water Reuse Studies. This review is limited to surface water but groundwater has been inexplicitly included. The paper concludes the best way to identify knowledge to cover the gap between water supply and demands and to guide future researches on water resources planning and management.

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