When rain falls on the city, it creates urban runoff that cause flooding, erosion, and water pollution. Municipal engineers manage a complex network of technical and natural systems to treat and ...remove these temporary water flows from cities as quickly as possible. Urban runoff is frequently discussed in terms of technical expertise and environmental management, but it encompasses a multitude of such nontechnical issues as land use, quality of life, governance, aesthetics, and community identity, and is central to the larger debates on creating more sustainable and livable cities. In this book, Andrew Karvonen uses urban runoff as a lens to view the relationships among nature, technology, and society. Offering theoretical insights from urban environmental history, human geography, landscape and ecological planning, and science and technology studies as well as empirical evidence from case studies, Karvonen proposes a new relational politics of urban nature.After describing the evolution of urban runoff practices, Karvonen analyzes the urban runoff activities in Austin and Seattle--two cities known for their highly contested public debates over runoff issues and exemplary stormwater management practices. The Austin case study highlights the tensions among urban development, property rights, land use planning, and citizen activism; the Seattle case study explores the city's long-standing reputation for being in harmony with nature. Drawing on these accounts, Karvonen suggests a new relational politics of urban nature that is situated, inclusive, and action-oriented to address the tensions among nature, technology, and society.
The primary reference for the modeling of hydrodynamics and water quality in rivers, lake, estuaries, coastal waters, and wetlands This comprehensive text perfectly illustrates the principles, basic ...processes, mathematical descriptions, case studies, and practical applications associated with surface waters. It focuses on solving practical problems in rivers, lakes, estuaries, coastal waters, and wetlands. Most of the theories and technical approaches presented within have been implemented in mathematical models and applied to solve practical problems. Throughout the book, case studies are presented to demonstrate how the basic theories and technical approaches are implemented into models, and how these models are applied to solve practical environmental/water resources problems. This new edition of Hydrodynamics and Water Quality: Modeling Rivers, Lakes, and Estuaries has been updated with more than 40% new information. It features several new chapters, including one devoted to shallow water processes in wetlands as well as another focused on extreme value theory and environmental risk analysis. It is also supplemented with a new website that provides files needed for sample applications, such as source codes, executable codes, input files, output files, model manuals, reports, technical notes, and utility programs. This new edition of the book: * Includes more than 120 new/updated figures and 450 references * Covers state-of-the-art hydrodynamics, sediment transport, toxics fate and transport, and water quality in surface waters * Provides essential and updated information on mathematical models * Focuses on how to solve practical problems in surface waters—presenting basic theories and technical approaches so that mathematical models can be understood and applied to simulate processes in surface waters Hailed as "a great addition to any university library" by the Journal of the American Water Resources Association (July 2009), Hydrodynamics and Water Quality, Second Edition is an essential reference for practicing engineers, scientists, and water resource managers worldwide.
The current study was carried out to delineate the seasonal hydrochemical characteristics and to quantify the suitability of groundwater for drinking and irrigation purposes in an alluvial plain ...adjacent to a paper wastewater irrigation zone, northwest China. Groundwater samples were collected from 14 groundwater monitoring wells in pre-monsoon, monsoon and post-monsoon seasons, respectively. Statistical analysis and Chadha diagram were used to delineate the groundwater hydrochemical characteristics. The matter element extension analysis (MEEA) model was proposed to quantify the overall groundwater quality. Irrigation water quality indicators were applied to assess the suitability of groundwater for irrigation purpose. The research results show that the hydrochemical facies for the majority of the groundwater samples is SO
4
·Cl–Na type with some minor hydrochemical facies of HCO
3
–Ca·Mg, HCO
3
–Na, and Cl·SO
4
–Ca·Mg types. The sequences of ions are Na
+
> Ca
2+
> Mg
2+
> K
+
for cations, and HCO
3
−
> Cl
−
> SO
4
2−
> CO
3
2−
for anions. The major ions and contaminants in the groundwater are controlled by multiple factors including hydrogeological conditions, rock weathering, water–rock interactions and human activities. The values of pH, TDS and TH show reduction in the monsoon season, indicating slight improvement of water quality during the monsoon season. Water quality assessment results based on MEEA show that the overall groundwater quality in the wastewater irrigation zone is generally fair to poor quality. Some groundwater samples are even classified as very poor quality, which is unsuitable for human consumption. They are also unsuitable for irrigation because of potential sodium hazard and salinity hazard. Groundwater from the Yellow River irrigation zone and the alluvial plain is generally suitable for domestic and irrigation uses. Some local water sampling locations may experience water quality improvement during the monsoon season, which, however, will generally not affect the final water quality classification for domestic and irrigation purposes. Interestingly, the study also finds that the variation trend of the correlation degree computed from MEEA can be useful in determining water quality improvement. This study may provide insights for people to make educated decisions in efficient groundwater quality protection and sustainable groundwater quality management.
Development of river water quality indices—a review Sutadian, Arief Dhany; Muttil, Nitin; Yilmaz, Abdullah Gokhan ...
Environmental monitoring and assessment,
2016, 1-2016, 2016-Jan, 2016-1-00, 20160101, Letnik:
188, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The use of water quality indices (WQIs) as a tool to evaluate the status of water quality in rivers has been introduced since the 1960s. The WQI transforms selected water quality parameters into a ...dimensionless number so that changes in river water quality at any particular location and time could be presented in a simple and easily understandable manner. Although many WQIs have been developed, there is no worldwide accepted method for implementing the steps used for developing a WQI. Thus, there is a continuing interest to develop accurate WQIs that suit a local or regional area. This paper aimed to provide significant contribution to the development of future river WQIs through a review of 30 existing WQIs based on the four steps needed to develop a WQI. These steps are the selection of parameters, the generation of sub-indices, the generation of parameter weights and the aggregation process to compute the final index value. From the 30 reviewed WQIs, 7 were identified as most important based on their wider use and they were discussed in detail. It was observed that a major factor that influences wider use of a WQI is the support provided by the government and authorities to implement a WQI as the main tool to evaluate the status of rivers. Since there is a lot of subjectivity and uncertainty involved in the steps for developing and applying a WQI, it is recommended that the opinion of local water quality experts is taken, especially in the first three steps (through techniques like Delphi method). It was also observed that uncertainty and sensitivity analysis was rarely undertaken to reduce uncertainty, and hence such an analysis is recommended for future studies.
In the recent times, water quality of most of the rivers in India has been steadily degrading due to increasing numbers of point and non-point sources of pollution. The tremendous increase in ...population, rapid urbanization, change in irrigation patterns, and unplanned growth of industries without proper enforcement of environmental standards are some of the major causes for poor quality of river water. In addition, unpredictable and scanty rainfall is resulting in uncertain natural stream flow which further leads to uncertainty in assessing and predicting the quality of river water. This paper deals with the assessment of the overall status of water quality of a river by developing a fuzzy-based water quality evaluation system. The quality of water needed for different beneficial uses is based on the value of various parameters. Since the quality attributes of the parameters are fuzzy in nature, they have been described by the linguistic variables. The water quality index of each specific site is then calculated by aggregating the attributes with respect to their degree of importance, which is also expressed in the form of linguistic terms. Finally, a case study of the river Yamuna has been carried out to evaluate the fuzzy comprehensive water quality index (FCWQI). In this study, the FCWQI has been determined only for the use of water for drinking purposes though this model can be applied for other uses as well. The FCWQI developed herein is based on an integrated approach, which clearly describes the overall state of the water quality by a single rational number. Spatial and parametric sensitivity of the FCWQI model of the river basin is also determined using GIS-based geographically weighted regression technique. The methodology suggests a novel way of introducing parametric sensitivity in defining water quality indices used for surface water quality assessment.
The nitrogen cycle has been radically changed by human activities
. China consumes nearly one third of the world's nitrogen fertilizers. The excessive application of fertilizers
and increased ...nitrogen discharge from livestock, domestic and industrial sources have resulted in pervasive water pollution. Quantifying a nitrogen 'boundary'
in heterogeneous environments is important for the effective management of local water quality. Here we use a combination of water-quality observations and simulated nitrogen discharge from agricultural and other sources to estimate spatial patterns of nitrogen discharge into water bodies across China from 1955 to 2014. We find that the critical surface-water quality standard (1.0 milligrams of nitrogen per litre) was being exceeded in most provinces by the mid-1980s, and that current rates of anthropogenic nitrogen discharge (14.5 ± 3.1 megatonnes of nitrogen per year) to fresh water are about 2.7 times the estimated 'safe' nitrogen discharge threshold (5.2 ± 0.7 megatonnes of nitrogen per year). Current efforts to reduce pollution through wastewater treatment and by improving cropland nitrogen management can partially remedy this situation. Domestic wastewater treatment has helped to reduce net discharge by 0.7 ± 0.1 megatonnes in 2014, but at high monetary and energy costs. Improved cropland nitrogen management could remove another 2.3 ± 0.3 megatonnes of nitrogen per year-about 25 per cent of the excess discharge to fresh water. Successfully restoring a clean water environment in China will further require transformational changes to boost the national nutrient recycling rate from its current average of 36 per cent to about 87 per cent, which is a level typical of traditional Chinese agriculture. Although ambitious, such a high level of nitrogen recycling is technologically achievable at an estimated capital cost of approximately 100 billion US dollars and operating costs of 18-29 billion US dollars per year, and could provide co-benefits such as recycled wastewater for crop irrigation and improved environmental quality and ecosystem services.
•Twenty-one different WQI models were identified and reviewed.•Rivers are by far the most common application of WQI models.•Most models comprised of four key components, the specifics of which varied ...significantly.•Uncertainty and eclipsing problems are key issues affecting model accuracy.
The water quality index (WQI) model is a popular tool for evaluating surface water quality. It uses aggregation techniques that allow conversion of extensive water quality data into a single value or index. Globally, the WQI model has been applied to evaluate water quality (surface water and groundwater) based on local water quality criteria. Since its development in the 1960s, it has become a popular tool due to its generalised structure and ease-of-use. Commonly, WQI models involve four consecutive stages; these are (1) selection of the water quality parameters, (2) generation of sub-indices for each parameter (3) calculation of the parameter weighting values, and (4) aggregation of sub-indices to compute the overall water quality index. Several researchers have utilized a range of applications of WQI models to evaluate the water quality of rivers, lakes, reservoirs, and estuaries. Some problems of the WQI model are that they are usually developed based on site-specific guidelines for a particular region, and are therefore not generic. Moreover, they produce uncertainty in the conversion of large amounts of water quality data into a single index.
This paper presents a comparative discussion of the most commonly used WQI models, including the different model structures, components, and applications. Particular focus is placed on parameterization of the models, the techniques used to determine the sub-indices, parameter weighting values, index aggregation functions and the sources of uncertainty. Issues affecting model accuracy are also discussed.
Water quality evaluation is fundamental for water resources management. Water quality index (WQI) is an accurate and easily understandable method for assessing water quality for different purposes. ...In this study, the Iraqi water quality index (Iraq WQI) was constructed to be used to evaluate the Iraqi rivers for drinking. For this purpose, some statistical techniques, experts’ advice, literature reviews, and authors’ experience were used. First, the principal component analysis (PCA) method and the modified Delphi method were used to select the most influential water quality parameters and their relative weights. Second, the quality curves of selected parameters were drawn to calculate the WQI scores basing on the water quality standards. Of twenty-seven parameters, six parameters were chosen to be within the index depending on their effect on water quality in order to reflect the specific characteristics of the Iraqi waters. The Iraq WQI was applied to the Tigris River within Baghdad as a case study and for some sites on other Iraqi rivers, and gave acceptable results. Results revealed that the statistical techniques used in this paper can be applied in all Iraqi rivers considering their specific characteristics. Based on the reliability of the Iraq WQI, there is no longer a need to use Indices designed for water for other countries.
This work provides those involved in water purification research and administration with a comprehensive resource of methods for analyzing water to assure its safety from contaminants, both natural ...and human caused. The book first provides an overview of major water-related issues in developing and developed countries, followed by a review of issues of sampling for water analysis, regulatory considerations and forensics in water quality and purity investigations. The subsequent chapters cover microbial as well chemical contaminations from inorganic compounds, radionuclides, volatile and semi- volatile compounds, disinfectants, herbicides, and pharmaceuticals, including endocrine disruptors, as well as potential terrorist-related contamination. The last chapter describes the Grainger prize-winning filter that can remove arsenic from water sources and sufficiently protect the health of a large number of people. * Covers the scope of water contamination problems on a worldwide scale * Provides a rich source of methods for analyzing water to assure its safety from natural and deliberate contaminants * Describes the filter that won the $1 million Grainger prize and thereby highlighting an important approach to remediation
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