Download or read book Temporal Changes of Nutrients Within the Lower Grand River Watershed and Selected Sites written by Weston Scott Duley and published by . This book was released on 2019 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report presents the results of a study carried out in collaboration with the U.S. Geological Survey (USGS) and the Missouri Department of Natural Resources (MDNR) to estimate total nitrogen (TN) and total phosphorus (TP) at five USGS monitoring sites within Lower Grand River Watershed (LGRW) and two monitoring sites on the Missouri River. The objective of this study was to quantify temporal changes in TN and TP concentrations and compare those to best management practices (BMPs). In this study, the approach to the analysis of long-term surface water-quality data by using Weighted Regressions on Time, Discharge and Seasons models (WRTDS). The model method is formulated to enable flexibility in long-term trend representations, discharge-related components, and concentrations of TN and TP seasonal components. The WRTDS model is designed make estimates of the actual concentrations and fluxes as well as estimates that eliminate the influence of year-to-year variations in discharge. The method is designed to use weighted regressions on time, discharge and season to estimate concentrations. This method is designed to be a tool which identifies changes that are taking place within a watershed related to surface-water nonpoint sources of contamination. In this case, the results given by the WRTDS models were used to determine if best management practices implemented over the study period, have had any significant effect on TN and TP concentrations. At each monitoring location, water quality data was compared to temporal changes within the watershed to determine the effectiveness of BMPs implemented over the study period"--Abstract, page iii.

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 1424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nitrous Oxide and Nitrate in the Grand River Ontario written by Madeline Simone Rosamond and published by . This book was released on 2013 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increased use of synthetic nitrogen fertilizers since the early 1900s has resulted in greater food production but also problems with nitrogen pollution in freshwaters. Nitrate (NO3-) is a common pollutant in rivers and groundwater in agricultural watersheds; the drinking water limit in Canada is 10 mg N/L. Microbial processing of NO3- and ammonium (NH4+) can produce nitrous oxide (N2O), a potent greenhouse gas responsible for about 5% of the greenhouse effect. Rivers provide a complex environment, where a variety of redox conditions, available substrates and microbial populations can co-exist on small spatial and temporal scales. Therefore, many questions remain about N cycling in river environments. N2O is produced during anoxic microbial NO3- or NO2- reduction to N2 (denitrification) and oxic microbial NH4+ oxidation to NO3- (nitrification). A significant portion (~25%) of global anthropogenic N2O is produced in rivers and estuaries, but mechanisms are not clear and predictability is poor. The United Nations Intergovernmental Panel on Climate Change (IPCC) provides default equations for calculating N2O emission estimates, in which annual NO3- loading to rivers is positively linearly related to N2O emissions. However, it is unclear how sound these linear relationships are and if measured N2O emissions are similar to IPCC estimates. The Grand River watershed is the largest in southern Ontario. Nutrient discharge to the Grand River is high due to extensive agriculture and high urban populations. The river often has a hypoxic water column due to high community respiration in summer. However, although nitrogen pollution is significant, N cycling is not well understood in the river. This thesis shows that NO3- and NH4+ do not typically change on the diel scale, with the exception of two sites downstream of wastewater treatment plants (WWTPs). However, N2O concentration changes dramatically. N2O concentrations are higher at night and lower during the day for most sites, but are reversed at very low-nutrient sites. N2O is therefore a sensitive indicator of changes in N cycling that may not be evident from NO3- and NH4+ concentrations or stable isotope ratios. Additionally, this work shows the importance of having a sampling design that captures diel variability in N2O. Previous work in rivers and streams worldwide focused on the appropriate N2O:NO3- ratio used to predict N2O emissions. In contrast, this thesis shows that there is a significant but very weak relationship between instantaneous N2O emissions and NO3- concentrations. However, there is a much stronger negative exponential relationship between DO and N2O. Annual N2O emissions tripled between 2006 and 2007 but NO3- masses in the river were only 10% higher, likely because river levels were lower and anoxia more prevalent in 2007. This research suggests that the IPCC needs a new conceptual model for N2O-NO3- relationships in rivers. N2O is produced in rivers, partially due to microbial processing of NO3- and NH4+ from WWTP effluent. However, WWTP effluent may also include dissolved N2O and CH4 but this previously had not been directly quantified. It was also unclear if stable isotopic ratios of NH4+, NO3-, N2O and CH4 in WWTP effluent were distinct from river sources and could be used for effluent tracing. N2O emissions from three WWTPs in the Grand River Watershed were measured over 24 hours in summer and winter. N2O emissions were similar to direct emissions from WWTPs but CH4 emissions were about an order of magnitude lower than direct WWTP emissions. This is a previously-ignored source of N2O and CH4 to the atmosphere. While stable isotopic ranges of NO3- and NH4+ were not always distinct from river sources, [delta]15N-N2O, [delta]18O-N2O and [delta]13C-CH4 were distinct, making them potentially useful tracers of WWTP effluent in rivers. N2O isotopic signatures may help determine production and removal processes in rivers, but isotopic effects of the major production pathway, denitrification, have not been characterized for river sediments. This was addressed by preparing anoxic laboratory incubations of river sediment from two sites (non-urban and urban) in the Grand River and measuring stable isotopic effects of N2O production via denitrification. Stable isotopic fractionations were similar to published values but, surprisingly, strongly negatively correlated to production rate, even though NO3- substrate was plentiful. This novel finding suggests that N2O reduction resulting in isotopic effects is more prevalent in high-substrate systems than previously thought, and that N2O reduction may be inhibited by high NO3- or NO2- or by lags in N2O reductase activity in high N2O-production incubations. This could explain why N2O emissions from the Grand River are lower than predicted by IPCC equations, which assume that N2O:(N2O+N2) ratios produced by denitrification are constant. Concern about NO3- export to freshwater lakes and to oceans is growing, but the role of large, eutrophic rivers in removing watershed NO3- loading via denitrification and biotic assimilation is not clear. To understand how much NO3- the Grand River receives, and how much it removes annually, a NO3- isotope mass balance for the Grand River was created. The river denitrified between 0.5% and 17% of incoming NO3-, less than the 50% suggested by the IPCC. This is surprising, as the river is well mixed, has moderate to high NO3- concentrations, experiences hypoxia (promoting denitrification), and has extensive biomass (biofilm and macrophytes) that assimilate N. However, the river's short residence time (~3 days not counting reservoirs), organic carbon-poor sediment and mineralization of organic matter could contribute to low denitrification rates. These findings suggest that denitrification rates in rivers worldwide could be lower than previously estimated. Although error was high, most [delta]15N-NO3- values for losses were in the expected range for denitrification and most [delta]15N-NO3- values for gains were within ranges from tributaries, WWTP effluent and groundwater measured in the watershed. The model suggests that 68% to 83% of N loads to the watershed are lost before entering the Grand River, and 13% is exported to Lake Erie, leaving 5 to 19% lost in the Grand River from a combination of denitrification, assimilation and storage. These findings suggest that large rivers are much less efficient in denitrification than other locations in watersheds such as small streams, ponds, groundwater and riparian zones. They also indicate that agricultural NO3- loading is much higher than WWTP effluent, suggesting that N management strategies should focus on agricultural runoff and groundwater. Given that N2O:NO3- relationships are weak and non-linear in the Grand River, a new conceptual model for N2O:NO3- relationships is presented. First, the Grand River dataset was supplemented with data from high-oxygen streams in southern Ontario. Regression tree analysis shows a weak relationship between NO3- and N2O in these streams with no other factors (temperature, DO, NH4+, TP, DOC, etc.) improving fit. A conceptual model was then created, which posits that N2O emission variability (between and within sites) increases with NO3- concentration when NO3- concentrations are above the threshold for NO3- limitation. The global dataset does not dispute this model, though a NO3- threshold was not clear. The lack of sites with both high NO3- and high N2O may indicate a paucity of research on eutrophic sites. Alternatively, high NO3- may indicate oxic conditions (i.e. little to no denitrification to remove it) which are incompatible with very high N2O emissions. In this case, the conceptual model can be modified such that N2O variability decreases when NO3- > ~ 4 mg N/L. The work also shows that low DO consistently results in high N2O emissions but high temperatures result in a very large range of N2O emissions. This approach allows N2O emissions, which have very high variability and are difficult to predict, to be constrained to likely ranges.

Download or read book US 31 from I 196 in Allegan County North to I 96 in Muskegon County written by and published by . This book was released on 2010 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Indicators written by Robert H. Armon and published by Springer. This book was released on 2015-01-05 with total page 1061 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental indicators are the first line of warning against hazards caused by humans or nature catastrophes to prevent diseases and death of living organisms. The present book covers a large variety of environmental indicators from physical-chemistry through economical, bioinformatics, electromagnetic irradiation and health aspects, all dealing with environmental pollution. This volume has been intended to environmentalists, engineers, scientists and policy makers as well to anybody interested in the latest development in the indicator field.

Download or read book General Technical Report RM written by and published by . This book was released on 1989 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Watershed Hydrology written by Vijay P. Singh and published by Allied Publishers. This book was released on 2003 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Michigan Water Chemistry Trend Monitoring Report written by and published by . This book was released on 1998 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Extreme Hydrology and Climate Variability written by Assefa M. Melesse and published by Elsevier. This book was released on 2019-07-03 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme Hydrology and Climate Variability: Monitoring, Modelling, Adaptation and Mitigation is a compilation of contributions by experts from around the world who discuss extreme hydrology topics, from monitoring, to modeling and management. With extreme climatic and hydrologic events becoming so frequent, this book is a critical source, adding knowledge to the science of extreme hydrology. Topics covered include hydrometeorology monitoring, climate variability and trends, hydrological variability and trends, landscape dynamics, droughts, flood processes, and extreme events management, adaptation and mitigation. Each of the book's chapters provide background and theoretical foundations followed by approaches used and results of the applied studies. This book will be highly used by water resource managers and extreme event researchers who are interested in understanding the processes and teleconnectivity of large-scale climate dynamics and extreme events, predictability, simulation and intervention measures. Presents datasets used and methods followed to support the findings included, allowing readers to follow these steps in their own research Provides variable methodological approaches, thus giving the reader multiple hydrological modeling information to use in their work Includes a variety of case studies, thus making the context of the book relatable to everyday working situations for those studying extreme hydrology Discusses extreme event management, including adaption and mitigation

Download or read book Predicting the Runoff from Storm Rainfall written by Max Adam Kohler and published by . This book was released on 1951 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The estimation of the volume of runoff to be expected from a given volume of rainfall is a fundamental problem in flood forecasting. Such estimates are necessary before the unit hydrograph or other techniques can be used to predict the streamflow hydrograph. The authors describe the technique now used at the River Forecast Centers of the U.S. Weather Bureau for evaluating the effect of season, antecedent conditions, duration of rainfall and rainfall amount in determining the portion of the rainfall contributing to storm runoff. Special problems encountered in flood forecasting are emphasized. The technique, developed and tested over several years, yields a high degree of accuracy in estimated runoff. Although prepared by empirical procedures, the close agreement between relations for basins of similar hydrologic characteristics suggests that rational parameter have been adopted. The similarity between relations also simplifies the work required for their preparation.

Download or read book The Seine River Basin written by Nicolas Flipo and published by Springer Nature. This book was released on 2021-01-30 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book reviews the water-agro-food and socio-eco-system of the Seine River basin (76,000 km2), and offers a historical perspective on the river’s long-term contamination. The Seine basin is inhabited by circa 17 million people and is impacted by intensive agricultural practices and industrial activities. These pressures have gradually affected its hydrological, chemical and ecological functioning, leading to a maximum chemical degradation between the 1960s and the 1990s. Over the last three decades, while major water-quality improvements have been observed, new issues (e.g. endocrine disruptors, microplastics) have also emerged. The state of the Seine River network, from the headwaters to estuary, is increasingly controlled by the balance between pressures and social responses. This socio-ecosystem provides a unique example of the functioning of a territory under heavy anthropogenic pressure during the Anthropocene era. The achievements made were possible due to the long-term PIREN Seine research program, established in 1989 and today part of the French socio-ecological research network “Zones Ateliers”, itself part of the international Long-term Socio-economic and Ecological Research Network (LTSER). Written by experts in the field, the book provides an introduction to the water budget and the territorial metabolism of the Seine basin, and studies the trajectories and impact of various pollutants in the Seine River. It offers insights into the ecological functioning, the integration of agricultural practices, the analysis of aquatic organic matter, and the evolution of fish assemblages in the Seine basin, and also presents research perspectives and approaches to improve the water quality of the Seine River. Given its scope, it will appeal to environmental managers, scientists and policymakers interested in the long-term contamination of the Seine River.

Download or read book Effects of urban development on stream ecosystems in nine metropolitan study areas across the United States written by James F. Coles and published by . This book was released on 2012 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Riparian Areas written by National Research Council and published by National Academies Press. This book was released on 2002-10-10 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Clean Water Act (CWA) requires that wetlands be protected from degradation because of their important ecological functions including maintenance of high water quality and provision of fish and wildlife habitat. However, this protection generally does not encompass riparian areasâ€"the lands bordering rivers and lakesâ€"even though they often provide the same functions as wetlands. Growing recognition of the similarities in wetland and riparian area functioning and the differences in their legal protection led the NRC in 1999 to undertake a study of riparian areas, which has culminated in Riparian Areas: Functioning and Strategies for Management. The report is intended to heighten awareness of riparian areas commensurate with their ecological and societal values. The primary conclusion is that, because riparian areas perform a disproportionate number of biological and physical functions on a unit area basis, restoration of riparian functions along America's waterbodies should be a national goal.

Download or read book Microbial Ecology in Reservoirs and Lakes written by Haihan Zhang and published by Frontiers Media SA. This book was released on 2020-08-14 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving Southwestern Riparian Areas Through Watershed Management written by Leonard F. DeBano and published by . This book was released on 1989 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microbial Source Tracking written by Jorge W. Santo Domingo and published by Emerging Issues in Food Safety. This book was released on 2007 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a state-of-the-art review of the current technology and applications being utilized to identify sources of fecal contamination in waterways. - Serves as a useful reference for researchers in the food industry, especially scientists investigating etiological agents responsible for food contamination. - Provides background information on MST methods and the assumptions and limitations associated with their use. - Covers a broad range of topics related to MST, including environmental monitoring, public health and national security, population biology, and microbial ecology. - Offers valuable insights into future research directions and technology developments.