Mass Balance of Nitrogen and Phosphorus in an Agricultural Watershed PDF Download

Author:
Publisher:
ISBN:
Category : Groundwater
Languages : en
Pages : 248

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Author: Kevin A. Erb
Publisher:
ISBN:
Category : Biomass chemicals
Languages : en
Pages : 274

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Author: OECD
Publisher: OECD Publishing
ISBN: 9264186212
Category :
Languages : en
Pages : 185

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Provides comprehensive data and analysis on the environmental performance of agriculture in OECD countries since 1990, covering soil, water, air and biodiversity and looking at recent policy developments in all 34 countries.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309069483
Category : Science
Languages : en
Pages : 422

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Book Description
Environmental problems in coastal ecosystems can sometimes be attributed to excess nutrients flowing from upstream watersheds into estuarine settings. This nutrient over-enrichment can result in toxic algal blooms, shellfish poisoning, coral reef destruction, and other harmful outcomes. All U.S. coasts show signs of nutrient over-enrichment, and scientists predict worsening problems in the years ahead. Clean Coastal Waters explains technical aspects of nutrient over-enrichment and proposes both immediate local action by coastal managers and a longer-term national strategy incorporating policy design, classification of affected sites, law and regulation, coordination, and communication. Highlighting the Gulf of Mexico's "Dead Zone," the Pfiesteria outbreak in a tributary of Chesapeake Bay, and other cases, the book explains how nutrients work in the environment, why nitrogen is important, how enrichment turns into over-enrichment, and why some environments are especially susceptible. Economic as well as ecological impacts are examined. In addressing abatement strategies, the committee discusses the importance of monitoring sites, developing useful models of over-enrichment, and setting water quality goals. The book also reviews voluntary programs, mandatory controls, tax incentives, and other policy options for reducing the flow of nutrients from agricultural operations and other sources.

Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309679702
Category : Science
Languages : en
Pages : 423

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Book Description
New York City's municipal water supply system provides about 1 billion gallons of drinking water a day to over 8.5 million people in New York City and about 1 million people living in nearby Westchester, Putnam, Ulster, and Orange counties. The combined water supply system includes 19 reservoirs and three controlled lakes with a total storage capacity of approximately 580 billion gallons. The city's Watershed Protection Program is intended to maintain and enhance the high quality of these surface water sources. Review of the New York City Watershed Protection Program assesses the efficacy and future of New York City's watershed management activities. The report identifies program areas that may require future change or action, including continued efforts to address turbidity and responding to changes in reservoir water quality as a result of climate change.

Author: Christopher Anand Scott
Publisher:
ISBN:
Category :
Languages : en
Pages : 296

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Author: Jimmy Ray Williams
Publisher:
ISBN:
Category : Soil conservation
Languages : en
Pages : 166

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Models are developed for predicting daily sediment, phosphorus, and nitrogen yields from small watersheds; routing the yields through large watersheds; and determining the optimal operating policy of the large watershed. Sediment yield prediction with MUSLE is refined by dividing subwatersheds into land capability classes to determine the linear factors. The phosphorus and nitrogen yield models, based on loading functions, are adapted to individual storm prediction by simulating nutrient concentrations in the soil, using daily predicted sediment yields, and computing enrichment ratios. Phosphorus and nitrogen balance models are developed to predict daily nutrient concentrations in the soil. The nitrogen balance model is also used in predicting nitrate yield. The routing model is based on sediment routing and phosphorus and nitrogen loading functions. Sediment routing is refined by replacing the median sediment particle size with the entire particle size distribution. Also the routing coefficient is determined for each reach instead of using one routing coefficient for the entire watershed as in the original method. Phosphorus and nitrogen routing is accomplished by using the routed particle size distributions to calculate enrichment ratios for the loading functions. Nitrate in the runoff is considered a conservative material for the duration of an individual flood. SPNM, a problem-oriented computer language is developed to make routing more convenient. SPNM is designed to predict sediment, phosphorus, and nitrogen yields for individual storms on small watersheds and to route the yields through large watersheds.

Author: Yehuda Benjamin Zitter
Publisher:
ISBN:
Category : Soil conservation
Languages : en
Pages : 464

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Author: Xiaoyi Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages : 61

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Book Description
Over the last century, human activities have dramatically increased the inputs of nitrogen (N) and phosphorus (P) to land, resulting in increased eutrophication of aquatic systems, and degradation of drinking water quality. Although many changes in management have been adopted to mitigate these impacts, little improvement has been observed in water quality. Multiple N and P mass balance studies have indicated imbalances between inputs and outputs of N and P in anthropogenic landscapes. In this work, historical (1901-2011) N and P budgets for the Grand River Watershed (GRW) in southwestern Ontario were developed using the NANI/NAPI (net anthropogenic N/P input) framework. NANI was calculated as the sum of four different components: commercial fertilizer N application, atmospheric N deposition, net food and feed imports, and biological N fixation. A similar budgeting method was used to estimate NAPI, which includes fertilizer P application, net food and feed imports and detergent P use by humans. Relevant data was obtained from the Canadian agricultural census, Environment Canada, and literature estimates. Our results showed that annual NANI and NAPI values increased approximate 2-fold since 1901, with peak net inputs in 1986 and 1976, respectively. Increases in NANI over time can primarily be attributed to high atmospheric N deposition, fertilizer N application and biological N fixation, while increases in NAPI are primarily due to increased fertilizer P application. Spatially, the hotspots for both NANI and NAPI have since the early 1950s shifted to the central sub-watersheds of the GRW, which can be attributed to greater urbanization and agricultural intensification in the central area. The historical NANI and NAPI estimates obtained for the GRW provide insights into the spatio-temporal patterns in NANI and NAPI, and can facilitate better N and P management strategies.

Author: Scott W. Ator
Publisher: Geological Survey (USGS)
ISBN: 9781411332621
Category : Chesapeake Bay Watershed
Languages : en
Pages : 27

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Book Description
Spatially Referenced Regression on Watershed Attributes (SPARROW) was used to provide empirical estimates of the sources, fate, and transport of total nitrogen (TN) and total phosphorus (TP) in the Chesapeake Bay watershed, and the mean annual TN and TP flux to the bay and in each of 80,579 nontidal tributary stream reaches. Restoration efforts in recent decades have been insufficient to meet established standards for water quality and ecological conditions in Chesapeake Bay. The bay watershed includes 166,000 square kilometers of mixed land uses, multiple nutrient sources, and variable hydrogeologic, soil, and weather conditions, and bay restoration is complicated by the multitude of nutrient sources and complex interacting factors affecting the occurrence, fate, and transport of nitrogen and phosphorus from source areas to streams and the estuary. Effective and efficient nutrient management at the regional scale in support of Chesapeake Bay restoration requires a comprehensive understanding of the sources, fate, and transport of nitrogen and phosphorus in the watershed, which is only available through regional models. The current models, Chesapeake Bay nutrient SPARROW models, version 4 (CBTN_v4 and CBTP_v4), were constructed at a finer spatial resolution than previous SPARROW models for the Chesapeake Bay watershed (versions 1, 2, and 3), and include an updated timeframe and modified sources and other explantory terms.