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Author Kang, Shujiang ♦ Lin, Henry ♦ Gburek, William J. ♦ Folmar, Gordon J. ♦ Lowery, Birl
Source World Health Organization (WHO)-Global Index Medicus
Content type Text
Publisher American Society of Agronomy
File Format HTM / HTML
Language English
Difficulty Level Medium
Subject Domain (in DDC) Social sciences ♦ Social problems & services; associations ♦ Social welfare problems & services ♦ Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Life sciences; biology ♦ Biochemistry ♦ Technology ♦ Medicine & health ♦ Personal health & safety ♦ Pharmacology and therapeutics ♦ Diseases ♦ Agriculture & related technologies ♦ Techniques, equipment & materials
Subject Domain (in MeSH) Inorganic Chemicals ♦ Chemicals and Drugs ♦ Technology, Industry, and Agriculture ♦ Technology and Food and Beverages ♦ Environment and Public Health ♦ Health Care
Subject Keyword Discipline Environmental Health ♦ Agriculture ♦ Nitrates ♦ Chemistry ♦ Water ♦ Environmental Monitoring ♦ Methods ♦ Journal Article ♦ Research Support, U.s. Gov't, Non-p.h.s.
Abstract Management of agricultural nonpoint-source pollution continues to be a challenge because of spatial and temporal variability. Using stream order as an index, we explored the distribution of nitrate concentration and load along the stream network of a large agricultural watershed in Pennsylvania-the East Mahantango Creek Watershed and two of its sub-watersheds. To understand nitrate concentration variation in the stream water contributed from ground water, this study focused on baseflow. Impacts of agricultural land use area on baseflow nitrate in the stream network were investigated. Nitrate concentration showed a general decreasing trend with increasing stream order based on stream order averaged values; however, considerable spatial and temporal variability existed within each snapshot sampling. Nitrate loads increased with stream order in a power function because of the dominant effect of stream flow rate over the nitrate concentration. Within delineated sub-watersheds based on stream orders, positive linear functions were found between agricultural land use area percentage and the baseflow nitrate concentration and between agricultural drainage area and the nitrate load. The slope of the positive linear regression between the baseflow nitrate concentration and percent agricultural land area seems to be a valuable indicator of a watershed's water quality as influenced by agricultural practices, watershed size, and specific physiographic setting. Stream order seems to integrate, to a certain degree, the source and transport aspects of nonpoint-source pollution on a yearly averaged basis and thus might provide a quick estimate of the overall trend in baseflow nitrate concentration and load distribution along complex stream networks in agricultural watersheds.
Description Country affiliation: United States
Author Affiliation: Kang S ( Department of Crop and Soil Science, The Pennsylvania State University, University Park, PA 16802, USA.)
ISSN 00472425
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Reading ♦ Research ♦ Self Learning
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2008-05-01
Publisher Place United States
e-ISSN 15372537
Journal Journal of Environment Quality
Volume Number 37
Issue Number 3


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Source: WHO-Global Index Medicus