scholarly journals Impacts of Land Use, Fertilizer and Manure Application on the Stream Nutrient Loadings in the Salmon River Watershed, South-Central British Columbia, Canada

2012 ◽  
Vol 03 (08) ◽  
pp. 809-822 ◽  
Author(s):  
Zhanxue Zhu ◽  
Klaas Broersma ◽  
Asit Mazumder
Keyword(s):  
Land Use ◽  
British Columbia ◽  
Manure Application ◽  
River Watershed ◽  
Salmon River ◽  
Nutrient Loadings ◽  
South Central

scholarly journals Continuous Simulation of Highly Urbanized Watershed to Quantify Nutrients’ Loadings

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2910
Author(s):  
Naila Mahdi ◽  
Krishna R. Pagilla
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Urban Land ◽  
Point Sources ◽  
Land Uses ◽  
River Watershed ◽  
Water Quality Simulation ◽  
Continuous Simulation ◽  
Nutrient Loadings ◽  
Chicago River

The United States has witnessed various extreme land use changes over the years. These changes led to alterations in watersheds’ characteristics, impacting their water quality and quantity. To quantify this impact in highly urbanized watersheds such as the Chicago Metropolitan Area, it is crucial to examine the characteristics and imperviousness distribution of urban land uses and available point and non-point sources. In this paper, the effect of urban runoff and nutrient loadings to water bodies in the Chicago River Watershed resulting from level (III) detailed urban land uses is investigated. A watershed scale hydrologic and water quality simulation using BASINS/HSPF model was developed for the highly urbanized watershed. Appropriate considerations were given to the effective impervious area (EIA). The results from the five-year calibrated water quality simulation were reasonably reflected with observed data in the study area and nutrient loadings of both point and non-point sources for 44 different land uses were found. The export coefficients (EC) values obtained are site-specific depending on conditions and variables at the watershed level such as physical characteristics, land use management practices, hydro-meteorological and topographical data, while using a continuous simulation approach and watershed perspective analysis. This is the first attempt to measure and model nutrients’ loadings using detailed land use types in the Chicago River Watershed. The proposed continuous calibrated and validated model can be used in the investigation and analysis of different scenarios and possible future conditions and land utilization.

Class 1 and class 2 integrons in multidrug-resistant gram-negative bacteria isolated from the Salmon River, British Columbia

2011 ◽  
Vol 57 (6) ◽  
pp. 460-467 ◽  
Author(s):  
Hai Xu ◽  
Klaas Broersma ◽  
Vivian Miao ◽  
Julian Davies
Keyword(s):  
British Columbia ◽  
Antibiotic Resistance Genes ◽  
Gene Cassette ◽  
Multidrug Resistant ◽  
Gram Negative ◽  
Salmon River ◽  
Resistance Determinants ◽  
South Central ◽  
Class 1 ◽  
Dihydrofolate Reductases

Using an enrichment protocol, we isolated 16 gram-negative, multidrug-resistant strains of known or opportunistic bacterial pathogens from the Salmon River in south-central British Columbia from 2005 to 2009, and investigated the genetic basis of their resistance to a variety of antibiotics. Of the 16 strains, 13 carried class 1 integrons and three carried class 2 integrons. Genes found in cassettes associated with the integrons included those for dihydrofolate reductases (dfrA1, dfrA12, dfrA17, and dfrB7), aminoglycoside adenyltransferases (aadA1, aadA2, aadA5, and aadB), streptothricin acetyltransferase (sat), and hypothetical proteins (orfF and orfC). A new gene cassette of unknown function, orf1, was discovered between dfrA1 and aadA5 in Escherichia sp. Other genes for resistance to tetracycline, chloramphenicol, streptomycin, and kanamycin (tetA, tetB, tetD; catA; strA-strB; and aphA1-Iab, respectively) were outside the integrons. Several of these resistance determinants were transferable by conjugation. The detection of organisms and resistance determinants normally associated with clinical settings attest to their widespread dispersal and suggest that regular monitoring of their presence in aquatic habitats should become a part of the overall effort to understand the epidemiology of antibiotic resistance genes in bacteria.

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