J. Magner

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Norazian Mohamed Noor (PhD)

Universiti Malaysia Perlis (UniMAP)

David Seamon

Kansas State University

Armando Marques-Guedes

UNL - New University of Lisbon

Iolanda Craifaleanu

Technical University Of Civil Engineering, Bucharest

Fabián Hoyos Patiño

Universidad Nacional de Colombia (National University of Colombia)

Omar Alharbi

Umm Al-Qura University, Makkah, Saudi Arabia

Kwasi Appeaning Addo

University Of Ghana, Accra,Legon

Henk Jan Verhagen

Delft University of Technology

Bertrand Michard

CEREMA

Kwasi Appeaning Addo

University of Ghana

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Papers by J. Magner

Integrated Watershed Management

World Environmental and Water Resource Congress 2006, 2006

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Managing Total Phosphorus Dynamic in a Small Rural/Urban Watershed using Geochemical Inference

Global Journal of Earth Science and Engineering, 2016

Watershed fingerprinting or geochemical tracing of hydrologic pathways and processes involves th... more Watershed fingerprinting or geochemical tracing of hydrologic pathways and processes involves the strategic spatial and temporal collection of water samples for chemical indicators. We used the stable isotopes of hydrogen and oxygen and major cations and anions found in fresh water systems to infer total phosphorus (TP) movement and storage in a small Midwestern rural/urban watershed. Typically in Minnesota, water chemistry is dominated by calcium and magnesium charge balanced by bicarbonate alkalinity unless altered by human activity. Ion concentrations will vary in a landscape depending on the relative amounts of new precipitation added to the sampled water. Pre-event water found in lakes, wetlands and groundwater are influenced by biotic and abiotic factors such as organic carbon and soil/rock mineralogy. Results of this study suggested that historically high concentrations of TP from years of wastewater treatment plant discharge were trapped in a down gradient wetland system. W...

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Riparian Corridor-Channel Restoration and Management in Elm Creek, Minnesota

Ecological Restoration, 2010

ABSTRACT The University of Minnesota’s Center for Integrated Natural Resources Management, with f... more ABSTRACT The University of Minnesota’s Center for Integrated Natural Resources Management, with funding support from the Minnesota Pollution Control Agency and Martin County Soil and Water Conservation District, established a multipurpose stream restoration on an impaired reach of Elm Creek, a 700 km2 subwatershed of the Minnesota River Basin in south central Minnesota. The purpose of the project was to demonstrate cost-effective stream restoration techniques within an economically productive agroecosystem to enhance channel stability, reduce sediment loads, and improve aquatic and riparian habitats. Along with its ecological and agricultural benefits, the project site serves as a unique opportunity for public education and outreach, featuring affordable alternatives for stream restoration, agroforestry practices, and cattle grazing management in southern Minnesota. Elm Creek is a substantial contributor of sediment to the Blue Earth River, the largest supplier of streamflow (46%) and total suspended solids (55%) to the Minnesota River (MPCA 2005). Draining approximately one-fifth of the state of Minnesota, the Minnesota River is of particular concern because it transports a disproportionate amount (88%) of the total sediment entering the Upper Mississippi River Basin (Engstrom et al. 2009). Accelerated sedimentation causes turbidity levels to exceed total maximum daily load (TMDL) standards and is also detrimental to aquatic biota. Engstrom and others (2009) found that the majority of sediment entering the Upper Mississippi River in recent decades originates from stream channel, ravine, and bluff erosion in the Minnesota River Basin (MRB). Increased rates of channel erosion have been caused by recent tile drainage expansion, land cover change, and precipitation increases. Cumulatively, native prairie conversion, extensive annual cropping, wetland drainage, ditch construction, and artificial subsurface drainage have increased stream flow throughout the MRB (Lenhart 2008), with continued soybean and corn expansion and subsurface drainage increases in the past 30–40 years. A 10%–15% increase in annual precipitation in southern Minnesota over the last three decades has likely contributed to increased streamflow as well. Though less widely recognized, the straightening of streams at road crossings has also exacerbated channel instability by decreasing channel sinuosity and instigating channel evolution. Elm Creek has lost approximately 15% of its length since 1938. Increases in slope and streamflow promote channel downcutting and subsequent channel adjustment until a new equilibrium state is reached (e.g., Schumm et al. 1984). However, within the MRB, altered flow regimes and channelization have kept streams in disequilibrium and reduced floodplain connectivity. Timeline of restoration activities at the Elm Creek restoration site in the Blue Earth River watershed of Minnesota. The watershed-scale disequilibrium in the MRB makes intensive streambank stabilization projects infeasible. While watershed management has helped reduce sediment loads, reductions of in-stream sediment sufficient to meet turbidity standards may also require extensive reduction of sediment from stream erosion, which is not economically viable or sustainable. Therefore, targeting channel reaches exceeding some threshold rate of lateral migration is needed. Since row-crop agriculture is the major economic driver in the MRB, covering 86% of the watershed, channel stabilization projects must address agroeconomic considerations. Multipurpose riparian management systems such as the Elm Creek restoration site are an attractive option because they provide a tool to help meet sediment reduction goals while maintaining agricultural productivity through perennial crop systems and managed grazing. Successful implementation depends on the acceptance by participating landowners, which is strongly influenced by economic incentives. The Elm Creek watershed consists of flat to rolling topography typical of the glacial Des Moines Lobe till plain, which contains fine-textured, loamy soils. Historically, land cover was predominantly prairie with numerous small lakes and wetlands, or prairie potholes. The project site was about 11 ha of riparian area located in a broad alluvial valley about 6.5 km from the stream terminus at the Blue Earth River, near Winnebago, Minnesota, and close to a county road for easy public access and high visibility. The Elm Creek site exemplified problems common to streams of southern Minnesota, including channel entrenchment, loss of channel sinuosity, floodplain disconnection, and high rates of bank erosion. At this particular site, channel entrenchment was initiated decades ago, following channel alterations during bridge construction at the county road, in conjunction with basinwide changes in stream...

Attenuating Excessive Sediment and Loss of Biotic Habitat in an Intensively Managed Midwestern Agricultural Watershed

Portions of the 700 km 2 Elm Creek watershed in southern Minnesota have undergone watershed and c... more Portions of the 700 km 2 Elm Creek watershed in southern Minnesota have undergone watershed and channel improvements over the past decade to mitigate turbidity and biota impairment. Increased row cropping, artificial drainage, channel modifications and precipitation have cumulatively contributed to impairment and channel instability. Uplands that were once a prairie pothole landscape are now predominately drained corn-soybean fields, providing little hydrologic storage and sediment attenuation during peak runoff. Riparian degradation and channel discontinuity characterize much of lower Elm Creek. Wetlands have been restored in the upper watershed to reduce runoff and nutrient loading from croplands. Downstream, a 750 meter riparian corridor of Elm Creek was restored and the channel improved by oxbow reconnection, bluff and streambank protection. Monitoring will document erosion and sediment deposition within the reach and Index of Biotic Integrity (IBI) data will be collected to cha...

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Hydrological engineering for sustainable shifting agriculture in the Eastern tropical Himalayas: A conceptual discussion

Science Vision, 2017

Shifting agriculture has been regarded as the cause of degradation to most types of natural resou... more Shifting agriculture has been regarded as the cause of degradation to most types of natural resources in the Eastern Himalayas. Attempts have been made by certain agencies to abolish the system or find alternatives but failed. Physical barriers arising from rugged topography along with the socio-economic conditions are the major hindrances for improved agricultural systems. Discussions on problems related to shifting agriculture and natural resources conservations have been made based on literature review and researches conducted in the region. Rainfall and vegetative cover being the major determinants of erosion intensity in the region, hydrological engineering model for on-farm soil conservation practices has been developed to control runoff, enhance rainfall interception and retain soil moisture and organic matter. Measures for on-site soil conservation include the use of locally available resources with the application of simple technology and economically inexpensive for the ig...

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Attenuating Excessive Sediment and Loss of Biotic Habitat in an Intensively Managed Midwestern Agricultural Watershed

by Britta Suppes and J. Magner

Natural Channel Design for Agricultural Ditches in SW Minnesota

Self-Sustaining Solutions for Streams, Wetlands, and Watersheds, 12-15, September 2004, 2004

Agricultural drainage ditches are a common occurrence throughout the Minnesota River Valley. Curr... more

Induction of mortality and malformation in Xenopus laevis embryos by water sources associated with field frog deformities

Environmental health perspectives, 1998

Water samples from several ponds in Minnesota were evaluated for their capacity to induce malform... more Water samples from several ponds in Minnesota were evaluated for their capacity to induce malformations in embryos of Xenopus laevis. The FETAX assay was used to assess the occurrence of malformations following a 96-hr period of exposure to water samples. These studies were conducted following reports of high incidences of malformation in natural populations of frogs in Minnesota wetlands. The purpose of these studies was to determine if a biologically active agent(s) was present in the waters and could be detected using the FETAX assay. Water samples from ponds with high incidences of frog malformations (affected sites), along with water samples from ponds with unaffected frog populations (reference sites), were studied. Initial experiments clearly showed that water from affected sites induced mortality and malformation in Xenopus embryos, while water from reference sites had little or no effect. Induction of malformation was dose dependent and highly reproducible, both with stored...

Flow path influence on an N:P ratio in two headwater streams: A paired watershed study

Journal of Geophysical Research, 2007

1] Hydrologic flow paths were assessed and stream water quality was monitored in two adjacent wat... more 1] Hydrologic flow paths were assessed and stream water quality was monitored in two adjacent watersheds to improve the understanding of how flow paths impact stream water nitrate nitrogen to total phosphorus ratios (NO 3 :TP). We hypothesized that a watershed with mostly subsurface flow paths will have high stream water NO 3 :TP ratios relative to a watershed with a greater tendency to have overland flow paths. Flow paths were assessed with end member mixing analysis (EMMA), stream water temperature, and stream discharge flashiness. The EMMA suggested that groundwater comprised a larger percentage of stream discharge in the west stream compared to the east stream. The analysis of stream water temperature and stream flashiness corroborated the results from the EMMA. Nitrate and TP concentrations were similar in both streams during low discharge. However, during storm flows nitrate decreased and TP increased in the east stream, while nitrate and TP concentrations remained similar during all discharge rates in the west stream. Thus, NO 3 :TP ratios in the east stream dramatically decreased during peak storm flows, while NO 3 :TP ratios remained relatively stable during all discharge rates in the west stream. Exploring hydrological processes helped explain the temporal variation within and spatial variation between the two streams, with regard to NO 3 :TP ratios. Further attention is necessary to understand whether hydrologic flow paths act as a control of other stream water N:P ratios and quantify flow path control relative to instream processes. Citation: Green, M. B., J. L. Nieber, G. Johnson, J. Magner, and B. Schaefer (2007), Flow path influence on an N:P ratio in two headwater streams: A paired watershed study,

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Strategies for Assessing the Implications of Malformed Frogs for Environmental Health

Environmental Health Perspectives, 1999

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Methods for Identifying Ravines and Quantifying Their Contribution to Sediment Loads in the Minnesota River Basin

The Minnesota River Basin generates a disproportionately high amount of total suspended sediments... more The Minnesota River Basin generates a disproportionately high amount of total suspended sediments to the Upper Mississippi River Basin. Many reaches in the Minnesota River Basin have impaired water quality due to turbidity. The primary sources of sediment in the Minnesota River Basin include upland erosion from agricultural land, streambluff slumping, and downcutting of ravines. No research has been conducted

Air-Water Temperature Relationships in the Trout Streams of Southeastern Minnesota's Carbonate-Sandstone Landscape

by Lori Krider and J. Magner

JAWRA Journal of the American Water Resources Association, 2013

ABSTRACT Carbonate-sandstone geology in southeastern Minnesota creates a heterogeneous landscape ... more ABSTRACT Carbonate-sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface-water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater-fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air-water temperature relationships for 40 GWFS in southeastern Minnesota. A 40-stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R2 of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface-water dominated streams. Regression models for streams with high R2 values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater-fed systems, but will do so at a slower rate than surface-water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.

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Integrated Watershed Management

World Environmental and Water Resource Congress 2006, 2006

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Managing Total Phosphorus Dynamic in a Small Rural/Urban Watershed using Geochemical Inference

Global Journal of Earth Science and Engineering, 2016

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Riparian Corridor-Channel Restoration and Management in Elm Creek, Minnesota

Ecological Restoration, 2010