Precision riparian buffers for the control of nonpoint source pollutant loading into surface water: A review

2005 ◽  
Vol 13 (3) ◽  
pp. 129-144 ◽  
Author(s):  
Viktor Polyakov ◽  
Ali Fares ◽  
Micah H Ryder
Keyword(s):  
Riparian Buffers ◽  
Riparian Buffer ◽  
Retention Rates ◽  
Practical Implementation ◽  
Nutrient Loads ◽  
Local Conditions ◽  
Agricultural Catchments ◽  
Buffer Design ◽  
Filter Water ◽  
Precision Conservation

Numerous studies have shown the effectiveness of riparian buffers in reducing sediment, pathogen, and nutrient loads into surface and groundwater in agricultural catchments. Reported retention rates of sediment, N, and P were as high as 97%, 85%, and 84%, respectively. Often, however, riparian buffers fail to perform their protective functions due to low adaptability of their designs to local settings. This is caused by our inadequate understanding of the conditions under which riparian buffers perform the best at field scale. Therefore, a precision oriented approach based on thorough analysis of spatially variable characteristics of landscape has to be undertaken in riparian buffer construction. Such an approach has a potential to improve the protective qualities and the economic viability of the riparian buffers. This paper gives an overview of the current level of research on riparian buffers and discusses the importance of spatial variability of local conditions on their performance. It presents the approaches for precision buffer design and its practical implementation and highlights the directions for future development of precision conservation. Key words: riparian buffer, vegetative filter, water quality, precision conservation.

scholarly journals Quantifying the Importance of Preferential Flow in a Riparian Buffer

2021 ◽  
Vol 64 (3) ◽  
pp. 937-947
Author(s):  
Lucie Guertault ◽  
Garey A. Fox ◽  
Todd Halihan ◽  
Rafael Muñoz-Carpena
Keyword(s):  
Preferential Flow ◽  
Riparian Buffers ◽  
Riparian Buffer ◽  
Design Tools ◽  
Soil Matrix ◽  
Innovative Method ◽  
Matrix Flow ◽  
Buffer Design ◽  
Flow Pathways ◽  
Preferential Flow Pathways

HighlightsRiparian buffers and vegetative filter strips are uniquely susceptible to preferential flow.An innovative method is proposed to partition infiltration into matrix and macropore domains.Riparian buffer matrix and plot-scale infiltration experiments were simulated with HYDRUS-1D and VFSMOD.Preferential flow accounted for 32% to 47% of infiltration depending on hydrologic conditions.Preferential flow mechanisms should be incorporated into riparian buffer design tools and models.Abstract. Riparian buffers are uniquely susceptible to preferential flow due to the abundance of root channels, biological activity, and frequent wetting and drying cycles. Previous research has indicated such susceptibility and even measured the connectivity of preferential flow pathways with adjacent streams and rivers. However, limited research has attempted to partition the riparian buffer infiltration between matrix and preferential flow domains. The objectives of this research were to develop an innovative method to quantify soil matrix infiltration at the plot scale, develop a method to partition infiltration into matrix and macropore infiltration at the plot scale, and then use these methods to quantify the significance of macropore infiltration at a riparian buffer site. This research further demonstrated the importance of considering preferential flow processes in design tools and models to evaluate riparian buffer effectiveness. Sprinkler and runon field experiments were conducted at an established riparian buffer site with sandy loam soil. Trenches were installed and instrumented with soil moisture sensors along the width of the riparian buffer (i.e., along the flow path toward the stream) for detecting non-uniform flow patterns due to preferential flow. Riparian buffer parameters, including soil hydraulic parameters, were estimated using HYDRUS-1D for the sprinkler experiments and VFSMOD for the runon experiments. This research partitioned the infiltration into matrix and preferential flow domains by assuming negligible exchange of water between the soil matrix and preferential flow pathways in comparison to the magnitude of soil matrix flow. For these experimental conditions with 0.20 to 0.48 L s-1 of runon and initial soil water contents of 0.29 to 0.32 cm3 cm-3, preferential flow accounted for at least 27% to 32% of the total runon water entering the riparian buffer. This corresponded to approximately 32% to 47% of the total infiltration. While increasing the riparian buffer plot soil hydraulic conductivity in single-porosity models can adequately predict the total infiltration and therefore the surface outflow from the buffer, design tools and models should specifically consider preferential flow processes to improve predictive power regarding the actual infiltration processes and correspondingly the non-equilibrium flow and solute transport mechanisms. Keywords: Flow partitioning, HYDRUS, Matrix flow, Preferential flow, Riparian buffer, VFSMOD.

scholarly journals Nitrate and dissolved nitrous oxide in groundwater within cropped fields and riparian buffers

2009 ◽  
Vol 6 (1) ◽  
pp. 651-685 ◽  
Author(s):  
D.-G. Kim ◽  
T. M. Isenhart ◽  
T. B. Parkin ◽  
R. C. Schultz ◽  
T. E. Loynachan
Keyword(s):  
Nitrous Oxide ◽  
N2o Emission ◽  
Riparian Buffers ◽  
Riparian Buffer ◽  
N2o Emissions ◽  
Cool Season ◽  
N2o Flux ◽  
Crop Fields ◽  
Ipcc Methodology ◽  
Cool Season Grass

Abstract. Transport and fate of dissolved nitrous oxide (N2O) in groundwater and its significance to nitrogen dynamics within agro-ecosystems are poorly known in spite of significant potential of N2O to global warming and ozone depletion. Increasing denitrification in riparian buffers may trade a reduction in nitrate (NO3−) transport to surface waters for increased N2O emissions resulting from denitrification-produced N2O dissolved in groundwater being emitted into the air when groundwater flows into a stream or a river. This study quantifies the transport and fate of NO3− and dissolved N2O moving from crop fields through riparian buffers, assesses whether groundwater exported from crop fields and riparian buffers is a significant source of dissolved N2O emissions, and evaluates the Intergovernmental Panel on Climate Change (IPCC) methodology to estimate dissolved N2O emission. We measured concentrations of NO3−; chloride (Cl−); pH; dissolved N2O, dissolved oxygen (DO), and organic carbon (DOC) in groundwater under a multi-species riparian buffer, a cool-season grass filter, and adjacent crop fields located in the Bear Creek watershed in central Iowa, USA. In both the multi-species riparian buffer and the cool-season grass filter, concentrations of dissolved N2O in the groundwater did not change as it passed through the sites, even when the concentrations of groundwater NO3− were decreased by 50% and 59%, respectively, over the same periods. The fraction of N lost to leaching and runoff (0.05) and the modified N2O emission factor, [ratio of dissolved N2O flux to N input (0.00002)] determined for the cropped fields indicate that the current IPCC methodology overestimates dissolved N2O flux in the sites. A low ratio between dissolved N2O flux and soil N2O emission (0.0003) was estimated in the cropped fields. These results suggest that the riparian buffers established adjacent to crop fields for water quality functions (enhanced denitrification) decreased NO3− and were not a source of dissolved N2O. Also, the flux of dissolved N2O from the cropped field was negligible in comparison to soil N2O emission in the crop fields.

scholarly journals Riparian buffer effectiveness as a function of buffer design and input loads

2020 ◽  
Vol 49 (6) ◽  
pp. 1599-1611
Author(s):  
Fei Jiang ◽  
Heather E. Preisendanz ◽  
Tamie L. Veith ◽  
Raj Cibin ◽  
Patrick J. Drohan
Keyword(s):  
Riparian Buffer ◽  
Buffer Design

Process-Based Design Strengthens theAnalysis of Stream and Floodplain Systems under a Changing Climate

2019 ◽  
Vol 62 (6) ◽  
pp. 1735-1742 ◽  
Author(s):  
Garey A. Fox
Keyword(s):  
Stream Restoration ◽  
Preferential Flow ◽  
Riparian Buffer ◽  
Specific Design ◽  
Flow Process ◽  
Site Specific ◽  
Climatic Extremes ◽  
Streambank Erosion ◽  
Vegetative Filter Strip ◽  
Buffer Design

HighlightsStream-riparian interactions and preferential flow remain two “unsolved” problems in hydrology.Using mechanistic approaches enables analysis of stream and floodplain systems under future climatic extremes.Engineers should verify stream restoration designs with models that consider stream-riparian interactions.Riparian buffer design models should consider preferential flow and be more widely used for site-specific design. Keywords: . Climate Variability, Floodplain, Preferential flow, Process-based design, Riparian buffer, Stream restoration, Streambank erosion, Vegetative Filter Strip.

Modelling the impact of increased lateral connectivity on nutrient retention in Austrian Danube floodplains

2020 ◽  
Author(s):  
Martin Tschikof ◽  
Stephanie Natho ◽  
Thomas Hein ◽  
Elisabeth Bondar-Kunze
Keyword(s):  
Water Quality ◽  
National Park ◽  
Nutrient Retention ◽  
Danube River ◽  
Retention Rates ◽  
Nutrient Loads ◽  
Lateral Connectivity ◽  
The Danube River ◽  
Nutrient Emissions ◽  
Semi Empirical

<p>In the last centuries, rivers in Central Europe have severely suffered from hydro-morphological alterations and excessive nutrient inputs. Their adjacent floodplains have the ability to retain transported nutrients in case of inundation, but are subject to progressing decoupling from the main river stem. In the Austrian Danube Floodplain National Park, restoration measures have been carried out and are planned for the near future to increase lateral connectivity in accordance with navigation purposes.</p><p>We investigated nutrient retention capacity in seven differently connected side arms and the potential effects of further proposed reconnection measures using two complementary modeling approaches. With existing monitoring data on hydrology, nitrate and total phosphorus concentrations for three side arms, we derived a multivariate statistical model and compared these results to a larger scaled semi-empirical retention model (Venohr et al. 2011). We modelled nutrient retention at current state and after completion of side arm reconnections in a dry (2003) and wet (2002) hydrologic year.</p><p>Both models show comparable annual retention rates and agree in calculating higher nutrient retention in floodplains where reconnection allows more frequent inundations at low discharges. The semi-empirical approach results in highest retention rates at low hydraulic loads and shows more reasonable results at high floods. On the other hand, the statistical approach predicts increasing retention rates with higher nutrient loads entering the side arms and also takes into account nitrate reduction in the remaining water bodies at times of no surface water connection.</p><p>Our results suggest that water quality of the Danube River could be improved by increasing parameters related to lateral connectivity between river and floodplain. These include in particular the frequency and area of inundation, as well as nutrient input loads into the reactive zones of floodplains. Still, a frequently hydrologically connected national park stretch after restoration reduces nutrient loads of the Upper Danube by less than 0.1% due to its small areal extent in relation to transported river nutrient loads. In order to sustain an adequate water quality in future, both a reduction in nutrient emissions and a larger area of functional floodplains along the Danube River are required.</p><p><strong>References:</strong></p><p>Venohr, M., Hirt, U., Hofmann, J., Opitz, D., Gericke, A., Wetzig, A., ... & Mahnkopf, J. (2011). Modelling of nutrient emissions in river systems–MONERIS–methods and background. International Review of Hydrobiology, 96(5), 435-483.</p><p><strong>Key words:</strong></p><p>River floodplains, lateral connectivity, nutrient retention, river restoration, floodplain reconnection, water quality</p>

scholarly journals Modelling of nitrogen turnover and leaching in Saxony

2010 ◽  
Vol 27 ◽  
pp. 139-144 ◽  
Author(s):  
M. Gebel ◽  
S. Halbfaß ◽  
S. Bürger ◽  
H. Friese ◽  
S. Naumann
Keyword(s):  
Management Practices ◽  
Regional Scale ◽  
Arable Land ◽  
Nitrogen Sources ◽  
Federal State ◽  
Nutrient Loads ◽  
Nitrogen And Phosphorus ◽  
Present Contribution ◽  
Local Conditions ◽  
Relationship Of

Abstract. From 2005 to 2009 we modelled the input of nitrogen and phosphorus in waters in the area of the Federal State of Saxony (Germany). The model results are an important component in elucidating the present situation of nutrient loads in groundwater and surface water as well as its future development. The present contribution focuses on the modelling of diffuse nitrogen leaching on arable land. Processes of mobilization and immobilization of nitrogen are included in the modelling. They will be estimated as induced by the respective types of fruit, management practices and local conditions. Source areas can be derived using the relationship of nitrogen sources (mobilization, deposition) and sinks (immobilization, denitrification) on the regional scale.

scholarly journals Forested Riparian Buffers Change the Taxonomic and Functional Composition of Stream Invertebrate Communities in Agricultural Catchments

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1028
Author(s):  
Jasmina Sargac ◽  
Richard K. Johnson ◽  
Francis J. Burdon ◽  
Amélie Truchy ◽  
Geta Rîşnoveanu ◽  
...  
Keyword(s):  
Riparian Vegetation ◽  
Human Impacts ◽  
Terrestrial Ecosystems ◽  
Species Traits ◽  
Taxonomic Composition ◽  
Riparian Buffers ◽  
Functional Composition ◽  
Invertebrate Communities ◽  
Agricultural Catchments ◽  
Stream Biodiversity

Riparian zones form the interface between stream and terrestrial ecosystems and play a key role through their vegetation structure in determining stream biodiversity, ecosystem functioning and regulating human impacts, such as warming, nutrient enrichment and sedimentation. We assessed how differing riparian vegetation types influence the structural and functional composition (based on species traits) of stream invertebrate communities in agricultural catchments. We characterized riparian and stream habitat conditions and sampled stream invertebrate communities in 10 independent site pairs, each comprising one “unbuffered” reach lacking woody riparian vegetation and a second downstream reach with a woody riparian buffer. Forested riparian buffers were associated with greater shading, increased gravel content in stream substrates and faster flow velocities. We detected changes in invertebrate taxonomic composition in response to buffer presence, with an increase in sensitive Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa and increases in key invertebrate species traits, including species with preference for gravel substrates and aerial active dispersal as adults. Riparian vegetation independently explained most variation in taxa composition, whereas riparian and instream habitat together explained most variation in functional composition. Our results highlight how changes in stream invertebrate trait distributions may indirectly reflect differences in riparian habitat, with implications for stream health and cross-ecosystem connectivity.

Learning about Language: Preparing pre-service subject teachers for multilingual classroom realities

2019 ◽  
Vol 9 (1) ◽  
pp. 223-240 ◽  
Author(s):  
Tobias Schroedler ◽  
Patrick Grommes
Keyword(s):  
Teacher Education ◽  
Skill Development ◽  
Testing Procedure ◽  
Practical Implementation ◽  
Local Conditions ◽  
Critical Reasoning ◽  
Innovation Project ◽  
Education Innovation ◽  
Multilingual Classroom ◽  
The University

Abstract This paper presents and discusses experiences gained in a German teacher education innovation project on competence and skill development in dealing with multilingualism. New seminar structures were developed, which go hand in hand with a reorganisation of the entire teacher education structure in the University of Hamburg. The aim of these reform implementations is to equip all future subject teachers with relevant skills for dealing with multilingualism and the challenges that learners of German as a second language (GSL) experience. In order to achieve this, a compulsory course on the foundations of multilingualism and language sensitive subject teaching was developed and implemented in the M.Ed. programme (Teacher Degree). In this class students learn about societal multilingualism, basics of contrastive theoretical linguistics, language development, strategies and methods for language sensitive subject teaching as well as practical implementation guidance. Based on a theoretical overview outlining the local conditions with regard to multilingualism and the necessity of language sensitive teaching, the contents of the course are described including a critical reasoning on their substance and place in the course. For a better understanding of the competence development and the effectiveness of the newly introduced seminar(s), a thoroughly validated test instrument is employed in a pre-post design to observe the participants’ skill development. The results of this testing procedure show positive tendencies, yet it remains clear that more work needs to be done in the area.

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