scholarly journals Deriving a Bayesian Network to Assess the Retention Efficacy of Riparian Buffer Zones

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 617 ◽  
Author(s):  
Andreas Gericke ◽  
Hong Hanh Nguyen ◽  
Peter Fischer ◽  
Jochem Kail ◽  
Markus Venohr
Keyword(s):  
Preferential Flow ◽  
Classification Tree ◽  
Design Guidelines ◽  
Riparian Buffer ◽  
Prediction Errors ◽  
Nitrogen And Phosphorus ◽  
Buffer Zones ◽  
Particulate Nitrogen ◽  
Riparian Buffer Zones ◽  
Flow Pathway

Bayesian networks (BN) have increasingly been applied in water management but not to estimate the efficacy of riparian buffer zones (RBZ). Our methodical study aims at evaluating the first BN to predict the RBZ efficacy to retain sediment and nutrients (dissolved, total, and particulate nitrogen and phosphorus) from widely available variables (width, vegetation, slope, soil texture, flow pathway, nutrient form). To evaluate the influence of parent nodes and how the number of states affects prediction errors, we used a predefined general BN structure, collected 580 published datasets from North America and Europe, and performed classification tree analyses and multiple 10-fold cross-validations of different BNs. These errors ranged from 0.31 (two output states) to 0.66 (five states). The outcome remained unchanged without the least influential nodes (flow pathway, vegetation). Lower errors were achieved when parent nodes had more than two states. The number of efficacy states influenced most strongly the prediction error as its lowest and highest states were better predicted than intermediate states. While the derived BNs could support or replace simple design guidelines, they are limited for more detailed predictions. More representative data on vegetation or additional nodes like preferential flow will probably improve the predictive power.

Nitrogen and phosphorus variation in shallow groundwater and assimilation in plants in complex riparian buffer zones

2001 ◽  
Vol 44 (11-12) ◽  
pp. 615-622 ◽  
Author(s):  
V. Kuusemets ◽  
Ü Mander ◽  
K. Lõhmus ◽  
M. Ivask
Keyword(s):  
Buffer Zone ◽  
Riparian Buffer ◽  
Alnus Incana ◽  
Nitrogen And Phosphorus ◽  
Buffer Zones ◽  
Total N ◽  
Purification Efficiency ◽  
N Removal ◽  
Riparian Buffer Zones ◽  
Total P

The study of purification efficiency and nutrient assimilation in plants was made in two riparian buffer zones with a complex of wet meadow and grey alder (Alnus incana) stand. In the less polluted Porijõgi test site, the 31 m wide buffer zone removed 40% of total nitrogen (total-N) and 78% of total phosphorus (total-P), while a heavily polluted 51 m wide buffer zone in Viiratsi retained 85% of total-N and 84% of total-P. The input of nutrients and purification efficiency displayed a significant relationship. The total-N removal in buffer zone was negative when the input value was less than 0.3 mg l-1 and the purification efficiency was always positive when the input value exceeded 5 mg l-1. The purification efficiency of total-P was positive when the input value exceeded 0.15 mg l-1. Grass vegetation plays an important role in nutrient retention in riparian buffer strips. The maximum phytomass production was measured in Porijõgi site where production of the Filipendula ulmaria community was up to 2,358 g m-2, assimilation of N 32.1 and of P 4.9 g m-2, respectively. This is much higher than the biomass production and N and P uptake of the grey alders (Alnus incana) at the same site - 1,730, 20.5 and 1.5 g m-2, respectively.

Dimensioning of riparian buffer zones in agricultural catchments at national level

2021 ◽  
Author(s):  
Evelyn Uuemaa ◽  
Ain Kull ◽  
Kiira Mõisja ◽  
Hanna-Ingrid Nurm ◽  
Alexander Kmoch
Keyword(s):  
Spatial Resolution ◽  
National Level ◽  
Agricultural Runoff ◽  
Riparian Buffer ◽  
Soil Types ◽  
Buffer Zones ◽  
Slope Length ◽  
Local Flow ◽  
Riparian Buffer Zones ◽  
Buffer Width

<p>Intensive agricultural production interferes with natural cycles of nutrients (mostly nitrogen and phosphorus) and may lead to water quality degradation due to excessive nutrient loadings. To mitigate this effect at the landscape level establishment of buffering vegetated strips is an efficient measure.</p><p>Recommending optimal widths for riparian buffer zones to reduce the agricultural runoff is still a challenging task, in particular when considering the spatial variability of the landscape. Empirical-based approaches include assessment of terrain, soil types, land use and vegetation, and are often realised in computationally expensive hydrological simulation. However, trade-offs have to be made between spatial resolution and areal extent. Another elegant empirical-based approach are nomographs, where via triangulation of a specific slope length, terrain slope and soil type recommended buffer width can be easily calculated. Mander and Kuusemets (1998) already developed such a nomograph for Estonian catchments in 1998, yet, a computational use case has not been explored.</p><p>We implemented the nomograph as a GIS algorithm in Python/QGIS to retrieve the recommended buffer width at national level. We synthesized a specific slope length via a weighted average of flow length, local flow accumulation and LS factor, and then use the specific slope length, slope derived from 5 m spatial resolution DEM and soil texture classes as inputs for the algorithm. We applied this algorithm and calculated recommendable buffer strip widths for the whole of country of Estonia, over an area of approx. 43,000 km<sup>2</sup>. We evaluated the uncertainty of the results as well the algorithm’s sensitivity to input weights.</p><p>The developed algorithm is applicable in any region with relevant adjustments to local soil types. The result directly informs policy making by being able to more specifically decide and explain variations of buffer zone widths along water bodies.</p>

Hydrogeologic controls on the transport and fate of nitrate in ground water beneath riparian buffer zones: results from thirteen studies across the United States

2004 ◽  
Vol 49 (3) ◽  
pp. 47-53 ◽  
Author(s):  
L.J. Puckett
Keyword(s):  
United States ◽  
Organic Carbon ◽  
Ground Water ◽  
Nutrient Management ◽  
Riparian Zone ◽  
The United States ◽  
Riparian Buffer ◽  
Buffer Zones ◽  
Flow Paths ◽  
Riparian Buffer Zones

During the last two decades there has been growing interest in the capacity of riparian buffer zones to remove nitrate from ground waters moving through them. Riparian zone sediments often contain organic carbon, which favors formation of reducing conditions that can lead to removal of nitrate through denitrification. Over the past decade the National Water Quality Assessment (NAWQA) Program has investigated the transport and fate of nitrate in ground and surface waters in study areas across the United States. In these studies riparian zone efficiency in removing nitrate varied widely as a result of variations in hydrogeologic factors. These factors include (1) denitrification in the up-gradient aquifer due to the presence of organic carbon or other electron donors, (2) long residence times (>50 years) along ground-water flow paths allowing even slow reactions to completely remove nitrate, (3) dilution of nitrate enriched waters with older water having little nitrate, (4) bypassing of riparian zones due to extensive use of drains and ditches, and (5) movement of ground water along deep flow paths below reducing zones. By developing a better understanding of the hydrogeologic settings in which riparian buffer zones are likely to be inefficient we can develop improved nutrient management plans.

scholarly journals Concentrated flow paths in riparian buffer zones of southern Illinois

2011 ◽  
Vol 84 (2) ◽  
pp. 191-205 ◽  
Author(s):  
R. C. Pankau ◽  
J. E. Schoonover ◽  
K. W. J. Williard ◽  
P. J. Edwards
Keyword(s):  
Riparian Buffer ◽  
Buffer Zones ◽  
Flow Paths ◽  
Southern Illinois ◽  
Concentrated Flow ◽  
Riparian Buffer Zones
Sign in / Sign up

Export Citation Format

Share Document