Vegetative Filter Research Articles

Correlation analysis of factors affecting removal efficiency in vegetative filter strips

Nonpoint pollution sources (NPSs) are difficult to manage because their pathways, pollutant load, and runoff characteristics are unclear, unlike point pollution sources. Hence, the Korean government plans to research and develop best management practices (BMPs) for the management of NPSs. The removal efficiency of BMPs varies due to several factors, including rainfall events. These BMPs can be evaluated by numerous methods, and continuous research is being conducted on improving them. In this study, a correlation analysis was conducted to investigate vegetation coverage and retention time as factors affecting the removal efficiency of a vegetative filter strip (VFS), which is a natural nonpoint pollution reduction facility. The results showed that a longer retention time was associated with a higher removal efficiency of a VFS when the vegetation coverage was maintained. Therefore, adequate vegetation coverage and retention time are required to increase the removal efficiency for the VFSs.

Impact of atmospheric correction and image filtering on hyperspectral classification of tree species using support vector machine

Hyperspectral images can be used to identify savannah tree species at the landscape scale, which is a key step in measuring biomass and carbon, and tracking changes in species distributions, including invasive species, in these ecosystems. Before automated species map- ping can be performed, image processing and atmospheric correction is often performed, which can potentially affect the performance of classification algorithms. We determine how three processing and correction techniques (atmospheric correction, Gaussian filters, and shade/ green vegetation filters) affect the prediction accuracy of classification of tree species at pixel level from airborne visible/infrared imaging spectrometer imagery of longleaf pine savanna in Central Florida, United States. Species classification using fast line-of-sight atmospheric analysis of spectral hypercubes (FLAASH) atmospheric correction outperformed ATCOR in the majority of cases. Green vegetation (normalized difference vegetation index) and shade (near-infrared) filters did not increase classification accuracy when applied to large and continu- ous patches of specific species. Finally, applying a Gaussian filter reduces interband noise and increases species classification accuracy. Using the optimal preprocessing steps, our classifica- tion accuracy of six species classes is about 75%. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) (DOI: 10.1117/1.JRS.9.095990)

Conservation practice effectiveness and adoption: unintended consequences and implications for sustainable phosphorus management

Phosphorus (P) runoff from agricultural land continues to receive attention due to a widespread lack of reduction in losses combined with a series of high profile P-induced harmful algal blooms. Many widely adopted conservation practices (CPs), aimed at reducing P loss, target particulate P (PP) through reductions in erosion or entrapment of P within the terrestrial landscape. However, there is increasing evidence that in time, these CPs may in fact increase dissolved P (DP) losses. We reviewed the effectiveness of current CPs promoted in the U.S., the results from long-term in-stream monitoring following implementation of conservation schemes and field studies investigating P loss from buffer zones designed to trap PP. These studies showed that different CPs are required to target different forms of P loss and the tendency for farmers to implement strategies targeting PP over DP resulted in an increase in dissolved reactive P export post-implementation of 37–250 % in three of the five catchment monitoring studies. Buffer zones, such as grass and vegetative filter strips, managed riparian zones and wetlands were found to accumulate labile forms of soil P over time and, in some studies, became significant sources of both inorganic and organic DP. Furthermore, often overlooked microbial processes appear to play a key role in P release. Consequently, to improve the effectiveness of future conservation schemes, practices need to specifically target DP losses in addition to PP and recognize that CPs trapping P within the landscape are at risk of becoming legacy P sources.

국내 경작지 특성을 고려한 SWAT 모형의 식생여과대 유사저감 효율 산정식 개선

Abstract In this study, considering the factors that affects sediment trapping efficiency of Vegetative Filter Strips (VFS), the scenarios were designed to develop a regression equation to estimate sediment trapping efficiency of VFS for agricultural fields in South-Korea. For this, general conditions of agricultural fields in South-Korea were investigated. Then, based on these results , total 53,460 scenarios were set and simulated by Vegetative Filter Strip MODel (VFSMOD-w). Two variables were determined from the results of 53,460 scenarios. These two variables were applied to CurveExpert for development of a equation, which can estimate sediment trapping efficiency of VFS. The equation developed in this study can be used in SWAT model for estimation of sediment reduction efficiency of VFS to upland field in Korea. Moreover, it is expected that VFS will be effectively applied to agricultural fields in South-Korea. Key words : Sediment, Sediment reduction, SWAT, Vegetative filter strips, VFSMOD-w

Avoiding social traps in the ecosystem stewardship: The Italian Fontanile lowland spring

Fontanile is a Po Valley (Italy) quasi-natural lowland spring built in the middle age. This paper identifies options for the conservation of the Fontanile water dependent ecosystem, using scenarios and simulations, and exploring different policy options. Three modeling analysis have been performed: the first was carried out for estimating groundwater contamination and recharge from above, the second for evaluating the function of vegetative filter strip on the surface water quality and the last one for testing pesticide drift reduction due to the vegetative filter strip. Uncertainty characterization included climate change projections. Despite the nitrate concentration in water could favorite the eutrophication phenomena, this not occurs because of the low phosphate concentration in water and of the presence of arboreal shade. Therefore, the protection strategies must focus on sustaining desirable water quantity conditions. Water saving and conservation technologies that improve the agricultural productivity but reduce the Fontanile water flow and large buffer strips that have a limited efficacy due to the Fontanile hydrological settings can be judged as ecological traps. Inefficient irrigation systems, good agricultural practices, integrated pest management and arboreal filter strip can preserve the quality of those ecosystems.

Simulating soil conservation measures to control soil and nutrient losses in a small, vineyard dominated, basin

In recent decades, newly planted vineyards have been adapted for labor–saving mechanization. This has facilitated the use of machinery, but has meant that most of the soil and water conservation measures, which were assets in the original plantations, have had to be eliminated. This work analyses the effects of introducing drainage terraces and vegetative filter strips in a small basin (0.46km2) whose main land use is vine cultivation. The basin is located in the municipality of Piera (Barcelona province, NE Spain). Soil and nutrient losses were simulated in scenarios with and without soil conservation measures, using SWAT, for years with different rainfall amounts and characteristics. The model was calibrated and validated using data collected in the basin during the period May 2010–December 2012. The annual rainfall during the study period ranged from 329.8 to 785mm, with runoff rates of between 4.1 and 21% of total precipitation. In the scenario without conservation measures, annual soil losses ranged from less than 1Mgha−1, in the driest year, to 13.9Mgha−1, in the wettest. Average annual nutrient losses were around 2.7kg nitrate (N–NO3)ha−1, 17kg organic nitrogen (OrgN)ha−1, 0.5kg soluble phosphorus (SolP)ha−1 and 5.5kg organic phosphorus (OrgP)ha−1. These results highlight the fact that soil and nutrient losses from vineyards contribute to non-point source pollution and also to economic losses for grape producers. The introduction of drainage terraces produced a reduction in soil losses of up to 20%. Introducing filter strips further reduced these soil losses by up to 57%, while nutrient losses were significantly reduced by the introduction of both measures.

Does mechanistic modeling of filter strip pesticide mass balance and degradation processes affect environmental exposure assessments?

Vegetative filter strips (VFS) are a widely adopted practice for limiting pesticide transport from adjacent fields to receiving waterbodies. The efficacy of VFS depends on site-specific input factors. To elucidate the complex and non-linear relationships among these factors requires a process-based modeling framework. Previous research proposed linking existing higher-tier environmental exposure models with a well-tested VFS model (VFSMOD). However, the framework assumed pesticide mass stored in the VFS was not available for transport in subsequent storm events. A new pesticide mass balance component was developed to estimate surface pesticide residue trapped in the VFS and its degradation between consecutive runoff events. The influence and necessity of the updated framework on acute and chronic estimated environmental concentrations (EECs) and percent reductions in EECs were investigated across three, 30-year U.S. EPA scenarios: Illinois corn, California tomato, and Oregon wheat. The updated framework with degradation predicted higher EECs than the existing framework without degradation for scenarios with greater sediment transport, longer VFS lengths, and highly sorbing and persistent pesticides. Global sensitivity analysis (GSA) assessed the relative importance of mass balance and degradation processes in the context of other input factors like VFS length (VL), organic-carbon sorption coefficient (Koc), and soil and water half-lives. Considering VFS pesticide residue and degradation was not important if single, large runoff events controlled transport, as is typical for higher percentiles considered in exposure assessments. Degradation processes become more important when considering percent reductions in acute or chronic EECs, especially under scenarios with lower pesticide losses.

Sediment deposition and overland flow hydraulics in simulated vegetative filter strips under varying vegetation covers

Vegetative filter strips (VFSs) can effectively trap sediment in overland flow, but little information is available on its performance in controlling high-concentration sediment and the runoff hydraulics in VFS. Flume experiments were conducted to investigate the sediment deposition, hydraulics of overland flow and their relationships in simulating VFS under a great range of sediment concentrations with four levels of vegetation cover (bare slope and 4%, 11% and 17%) and two flow rates (15 and 30 L min−1). Sediment concentrations varied from 30 to 400 kg m−3 and slope gradient was 9°. Both the deposited sediment load and deposition efficiency in VFS increased as the vegetation cover increased. Sediment concentration had a positive effect on the deposited load but no effect on deposition efficiency. A lower flow rate corresponded to greater deposition efficiency but had little effect on deposited load. Flow velocities decreased as vegetation cover increased. Sediment concentration had a negative effect on the mean velocity but no effect on surface velocity. Hydraulic resistance increased as the vegetation cover and sediment concentration increased. Sediment deposition efficiency had a much more pronounced relationship with overland flow hydraulics compared with deposited load, especially with the mean flow velocity, and there was a power relationship between them. Flow regime also affected the sediment deposition efficiency, and the efficiency was much higher under subcritical than supercritical flow. The results will be useful for the design of VFS and the control of sediment flowing into rivers in areas with serious soil erosion. Copyright © 2015 John Wiley & Sons, Ltd.

A spatial analysis model to assess the feasibility of short rotation forestry fertigated with urban wastewater: Basilicata region case study

The large-scale cultivation of energy crops irrigated with non-conventional water resources could reduce the negative impacts of fossil fuel use, while still saving potable supplies and decreasing pollution in surface water, particularly in water-deficient environments, like the Mediterranean region. Energy planning is a complex process involving multiple decision makers and criteria. Given the spatial nature of the problem, the research proposes a spatial analysis model to assess the agronomic and economic feasibility of vegetation filter systems in Basilicata region, southern Italy. The model chosen for land suitability analysis is the ordered weighted averaging (OWA) with the use of linguistic quantifiers. The suitability map obtained from the OWA model was used as input in the spatial analysis functions to quantify the productivity and irrigation needs of the species, the potential irrigable service area of the wastewater treatment plants (WWTPs), as well as the distances between them and SRF, which are all key elements in the economic evaluation. The results show that the distance is the main element that influences the feasibility: only 25 out of 163 WWTPs are cost-effective and can actually irrigate 864ha of SRF. The research demonstrates that there is a great potential for bio-energy development in the region with significant economic advantages; in fact, there is a large number of sites with positive NPV up to 50,876.43€/ha and payback period between 3 and 10 years. The implementation of vegetation filter systems could create chains with a high number of local actors (farmers, intermediaries, forest nurseries, etc.) and contribute to promoting territorial development and employment.

Removal efficiencies of vegetation-specific filter strips on nonpoint source pollutants

A field experiment was conducted to examine the removal efficiencies of different autochthonous vegetation-specific filter strips on nonpoint source pollutants (NPSPs) and to identify their major influencing factors under various conditions. Furthermore, the effects of five major influencing factors on the removal efficiencies were analyzed. We found that the removal efficiencies in total suspended solid (SS), total nitrogen (TN) and total phosphorus (TP) of the grass vegetation filter strip were significantly higher than those of the seabuckthorn bushy vegetation filter strip. The averaged SS concentration and mass removal efficiencies of the VFS were commonly above 90%, respectively. The TN concentration removal efficiency ranged from 50 to 70%, and the mean TN mass removal efficiency ranged from 70 to 90%. The mean concentration and mass removal efficiencies in particulate nitrogen (PN) were approximately 85 and 95%, respectively. However, the concentration and mass efficiencies in dissolved nitrogen (DN) were lower. The TP concentration removal efficiency averaged 86%, and the mean TP mass removal efficiency was about 94%. The mean concentration and mass removal efficiencies in particulate phosphorus (PP) were approximately 88 and 96%, respectively. Moreover, the concentration and mass efficiencies in dissolved phosphorus (DP) were not significantly high. This suggests that PN is the main loss form of N and PP is the major loss form of P. Overall, the mass removal efficiencies of various species of VFS on nonpoint source pollutants in various forms were higher than the concentration removal efficiencies. Additionally, the removal efficiencies of VFS on nonpoint source pollutants were subject to many factors such as vegetation coverage, initial soil water content, width of VFS, inflow discharge and inflow concentration. However, the most important influencing factors are vegetation coverage, width of VFS and inflow concentration. The width of VFS plays an essential role in N and P removal efficiencies, in that even though the width of VFS is longer, the removal efficiency of VFS is not really better. Additionally, the removal of SS should be firstly considered during the course of the application of VFS due to the SS correlating well linearly with TN and TP. Nevertheless, routine maintenance is also quite necessary to keep in good removal performance of VFS.

Willows for the treatment of municipal wastewater: Performance under different irrigation rates

Willow cropping is increasingly spreading worldwide for various purposes including vegetation filter. Willow plantations are highly nutrient-demanding and site fertilization may be required to maintain soil fertility and nutrient balance. In this context, municipal wastewater could be a valuable source of nutrients (especially N and P) and water for plant growth. The aim of this study was to assess the performance of willows to recycle municipal wastewater supplied at different rates. In particular, we sought to evaluate the quality of groundwater water collected under willow and assess the effect of wastewater supply on willow growth. Irrigation with wastewater had a positive effect on willow growth and biomass yield. It was also estimated that willows were able to remove nearly 90% of the N and 85% of the P found in the wastewater. This study shows that a willow vegetation filter is very efficient at removing nutrients found in wastewater.

Watering or buffering? Runoff and sediment pollution control from furrow irrigated fields in arid environments

Surface irrigated agriculture in arid and semi-arid regions contributes to downstream environmental degradation. Changes in irrigation system operational scenarios (ISOS) can represent an economic alternative to reduce surface runoff impacts. At the same time the use of vegetative filter strips (VFS) can have a positive impact on the ecological health of rural landscapes by reducing erosion, improving water quality, increasing biodiversity, and expanding wildlife habitat. The goal of this paper is, using a combination of field data and mechanistic modeling results, to evaluate and compare the spatial effectiveness of improvements in ISOS and introduction of VFS to reduce surface runoff pollution in the semi-arid/arid furrow irrigation agroecosystem that exceeds current regulatory turbidity limits (25 NTU). Five main factor interactions were studied: four soil textures, two field slopes, three ISOS, six filter vegetation types, and ten filter lengths. Slope and runoff volume were identified as the two main drivers of sediment export from furrows. Shifting from current ISOS to less water consumptive irrigation practices reduce runoff in addition to sediment delivery to comply with environmental regulations. The implementation of 3–9m vegetative buffers on experimental parcels were found to mitigate sediment delivery (greater than 90% sediment reduction) on tail drainage ditches but had limited effect in the reduction of runoff flow that can transport other dissolved pollutants. These findings were insensitive to filter vegetation type. Thus, introduction of improved ISOS is desirable while VFS may be targeted to specific hot spots within the irrigation district. This study shows that the adoption of dense vegetation buffers in vulnerable semi-arid irrigated regions can be effective to mitigate agricultural impacts and provide environmental protection. However, it should not be adopted as an alternative to proper on-site irrigation practices, rather as a complementary off-site pollution control practice.

Water, Sediment and Nutrient Retention in Native Vegetative Filter Strips of Southern Brazil

Vegetative filter strips (VFS) are areas adjacent to watercourses with the purpose of reducing sediment and nutrients contained within runoff water from cropland. The aim of this study was to evaluate the retention of water, sediment and nutrients in VFSs with 5, 10, 20 and 30 m widths exposed to simulated runoff water. The VFS chosen for this study were populated by native herbaceous vegetation with a predominance of grasses from South of Brazil. To simulate runoff water, a flow of 30 L min -1 was applied to all plots. Simulated runoff water contained 3.22 g L -1 of sediment and the nutrients concentration was 62.2; 40.9 and 170.3 mg L -1 de P, NH 4-N and NO 3-N,

Denitrification and Nitrous Oxide Emissions in Annual Croplands, Perennial Grass Buffers, and Restored Perennial Grasslands

Inclusion of perennial vegetation filter strips (PFSs) in the toeslope of annual cropland watersheds can decrease NO₃⁻–N losses to ground and surface waters. Although PFSs are similar to riparian buffers, the processes responsible for NO₃⁻–N removal from PFSs are not well understood. Our objectives were to (i) determine the importance of denitrification as a sink for NO₃⁻–N loss from PFSs and (ii) evaluate how PFSs alter the biophysical processes that affect the relative importance of N₂O and N₂ emissions. To address our objectives, we used a coupled field laboratory approach with experimental watersheds that included the following treatments: (i) PFSs covering the bottom 10% of the watershed and an annual corn–soybean crop rotation covering the remaining upslope 90% (PFS); (ii) 100% corn–soybean rotation (CORN); and (iii) 19-yr-old 100% restored native grassland (RNG). In situ N₂O flux rates and laboratory N₂O/(N₂ + N₂O) ratios were highest in CORN watersheds followed by PFS and RNG watersheds. In contrast, potentially mineralizable C and denitrification enzyme activity (DEA) were highest in PFS and RNG watersheds and lowest in CORN watersheds. Furthermore, there was a negative correlation between N₂O/(N₂ + N₂O) ratio and DEA. In the laboratory, N₂ fluxes were highest in PFS followed by RNG and CORN. These results indicate that PFS watersheds support greater total denitrification while emitting less N₂O than croplands. Greater potentially mineralizable C in PFS and RNG suggest C availability is an important factor affecting more complete denitrification. These results suggest PFSs function similar to riparian buffers and have potential to reduce NO₃⁻–N losses from annual croplands by denitrification to N₂.

Willow Root Development and Morphology Changes Under Different Irrigation and Fertilization Regimes in a Vegetation Filter

Determining the appropriate wastewater dose to supply nutrients while avoiding overirrigation is essential for achieving more balanced above- and belowground development of the plants, thereby ensuring high filtering functionality of a willow vegetation filter system. Aboveground biomass and root development of a 3-year-old willow vegetation filter in response to three increasing doses of secondary-treated urban wastewater under both fertilized and unfertilized conditions were evaluated. Fine, coarse and total root biomass, fine root length density (FRLD), specific fine root length (SFRL) and specific root area (SRA) were assessed in soil core samples collected at four different depths (0–20, 20–40, 40–60 and 60–80 cm) in all treatments. While aboveground biomass increased as wastewater amounts and fertilization increased (from 23.89 Mg ha−1 in non-irrigated condition to 47.07 Mg ha−1 in the highest wastewater dose, from 31.5 Mg ha−1 in unfertilized plots to 40.1 Mg ha−1 in the fertilized), total and fine root biomass decreased when willow was irrigated with the highest wastewater dose (i.e. total root biomass is 2.54 Mg ha−1 in non-irrigated condition—1.36 Mg ha−1 in the highest wastewater dose). The root biomass did not follow the same development pattern, and a significant decrease in fine root biomass was observed when the highest irrigation dose was applied. In these circumstances, we believe that the supply in water and nutrient is sufficient to the development of the willows which react by diminishing the amount of roots proportionally to the aboveground parts. This may lead to a higher transpiration rate and allow willows to avoid a surplus of water in the soil.

Determination of removal efficiency using vegetative filter strips based on various efficiency evaluation methods

In this study, through the monitoring of 17 rainfall events over the course of a 3-year period, and in conjunction with the use of vegetative filter strips (VFS), five cases were calculated using different methods and they were evaluated in terms of the non-point source contamination removal efficiency. The efficacy of the methods used for evaluating the removal efficiencies can change considerably depending on several factors such as the removal device type, drainage basin, and rainfall event. With VFS, the removal efficiencies were found to change in accordance with the vegetation coverage ratio, except in June and July, which for watersheds in Korea are the months when rainfall amounts are concentrated. As such, it is assumed that because the VFS removal efficiencies are significantly affected by the vegetation coverage ratio, a method that explicitly considers the vegetation coverage ratio would be most appropriate when calculating the efficiency of a removal facility such as VFS.

Evaluating the Impact of the Spatial Distribution of Land Management Practices on Water Erosion: Case Study of a Mediterranean Catchment

Abstract: The spatial distribution of land management practices (LMPs), such as the use of vegetated filters, may have a strong impact on their efficiency in trapping sediments and pollutants. Distributed water erosion models help managers, planners, and policymakers optimize the efficiency of these LMPs regarding their location relative to water and sediment pathways. In this work, the authors analyzed the impact of the spatial distribution of LMPs using an existing distributed model and sensitivity analysis procedures. The distributed model that was used is a distributed single-event physically based water erosion model developed to calculate erosion rates and sediment flow for small (less than 10 km2) agricultural catchments. To measure the impact of the spatial distribution of LMPs, the authors developed a stochastic model that generates LMP locations over the entire catchment. The stochastic model has three input parameters: the density of LMPs, their downslope/ upslope location probability, and the probability density function shape controller. Because of its ability to account for the cross effects between parameters, the variance-based Sobol method was used to calculate the sensitivity of the soil loss ratio of a typical Mediterranean agricultural catchment (Roujan, southern France) to the LMP location model parameters. Three measurement points (two subcatchment outlets and the main outlet) were used to examine the spatially distributed effects of the LMP locations. The simulation results indicated that 70% of the variation of the net erosion is explained by variations in LMP density for the main outlet catchment, making LMP density the most sensitive parameter. However, the total Sobol sensitivity indices indicate a strong interaction among the three parameters when the density values are low (few LMPs are applied). Thus, although the density of the LMPs is the most sensitive parameter, their location may influence their global trapping efficiency in (real) cases where few LMPs are applied.

Treating municipal wastewater through a vegetation filter with a short-rotation poplar species

The performance of a vegetation filter using a short-rotation coppice of poplars was evaluated over a 3-year period in terms of pollutant removal capacity. The vegetation filter was designed for scattered and small populations with no storage facilities and a wastewater application constrained by the own production of effluent. Wastewater effluent was pre-treated in an Imhoff tank and applied to the vegetation filter. The chemical compositions of drainage water and groundwater were regularly monitored. Surface soil samples at the beginning and the end of the study were also collected. The monitored chemical species in drainage water and groundwater were DOC, COD, NT, NO3–N, NH4–N, PT, PO4-P, and other major ions. Electrical conductivity, organic matter content (%), NO3–N, available P, cation exchange capacity and major cations were analysed for soil. The vegetation filter presented efficient removal of wastewater-originated pollutants. DOC and COD removal reached values of 85%. A correlated increase in soil organic matter content was detected (from 1.0% to almost 2.8%). A similar removal capacity was observed for PT which is interpreted as due to plant uptake mechanisms and PO43− precipitation in the presence of soil Ca2+. Around 73% of NT was removed. However, due to the high applied NT load, the average NT concentration in drainage water was about 41.9mg/L, higher than the admissible concentration limit. When considering NT mass, about 10% of the cumulative applied NT leached through the vadose zone. Groundwater quality was not affected by the vegetation filter operation.

Spatial characterization of riparian buffer effects on sediment loads from watershed systems.

Understanding all watershed systems and their interactions is a complex, but critical, undertaking when developing practices designed to reduce topsoil loss and chemical/nutrient transport from agricultural fields. The presence of riparian buffer vegetation in agricultural landscapes can modify the characteristics of overland flow, promoting sediment deposition and nutrient filtering. Watershed simulation tools, such as the USDA-Annualized Agricultural Non-Point Source (AnnAGNPS) pollution model, typically require detailed information for each riparian buffer zone throughout the watershed describing the location, width, vegetation type, topography, and possible presence of concentrated flow paths through the riparian buffer zone. Research was conducted to develop GIS-based technology designed to spatially characterize riparian buffers and to estimate buffer efficiency in reducing sediment loads in a semiautomated fashion at watershed scale. The methodology combines modeling technology at different scales, at individual concentrated flow paths passing through the riparian zone, and at watershed scales. At the concentrated flow path scale, vegetative filter strip models are applied to estimate the sediment-trapping efficiency for each individual flow path, which are aggregated based on the watershed subdivision and used in the determination of the overall impact of the riparian vegetation at the watershed scale. This GIS-based technology is combined with AnnAGNPS to demonstrate the effect of riparian vegetation on sediment loadings from sheet and rill and ephemeral gully sources. The effects of variability in basic input parameters used to characterize riparian buffers, onto generated outputs at field scale (sediment trapping efficiency) and at watershed scale (sediment loadings from different sources) were evaluated and quantified. The AnnAGNPS riparian buffer component represents an important step in understanding and accounting for the effect of riparian vegetation, existing and/or managed, in reducing sediment loads at the watershed scale.

유역단위 유사 저감 효과 모의를 위한 HRSM4BMP모형의 개선

The objectives of study are 1) to enhance the filed scale BMPs model of HRSM4BMP for simulation of watershed scale and 2) to evaluate the enhanced HRSM4BMP model. Thus pre-process and post-process module were developed and HRSM4BMP was linked to SWAT routing module. After enhancement of model, enhanced HRSM4BMP model was applied to Heaan watershed in Kangwon province with Vegetative filter strip (2 m) in subwatershed #14 and reduction of sediment load was evaluated by watershed scale in outlet. The results of simulation, sediment load was reduced by 4 percent during 3 years in outlet. The result of this study is expected to be used Long-term BMPs establishing plan in South Korea