Channel Banks Research Articles

Autogenic translation and counter point bar deposition in meandering rivers

AbstractAlthough it has long been recognized that deposition along meandering rivers is not restricted to convex banks (i.e., point bars), the consensus is that sediment deposition on concave banks of channel bends mostly occurs when meander bends translate downstream because erosion-resistant barriers inhibit their lateral migration. Using a kinematic model of channel meandering and time lapse satellite imagery from the Mamoré River in Bolivia, we show that downstream translation and associated concave bank deposition are essential, autogenic parts of the meandering process, and resulting counter point bars are expected to be present whenever perturbations such as bend cutoffs and channel reoccupations create short bends with high curvatures. The implication is that zones of concave bank deposition with lower topography, finer-grained sediment, slack water, and riparian vegetation that differs from point bars are more common than previously considered.

A comparative study on assessing rodent damage intensity in rice crop based on two different methods

Rodent damage is commonly concentrated towards the center of rice fields. There are some approaches to assess the damage, two of them are the transect and the Malayan method. The transect technique is a well-known applicable practice employed among agricultural workers in Indonesia, while the Malayan method is generally performed in Malaysia. The objective of this study was to compare both methods in terms of determining the more representative technique for assessing rodent damage. The study was conducted in Karanggetas village, Bangodua subdistrict, Indramayu district, West Java (6°51’S, 108°29’E) in 2018. Two plots (0.35 ha and 0.56 ha) were selected as the study site which was planted with Inpari 32. Since the generative stage of the rice crop is the most preferable phase for rodents, therefore we solely observed the damage within this period. We recorded the damage intensity four times with weekly intervals by both methods in each plot. To confirm the rodent population and reproduction status, we installed a linear trap barrier system and dug some active burrows along the irrigation channel bank as their main habitat. The result showed that the damage intensity was significantly different between both methods. The damage intensity was higher when it was assessed by the transect method compared to the Malayan one. The result indicated that the transect method is a better technique representing the damage than the Malayan method. This due to the first method covered almost entirely the damaged spot. This finding suggested that the transect method is the representative technique for assessing rodent damage intensity.

A propositive contribution to the mitigation of the credit problem on Brazilian solidarity economy enterprises

The biggest impediment to the viability of Solidarity Economy Enterprises (SEE) is the credit issue, which due to lack of guarantees means that they cannot access credit through traditional banking channels and end up failing. In view of this unfavorable scenario, the objective of this work is to make a propositive contribution, evidencing elements that are useful to enterprises of solidarity economy in relation to obtaining credit. To do so, it relied on bibliographic research to link these factors, highlighting those that can be controlled by the SEE, as well as those external so that the credit assignment occurs, which resulted in the elaboration of a propositive instrument, with elements that facilitate the assignment of credits both in the user's view and in the institutional view. Its usefulness could be verified with a field research, conducted with 25 solidarity economy enterprises, which answered a questionnaire informing whether the existence of such an instrument would help in reducing the difficulties of obtaining credit, as well as being able to contribute with eventual adjustments.

Novel approaches to investigating spatial variability in channel bank total phosphorus at the catchment scale

Phosphorus (P) is often a limiting nutrient that leads to the eutrophication of aquatic systems. While dissolved P forms are the most bioavailable, the form, mobility, transport and fate of P are directly related to its association with fine-grained riverine sediment. Therefore, to implement successful P catchment management strategies it is important to understand the relative contribution of different sediment sources to P loads across the river continuum. While agricultural topsoil and, to a lesser extent, riverbed sediment are important sources of sediment-associated P, channel banks have been shown to be an important sediment source in some catchments. However, comparatively little is known about the P concentration and corresponding spatial variability in channel bank sediment and the associated implications for catchment management. The present study examines the spatial variability of P associated with channel bank profiles within a series of three nested catchments using both non-spatial and spatial statistical methods, where for the latter, a novel spatial approach was used to estimate the spatial averages and variances of P in channel bank sediment along the stream network. Channel bank P concentrations were compared to factors such as catchment scale, stream order, land use, bank exposure and location along the stream network. Concentrations of TP ranged between 129.6 and 1206.9 mg P kg−1 of which the water extractable P (WEP) content ranged from 0.01 to 0.12%. Stream order was found to influence TP concentrations, while land use and catchment scale provided only a moderate influence. This suggested that focussing channel bank sampling strategies at the largest catchment scale would capture key drivers of TP variability provided stream order is sufficiently represented. Whether the bank was had limited vegetation and was exposed and potentially eroding had a slight influence on TP variability in second-order stream banks in the larger of the two nested catchments. However, the slightly lower TP concentrations measured at these sites indicated that banks that are actually eroding may be contributing less TP than the total channel bank TP values measured across the catchments as a whole. The results of an explicitly spatial analysis demonstrated that local channel bank TP averages and TP variances vary along the stream network. Specifically, the most accurate spatial predictor of TP was local TP means with the use of ‘crow flies’ rather than stream network distances. Local TP variances were used to provide optimal designs for future channel bank TP sampling campaigns, given available resources. Throughout, both standard and outlier-resistant statistical analyses were applied to improve interpretation of the study findings.

Sediment source apportionment using optical property composite signatures in a rural catchment, Brazil

Identifying the key sources of fine-grained sediment is essential for protecting and improving soil and water quality. Accordingly, this contribution tested a combination of low-cost analytical procedures for assembling information on key sediment sources in an agricultural catchment in Brazil and in so doing, tested 24 components derived from a conventional printer scanner using various colourimetric models, 18 organic compounds derived from near-infrared (NIR) spectra and 13 soil constituents derived from mid-infrared (MIR) spectra. In combining the application of these low-cost tracers, the study also aimed to investigate potential scale-dependency in sediment sources. Four main sediment sources were sampled: (i) sugarcane; (ii) unpaved roads; (iii) cropland, and; (iv) channel banks and samples were collected from these at two different scales; sub-catchment (~1453 km2) and catchment-wide (~2857 km2). At both scales, channel banks were the most important sediment source followed by sugarcane. At catchment-wide scale, channel banks accounted for 75.9 ± 6.7%, 56.4 ± 16.3%, 39.1 ± 20.7% and 68.3 ± 4.9% of sampled suspended sediment using composite signatures comprising NIR, MIR or colour tracers only, or a combination of all three types of low-cost tracers, respectively. For bed sediment samples, the corresponding respective source contributions were estimated to be 43.4 ± 4.7%, 32.8 ± 7.8%, 49.2 ± 18.6% and 32.0 ± 4.6%. Our results, regardless of optical property, target sediment type, or scale, suggest that channel banks represent the primary source of the sediment problem in the study area. Targeted remedial actions therefore especially need to deliver protection for eroding channel banks.

Elucidating intra-storm variations in suspended sediment sources using a Bayesian fingerprinting approach

There is an increasing need for reliable information on the origin of fine-grained sediment transported by river systems, but critically, at temporal scales that reflect the timing and pattern of sediment mobilization and delivery in response to effective precipitation events. Temporal variability is likely to be more pronounced in steep mountainous catchments. Accordingly, the main objective of this study was to investigate the temporal variability of sediment sources during and between flood events, in a mountainous catchment in Iran, using a geochemical fingerprinting approach and Bayesian un-mixing model. Potential sediment sources were classified as either tributary sub-basin spatial end members or individual source types represented by surface soils and channel banks. A total of 34 geochemical elements, elemental ratios and weathering indices were measured as potential tracers on a total of 155 samples, including 40 target samples collected across the hydrographs of four flood events at the overall catchment outlet. Virtual mixture tests, used to compare the computed source estimates with known source mixtures, revealed better fits in the case of spatial, rather than source type apportionment. The Bayesian un-mixing model results revealed pronounced intra-storm variations in the relative contributions from both the spatial sources and source types, but with Quaternary surface soils and channel banks being dominant at different stages of the hydrographs. For all the suspended sediment samples collected throughout the three small to medium size events, the Babazid, middle upstream sub-catchment, was the major (84%–99%) sediment source while for the largest sampled event, suspended sediment samples predominantly (>98%) originated from the Kalkoshan, the most southern sub-catchment. By investigating both spatial sources and source types, temporal variations in the dominant sources were revealed. Quaternary geology and channel banks were identified as the main sediment sources. By combining instantaneous suspended sediment loads through the sampled flood events (across all floods) and using the corresponding source proportions derived from the MixSIR un-mixing model, channel banks and channel bank and surface soils generated 2911 kg and 34,171 kg of suspended sediment, respectively. Whilst the use of spatial source end members is practical in medium-size drainage basins, integration with estimates of sediment source type contributions is more informative to managers in selecting relevant sediment mitigation methods. The intra-storm results underscore the need to manage sediment loss from both surface soils and channel banks.

How do bank characteristics affect the bank liquidity creation channel of monetary policy?

The paper examines how monetary policy affects bank liquidity creation, particularly highlighting the asymmetric effects induced by bank-specific characteristics. Using a sample of Vietnamese commercial banks during 2008–2018, we confirm the existence of the bank liquidity creation channel of monetary policy. We further document the conditionality on this new banking channel that liquidity creation rises more among smaller and more liquid banks amid monetary policy easing. These findings call for the focus of regulators on monitoring monetary policy and bank characteristics to shape the functioning of the bank liquidity creation channel.

Adoption of digital banking channels in an emerging economy: exploring the role of in-branch efforts

The aim of this qualitative study is to analyse the role of in-branch efforts of banks on migrating customers from branch banking to digital banking in India. In-depth semi-structured interviews were conducted with bank executives representing senior management from public and private sector banks in India. Qualitative content analysis technique was used to analyse the data. Varieties of responses received during interviews were clubbed into four main themes based on data reduction, display, and conclusion-drawing processes. In-branch communication with customers, digital transformation of the branch, customer-centric initiatives, and redefined role of branch staff hold the potential to bridge the customers’ migration to digital banking. The paper suggests that the key identified factor in improving digital banking acceptance in India is the requirement of integrated cultural and organisational changes at the bank’s level to gain the customers’ confidence and trust in digital banking.

New security approach-based Steganography and Cryptography by modified AES algorithm

The transmission of information through any channel of correspondence needs solid encryption procedures with the end goal of information security. The computerized watermarking assumes a significant part in inserting data into an advanced picture signal, for the check and character of its proprietors. In discrete wavelet change, "investigation channel bank" can be utilized for dissecting picture signals by going through. The channel bank comprises high and low pass channels at every deterioration stage. In this paper, a technique to consolidate steganography (Least Significant Method-LSM) and cryptography Advanced Encryption Standard (AES) is thought to give a safer method to information transmission through any unstable or public organizations. Prior to inserting the content in the picture, the text is scrambled utilizing AES calculation. Utilizing least significant bit (LSB) strategy, encoded the text installed in low-low (LL) subband wavelet decayed of a picture. Converse wavelet changes applied will lead to the output picture is communicated to the recipient. Presently at the collector's end, the picture changed utilizing wavelet and encoded text will be extricated by utilizing the LSB technique. This paper shows how AES calculation is utilized in the decoding of the outcome.

To whom do banks channel central bank funds?

This paper examines the relationship between central bank funding and credit risk-taking. Employing bank-firm-level data from the German credit registry during 2009:Q1-2014:Q4, we find that banks borrowing from the central bank rebalance their portfolios towards ex-ante riskier firms. We further establish that this effect is driven by the ECB’s maturity extensions and that the risk-taking sensitivity of banks borrowing from the ECB is independent of idiosyncratic bank characteristics. Finally, we show that these shifts in bank lending are associated with an increase in firm-level investment and employment, but also with a deterioration of bank balance sheet quality in the following year.

Oversampled filter bank channelizer for cryogenic detectors.

We present the field-programmable gate array (FPGA) implementation of an oversampled generalized discrete Fourier transform (GDFT) filter bank (FB), optimized for its usage in the readout of cryogenic detectors, such as microwave kinetic inductance detectors. A polyphase structure is derived underlining the efficiency of complex-valued subband processing, raised by a GDFT modulation. For the latter, a fast Fourier algorithm realization may be used, yielding a highly efficient polyphase implementation for arbitrary integer decimation ratios. The FB is tested through a 16-channel GDFT channelizer. The implementation is based on the Xilinx Zynq family of FPGAs and aims to show the data reuse and flexibility offered by the GDFT channelizer structure. General design criteria are summarized for the 16-channel polyphase FB channelizer. The performance in hardware resource usage is also presented, taking into account one of the main objectives of the current physics experiments, aiming to have an extremely large readout format.

Water and Sediment Supply Requirements for Post-Wildfire Debris Flows in the Western United States

ABSTRACT This work explores two hypotheses related to runoff-related post-wildfire debris flows: 1) their initiation is limited by rainstorm intensity rather than cumulative rainfall depths and 2) they are not sediment supply limited. The first hypothesis suggests that it is common to generate more than enough rainfall to account for the volume of water in the debris flow, but to actually produce a debris flow, the water must be delivered with sufficient intensity. This is demonstrated by data from 44 debris flows from eight burned areas in California, Colorado, and Utah. Assuming a debris flow comprises 30 percent water and 70 percent solids, these events were generated during rainstorms that produced an average of 17 times as much water as necessary to develop a debris flow. Even accounting for infiltration, the rainstorms still generated an overabundance of water. Intensity dependence is also shown by numerous cases in which the exact timing of debris flows can be pinpointed and is contemporaneous with high-intensity bursts of rainfall. The hypothesis is also supported by rainfall intensity-duration thresholds where high-volume storms without high-intensity bursts do not generate debris flows. The second hypothesis of sediment-supply independence for the initiation of debris flows is supported by a significant increase in flow volume occurring directly after wildfire, compared to flows in unburned terrain. Also, repeated flows within short time intervals are only possible with an abundance of channel sediment, dry ravel, and bank failure material that can be mobilized. Field observations confirm these sediment sources, even directly after a debris-flow.

Integrating Rangeland Health and Stream Stability in Assessments of Rangeland Watersheds

Watersheds are distinct hydrologic units that comprise a range of terrestrial upland and riparian complex ecological sites. Since the hydrologic function of the entirety of the watershed is linked, other ecological functions and processes are also likely linked. No single assessment tool is available to describe the ecological status of both terrestrial upland sites and riparian complexes in a single watershed. We investigated the relationship by integrating two assessment tools, Interpreting Indicators of Rangeland Health protocol (IIRH) and stream geomorphic surveys in prairie ecosystems. The qualitative values from the IIRH protocol were different among upland sites associated with 35 intermittent stream reaches in North Dakota in the United States. Riparian complex sites were separated using three metrics of stream stability: stream channel type, bank-height ratio, and Bank Erosion Hazard Index. Stream channel type had the strongest relationship with two attributes of rangeland health, Soil & Site Stability and Hydrologic Function, while bank-height ratio had the strongest relationship with the Biotic Integrity attribute. The influences of individual indicators were identified using a principal components analysis, which revealed unstable streams were typified by departures from the reference state in compaction, soil loss, bare ground, litter dynamics, infiltration, and invasive species. These findings suggest that changes in these IIRH indicators should be monitored and managed by land managers to ensure that riparian function and ecosystem services are not compromised. Future research must continue to investigate the link between upland and riparian functions within a watershed, with special emphasis on vegetation dynamics. In the meantime, integrating these two assessments can provide land managers with vital information about maintaining ecological function throughout the watershed.

Credit expansion, bank liberalization, and structural change in bank asset accounts

This paper studies the links among credit supply expansion, commercial bank asset account structures, and the housing boom preceding the 2007–2009 financial crisis. We propose a real business cycle model with a housing market and financial intermediaries (banks) subject to leverage constraints. In our model, banks channel funds to firms for production and provide collateralized loans to mortgage borrowers; thus, banks determine their asset account structures endogenously. We show that a credit supply expansion to banks can account for four key facts that characterize the housing boom: (1) an increase in real house prices; (2) an increase in the mortgage-to-GDP ratio; (3) a decrease in the real mortgage interest rate; and (4) an increase in the ratio of mortgages to firm loans in commercial bank asset accounts. In our model, a credit supply expansion to banks can also generate a boom-bust cycle through the collateral value channel via mortgage borrowers. Asset-side bank regulations that reduce excessive mortgage issuance during a credit boom can help to dampen the subsequent economic downturn.

MORPHODYNAMIC CLASSIFICATION OF CHANNEL OF SUKIL RIVER

The morphodynamic classification of the Sukil river channel made it possible to determine the hydromorphological processes and to study the factors that determine them. The channel was classified according to the method of R.S. Chalov. Three main classification criteria were taken into account: the geomorphological type of conditions for the formation of the channel; the type of channel processes; the mophrodynamic type of channel. According to the geomorphological type of channel-forming conditions, the channel is divided into the incised channel – located mainly in mountainous and semi-mountainous parts with a characteristic the narrow valley, laid in sandstones, siltstones, and argillites; confined channel – located in intermountain basins, with one bank of channel composed of bedrock, and the other – of Quaternary sediments; wide-floodplain channel – mainly located in the lower part of the channel on the Stryi-Zhydachiv basin, laid in the Quaternary deposits of loams and sands. According to the type of channel processes, the channels with developed alluvial forms and without developed alluvial forms are dominant. Together they make up 2/3 of the channel. Other types of channels are wide-floodplain – characterized by slow flow and stable development of the meandering process, and rapid-waterfall – located in the upper reaches of the channel. The latter is characterized by a stormy current and the presence of numerous rapids made of boulders and wood. There are 3 main morphodynamic types of the channel – meandering, branched, and straightforward, and 6 their subtypes. Meandering, incised channels are characterized by structural meanders, their shores are composed of hard rocks, mostly sandstones. The meandering confined channels are defined by the root bank in the apical part and the upper wing along the root bank, which leads to the formation of segmental and blockage convolutions. Meandering, broad-flooded channels are characterized by longitudinal displacement of meanders, their convolutions are segmented, rarely loop-shaped. The coefficient of meandering gradually increases from the mountainous part of the channel to the plain one (1.10–1.35). Branched type is represented by a single complex and floodplain-channel subtypes. The size of the islands that divide the channel into arms is from a few meters to 350–400 m. The straightforward type of channel is widespread and is 1/3 of the total length of the river. Key words: channel type; straightforward; branched; meandering; incised; confined; floodplain.

Seismic record of a cyclic turbidite-contourite system in the Northern Campos Basin, SE Brazil

A new mixed turbidite-contourite system is described in the northern Campos Basin, southeastern Brazilian margin. This system is developed in a middle slope setting, and was formed through non-synchronous interaction between the turbidity current and a contour current in the same stratigraphic interval (Miocene). Depositional cycles were differentiated based on diagnostic seismic features. Seismic attributes, seismic facies, and isochron maps were used to identify alternating cycles of downslope and alongslope processes in the study area, along with the intermediate stage with features from both processes (mixed system). Seismic units were then associated with the dominant type of current. Alongslope current activity can be distinguished from the downslope current based on its acoustic characteristics (mainly low root-mean-square (RMS) amplitude values), internal architecture (clinoforms), and external geometry pattern (alongslope trend).On the other hand, downslope gravity currents develop deposits with high-amplitude or chaotic seismic facies, usually higher values of RMS amplitude, channel or channel-lobe features, erosive surfaces, and a basinward depositional trend. The first and oldest seismic unit (S1) was interpreted as a dominantly alongslope system, with vertical aggrading sigmoidal clinoforms and high-frequency, low-amplitude reflections commonly associated with fine-grained sedimentary deposits, typical of a plastered drift, along with a basinward mass transport deposit (MTD) from previous drift instability. Seismic unit S2 represents the intermediate stage where both gravity-driven and along-slope currents act asynchronously. Its is refered to as a mixed turbidite-contourite sequence that shows high-amplitude sediment waves migrating upslope and a moat feature that is carved in its upslope front. The interfingering between high- and low-amplitude reflectors, distal chaotic facies, together with sediment waves and a channel moat, points to a sand-rich deposit reworked by northward-flowing contour currents. Seismic units S3 and S4 show downslope features with chaotic facies (S3) and paleochannels with coarse basal lag deposits (high RMS amplitude values) (S4). In S4, a series of long-lived submarine channels formed. Last, seismic unit S5, referred to as the second plastered drift sequence, is marked by low-amplitude clinoforms that thin basinward. At the seafloor, submarine channel banks (formed at S4) covered by fine sediment deposits (from S5) show asymmetrical features with a slight northward depositional trend, indicating a northward-flowing bottom current, as the deposits are known to pile up in a downcurrent trend. Important information on the paleocurrents' direction was also made based on the final deposits display (e.g. terraces, sediment waves, paleochannels). Research on alternating dominant processes and transitional stages or mixed depositional systems, with both turbidites and contour currents, may provide a better understanding of deep-water depositional processes. Because these processes do not always fit previous depositional models that are mainly described for synchronous systems, new insights on cyclic non-synchronous mixed systems can improve our understanding of how mixed systems are organized through time and space. Being able to determine which were the dominant processes that controlled the sedimentation by indicating periods where the margin was mostly submitted to sediment transfer from continent to the basin and periods where the oceanic currents prevailed by redistributing sediments along the isobaths and replacing the axis of downslope transfer conduits. Setting new models on cyclic deposits and intermediate stages can have a future economic impact on potential hydrocarbon reservoir architecture.

RESEARCH ON THE PRACTICAL ASPECTS OF THE PROVIDING EFFICIENCY OF MARKETING COMMUNICATIONS’ BANK

The marketing communications play an important role in the activities of banks, because it is one of the most important elements of the marketing activity. As an element of a banking institution’s marketing activity, they must be carefully planned, organized and controlled. The need to plan marketing communications in the bank stems from the fact that today it is difficult for consumers to navigate the banking services market. The ongoing competition for each consumer in the banking market drives banks to integrate marketing communications.
 Banks are in constant contact with customers of banking services, financial institutions, central banks, etc. Any bank requires interconnected communications that are constantly evolving to meet the changing external and internal environment. Thus, marketing communications play an important stage in the bank’s marketing activity.
 In an age of digital economy, marketing communications are a prerequisite for improving the increasing the effectiveness of banks and their profitability.
 The practical aspects of ensuring the effectiveness of a bank’s marketing communications are considered and explored in the article. The structure of the bank’s marketing communications complex is influenced by the following factors: the level of management of the bank, the degree of purchasing power of the potential client, the strategy of promotion of banking services, the peculiarities of the complex of marketing communications of competitors and the financial capacity of the bank.
 In particular, digitalization (digitization) of the bank involves the modernization of the banking structure, products and channels of interaction with its customers by applying modern technologies to increase the effectiveness of marketing communications, increase profits and its competitiveness.

Flow Redistribution at Bridge Contractions in Compound Channel for Extreme Hydrological Events and Implications for Sediment Scour

This study investigates the flood flow characteristics in a compound channel subject to both lateral contraction (caused by bridge abutment/embankment) and vertical contraction (caused by bridge deck submergence) at bridge sites. Three abutment setback distances and three pressure flow types [free surface (FS), submerged orifice (SO) and overtopping (OT)] are tested. The results show that turbulence structures in the approach channel remained the same irrespective of downstream obstruction. However, lesser abutment setback from the main channel led to greater flow acceleration as the flow approached the bridge section, where SO flow had the highest flow intensity and FS flow had the lowest. At a bridge contraction, the distributions of flow velocity, turbulence intensity, and Reynolds shear stress are significantly affected by the type of pressure flow and the extent of contraction. Enclosed counterclockwise secondary circulating flows in the main channel may occur for a combination of long or medium setback abutments and a FS flow, while other conditions usually feature open-ended upward flows due to flow relief. The strong downslope flow component detected at the main channel bank has a noticeable bank erosion capability. The bed shear stress, which is an indicator of sediment scour, is highlighted by apparent peak zones at the main channel bank and abutment toe. Finally, clear relationships between turbulence intensity, unit discharge ratio, and lateral contraction length are found. In general, normalized turbulence intensities on the floodplain and in the main channel can be used to assess the contribution of macroturbulence to the final bed topography after scour.

Thixotropic Behavior of Reconstituted Debris-Flow Mixture

Time-dependent rheological properties and thixotropy of reconstituted debris-flows samples taken from channel bank deposits are examined using a commercial rheometer equipped with a vane rotor geometric system. Sweep tests and creep tests were carried out involving mixtures having different grain concentrations ranging between 50% and 58%. Different initial conditions of the mixtures were considered in order to analyze the effects of aging and rejuvenation (thixotropy) over a short period of time and long period of time. Tested slurries show viscosity bifurcation, yield stress and time-dependent behavior. According to the experimental results, three different regimes were identified: a lower shear rate regime, corresponding to a shear rate lower than the critical value; an intermediate banding shear rate regime characterized by static and dynamic yield stress level; and a higher shear rate regime where the flowing debris behaves as a non-Newtonian fluid characterized by a constant steady state ultimate apparent viscosity. In any case, the initial state of the mixture and the sediment concentration affects the ultimate steady state rheology and the time-dependent (thixotropy) slurries’ behavior.

Successful mitigation of stormwater-driven nutrient, fecal bacteria and suspended solids loading in a recreational beach community

Marine and estuarine waterways adjacent to urban areas are often the final recipient of polluted stormwater runoff. Microbial degradation of coastal water quality is a direct threat to human health through fecal contamination of bathing waters and shellfish, as well as distressing local economies through the loss of waterways to commercial (shellfishing) and recreational use. In coastal waters reduction of nitrogen loading is a key strategy for prevention of noxious and toxic algal blooms. Best management practices (BMPs) can be successful tools for mitigating such pollutants in runoff, but BMPs must be tailored to individual situations for maximum effectiveness. This study examines the efficacy of a set of BMPs installed in the coastal resort Town of Wrightsville Beach, North Carolina, USA. The BMPs targeted the highly-impervious (90%+) drainage area of two stormwater outfall pipes emptying into recreationally used Banks Channel. Mitigation measures included replacement of impervious pavement with pervious concrete and construction of an infiltration chamber in the parking lot of a local recreational seaside club. Significant reductions were achieved in total stormwater discharge (62%), as well as loading of the fecal indicator bacteria Enterococcus (76%) and total nitrogen (TN – 87% decrease). Additionally, there were reductions in loading of total phosphorous (TP) and total suspended solids (TSS) to estuarine waters following BMP installment. The set of BMPs applied here have wide management applicability to coastal ecosystems, as well as freshwater riparian areas characterized by sandy, porous soils.