Anand Jayakaran | Washington State University (original) (raw)

Papers by Anand Jayakaran

Research paper thumbnail of Relating stream function and land cover in the Middle Pee Dee River Basin, SC

Study region: The study region comprised sixteen stream sites and associated contributing watersh... more Study region: The study region comprised sixteen stream sites and associated contributing watersheds located in the Middle Pee Dee River Basin (MPDRB) of South Carolina, USA. Study focus: The study was conducted between 2008 and 2010 to quantify how indices of streamflow varied with land cover characteristics analyzed at multiple spatial scales and fluvial geomorphic characteristics of sampled streams in the MPDRB. Study objectives were to relate three indices of streamflow that reflect recent temporal flow variability in a stream, with synoptic stream geomorphological measurements, and land cover type at specific spatial domains. New hydrological insights for the region: Modifications to the landscape, hydrologic regime, and alteration to channel morphology, are major threats to the functioning of riparian ecosystem functions but can rarely be linked to a single common stressor. Results from the study showed that in the MPDRB, wetland cover in the riparian corridor was an important factor, correlating significantly with stream flashiness, channel enlargement, and bed substrate character. It was also shown that a combination of stream geomorphological characteristics when combined with landscape variables at specific spatial scales were reasonable predictors of all three indices of streamflow. The study also highlights an innovative statistical methodology to relate land cover data to commonly measured metrics of streamflow and fluvial geomorphology.

Research paper thumbnail of Dimensioning the Sine-Generated Curve Meander Geometry1

JAWRA Journal of the American Water Resources Association, 2012

The sine-generated curve (SGC) presented by is widely acknowledged as an idealized description of... more The sine-generated curve (SGC) presented by is widely acknowledged as an idealized description of river meander form. However, as originally presented, the SGC application to the field, laboratory, or models is not a trivial task. The SGC function simply provides the direction of the flow path as its rate of change continually varies from most gradual at the crossover to most rapid at the apex of bends. Although the commonly used dimensions of meander length, stream length per meander, sinuosity, and amplitude have been approximated previously, this technical note precisely defines these dimensions by solving the integrals of the sine and cosine of the SGC function. This is performed using integral representations of the Bessel and Struve functions for the zero order and their power-series expansions. Higher precision offered by this technique will be of particular value to modeling and flume-based studies where better conformity to the SGC is necessary. The note goes on to present two simple line and arc patterns optimally fit to the SGC as simplified yet more precise methods for practical design in river restoration schemes. Equations are presented defining the geometry of the arc and line pattern and relating meander length, amplitude, radius of curvature, and sinuosity.

Research paper thumbnail of Floodplains and Streamway Setbacks

Research paper thumbnail of Hydraulic Modeling to Inform Stream Maintenance Strategies in South Carolina

The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed ... more The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed that has undergone considerable urbanization in the last few decades. Evidence of bank instability and inchannel erosion is widely seen in the Crabtree Canal system. Principal sediment inputs are landscape sources and in-channel sources. A study was initiated to provide a working management tool to determine hydrodynamic conditions on the watershed driven by a hypothetical storm event and alternative channel configurations. The management tool comprised of a one-dimensional HEC-RAS model of the Crabtree Canal and was developed to aid the Horry County stormwater department in determining potential zones of stream instability and in evaluating alternate stream management techniques. Average velocity, hydraulic depth and shear stress were used to quantify changes in flow regime. Alternative stream management techniques included different floodplain configurations being implemented on the existing geometry of the channel. The management tool modeled average velocity, hydraulic depth, and shear stress decreasing as floodplain width increased relative to the top width of the main channel. The model also suggested that potential points of stream instability in the system were located at points of inflection in the stream bed profile and at points where the bed profile transitioned to a steeper slope.

Research paper thumbnail of Modeling channel maintenance in a coastal plain watershed

The Crabtree Canal, located in Horry County, SC is the main conveyor of stormwater in a watershed... more The Crabtree Canal, located in Horry County, SC is the main conveyor of stormwater in a watershed that has undergone considerable urbanization in the last few decades. A study was initiated to provide a working management tool to determine hydrodynamic conditions on the watershed driven by hypothetical storm events and alternative ditch management techniques. The tool will comprise a one dimensional hydrodynamic model of the Crabtree Canal that will aid the Horry County Stormwater Department in evaluating alternate stream management techniques.

Research paper thumbnail of FACT SHEET Agriculture and Natural Resources

This fact sheet addresses the role and importance of floodplains, riparian zones, and streamway o... more This fact sheet addresses the role and importance of floodplains, riparian zones, and streamway or riparian setbacks for sustaining or establishing stability in stream systems. The goal of this fact sheet is to aid

Research paper thumbnail of Creating Ditches with Floodplains

Two-stage channel systems incorporate benches that function as floodplains. In comparison to floo... more Two-stage channel systems incorporate benches that function as floodplains. In comparison to floodplains in natural streams, the width of the benches is often small due economic and land loss considerations. This manuscript outlines measurement and analysis procedures that can be used to size two-stage channel systems that are more self-sustaining than conventional one-stage constructed channels. The analysis procedures are incorporated in the STREAMS spreadsheet tools that have been developed by the Ohio Department of Natural Resources and the Ohio State University. Construction of a two-stage channel system requires a significant capital investment to create a wider surface width.

Research paper thumbnail of Hydraulic Geometry Curves and Bankfull Recurrence in the Pee Dee River Basin

Hydraulic bankfull geometry or regional curves are a useful metric for evaluating stream stabilit... more Hydraulic bankfull geometry or regional curves are a useful metric for evaluating stream stability and plan stream restoration projects. Streams and tributaries within the middle Pee Dee watershed in South Carolina drain a highly productive landscape that is characterized by forest and agricultural practices. While stream in the region are generally stable, pockets of this landscape is beginning to face increase pressure from development and showing signs of stream instability. In order provide a foundation for potential stream restoration projects in the area, sixteen sites in the watershed were selected on the basis of catchment area, in categories of small (<50 km 2), small-medium (50-500 km 2), medium (500-1000 km 2), and large (>1000 km 2). Bankfull geometries, channel substrate, flow and temperature were measured at all the sites and a set of regional hydraulic geometry curves developed. We also estimated the frequency of bankfull flows that occurred over the period of s...

Research paper thumbnail of Geometry of inset channels and the sediment composition of fluvial benches in agricultural drainage systems in Ohio

Journal of Soil and Water Conservation

In Ohio, agricultural channels have been constructed or modified to transport surface runoff and ... more In Ohio, agricultural channels have been constructed or modified to transport surface runoff and subsurface drainage away from agricultural fields. The development of depositional bars, or benches, in these agricultural channel systems has been a focus of maintenance activities. Objectives of the reported study were to: (1) determine if there was a relationship between inset channel geometry, as defined by its benches, and geometry predicted by regional curves that relate bankfull geometry to drainage area; (2) evaluate the effect of channel geometry on bed material particle size distribution; and (3) determine if the particle size distribution of bench materials was related to depth from the surface and position on the bench. The study was conducted on low gradient ditches that are headwaters of the Mississippi River and Lake Erie. An analysis to determine the extent of bench and inset channel formation was undertaken using 0.15 m (0.5 ft) resolution panchromatic digital orthophotos. Geomorphology measurements were made at 13 sites, and a 61 cm (24 in) long split-spoon sampler, with a 7.6 cm (3 in) inner diameter, was used to extract cores from the benches at each site. About 59% of the assessed channels showed inset channel development and bench formation. For 12 of the 13 sites, the bankfull dimensions of the inset channel were consistent with regional curves. All benches showed fining of materials with distance away from the inset channel. It was concluded that benches evolve much like floodplains that build because of overbank accretion. The results will be helpful in determining alternative strategies for improving the drainage function of these systems while enhancing ecological habitat and water quality.

Research paper thumbnail of Two-stage channel design procedures

Two-stage channel systems incorporate benches that function as floodplains. However, in compariso... more Two-stage channel systems incorporate benches that function as floodplains. However, in comparison to floodplains in natural streams, the width of the benches is often small due to the confining geometry of the constructed channel. This manuscript outlines measurement and analysis procedures that can used to size two-stage channel systems that are more self-sustaining than conventional one-stage constructed channels. The analysis procedures are incorporated in the STREAMS spreadsheet tools that have been developed by the Ohio Department of Natural Resources and the Ohio State University. Channel design dimensions are determined by measuring the effective discharge features at the project site and making regional curve measurements. Bench elevations are dependent on correctly determining the size of the effective discharge channel. The minimum total widths of the constructed benches are at least double the width of the effective discharge channel and the overall conveyance capacities...

Research paper thumbnail of Monitoring Water Quality Changes in a Forested Freshwater Wetland Threatened By Salinity

Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large ... more Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large tidally-influenced or storm-driven incursions of estuarine waters that may also indicate rising sea levels associated with climate change. A coastal freshwater forested wetland in coastal South Carolina has experienced dieback of freshwater forested wetland trees due to increased salinity within the wetland. Vegetation in the wetland is transitioning from a closed canopy of common freshwater wetland trees such as bald cypress, water tupelo and swamp tupelo, to a more open canopy due to the establishment of salt tolerant grasses. The swamp is prime habitat for several wildlife species as evidenced by game cameras and amphibian recorders installed within the swamp. A team of researchers at the Baruch Institute examined a series of historical aerial images to track changes in vegetation through the years. In June 2013, several water level and conductivity sensors were installed along the sa...

Research paper thumbnail of Runoff Generation from Shallow Water Table Southeastern Forests: Unusual Behavior of Paired Watersheds Following a Major Disturbance

2012 Dallas, Texas, July 29 - August 1, 2012, 2012

Research paper thumbnail of Hydraulic modeling to inform stream maintenance strategies in South Carolina

2009 Reno, Nevada, June 21 - June 24, 2009, 2009

The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed ... more The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed that has undergone considerable urbanization in the last few decades. Evidence of bank instability and inchannel erosion is widely seen in the Crabtree Canal system. Principal sediment inputs are landscape sources and in-channel sources. A study was initiated to provide a working management tool to determine hydrodynamic conditions on the watershed driven by a hypothetical storm event and alternative channel configurations. The management tool comprised of a one-dimensional HEC-RAS model of the Crabtree Canal and was developed to aid the Horry County stormwater department in determining potential zones of stream instability and in evaluating alternate stream management techniques. Average velocity, hydraulic depth and shear stress were used to quantify changes in flow regime. Alternative stream management techniques included different floodplain configurations being implemented on the existing geometry of the channel. The management tool modeled average velocity, hydraulic depth, and shear stress decreasing as floodplain width increased relative to the top width of the main channel. The model also suggested that potential points of stream instability in the system were located at points of inflection in the stream bed profile and at points where the bed profile transitioned to a steeper slope.

Research paper thumbnail of Green infrastructure assessment tools for varying scales in coastal South Carolina

Potential impacts from changing coastal landscapes, specifically the conversion of forested and a... more Potential impacts from changing coastal landscapes, specifically the conversion of forested and agricultural lands to residential and commercial development, can be reduced by more informed decisionmaking related to green infrastructure if the appropriate tools are available.

Research paper thumbnail of A Study of Coastal Headwater Stream Hydrology: Bannockburn Plantation, Georgetown County, SC

2009 Reno, Nevada, June 21 - June 24, 2009, 2009

ABSTRACT Coastal headwater streams in undeveloped forested landscapes function as a natural stora... more ABSTRACT Coastal headwater streams in undeveloped forested landscapes function as a natural storage and conveyance mechanism for rainfall and groundwater. Stream flows are often driven by groundwater table depth, while soil saturation with a high water table may drive rainfall response. Evapotranspiration also plays a significant role in groundwater levels and influences stream flows both seasonally and diurnally. The dynamics of coastal forested watersheds are complex, and water budgets of these low gradient headwater streams are difficult to quantify.The importance of understanding these hydrologic dynamics is critical to water resources protection and flooding prevention in coastal landscapes, especially as forested areas are being converted to residential and commercial development. Baseline hydrology must be assessed as a benchmark for sustainable development goals over the course of land use change, and understanding short- and long-term responses from the conversion of forest lands to urban areas can minimize negative effects in terms of water quantity and quality. Toward the goal of quantifying the water budget in a pre-development forested watershed, stream flows, groundwater levels, and rainfall are being measured in an approximately 800-acre coastal watershed, Upper Debidue Creek, at Bannockburn Plantation in coastal South Carolina, USA. Evapotranspiration rates are also being estimated as photosynthetically active radiation (PAR) is being measured on site with nearby total solar radiation measurements also being taken. Water quality measurements (temperature, conductivity, pH, and dissolved oxygen) are also being collected. Preliminary data being used for water budget estimates and rainfall-runoff relationships from Upper Debidue Creek will be presented.

Research paper thumbnail of Modeling the formation of depositional features in agricultural channels

2008 Providence, Rhode Island, June 29 - July 2, 2008, 2008

ABSTRACT The formation of fluvial bench features in constructed agricultural channels has been sh... more ABSTRACT The formation of fluvial bench features in constructed agricultural channels has been shown to be a function of the net depositional environment typifying many headwater agricultural channels in Ohio. Channels are traditionally constructed to an oversized trapezoidal shape; clean out operations remove accumulated deposits from the channel bottom, restoring the original trapezoidal form. Lowered sediment transport capacities; increased sediment loads due to in-channel earthwork; and the preclusion of channel incision by a hard-pan layer; contribute to the net depositional character of agricultural channels. The goal of this study was to simulate bench formation in a trapezoidal ditch, and determine likely processes that lead to bench formation. A 2-dimensional numerical finite element model was calibrated and verified based on measured sediment flux information. An attempt was made to simulate depositional and scour processes in a recently constructed agricultural channel, over a range of flows and sediment loadings. The modeling exercise yielded encouraging results. The formation of migrating lateral bars that enclosed a deep inset channel under high sediment loading conditions was simulated. Under lowered sediment concentrations, sediment deposition tended to be re-mobilized by larger flow events, producing small depositional features at the channel margins. The availability of high sediment loadings was shown to be the principal factor in the formation of benches. The model presented in the study could not capture the stabilizing effects of vegetation on depositional features. Future versions are slated to incorporate the effects of vegetation and bank collapse, which could yield results that are more representative.

Research paper thumbnail of Insight on the Variable Nature of Channel and Bank-Forming Discharges

2003, Las Vegas, NV July 27-30, 2003, 2003

... Jon Witter, Graduate Associate1 Anand Jayakaran, Graduate Associate1 ... In a study in the no... more ... Jon Witter, Graduate Associate1 Anand Jayakaran, Graduate Associate1 ... In a study in the northernRocky Mountains, Emmett and Wolman (2001) report RIs ranging from 1.5 to 1.7 years, while MacRae (1996) reports RIs of 1.6 to 10 years for a study in British Columbia. ...

Research paper thumbnail of Designing Two-Stage Agricultural Drainage Ditches

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

... 25 10162 22495 10148 546 247 246 50 11809 30121 11141 663 260 274 100 13456 37488 12148 786 2... more ... 25 10162 22495 10148 546 247 246 50 11809 30121 11141 663 260 274 100 13456 37488 12148 786 282 301 Ditch Geometry and Two-Stage Design A survey of a 2100 ft length of ditch was performed by Joe Draper, Erick Powell, and Andy Ward on July 17, 2003. ...

Research paper thumbnail of Comparing spatio-temporal clusters of arthropod-borne infections using administrative medical claims and state reported surveillance data

Spatial and Spatio-temporal Epidemiology, 2012

Considered separately, notifiable disease registries and medical claims data have certain advanta... more Considered separately, notifiable disease registries and medical claims data have certain advantages (e.g., consistent case definitions and electronic records, respectively) and limitations (e.g., incomplete reporting and coding errors, respectively) within disease outbreak research. Combined however, these data could provide a more complete source of information. Using a retrospective space-time permutation scan statistic, zoonotic case information from a state registry system (TDH) was compared with administrative medical claims information from a managed care organization (MCO) to examine how data sources differ. Study observations included case information for four tick-borne (Lyme disease, ehrlichiosis, Rocky Mountain spotted fever, tularemia) and two mosquito-borne diseases (West Nile virus, La Crosse viral encephalitis) occurring in Tennessee. One hundred and three clusters were detected, of which nine were significant (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). Considering only significant clusters, no spatial or temporal overlapping between data sources occurred. In conclusion, data integration efforts and data limitations should be considered to provide more comprehensive case information.

Research paper thumbnail of Flow, Organic, and Inorganic Sediment Yields from a Channelized Watershed in the South Carolina Lower Coastal Plain

JAWRA Journal of the American Water Resources Association, 2013

Many small streams in coastal watersheds in the southeastern United States are modified for agric... more Many small streams in coastal watersheds in the southeastern United States are modified for agricultural, residential, and commercial development. In the South Carolina Lower Coastal Plain, low-relief topography and a shallow water table make stream channelization ubiquitous. To quantify the impacts of urbanization and stream channelization, we measured flow and sediment from an urbanizing watershed and a small forested watershed. Flow and sediment export rates were used to infer specific yields from forested and nonforested regions of the urbanizing watershed. Study objectives were to: (1) quantify the range of runoff-torainfall ratios; (2) quantify the range of specific sediment yields; (3) characterize the quantity and quality of particulate matter exported; and (4) estimate sediment yield attributable to agriculture, development, and channelization activities in the urbanizing watershed. Our results showed that the urban watershed exported over five times more sediment per unit area compared with the forested watershed. Sediment concentration was related to flow flashiness in the urban watershed and to flow magnitude in the forested watershed. Sediments from the forested watershed were dominated by organic matter, whereas mineral matter dominated sediment from the urban stream. Our results indicated that a significant shift in sediment quality and quantity are likely to occur as forested watersheds are transformed by urbanization in coastal South Carolina.

Research paper thumbnail of Relating stream function and land cover in the Middle Pee Dee River Basin, SC

Study region: The study region comprised sixteen stream sites and associated contributing watersh... more Study region: The study region comprised sixteen stream sites and associated contributing watersheds located in the Middle Pee Dee River Basin (MPDRB) of South Carolina, USA. Study focus: The study was conducted between 2008 and 2010 to quantify how indices of streamflow varied with land cover characteristics analyzed at multiple spatial scales and fluvial geomorphic characteristics of sampled streams in the MPDRB. Study objectives were to relate three indices of streamflow that reflect recent temporal flow variability in a stream, with synoptic stream geomorphological measurements, and land cover type at specific spatial domains. New hydrological insights for the region: Modifications to the landscape, hydrologic regime, and alteration to channel morphology, are major threats to the functioning of riparian ecosystem functions but can rarely be linked to a single common stressor. Results from the study showed that in the MPDRB, wetland cover in the riparian corridor was an important factor, correlating significantly with stream flashiness, channel enlargement, and bed substrate character. It was also shown that a combination of stream geomorphological characteristics when combined with landscape variables at specific spatial scales were reasonable predictors of all three indices of streamflow. The study also highlights an innovative statistical methodology to relate land cover data to commonly measured metrics of streamflow and fluvial geomorphology.

Research paper thumbnail of Dimensioning the Sine-Generated Curve Meander Geometry1

JAWRA Journal of the American Water Resources Association, 2012

The sine-generated curve (SGC) presented by is widely acknowledged as an idealized description of... more The sine-generated curve (SGC) presented by is widely acknowledged as an idealized description of river meander form. However, as originally presented, the SGC application to the field, laboratory, or models is not a trivial task. The SGC function simply provides the direction of the flow path as its rate of change continually varies from most gradual at the crossover to most rapid at the apex of bends. Although the commonly used dimensions of meander length, stream length per meander, sinuosity, and amplitude have been approximated previously, this technical note precisely defines these dimensions by solving the integrals of the sine and cosine of the SGC function. This is performed using integral representations of the Bessel and Struve functions for the zero order and their power-series expansions. Higher precision offered by this technique will be of particular value to modeling and flume-based studies where better conformity to the SGC is necessary. The note goes on to present two simple line and arc patterns optimally fit to the SGC as simplified yet more precise methods for practical design in river restoration schemes. Equations are presented defining the geometry of the arc and line pattern and relating meander length, amplitude, radius of curvature, and sinuosity.

Research paper thumbnail of Floodplains and Streamway Setbacks

Research paper thumbnail of Hydraulic Modeling to Inform Stream Maintenance Strategies in South Carolina

The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed ... more The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed that has undergone considerable urbanization in the last few decades. Evidence of bank instability and inchannel erosion is widely seen in the Crabtree Canal system. Principal sediment inputs are landscape sources and in-channel sources. A study was initiated to provide a working management tool to determine hydrodynamic conditions on the watershed driven by a hypothetical storm event and alternative channel configurations. The management tool comprised of a one-dimensional HEC-RAS model of the Crabtree Canal and was developed to aid the Horry County stormwater department in determining potential zones of stream instability and in evaluating alternate stream management techniques. Average velocity, hydraulic depth and shear stress were used to quantify changes in flow regime. Alternative stream management techniques included different floodplain configurations being implemented on the existing geometry of the channel. The management tool modeled average velocity, hydraulic depth, and shear stress decreasing as floodplain width increased relative to the top width of the main channel. The model also suggested that potential points of stream instability in the system were located at points of inflection in the stream bed profile and at points where the bed profile transitioned to a steeper slope.

Research paper thumbnail of Modeling channel maintenance in a coastal plain watershed

The Crabtree Canal, located in Horry County, SC is the main conveyor of stormwater in a watershed... more The Crabtree Canal, located in Horry County, SC is the main conveyor of stormwater in a watershed that has undergone considerable urbanization in the last few decades. A study was initiated to provide a working management tool to determine hydrodynamic conditions on the watershed driven by hypothetical storm events and alternative ditch management techniques. The tool will comprise a one dimensional hydrodynamic model of the Crabtree Canal that will aid the Horry County Stormwater Department in evaluating alternate stream management techniques.

Research paper thumbnail of FACT SHEET Agriculture and Natural Resources

This fact sheet addresses the role and importance of floodplains, riparian zones, and streamway o... more This fact sheet addresses the role and importance of floodplains, riparian zones, and streamway or riparian setbacks for sustaining or establishing stability in stream systems. The goal of this fact sheet is to aid

Research paper thumbnail of Creating Ditches with Floodplains

Two-stage channel systems incorporate benches that function as floodplains. In comparison to floo... more Two-stage channel systems incorporate benches that function as floodplains. In comparison to floodplains in natural streams, the width of the benches is often small due economic and land loss considerations. This manuscript outlines measurement and analysis procedures that can be used to size two-stage channel systems that are more self-sustaining than conventional one-stage constructed channels. The analysis procedures are incorporated in the STREAMS spreadsheet tools that have been developed by the Ohio Department of Natural Resources and the Ohio State University. Construction of a two-stage channel system requires a significant capital investment to create a wider surface width.

Research paper thumbnail of Hydraulic Geometry Curves and Bankfull Recurrence in the Pee Dee River Basin

Hydraulic bankfull geometry or regional curves are a useful metric for evaluating stream stabilit... more Hydraulic bankfull geometry or regional curves are a useful metric for evaluating stream stability and plan stream restoration projects. Streams and tributaries within the middle Pee Dee watershed in South Carolina drain a highly productive landscape that is characterized by forest and agricultural practices. While stream in the region are generally stable, pockets of this landscape is beginning to face increase pressure from development and showing signs of stream instability. In order provide a foundation for potential stream restoration projects in the area, sixteen sites in the watershed were selected on the basis of catchment area, in categories of small (<50 km 2), small-medium (50-500 km 2), medium (500-1000 km 2), and large (>1000 km 2). Bankfull geometries, channel substrate, flow and temperature were measured at all the sites and a set of regional hydraulic geometry curves developed. We also estimated the frequency of bankfull flows that occurred over the period of s...

Research paper thumbnail of Geometry of inset channels and the sediment composition of fluvial benches in agricultural drainage systems in Ohio

Journal of Soil and Water Conservation

In Ohio, agricultural channels have been constructed or modified to transport surface runoff and ... more In Ohio, agricultural channels have been constructed or modified to transport surface runoff and subsurface drainage away from agricultural fields. The development of depositional bars, or benches, in these agricultural channel systems has been a focus of maintenance activities. Objectives of the reported study were to: (1) determine if there was a relationship between inset channel geometry, as defined by its benches, and geometry predicted by regional curves that relate bankfull geometry to drainage area; (2) evaluate the effect of channel geometry on bed material particle size distribution; and (3) determine if the particle size distribution of bench materials was related to depth from the surface and position on the bench. The study was conducted on low gradient ditches that are headwaters of the Mississippi River and Lake Erie. An analysis to determine the extent of bench and inset channel formation was undertaken using 0.15 m (0.5 ft) resolution panchromatic digital orthophotos. Geomorphology measurements were made at 13 sites, and a 61 cm (24 in) long split-spoon sampler, with a 7.6 cm (3 in) inner diameter, was used to extract cores from the benches at each site. About 59% of the assessed channels showed inset channel development and bench formation. For 12 of the 13 sites, the bankfull dimensions of the inset channel were consistent with regional curves. All benches showed fining of materials with distance away from the inset channel. It was concluded that benches evolve much like floodplains that build because of overbank accretion. The results will be helpful in determining alternative strategies for improving the drainage function of these systems while enhancing ecological habitat and water quality.

Research paper thumbnail of Two-stage channel design procedures

Two-stage channel systems incorporate benches that function as floodplains. However, in compariso... more Two-stage channel systems incorporate benches that function as floodplains. However, in comparison to floodplains in natural streams, the width of the benches is often small due to the confining geometry of the constructed channel. This manuscript outlines measurement and analysis procedures that can used to size two-stage channel systems that are more self-sustaining than conventional one-stage constructed channels. The analysis procedures are incorporated in the STREAMS spreadsheet tools that have been developed by the Ohio Department of Natural Resources and the Ohio State University. Channel design dimensions are determined by measuring the effective discharge features at the project site and making regional curve measurements. Bench elevations are dependent on correctly determining the size of the effective discharge channel. The minimum total widths of the constructed benches are at least double the width of the effective discharge channel and the overall conveyance capacities...

Research paper thumbnail of Monitoring Water Quality Changes in a Forested Freshwater Wetland Threatened By Salinity

Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large ... more Coastal forested wetland swamps are sentinel sites for salinity intrusions associated with large tidally-influenced or storm-driven incursions of estuarine waters that may also indicate rising sea levels associated with climate change. A coastal freshwater forested wetland in coastal South Carolina has experienced dieback of freshwater forested wetland trees due to increased salinity within the wetland. Vegetation in the wetland is transitioning from a closed canopy of common freshwater wetland trees such as bald cypress, water tupelo and swamp tupelo, to a more open canopy due to the establishment of salt tolerant grasses. The swamp is prime habitat for several wildlife species as evidenced by game cameras and amphibian recorders installed within the swamp. A team of researchers at the Baruch Institute examined a series of historical aerial images to track changes in vegetation through the years. In June 2013, several water level and conductivity sensors were installed along the sa...

Research paper thumbnail of Runoff Generation from Shallow Water Table Southeastern Forests: Unusual Behavior of Paired Watersheds Following a Major Disturbance

2012 Dallas, Texas, July 29 - August 1, 2012, 2012

Research paper thumbnail of Hydraulic modeling to inform stream maintenance strategies in South Carolina

2009 Reno, Nevada, June 21 - June 24, 2009, 2009

The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed ... more The Crabtree Canal located in Horry County, SC is the main conveyor of stormwater in a watershed that has undergone considerable urbanization in the last few decades. Evidence of bank instability and inchannel erosion is widely seen in the Crabtree Canal system. Principal sediment inputs are landscape sources and in-channel sources. A study was initiated to provide a working management tool to determine hydrodynamic conditions on the watershed driven by a hypothetical storm event and alternative channel configurations. The management tool comprised of a one-dimensional HEC-RAS model of the Crabtree Canal and was developed to aid the Horry County stormwater department in determining potential zones of stream instability and in evaluating alternate stream management techniques. Average velocity, hydraulic depth and shear stress were used to quantify changes in flow regime. Alternative stream management techniques included different floodplain configurations being implemented on the existing geometry of the channel. The management tool modeled average velocity, hydraulic depth, and shear stress decreasing as floodplain width increased relative to the top width of the main channel. The model also suggested that potential points of stream instability in the system were located at points of inflection in the stream bed profile and at points where the bed profile transitioned to a steeper slope.

Research paper thumbnail of Green infrastructure assessment tools for varying scales in coastal South Carolina

Potential impacts from changing coastal landscapes, specifically the conversion of forested and a... more Potential impacts from changing coastal landscapes, specifically the conversion of forested and agricultural lands to residential and commercial development, can be reduced by more informed decisionmaking related to green infrastructure if the appropriate tools are available.

Research paper thumbnail of A Study of Coastal Headwater Stream Hydrology: Bannockburn Plantation, Georgetown County, SC

2009 Reno, Nevada, June 21 - June 24, 2009, 2009

ABSTRACT Coastal headwater streams in undeveloped forested landscapes function as a natural stora... more ABSTRACT Coastal headwater streams in undeveloped forested landscapes function as a natural storage and conveyance mechanism for rainfall and groundwater. Stream flows are often driven by groundwater table depth, while soil saturation with a high water table may drive rainfall response. Evapotranspiration also plays a significant role in groundwater levels and influences stream flows both seasonally and diurnally. The dynamics of coastal forested watersheds are complex, and water budgets of these low gradient headwater streams are difficult to quantify.The importance of understanding these hydrologic dynamics is critical to water resources protection and flooding prevention in coastal landscapes, especially as forested areas are being converted to residential and commercial development. Baseline hydrology must be assessed as a benchmark for sustainable development goals over the course of land use change, and understanding short- and long-term responses from the conversion of forest lands to urban areas can minimize negative effects in terms of water quantity and quality. Toward the goal of quantifying the water budget in a pre-development forested watershed, stream flows, groundwater levels, and rainfall are being measured in an approximately 800-acre coastal watershed, Upper Debidue Creek, at Bannockburn Plantation in coastal South Carolina, USA. Evapotranspiration rates are also being estimated as photosynthetically active radiation (PAR) is being measured on site with nearby total solar radiation measurements also being taken. Water quality measurements (temperature, conductivity, pH, and dissolved oxygen) are also being collected. Preliminary data being used for water budget estimates and rainfall-runoff relationships from Upper Debidue Creek will be presented.

Research paper thumbnail of Modeling the formation of depositional features in agricultural channels

2008 Providence, Rhode Island, June 29 - July 2, 2008, 2008

ABSTRACT The formation of fluvial bench features in constructed agricultural channels has been sh... more ABSTRACT The formation of fluvial bench features in constructed agricultural channels has been shown to be a function of the net depositional environment typifying many headwater agricultural channels in Ohio. Channels are traditionally constructed to an oversized trapezoidal shape; clean out operations remove accumulated deposits from the channel bottom, restoring the original trapezoidal form. Lowered sediment transport capacities; increased sediment loads due to in-channel earthwork; and the preclusion of channel incision by a hard-pan layer; contribute to the net depositional character of agricultural channels. The goal of this study was to simulate bench formation in a trapezoidal ditch, and determine likely processes that lead to bench formation. A 2-dimensional numerical finite element model was calibrated and verified based on measured sediment flux information. An attempt was made to simulate depositional and scour processes in a recently constructed agricultural channel, over a range of flows and sediment loadings. The modeling exercise yielded encouraging results. The formation of migrating lateral bars that enclosed a deep inset channel under high sediment loading conditions was simulated. Under lowered sediment concentrations, sediment deposition tended to be re-mobilized by larger flow events, producing small depositional features at the channel margins. The availability of high sediment loadings was shown to be the principal factor in the formation of benches. The model presented in the study could not capture the stabilizing effects of vegetation on depositional features. Future versions are slated to incorporate the effects of vegetation and bank collapse, which could yield results that are more representative.

Research paper thumbnail of Insight on the Variable Nature of Channel and Bank-Forming Discharges

2003, Las Vegas, NV July 27-30, 2003, 2003

... Jon Witter, Graduate Associate1 Anand Jayakaran, Graduate Associate1 ... In a study in the no... more ... Jon Witter, Graduate Associate1 Anand Jayakaran, Graduate Associate1 ... In a study in the northernRocky Mountains, Emmett and Wolman (2001) report RIs ranging from 1.5 to 1.7 years, while MacRae (1996) reports RIs of 1.6 to 10 years for a study in British Columbia. ...

Research paper thumbnail of Designing Two-Stage Agricultural Drainage Ditches

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

... 25 10162 22495 10148 546 247 246 50 11809 30121 11141 663 260 274 100 13456 37488 12148 786 2... more ... 25 10162 22495 10148 546 247 246 50 11809 30121 11141 663 260 274 100 13456 37488 12148 786 282 301 Ditch Geometry and Two-Stage Design A survey of a 2100 ft length of ditch was performed by Joe Draper, Erick Powell, and Andy Ward on July 17, 2003. ...

Research paper thumbnail of Comparing spatio-temporal clusters of arthropod-borne infections using administrative medical claims and state reported surveillance data

Spatial and Spatio-temporal Epidemiology, 2012

Considered separately, notifiable disease registries and medical claims data have certain advanta... more Considered separately, notifiable disease registries and medical claims data have certain advantages (e.g., consistent case definitions and electronic records, respectively) and limitations (e.g., incomplete reporting and coding errors, respectively) within disease outbreak research. Combined however, these data could provide a more complete source of information. Using a retrospective space-time permutation scan statistic, zoonotic case information from a state registry system (TDH) was compared with administrative medical claims information from a managed care organization (MCO) to examine how data sources differ. Study observations included case information for four tick-borne (Lyme disease, ehrlichiosis, Rocky Mountain spotted fever, tularemia) and two mosquito-borne diseases (West Nile virus, La Crosse viral encephalitis) occurring in Tennessee. One hundred and three clusters were detected, of which nine were significant (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). Considering only significant clusters, no spatial or temporal overlapping between data sources occurred. In conclusion, data integration efforts and data limitations should be considered to provide more comprehensive case information.

Research paper thumbnail of Flow, Organic, and Inorganic Sediment Yields from a Channelized Watershed in the South Carolina Lower Coastal Plain

JAWRA Journal of the American Water Resources Association, 2013

Many small streams in coastal watersheds in the southeastern United States are modified for agric... more Many small streams in coastal watersheds in the southeastern United States are modified for agricultural, residential, and commercial development. In the South Carolina Lower Coastal Plain, low-relief topography and a shallow water table make stream channelization ubiquitous. To quantify the impacts of urbanization and stream channelization, we measured flow and sediment from an urbanizing watershed and a small forested watershed. Flow and sediment export rates were used to infer specific yields from forested and nonforested regions of the urbanizing watershed. Study objectives were to: (1) quantify the range of runoff-torainfall ratios; (2) quantify the range of specific sediment yields; (3) characterize the quantity and quality of particulate matter exported; and (4) estimate sediment yield attributable to agriculture, development, and channelization activities in the urbanizing watershed. Our results showed that the urban watershed exported over five times more sediment per unit area compared with the forested watershed. Sediment concentration was related to flow flashiness in the urban watershed and to flow magnitude in the forested watershed. Sediments from the forested watershed were dominated by organic matter, whereas mineral matter dominated sediment from the urban stream. Our results indicated that a significant shift in sediment quality and quantity are likely to occur as forested watersheds are transformed by urbanization in coastal South Carolina.