Tracking the hydrologic response of agricultural tile outlet terraces to storm events

Abstract Rapid urbanization and increasing impervious surfaces in cities lead to a serious reduction in infiltration rate of the surface and cause challenges in stormwater management. The Low Impact Development (LID) concept is considered as a potential solution for sustainable urban growth by contributing in urban flood mitigation. However, its effects on hydrologic response of the urbanized catchments, especially in broad scale implementation, are not fully understood and practically examined. In this study a hydrologic-hydraulic model of a small catchment was developed in EPA storm water management model (SWMM) program and calibrated and validated through field measurements. The hydrologic response of the catchment was investigated after replacing proportions of impervious surfaces with combinations of LID practices such as green roof, permeable pavement and bio-retention cell, through four land cover conversion scenarios and under five different designed storm events. The simulation results which are derived by comparison of outflow hydrographs between each scenario and conventional drainage system indicated that implementing 5–20% of LIDs has a noticeable impact on runoff peak flow and volume reduction, especially in storm events with shorter return periods. Also the runoff reduction trends show a linear response due to the increase in LID implementation ratio in the study area.

Download Full-text

Hydrologic conditions leading to debris-flow initiation

Canadian Geotechnical Journal ◽

10.1139/t90-092 ◽

1990 ◽

Vol 27 (6) ◽

pp. 789-801 ◽

Cited By ~ 164

Author(s):

K. A. Johnson ◽

N. Sitar

Keyword(s):

Debris Flow ◽

Pore Pressure ◽

Debris Flows ◽

Field Investigation ◽

Hydrologic Response ◽

Storm Events ◽

Hillslope Hydrology ◽

Antecedent Moisture ◽

Pressure Pulses ◽

Flow Activity

Mitigation of the hazards posed by debris flows requires an understanding of the mechanisms leading to their initiation. The objectives of this study were to evaluate and document the hydrologic response of a potential debris-flow source area to major rainstorms and to evaluate whether traditional models of hillslope hydrology can account for the observed response. A field site in an area of previous debris-flow activity was instrumented and monitored for two winter seasons. Hydrologic responses for a wide variety of antecedent conditions were recorded, including two storm events that produced well-defined positive pore-pressure pulses at the site and initiated numerous debris flows in the immediate vicinity of the site. The observed hydrologic response was highly dependent on antecedent moisture conditions which can be characterized by soil matric suction measurements. The pressure-head pulses observed had a magnitude of approximately 50 cm of water, were transient, traveled downslope, and exhibited some spatial variability. Traditional models of hillslope hydrology do not fully account for the positive pore-pressure pulses observed high on the hillslope. Key words: debris flow, hillslope hydrology, pore pressure, antecedent moisture, tensiometer, piezometer, field investigation.

Download Full-text

Post-Hurricane Michael damage assessment using ADCIRC storm surge hindcast, image classification, and LiDAR

Shore & Beach ◽

10.34237/1008741 ◽

2019 ◽

pp. 3-14 ◽

Cited By ~ 1

Author(s):

Joshua Davis ◽

Diana Mitsova ◽

Tynon Briggs ◽

Tiffany Briggs

Keyword(s):

Wave Energy ◽

Field Studies ◽

Feedback Mechanism ◽

Water Velocity ◽

Airborne Lidar ◽

Storm Events ◽

Magnetic Current ◽

Coastal Mapping ◽

Electro Magnetic

Wave forcing from hurricanes, nor’easters, and energetic storms can cause erosion of the berm and beach face resulting in increased vulnerability of dunes and coastal infrastructure. LIDAR or other surveying techniques have quantified post-event morphology, but there is a lack of in situ hydrodynamic and morphodynamic measurements during extreme storm events. Two field studies were conducted in March 2018 and April 2019 at Bethany Beach, Delaware, where in situ hydrodynamic and morphodynamic measurements were made during a nor’easter (Nor’easter Riley) and an energetic storm (Easter Eve Storm). An array of sensors to measure water velocity, water depth, water elevation and bed elevation were mounted to scaffold pipes and deployed in a single cross-shore transect. Water velocity was measured using an electro-magnetic current meter while water and bed elevations were measured using an acoustic distance meter along with an algorithm to differentiate between the water and bed during swash processes. GPS profiles of the beach face were measured during every day-time low tide throughout the storm events. Both accretion and erosion were measured at different cross-shore positions and at different times during the storm events. Morphodynamic change along the back-beach was found to be related to berm erosion, suggesting an important morphologic feedback mechanism. Accumulated wave energy and wave energy flux per unit area between Nor’easter Riley and a recent mid-Atlantic hurricane (Hurricane Dorian) were calculated and compared. Coastal Observations: JALBTCX/NCMP emergency-response airborne Lidar coastal mapping & quick response data products for 2016/2017/2018 hurricane impact assessments

Download Full-text

Unpacking storm damages on a developed shoreline: Relating dune erosion and urban runoff

Shore & Beach ◽

10.34237/1008733 ◽

2019 ◽

pp. 35-45

Author(s):

Patrick Barrineau ◽

Timothy Kana

Keyword(s):

South Carolina ◽

Storm Events ◽

Near Surface ◽

Dune Erosion ◽

Groundwater Flux ◽

Impact Scale ◽

Cape Hatteras ◽

Myrtle Beach ◽

Rain Events ◽

Elevation Model

Hurricane Matthew (2016) caused significant beach and dune erosion from Cape Hatteras, North Carolina, USA, to Cape Canaveral, Florida, USA. At Myrtle Beach, South Carolina, the storm caused beach recession, and much of the southern half of the city’s beaches appeared to be overwashed in post-storm surveys. Around half of the city’s beaches appeared overwashed following the storm; however, the Storm Impact Scale (SIS; Sallenger 2000) applied to a pre-storm elevation model suggests less than 10% of the city’s beaches should have experienced overwash. Spatial analysis of elevation and land cover data reveals dunes that were “overwashed” during Matthew drain from watersheds that are >35% impervious, where those showing only dune recession are <5% impervious. The densely developed downtown of Myrtle Beach sits on a low seaward-sloping terrace. Additionally, indurated strata beneath the downtown area can prevent groundwater from draining during excessive rain events. As a result, the most continuous impervious surface cover and near-surface strata lie within a half-kilometer of the beach and drain directly to the backshore. Along the U.S. Southeast coast, this is somewhat rare; many coastal systems feature a lagoon or low-lying bottomland along their landward border, which facilitates drainage of upland impervious surfaces following storm passage. At Myrtle Beach, all of the stormwater runoff is drained directly to the beach through a series of outfall pipes. Many of the outfall pipes are located along the backshore, near the elevation of storm surge during Matthew. Runoff from Matthew’s heavy rains was observed causing ponding on the landward side of the foredune and scouring around beach access walkways. Based on these observations, the severe dune erosion experienced near downtown Myrtle Beach during Hurricane Matthew may have been caused by runoff and/or groundwater flux rather than overwash. These results highlight an unexpected relationship between upland conditions and dune erosion on a developed shoreline. That is, dune erosion can be caused by mechanisms beside overwash during storm events.

Download Full-text

Quantifying the Complex Hydrologic Response of a Desert Ephemeral Wash

10.21236/ada544641 ◽

2011 ◽

Author(s):

Susan Howe ◽

Jorge A. Ramirez

Keyword(s):

Hydrologic Response

Download Full-text

Mixed Layer Models and Their Application to Water Quality Problems

Water Quality Research Journal ◽

10.2166/wqrj.1994.015 ◽

1994 ◽

Vol 29 (2-3) ◽

pp. 221-232

Author(s):

M.J. McCormick

Keyword(s):

Water Quality ◽

Mixed Layer ◽

Thermal Structure ◽

Mass Conservation ◽

Eddy Diffusion ◽

Rate Of Change ◽

Surface Mixed Layer ◽

Storm Events ◽

Quality Model ◽

Mixing Processes

Abstract Four one-dimensional models which have been used to characterize surface mixed layer (ML) processes and the thermal structure are described. Although most any model can be calibrated to mimic surface water temperatures, it does not imply that the corresponding mixing processes are well described. Eddy diffusion or "K" models can exhibit this problem. If a ML model is to be useful for water quality applications, then it must be able to resolve storm events and, therefore, be able to simulate the ML depth, h, and its time rate of change, dh/dt. A general water quality model is derived from mass conservation principles to demonstrate how ML models can be used in a physically meaningful way to address water quality issues.

Download Full-text

Implementation of Hamilton-Wentworth Region’s Pollution Control Plan

Water Quality Research Journal ◽

10.2166/wqrj.1996.026 ◽

1996 ◽

Vol 31 (3) ◽

pp. 453-472 ◽

Cited By ~ 2

Author(s):

M. Stirrup

Keyword(s):

Wastewater Treatment ◽

Pollution Control ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Control Measures ◽

Storm Events ◽

Combined Sewer Overflows ◽

Control Plan ◽

Combined Sewer ◽

Sewer Overflows

Abstract The Regional Municipality of Hamilton-Wentworth operates a large combined sewer system which diverts excess combined sewage to local receiving waters at over 20 locations. On average, there are approximately 23 combined sewer overflows per year, per outfall. The region’s Pollution Control Plan, adopted by Regional Council in 1992, concluded that the only reasonable means of dealing with large volumes of combined sewer overflow in Hamilton was to intercept it at the outlets, detain it and convey it to the wastewater treatment plant after the storm events. The recommended control strategy relies heavily on off-line storage, with an associated expansion of the Woodward Avenue wastewater treatment plant to achieve target reductions of combined sewer overflows to 1–4 per year on average. The region has begun to implement this Pollution Control Plan in earnest. Three off-line detention storage tanks are already in operation, construction of a fourth facility is well underway, and conceptual design of a number of other proposed facilities has commenced. To make the best possible use of these facilities and existing in-line storage, the region is implementing a microcomputer-based real-time control system. A number of proposed Woodward Avenue wastewater treatment plant process upgrades and expansions have also been undertaken. This paper reviews the region's progress in implementing these control measures.

Download Full-text

First flush effects in an urban catchment area in Aalborg

Water Science & Technology ◽

10.2166/wst.1998.0060 ◽

1998 ◽

Vol 37 (1) ◽

pp. 251-257 ◽

Cited By ~ 20

Author(s):

Torben Larsen ◽

Kirsten Broch ◽

Margit Riis Andersen

Keyword(s):

Water Quality ◽

Catchment Area ◽

Quality Parameters ◽

Average Concentration ◽

First Flush ◽

Storm Events ◽

Urban Catchment ◽

Discharge Measurements ◽

Quality Measurements

The paper describes the results of measurements from a 2 year period on a 95 hectare urban catchment in Aalborg, Denmark. The results of the rain/discharge measurements include 160 storm events corresponding to an accumulated rain depth of totally 753 mm. The water quality measurements include 15 events with time series of concentration of SS, COD, BOD, total nitrogen and total phosphorus. The quality parameters showed significant first flush effects. The paper discusses whether either the event average concentration or the accumulated event mass is the most appropriate way to characterize the quality of the outflow.

Download Full-text