Observations of Coastal Sediment Dynamics of the 

Tijuana Estuary Fine Sediment Fate and Transport 

Demonstration Project, Imperial Beach, California

By Jonathan A. Warrick, Kurt Rosenberger, Angela Lam, Joanne Ferreira, Ian M. Miller, 

Meg Rippy, Jan Svejkovsky, and Neomi Mustain

Open File Report 2012–1083

U.S. Department of the Interior 

U.S. Geological Survey 
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey: Reston, Virginia: 2012 

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Suggested citation:

Warrick, J.A., Rosenberger, K., Lam, A., Ferreira, J., Miller, I.M., Rippy, M., Svejkovsky, J., and Mustain, 

N., 2012, Observations of coastal sediment dynamics of the Tijuana Estuary Fine Sediment Fate and 

Transport Demonstration Project, Imperial Beach, California, U.S. Geological Survey Open-File Report 

2012–1083, 29 p and data files. (Available at http://pubs.usgs.gov/of/2012/1083/.)

Any use of trade, product, or firm names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual 

copyright owners to reproduce any copyrighted material contained within this report.
iii

Contents

Abstract ...........................................................................................................................................................1

Introduction......................................................................................................................................................1

Project Objectives ...........................................................................................................................................2

Study Area...................................................................................................................................................3

The 2008–2009 Demonstration Project...........................................................................................................5

Physical Monitoring Techniques and Data ......................................................................................................7

Sampling of the Sediment Stockpile............................................................................................................8

Bathymetric Sonar Mapping ........................................................................................................................9

Seafloor-Sediment Sampling.......................................................................................................................9

Beach-Sediment Sampling ........................................................................................................................11

Swash-Water Sampling—Suspended Sediment .......................................................................................12

Coastal-Water Sampling—Small Vessel ...................................................................................................13

Aerial Remote Sensing..............................................................................................................................14

Oceanographic Observations—Tripods and Moored Buoys .....................................................................15

Acoustic Doppler Current Profilers (ADCP and ADP)............................................................................17

AquaDopp Current Profiler.....................................................................................................................17

Acoustic Doppler Velocimeters (ADV) ...................................................................................................19

Optical Backscatter Sensors (OBS).......................................................................................................19

Light Transmissometers.........................................................................................................................20

Conductivity-Temperature (CT) and Conductivity-Temperature-Depth (CTD) Recorders.....................20

Oceanographic Data Processing...............................................................................................................20

Data-File Identifiers................................................................................................................................20

Time .......................................................................................................................................................21

Current Meter Data ................................................................................................................................21

Instrument Orientations ......................................................................................................................21

Acoustic Doppler Current Meter (ADCP) Data ...................................................................................21

Acoustic Doppler Velocimeter (ADV) Data.........................................................................................22

Optical Backscatter Sensor (OBS) Data ............................................................................................22

Transmissometer Data .......................................................................................................................22

MicroCAT (MC) ..................................................................................................................................22

Additional Data-Collection Resources .......................................................................................................22

Weather and Hydrology .........................................................................................................................22

Beach Topographic Mapping .................................................................................................................23

References Cited...........................................................................................................................................23

Appendix 1 – Sediment grain-size distribution data from the pre-placement stockpile. ................................24

Appendix 2 – Sediment grain-size distribution data from seafloor samples..................................................25

Appendix 3 – Sediment grain-size distribution data from beach samples.....................................................26

Appendix 4 – Suspended-sediment concentration and grain-size distribution data from beachswash samples.................................................................................................................................26

Appendix 5 – Conductivity-temperature depth (CTD) and optical turbidity measurements from small 

vessel water sampling......................................................................................................................27

Appendix 6 – Suspended-sediment concentration measurements from small vessel water 

sampling...........................................................................................................................................28

Appendix 7 – Remote-sensing imagery. .......................................................................................................28

Appendix 8 – Oceanographic data. ...............................................................................................................29
iv

Figures

1. Map of the study area and sampling sites, Imperial Beach, California. .....................................................4

2. Photographs of the study site and sediment-nourishment project..............................................................5

3. Nourishment and sampling schedule during Phase I (2008) of the Demonstration Project. ....................7

4. Nourishment and sampling schedule during Phase II (2009) of the Demonstration Project. ....................8

5. Map of seafloor sediment-sampling locations during the May 2008 investigations of the study 

area. .................................................................................................................................................10

6. Photograph of the conductivity-temperature-depth (CTD) instrument with the additional optical 

backscatterance sensor (OBS) and 25-cm pathlength transmissometer.........................................14

7. Photographs of moorings utilized in the Demonstration Project...............................................................16

Tables

1. Roles of project partners for the Demonstration Project .............................................................................2 

2. Sediment placement schedule for Phase I (2008) of the Demonstration Project........................................6 

3. Sediment placement schedule for Phase II (2009) of the Demonstration Project.......................................6 

4. Ocean sampling locations for seafloor sediment samples and water column sampling by 

conductivity-temperature depth (CTD) sensor. ................................................................................11

5. Beach swash sampling locations for the Demonstration Project...............................................................12

6. Oceanographic platform stations for Phase I (2008) of the Demonstration Project ..................................16

7. Oceanographic platform stations for Phase II (2009) of the Demonstration Project .................................17

8. Oceanographic instrumentation for the stations during Phase I (2008) of the Demonstration 

Project ..............................................................................................................................................18

9. Oceanographic instrumentation for the stations during Phase II (2009) of the Demonstration 

Project. .............................................................................................................................................19
Observations of Coastal Sediment Dynamics of the 

Tijuana Estuary Fine Sediment Fate and Transport 

Demonstration Project, Imperial Beach, California

By Jonathan A. Warrick1, Kurt Rosenberger1, Angela Lam1, Joanne Ferreira1, Ian M. Miller1,2, 

Meg Rippy3, Jan Svejkovsky4, and Neomi Mustain4

Abstract

Coastal restoration and management must address the presence, use, and transportation of 

fine sediment, yet little information exists on the patterns and/or processes of fine-sediment 

transport and deposition for these systems. To fill this information gap, a number of State of 

California, Federal, and private industry partners developed the Tijuana Estuary Fine Sediment 

Fate and Transport Demonstration Project (“Demonstration Project”) with the purpose of 

monitoring the transport, fate, and impacts of fine sediment from beach-sediment nourishments 

in 2008 and 2009 near the Tijuana River estuary, Imperial Beach, California. The primary 

purpose of the Demonstration Project was to collect and provide information about the 

directions, rates, and processes of fine-sediment transport along and across a California beach 

and nearshore setting. To achieve these goals, the U.S. Geological Survey monitored water, 

beach, and seafloor properties during the 2008–2009 Demonstration Project. The project utilized 

sediment with ~40 percent fine sediment by mass so that the dispersal and transport of fine 

sediment would be easily recognizable. The purpose of this report is to present and disseminate 

the data collected during the physical monitoring of the Demonstration Project. These data are 

available online at the links noted in the “Additional Digital Information” section. Synthesis of 

these data and results will be provided in subsequent publications. 

Introduction Each year millions of tons of fine sediment (silt and clay) are released into the coastal 

waters of California from the natural erosion of the adjacent landscape. The majority of this 

sediment enters from coastal streams and rivers, although the failure of coastal bluffs and cliffs 

also may contribute significantly within certain regions (Inman and Jenkins, 1999; Farnsworth 

and Warrick, 2007). Fine sediment (here defined to be sediment particles with diameters less 

than or equal to 0.063 mm) is an important constituent of these coastal systems because of its 

role in nutrient cycling, habitat formation, and the geological cycle; however, fine sediment also 

is responsible for elevating water turbidity and burying sandy or rocky benthic habitats, and fine 

sediment is a common vector for pollutant transport (Olson and others, 1982; Fowlera, 1990). 

 

1

U.S. Geological Survey.

2

University of California, Santa Cruz.

3 Scripps Institute of Oceanography.

4

Ocean Imaging Corporation.
2

Coastal restoration and management must address the presence, use, and potential 

transportation of fine sediment, yet little information exists on the patterns and/or processes of 

fine-sediment transport and deposition for these systems. To fill this information gap, a number 

of State of California, Federal, and private industry partners developed the Tijuana Estuary Fine 

Sediment Fate and Transport Demonstration Project (“Demonstration Project”) with the purpose 

of monitoring the transport, fate, and impacts of fine sediment from beach-sediment 

nourishments in 2008 and 2009 near the Tijuana River estuary, Imperial Beach, California. The 

lead agency of the Demonstration Project was the California Coastal Conservancy, and project 

funding was provided by the California Ocean Protection Council, the California Coastal 

Conservancy, the California Department of Boating and Waterways, the U.S. Army Corps of 

Engineers, and the U.S. Geological Survey (USGS). Important project support came from the 

Tijuana River National Estuarine Research Reserve, Southwest Wetlands Interpretive 

Association, California State Parks–Border Field State Park, California Sediment Management 

Workgroup (CSMW), Moffatt and Nichol Engineers, Nautilus Environmental, Nordby 

Biological Consulting, Diamond Lane Contractors, Ocean Imaging Corporation, CoastalCOMS, 

and Deltares. A summary of the roles and responsibilities of the project partners is included in 

table 1. 

Table 1. Roles of project partners for the Demonstration Project. 

Role Project Partner (contact)

Project Manager California Coastal Conservancy (Karen Bane) 

Border Field State Park (Clay Parks)

Project environmental permitting Border Field State Park (Chris Peregrin)

Moffet & Nichols (Brian Leslie)

Pre-project sediment sampling and analysis Moffet & Nichols (Brian Leslie) 

AMEC Earth & Environmental (Nick Buhbe)

Physical monitoring study design and implementation U.S. Geological Survey (Jonathan Warrick)

Univ. of California, Santa Cruz (Ian Miller)

Scripps Institue of Oceanography (Meg Rippy)

Ocean Imaging Corporation (Jan Svejkovsky)

CoastalCOMS (Dave Revell)

Numerical modeling of sediment tranport Deltares (Jamie Lescinski)

Biological monitoring study design and Implementation Nautilus Environmental (Nick Buhbe)

Sediment excavation, sorting and placement Diamond Lane Contractors (Mike Adams)

Sediment placement management Nordby Consulting (Chris Norby)

Project Funding California Ocean Protection Council 

California Coastal Conservancy

California Department of Boating and Waterways

U.S. Army Corps of Engineers 

U.S. Geological Survey 

The purpose of this report is to present the data collected during the physical monitoring 

plan of the Demonstration Project. The USGS was the lead agency for this data collection, and 

assistance and partnering was provided by Ocean Imaging Corporation; the University of 

California, Santa Cruz; and Scripps Institute of Oceanography. Data are presented below in 

sections organized by the project schedule and sampling methods. These data are available 

online at the links noted in the “Additional Digital Information” section. 

Project Objectives

The purpose of the Demonstration Project was to collect and provide information about 

the directions, rates, and processes of fine-sediment transport along and across a California beach 
3

and nearshore setting. A better understanding of fine-sediment transport and fate is necessary to 

protect and enhance marine resources and better manage and regulate sediment resources along 

the California coastline. Little information exists about the transport and fate of fine sediment in 

these coastal settings; thus, a primary goal of the Demonstration Project was to collect physical 

information about the rates, pathways, and fate of fine sediment. The second goal of the 

Demonstration Project was to use these physical data to develop a process-based understanding 

and mass balance of fine-sediment transport and deposition so that the results of this work could 

be more broadly applied to other physical settings. Although this second goal was critical for the 

proper application of the results of the Demonstration Project, it is not a primary goal of this 

report but will be addressed in subsequent publications. 

To achieve these goals, scientists monitored the water, beach, and seafloor properties 

near a beach-nourishment project adjacent to the Tijuana River estuary. This nourishment project 

utilized sediment with substantial levels (~40 percent by mass) of fine sediment so that the 

dispersal and transport of fine sediment would be easily recognizable. The project consisted of 

two beach nourishments—one in 2008 and the other in 2009—during which several tens of 

thousands of cubic meters of sediment were placed directly into the surf zone at the Border Field 

State Park beach. Monitoring included airborne remote sensing, beach-water and sediment 

sampling, nearshore water-column and seafloor sampling from small boats, and oceanographic 

sampling from moored stations. These observations revealed the spatial and temporal patterns of 

turbidity and sedimentation associated with the nourishment project’s fine sediment and how 

environmental conditions (waves, winds, and ocean currents) influenced these patterns. 

Study Area

The study site for the Demonstration Project is the southern beach of the Tijuana River 

National Estuarine Research Reserve and Border Field State Park of southern California (fig. 1). 

Substantial wetland loss in the southern Tijuana River estauary has occurred during the past few 

decades owing to sedimentation resulting from sediment discharge from the increased 

urbanization of tributaries within Mexico. To help alleviate this problem, two debris basins, 

which annually trap approximately 30,000 m3 of sediment, were built at the mouth of the largest 

tributary, Goat Canyon. This sediment is expensive for the State Park to remove and dispose of, 

and it could provide beneficial reuse as a supply for beach nourishment. This sediment also 

contains a high percentage (approximatlely 40 percent) of fine sediment (silt and clay), and 

therefore it would not be considered suitable for beach nourishment under present-day 

regulations. 

The beach of the project site is part of the greater Silver Strand littoral cell, which 

extends north to the Coroado Peninsula and south past the United States-Mexico international 

border (Inman, 1976; Kuhn and Shepard, 1984; Flick, 1993). The beaches of this littoral cell are 

primarily sandy, and although the primary source of this beach sand is the Tijuana River, there 

have been numerous sand-nourishment projects in this littoral cell to attempt to limit, stop, or 

reverse coastal erosion (Flick, 1993; San Diego Association of Governments, 2012). 
4

Figure 1. Map of the study area and sampling sites, Imperial Beach, California. Sites are color coded for 

swash sampling (yellow), nearshore small boat sampling (orange), buoy and tripod sampling (blue, 

Phase I; green, Phase II), and weather station (white). Coastal bathymetry (blue lines) shown at 2 m 

increments from -3 to -19 m. The locations of the Tijuana River National Estuarine Research Reserve 

(TJNERR) and the Border Field State Park (BFSP) also are shown. 

Bisecting the study area beach is the Tijuana River mouth, which serves as the inlet of 

tidal exchange between the ocean and the Tijuana River estuary and as the outlet for Tijuana 

River discharge (Zedler and others, 1992; fig. 1). The mouth of the Tijuana River is rarely 

closed, resulting in regular tidal pumping and exchange of water and sediment through the river 

mouth. The river discharges elevated rates of water, sediment, and pollutants after winter rainfall 

events (Svejkovsky and others, 2010). Using 46 years of historical data, Farnsworth and Warrick 

(2007) calculated that the Tijuana River annually discharges approximately 90,000 m3

 of 

suspended sediment to the Pacific Ocean, roughly 70,000 m3

—or 77 percent—of this river 

sediment being fine-grained (less than 0.063 mm). The annual discharge of sediment from the 

Tijuana River is highly variable, however, ranging from 0 to ~2,000,000 m3 over the historical 

record. Tijuana River sediment represents roughly 18 percent of the total fine sediment input into 

the Pacific Ocean—combined river discharge and cliff erosion—from the Peninsular Range of 

California (San Diego County to southern Orange County; Farnsworth and Warrick, 2007). 

Imperial Beach

Imperial Beach Blvd. 

Horse Trail Rd. 

TJR

N2

F1

N1

BF

S1

HT

M

N1

S1

CDIP 

155

Pier 

U.S.-Mexico Border

Tijuana

Tijuana River

Nourishment 

Site 

Seacoast Dr. 

Elm Ave.

Naval Air 

Station

D14,D12,D10,D8

C14,C12,C10,C8

B14,B12,B10,B8 

A14,A12,A10,A8

W 500 m

N

BFSP

TRNERR

C2

C1

N1

S1
5

The 2008–2009 Demonstration Project 

The goal of the Demonstration Project was to monitor the transport and fate of fine 

sediment placed on the beach, and a number of activities were required to get the sediment from 

the debris basins to the shoreline. These activities included: (1) environmental permitting of the 

project, (2) excavation of sediment from the debris basins, (3) stockpiling the sediment on the 

processing pad, (4) sorting the sediment for trash and debris, (5) testing the sediment for grain 

size and environmental contaminants, and (6) hauling and placement of sediment on the beach. 

Although steps (1) to (5) were lengthy and critical elements to the success of this project, the 

focus of this report is on the hauling and placement routine and schedule. Project partners that 

managed other elements of the Demonstration Project are listed in table 1. 

Once dry sediment was acquired from the sediment basins and trash and debris (including 

gravel-sized sediment) were sorted out, the sediment was stockpiled on a processing pad roughly 

1.5 km from the beach. During sediment placement operations, dump trucks were filled with 

sorted sediment and driven down Horse Trail Road to the beach, where the sediment was placed 

in the intertidal zone immediately north of the road’s end (fig. 2). There were two styles of 

placement utilized during the Demonstration Project. The first placement style consisited of 

opening up the dump truck bay while driving through the intertidal swash zone (fig. 2b). This 

technique produced an elongated strip of sediment that was rapidly suspended into the swash. 

The second technique consisted of backing the trucks into the intertidal zone and dumping 

sediment in large piles. Sediment placed using this technique remained in piles for minutes to 

hours, depending on placement location and wave energy in the swath (fig. 2c). The sediment 

was not manipulated after being placed on the beach. 

Figure 2. Photographs of the study site and sediment-nourishment project. (a) Overview perspective from 

the United States-Mexico border showing the sediment placement site (arrow) and southern-directed 

turbid plume on October 1, 2009,1447 PDT. (b and c) Sediment placement within the swash zone. (d) 

A recently placed pile of sediment in the swash. (e) Turbid surf zone immediately adjacent to the 

sediment placement site. 

There were two sediment placements—one in 2008 (Phase I) and the other in 2009 

(Phase II)—and schedules for each are given in tables 2 and 3 and shown graphically in figures 3 

and 4. The volumetric estimates were made by using daily counts of truck deliveries; each truck 

a

b c d e
6

carried approximately 19 m3. The 2008 Phase I placement consisted of 7,600 m3 of sediment 

placed during an interval of 10 days. This intial placement was hampered by rain on November 

6–8, 2008, which slowed operations and led to the eventual failure of Horse Trail Road during 

the afternoon of November 6th. The road was repaired temporarally and placement activities 

were resumed, allowing for intermittment sediment placement during November 10–13. Phase I 

of the project was discontinued after 7,600 m3

 of sediment was placed on the beach (table 2). 

Phase II could not begin until significant improvements were made to Horse Trail Road. After 

reconstruction of the road in the summer of 2009, Phase II of the Demonstration Project was 

initiated on September 21, 2009, and finished on October 2, 2009. During Phase II, 26,800 m3 of 

sediment was placed during a 12-day interval (table 3). 

Table 2. Sediment placement schedule for Phase I (2008) of the Demonstration Project. 

Date Start Time 

(PDT)

End Time 

(PDT)

Placement 

volume (m3)

Notes

03 Nov 2008 10:15 10:30 12 Initial testing of technique and roads. 

04 Nov 2008 1910 First full day of sediment placement

05 Nov 2008 ~1000 Road to beach fails at midday

06 Nov 2008 No placement - road repair

07 Nov 2008 No placement - road repair

08 Nov 2008 No placement - road repair

09 Nov 2008 No placement - road repair

10 Nov 2008 ~2000

11 Nov 2008 No placement

12 Nov 2008 1910

13 Nov 2008 760

Table 3. Sediment placement schedule for Phase II (2009) of the Demonstration Project. 

Date Start Time 

(PDT)

End Time 

(PDT)

Placement 

volume (m3)

Notes

21 Sept 2009 7:40 17:00 2980

22 Sept 2009 7:15 16:40 3150

23 Sept 2009 7:00 16:40 2700

24 Sept 2009 7:00 16:40 3300

25 Sept 2009 7:00 16:40 3920

26 Sept 2009 No placement - weekend

27 Sept 2009 No placement - weekend

28 Sept 2009 7:00 16:40 3490

29 Sept 2009 7:00 13:00 1710 Placement ended early

30 Sept 2009 No placement

01 Oct 2009 7:00 16:15 4000

02 Oct 2009 7:00 13:00 1520
7

Figure 3. Nourishment and sampling schedule during Phase I (2008) of the Demonstration Project. (a) 

Sediment-nourishment schedule in total placement per day. (b) Sampling schedule from the various 

monitoring methods (see text for details). (c) Significant wave height and dominant wave direction from 

Coastal Data Information Program (CDIP) buoy 155. 

Physical Monitoring Techniques and Data

An integrated monitoring program was developed to examine the physical transport and 

fate of fine sediment placed in the nearshore for the Demonstration Project. The primary research 

questions addressed in this program were: 

1. What are the patterns, residence times, and mechanisms of water turbidity due to the 

introduced fine sediment? 

2. What are the patterns, residence times, and mechanisms of sedimentation on the seafloor 

due to the introduced fine sediment? 

3. What are the sediment-transport pathways that lead to the final sink for the fine 

sediment? 

4. How does project implementation (volume and mechanism of placement) influence 

sediment transport and fate? 

Project Day

 0 2 4 6 8 10 12 

0

1

2

3

210

230

250

270

290

Significant 

wave 

height 

(m)

1000

2000

12/12

1/09

Boat Sampling

Beach Sampling (A.M.)

Remote Sensing

Beach Topo (8 surveys to date)

Oceanographic Instrumentation

10/16 10/23 10/30 11/6 11/13 11/20 11/27

10/16 10/23 10/30 11/6 11/13 11/20 11/27

Wave 

direction 

(dir)

10/16 10/23 10/30 11/6 11/13 11/20 11/27

Total = 7,600 m3

Sediment 

nourishment

(m3

)

(a) 

(b) 

(c) 
8

Figure 4. Nourishment and sampling schedule during Phase II (2009) of the Demonstration Project. (a) 

Sediment nourishment schedule in total placement per day. (b) Sampling schedule from the various 

monitoring methods (see text for details). (c) Significant wave height and dominant wave direction from 

Coastal Data Information Program (CDIP) buoy 155. 

The physical monitoring program consisted of four major stages: (1) pre-project, (2) 

Phase I, (3) Phase II, and (4) post-project. Several monitoring and analysis techniques were used 

for each stage, and a description of these techniques are provided below. A summary of the 

schedule for these monitoring activities is shown in figures 3 and 4. Data from these monitoring 

activities are provided in the appendixes of this report. 

Sampling of the Sediment Stockpile

Although sampling and description of the stockpiled sediment was done by Moffet and 

Nichols and AMEC Earth and Environmental for pre-project permitting, additional samples of 

the stockpiled sediment were obtained to evaluate grain-size distributions by using techniques 

identical to those utilized for the remainder of the physical monitoring. On May 15, 2009, Chris 

Peregrin, Environmental Coordinator of the Border Field Station State Park, collected three 1-kg 

samples of the stockpiled sediment. Samples were obtained by removing 10 cm of the surface of 

the sediment stockpile to eliminate sample biasing from wind winnowing of the fines and 

sampling with a small spade. 

9/10 9/15 9/20 9/25 9/30 10/5 10/10 10/15 

9/10 9/15 9/20 9/25 9/30 10/5 10/10 10/15 

Sediment 

nourishment 

(m3

) 1500 

3000 

Total = 27,000 m3 

Boat Seafloor Sampling 

Beach Sampling (P.M.) 

Beach Sampling (A.M.) 

Remote Sensing 

Oceanographic Instrumentation 11/17 

Boat CTD Sampling 

Significant 

wave 

height 

(m) 

Wave 

direction 

(dir) 

(a) 

(b) 

(c) 

0 

1 

9/10 9/15 9/20 9/25 9/30 10/5 10/10 10/15 

250 

290 

2 

210 

230 

270 

Project Day 

 0 2 4 6 8 10 12 14 16 18 20 
9

All samples were analyzed for grain-size distributions at the USGS Coastal and Marine 

Geology Sediment Laboratory in Menlo Park, California, using the techniques detailed in the 

“Seafloor Sediment Sampling” section. The results of these analyses are provided in appendix 1. 

Bathymetric Sonar Mapping

During the pre-project monitoring, the bathymetry and seafloor characteristics of the 

nearshore region of the study area were mapped using swath sonar technology from the R/V

Parke Snavely. During May 2008, approximately 14 km2

 of seafloor was mapped with a 234.5-

kHz SEA (Systems Engineering and Assessment, Ltd.) SWATHplus-M phase-differencing 

sidescan sonar. Real-time kinematic (RTK) GPS position data were passed through a 

CodaOctopus F180 inertial measurement unit (IMU) to the sonar hardware and data-collection 

software. 

Two seafloor products are generated by swath sonar mapping: bathymetry and acoustic 

backscatter. Acoustic backscatter of the seafloor is related to the general hardness properties of 

the seafloor; bedrock and very coarse sediment (gravel) generally have high acoustic backscatter, 

while sand and mud have lower backscatter. Final data from the USGS sonar mapping will be 

available in a forthcoming USGS Open-File Report. 

Seafloor-Sediment Sampling 

Seafloor-sediment samples were taken before, during, and after both phases of the 

Demonstration Project to track changes in the grain-size distribution of the seafloor surface. 

Samples were obtained by using a small (6-inch) Ponar Type grab sampler. The sampler was 

dropped to the seafloor on isobath contours and at regular spaced transects as described. For each 

grab sample, a subsample of the sediment surface 2–3 cm deep was obtained from the upper 

surface of the sediment in the sampler. 

Two sampling grids were used during this study. First, during the pre-project monitoring 

of May 2008, seafloor samples were collected along several across-shore transects at regular 2-m 

depth intervals from 6 to 24 m water depths (fig. 5). Samples also were taken at numerous 

“targeted” sites, which were chosen from the unique or defining features observed in the sonar 

bathymetry backscatter results from the swath mapping (fig. 5). It was not possible to sample the 

seafloor within dense kelp beds, owing to limited accessability for the vessel. Second, during 

Phase II, seafloor samples were collected along four across-shore transects (labeled A through D) 

at regular 2-m depth intervals from 8 to 14 m water depth (fig. 1; table 4). Additionally, samples 

were taken adjacent to the tripods and buoys during Phase II of the project. These sites also were 

used for water-sampling stations as discussed below. No seafloor samples were taken during 

Phase I of the project owing to a failed attempt to use the underwater camera technologies 

(Rubin and others, 2007) to measure grain size at these sites. 
10

Figure 5. Map of seafloor sediment-sampling locations during the May 2008 investigations of the study 

area.

All samples were analyzed for grain-size distributions at the USGS Pacific Coastal and 

Marine Geology Science Center (PCMSC) Sediment Laboratory in Menlo Park, California, 

according to procedures standardized by the lab. Approximately 25 grams of homogenized 

sample was placed into 1,000-mL beakers with 300 mL of deionized (DI) water and 10 mL of 

35-percent hydrogen peroxide overnight to digest organics. Samples were heated to drive off 

excess hydrogen peroxide and then placed in an ultrasonic bath for 10 minutes to disperse the 

silt- and clay-size sediments. Subsequently, the samples were washed twice with DI water by 

centrifugation for 1 hour and for 30 minutes, respectively, to remove solubles. The samples were 

then wet-sieved though 2-mm and 63-μm sieves to isolate the gravel (greater than 2 mm), sand 

(63 μm to 2 mm), and mud (less than 63 μm) sediment fractions. The gravel and sand fractions 

were collected and dried in evaporating dishes and then weighed. The mud fraction was collected 

in a 1,000-mL graduated cylinder, and 5 mL of the dispersant “calgon” (sodium 

hexametaphosphate) was added to the suspension to facilitate dispersal of the silt and clay. A 20-

mL aliquot of the mud suspension was taken from the graduated cylinder, dried, and weighed. 

The total weight of the mud fraction was determined by multiplying the 20-mL aliquot weight by 

a factor of 50, owing to the 50-fold dilution of this sediment mass (that is, 1,000 mL÷20 ml=50). 

Imperial Beach

Imperial Beach Blvd. 

Horse Trail Rd. 

TJR

N2

F1

BF

S1

HT

M

N1

Pier 

U.S.-Mexico Border

Tijuana

Tijuana River

Nourishment 

Site 

Seacoast Dr. 

Elm Ave.

Naval Air 

Station

W 500 m

N

BFSP

TRNERR
11

Table 4. Ocean sampling locations for seafloor sediment samples and water column sampling by CTD. 

Station Name Water Depth 

(m)

Latitude 

(decimal degrees)

Longitude

(decimal degrees)

A08 8 32.536100 -117.127200

A10 10 32.536100 -117.128100

A12 12 32.536100 -117.130600

A14 14 32.536100 -117.134700

B08 8 32.541700 -117.127800

B10 10 32.541700 -117.128900

B12 12 32.541700 -117.131700

B14 14 32.541700 -117.135600

C08 8 32.547200 -117.128900

C10 10 32.547200 -117.130600

C12 12 32.547200 -117.134200

C14 14 32.547200 -117.138100

D08 8 32.552800 -117.131700

D10 10 32.552800 -117.134400

D12 12 32.552800 -117.137800

D14 14 32.552800 -117.141700

Buoy151 15 32.542600 -117.139500

Buoy201 20 32.540700 -117.157000

TRBM-N1 15 32.548600 -117.142000

TRBM-S1 15 32.534900 -117.136800

N152 15 32.548050 -117.141917

S152 15 32.538400 -117.137833

1

 – Stations Buoy15, Buoy20, TRBM-N, and TRBM-S were sampled only during 2008 (Phase I) 

of the Demonstration Project. 

2

 – Stations N15 and S15 were sampled only during 2009 (Phase II) of the Demonstration 

Project. 

Particle-size distribution was determined by using a Beckman Coulter LS230 laser 

diffraction particle-size analyzer. The sample’s sand and mud fractions were processed 

separately, and these data were merged and integrated together using the mass concentration of 

sand and mud. Results of the seafloor sampling are provided in appendix 2. 

Beach-Sediment Sampling

Sediment of the foreshore of the study area beach was sampled and analyzed for grainsize distributions to evaluate the potential influence of the Demonstration Project sediment on 

the native beach sand. Two sampling techniques were utilized for beach sediment. First, surface 

grab samples of the upper 2–3 cm of beach sand were obtained using a small spoon. Twenty-one 

beach samples were taken in May 2008 during the pre-project phase. Additional beach surface 

samples were obtained before, during, and after the sediment placement during Phase II of the 

Demonstration Project at the swash-water sampling stations (fig. 1; table 5). For each sampling 

station, three samples were obtained, each at a different elevation on the beach shoreface. 

“Upper” beach samples were obtained approximately 10 cm downslope of the uppermost swash 

line from the previous high tide; “mid-beach” samples were obtained at the upper limit of the 

wetted swash caused by the active swash on the beach at the time of sampling; and “lower” 

beach samples were taken in the middle of the swash zone at the time of sampling. 
12

Table 5. Beach swash sampling locations for the Demonstration Project. 

Station Name Location Description Latitude1

(decimal degrees)

Longitude1

(decimal degrees)

F12 Imperial Beach, 50 m 

south of municipal pier.

32.578228 -117.133486

TJR3 Beach immediately south 

of the Tijuana River 

mouth.

2008: 32.554300

2009: 32.552950

2008: -117.127850

2009: -117.127667

N2 Between Horse Trail Rd. 

and Tijuana River mouth.

32.551617 -117.127317

N1 Between Horse Trail Rd. 

and Tijuana River mouth.

32.548917 -117.126500

M The middle of the State 

Park beach. 

32.546217 -117.125700

HT At terminus of Horse Trail 

Road

32.543333 -117.125033

S1 Between Horse Trail Rd. 

and the U.S.-Mexico 

border fence.

32.540367 -117.124533

BF 200 m north of the U.S.-

Mexico border fence.

32.537383 -117.124267

1

 – These sample locations correspond to the approximate crest of the beach berm. Water 

samples were obtained immediately downslope (westward) of these locations in ankle to 

knee (20-30 cm) water depths of the beach swash. 

2

 – Station F1 was sampled only during 2009 (Phase II) of the Demonstration Project. 

3

 – The location of this station was moved southward between 2008 and 2009 owing to a lateral 

shift of the river mouth during the winter of 2008-’09. 

The second sampling technique consisted of surface and subsurface samples collected to 

characterize the sediment grain-size distributions remaining on and within the beach during the 

post-project stage. This sampling was done only following the completion of Phase II. For 

subsurface sampling, pits were dug (approximately 30 cm by 30 cm) at several locations within 

and nearby the sediment-nourishment site, and a 20-m-long trench was dug across the beach face 

to evaluate the cross-shore patterns in sediment grain size. The location of these sites was 

recorded with handheld Garmin GPSmap 76CSx GPS with reported accuracy of ±2 m. The pits 

and trench were subsampled by using a spoon along cleaned vertical faces at several depths. All 

beach samples were processed for grain-size distributions at the USGS PCMSC Sediment 

Laboratory in Menlo Park, California, using the techniques detailed in the “Seafloor-Sampling” 

section. Results of the beach-sediment sampling are provided in appendix 3. 

Swash-Water Sampling—Suspended Sediment

Samples of the beach swash water were obtained before, during, and after the two project 

phases for analysis of suspended-sediment concentration and grain-size distribution. Swash 

samples were obtained using techniques consistent with swash-bacteria sampling (for example, 

Noble and Xu, 2004), which consists of dipping 250-mL sample bottles under the water surface 

at “ankle depth” (approximately 10–20 cm water depth) immediately following the passage of a 

wave bore. Bottles were not overfilled (sample volumes were 100–200 mL) and were obtained in 

duplicate so that concentration and grain-size analyses could be run on separate samples. Swashwater samples were obtained from the beach-swash sampling site shown in table 5 and figure 1. 

Beach-water sampling typically consisted of an early morning sampling before the initial 
13

sediment placement to characterize residual suspended-sediment concentrations from the 

previous day, sampling in the afternoon during active sediment placement, and occasional highfrequency sampling during the day or night to track the temporal evolution and variability of 

suspended-sediment concentrations. The early morning and overnight sampling was done by 

Meg Rippy of Scripps Institute of Oceanography, who also collected samples for nutrient and 

bacteria analyses. Results of these additional samples are not included in this report and will be 

presented and summarized in her dissertation research. The other samples were collected by 

USGS staff and volunteers and did not include nutrient or bacteria samples. 

All beach-water samples were processed for suspended-sediment concentration and 

grain-size distributions at the USGS PCMSC Sediment Laboratory in Menlo Park, California. 

One of the duplicate water samples obtained from the beaches was processed to determine 

suspended-sediment concentration. These samples were wet sieved through a 63-μm sieve, 

which separated the sample into sand (greater than 63 μm) and mud (less than 63 μm) fractions. 

The volume of water was measured with a graduated cylinder. The sand fraction was dried, 

weighed, and processed through the Beckman Coulter LS230 for particle-size distribution. The 

mud fraction was filtered through pre-tared glass fiber filters, dried, and weighed. The weights of 

the sand and mud fractions allowed for the determination of the mud concentration, sand 

concentration, and—through summation—the total sediment concentration. The suspended sand 

concentrations were exceptionally high in almost all of these samples owing to the resuspended 

native beach sand in the swash zone; however, suspended mud concentrations were low 

(approximately 10 mg/L or less) in waters without influence from the sediment placement and 

high (10s to 100s of mg/L) in waters influenced by the placement. 

The majority of samples had adequate mass of mud-sized sediment in the duplicate 

sample to characterize the grain-size distribution of the mud fraction (that is, less than 63 μm). 

Samples were first wet sieved through a 63-μm sieve, and the liquid and sediment passing 

through the sieve were collected in a graduated cylinder. The retained sediment was oven dried, 

and the the particle-size distribution of this sediment was determined with the Beckman Coulter 

LS230 analyzer. Results of the swash-water sampling are provided in appendix 4. 

Coastal-Water Sampling—Small Vessel

Coastal waters were sampled at regular stations from a small research vessel for water 

properties, turbidity, and suspended-sediment concentrations. A station list and map are included 

in table 4 and figure 1, respectively. Coastal-water properties were measured using a Sea-Bird 

Electronics SEACAT 19Plus Profiler CTD (conductivity, temperature, and depth) sensor (fig. 6). 

Also attached to the CTD were a Wetlabs 650-nm (red) C-Star transmissometer with a 25-cm 

pathlength and a D&A Instruments 850-nm (infrared) OBS-3 turbidity sensor, which were both 

powered and logged by the CTD. The CTD and additional instruments were sampled at 4 Hz. At 

each station the CTD was turned on and lowered into the water. Once the pump was primed, the 

CTD was raised to just below the water surface and then lowered to the seafloor at a rate of 

approximately 0.5 m/sec. CTD and turbidity data were output in engineering units (salinity, 

temperature, density, depth, beam attenuation, and optical backscatterance) using the Sea-Bird 

Seasoft software, and only the downcast portion of the output was utilized and reported here. The 

CTD data are provided in appendix 5. 
14

Figure 6. Photograph of the conductivity-temperature-depth (CTD) instrument with the additional optical 

backscatterance sensor (OBS) and 25-cm pathlength transmissometer. 

After profiling the water column with the CTD, a surface-water grab sample was 

obtained at approximately 25 cm below the water surface directly into a 1-L Nalgene bottle for 

suspended-sediment concentration analysis. Samples were analyzed at the USGS PCMSC 

Sediment Laboratory in Menlo Park, California, with the mud-fraction techniques for 

determining suspended-sediment concentration for the swash samples as detailed above. Particle 

grain-size distributions were not evaluated for any of these water samples. Concentration data are 

provided in appendix 6. 

Aerial Remote Sensing

High-resolution multispectral imagery was obtained to help determine the dispersal 

pathways of fine sediment on the beach under various environmental conditions of the 

Demonstation Project. The imagery also was collected to augment field measurements from 

moored and vessel-based instruments and aid in their data interpretation. Ocean Imaging 

OBS

Transmissometer

CTD 

pump

CTD
15

Corporation (OI), based in Solana Beach, California, was contracted to collect and process 

multispectral imagery. For the Demonstatration Project, OI operated the DMSC-Mk2 aerialimaging system manufactured by SpecTerra, Limited, in Australia. This sensor provides 12-bit 

radiometric resolution digital data from 4 independent channels. The channel wavelengths are 

customizable to any wavelength combination between 400 and 950 nm. Additionally, OI’s 

aerial-imaging system included a fully integrated thermal infrared (IR) camera manufactured in 

Germany by Jenoptik as a fifth channel. This camera allowed for simultaneous acquisition of 

multispectral visible, near IR, and thermal IR imagery. Positional information for each image 

frame and aircraft roll, pitch, and yaw information needed to correct the image frames for 

viewing geometry is supplied by an integrated differential GPS and an inertial motion sensing 

unit (IMU) manufactured by Oxford Technologies of England. 

For this project, the sensor channels of the imaging system were configured with the 

following interference filters with 10-nm bandwith: 450, 551, 577, and 640 nm. The wavelengths 

were chosen based on deductive spectrometer analyses (see below) in order to maximize the 

potential for detecting suspended sediment and to separate the newly deposited sediment 

spectrally from resuspended native beach and shelf sediment. The imagery was collected at an 

altitude of 1,372 m, resulting in spatial resolution of 70 cm. 

Following each image data acquisition, the image frames were subject to pre-processing 

algorithms for band-to-band alignment and vigneting correction. Each image set was then run 

through a calibration procedure, which was necessary to enable quantitative comparisons 

between multiple image sets collected under differing sun angle and atmospheric conditions. The 

calibration method utilizes a standard white teflon target that is imaged before each flight by 

both the DMSC sensor and an Ocean Optics Spectrometer. Additional Teflon spectra also are 

taken during the flight with the spectrometer. The measured output values from the sensor are 

compared to the irradiance values measured from the spectrometer to determine a calibration 

factor for each band. This factor is applied to each frame in the dataset before the frames are 

mosaicked into a final image. The result is a band-to-band standardization of the reflectance 

signal over an evenly reflecting target (the Teflon) during the entire image acquisition time 

interval to account for changes in atmospheric attenuation and sun angle. The system-integrated 

IMU and autogeoreferencing software that uses the IMU information results in circular error 

geopositioning accuracies of 3–7 pixels. In order to increase the final image accuracy, the 

individual image frames were further manually adjusted for any systematic bias to match a 

USGS orthoquad 1-m-resolution image of the beach and inshore areas. Remote-sensing imagery 

was output in truecolor using the red, green, and blue wavelengths. These images are available in 

GeoTIFF format with additional metadata in appendix 7. 

Oceanographic Observations—Tripods and Moored Buoys

The USGS deployed several bottom platforms and moored buoys offshore of the 

Demonstration Project to record oceanographic conditions before, during, and after sediment 

placement. Three types of platforms were used for this study: tripods, trawl-resistent bottom 

mounts (TRBMs), and moored buoys (fig. 7). A summary of the locations and depths of these 

platforms for each phase of this study area is provided in tables 6 and 7. Each platform contained 

oceanographic sensors to characterize water properties, flow conditions, and suspended-sediment 

properties in the water. 
16

Figure 7. Photographs of moorings utilized in the Demonstration Project, including (a, d) buoys, (b) 

tripods, and (c) trawl-resistent bottom mounts (TRBMs). 

Table 6. Oceanographic platform stations for Phase I (2008) of the Demonstration Project. 

Station Name Description Water Depth 

(m)

Latitude 

(decimal degrees)

Longitude

(decimal degrees)

TJR08C1S Central Inshore Buoy 13.5 32.542567 -117.139450

TJR08C2S Central Offshore Buoy 18.5 32.540667 -117.156950

TJR08C1T Central Inshore Tripod 13.4 32.542583 -117.138517

TJR08C2T Central Offshore Tripod 19.2 32.540183 -117.157583

TJR08N1T Northern TRBM 14 32.548552 -117.141950

TJR08S1T Southern TRBM 14 32.534883 -117.136833

OBS

(c) TRBM

CTD & OBS 

(b) Tripod (a) Buoys

CTD & OBS Base

Top

(d) Buoy

ADCP

CTD

OBS

ADV

Trans

ADCP
17

Table 7. Oceanographic platform stations for Phase II (2009) of the Demonstration Project. 

Station Name Description Water Depth 

(m)

Latitude 

(decimal degrees)

Longitude

(decimal degrees)

TJR09N1S Northern Buoy 15 32.548050 -117.141917

TJR09S1S Southern Buoy 15 32.538400 -117.137833

TJR09N1T Northern Tripod 15 32.547900 -117.141100

TJR09S1T Southern Tripod 15 32.538167 -117.137083

The tripods housed numerous instruments for the purpose of measuring water flow and 

properties, including temperature, salinity, and turbidity. Tripods housed: (1) upward-facing 

acoustic Doppler current profilers (ADCPs) to obtain profiles of overlying currents and, when 

available, directional wave spectra; (2) downward-facing acoustic current profilers (AquaDopps) 

to obtain detailed profiles of currents down to the seabed—although these instruments failed to 

record adequate data; (3) near-bottom single-point current meters (ADVs) capable of current and 

directional wave measurements; (4) conductivity, temperature, and depth (CTD) sensors; (5) 

optical backscatterance sensors (OBSs) and light transmissometers to measure turbidity; and (6) 

a LISST laser particle size distribution analyzer. The OBSs were housed with brushes to clean 

the sensor faces regularly. Detailed descriptions of these instruments are presented below. 

Two TRBMs were utilized during Phase I of the Demonstration Project. These TRBMs 

were housed with ADCPs to obtain profiles of overlying currents and OBSs with automated 

wipers to measure turbidity. Moored buoys were deployed with CTD and OBS sensors to 

measure water properties just below the ocean surface. Two buoys were utilized for both Phase I 

and II of the project, although they were located at different sites each year (tables 6 and 7; fig. 

1). Below is a description of the instrument types utilized for this study. Detailed descriptions of 

the instrumentation and setup for each platform is provided in tables 8 and 9. 

Acoustic Doppler Current Profilers (ADCP and ADP)

ADCPs and ADPs estimate current velocities in the water by sending an acoustic pulse 

and measuring the Doppler shift of the returned echos, which are reflected back by particulate 

matter. The instruments can obtain a profile of current velocity by measuring the Doppler shift at 

different time lags, which correspond to different distances away from the instrument. ADCPs 

and ADPs also provide measurements of the acoustic backscatter intensity throughout the 

profiled water column, which is a function of the amount and type of particles in the water. 

For this project RDI Workhorse 1200 KHz ADCPs and Nortec 1MHz AWAC ADPs 

were used to measure mean flow rates and directional wave properties, which included wave 

height, period, and direction. For profiles of currents, each instrument was sampled at 2 Hz for 

30 sec, resulting in 60 pings. All ADCPs were set to record currents in 1-m vertical bins. These 

instruments also measured directional wave parameters every 2 hrs in 20-min burst intervals. 

AquaDopp Current Profiler

A Nortek AquaDopp current profiler was used to measure current profiles immediately 

above the seafloor at the tripod locations, although the system did not properly record data. 
18

Table 8. Oceanographic instrumentation for the stations during Phase I (2008) of the Demonstration 

Project. 

Station Name Description Sensor Type Sampling 

depth or 

height1

Sampling schedule and notes

TJR09N1S Inshore Buoy FSI Inductive CTD 0.94 mbw2 5 min

D&A OBS3 0.84 mbw2 5 min, OBS at high gain setting

TJR08C2S Offshore Buoy FSI Inductive CTD 0.95 mbw2 5 min

D&A OBS3 0.85 mbw2 5 min, OBS at high gain setting

TJR08C1T Inshore Tripod RDI 1200 kHz ADCP 2.04 mab Currents at 5 min

Sontek ADV-O 0.65 mab 15 min, downward looking

Nortek Aquadopp Profiler 1.05 mab Downward looking, Instrument 

failed

D&A OBS3 1.50 mab 15 min, OBS at medium gain 

setting

D&A OBS3+ 0.34 mab 5 min, OBS dual range at 0-250 and 

0-1000

Wetlabs 10 cm 

transmissometer

1.49 mab 15 min

Sequoia LISST 0.35 mab 5 min, sensor failed within days of 

deployment 

SBE Microcat CT 1.95 mab 5 min

Paroscientific Pressure Sensor 1.05 mab 15 min

TJR08C2T Offshore Tripod Nortek 1 MHz AWAC ADP 2.02 mab Currents at 5 min, waves at 2 hr, 

sensor failed between Oct-31 and 

Nov-23, 2008

Sontek ADV-O 0.67 mab 15 min, downward looking

D&A OBS3 1.48 mab 15 min, OBS at medium gain

D&A OBS3+ 0.28 mab 5 min, OBS dual range at 0-250 and 

0-1000, sensor failed between Oct31 and Nov-23, 2008

Wetlabs 25 cm 

transmissometer

1.48 mab 15 min

SBE Microcat CTD 1.67 mab 5 min

Paroscientific Pressure Sensor 1.26 mab 15 min

TJR08N1T Northern TRBM Nortek 1 MHz AWAC ADP 0.68 mab Currents at 5 min

D&A OBS3+ 0.75 mab 5 min, OBS dual range at 0-500 and 

0-2000

TJR08S1T Southern TRBM Nortek 1 MHz AWAC ADP 0.68 mab Currents at 5 min

D&A OBS3+ 0.75 mab 5 min, OBS dual range at 0-500 and 

0-2000

1

 – Sensor depths are shown in meters below the water surface (mbw) and sensor heights are 

shown in meters above the bed (mab). 

2

 – The depth of the CTD calculated by the median pressure value of record. The depth of the 

OBS calculated by the measured vertical difference between the CTD and OBS sensors. 
19

Table 9. Oceanographic instrumentation for the stations during Phase II (2009) of the Demonstration 

Project. 

Station Name Description Sensor Type Sampling 

depth or 

height1

Sampling intervals and notes

TJR09N1S Northern 

Buoy

FSI Inductive CTD 0.67 mbw 5 min 

D&A OBS3 0.56 mbw 5 min; OBS at high gain setting

TJR09S1S Southern 

Buoy

FSI Inductive CTD 1.03 mbw 5 min 

D&A OBS3 0.91 mbw 5 min; OBS at high gain setting

TJR09N1T Northern 

Tripod 

RDI 1200 kHz ADCP 2.03 mab Currents at 5 min, waves at 2 hr 

Sontek ADV-O 0.65 mab Currents at 15 min, waves at 30 

min, downward looking

Nortek Aquadopp Profiler 1.05 Currents at 5 min, downward 

looking, instrument failed

D&A OBS3 1.50 mab 15 min, OBS at medium gain 

setting

D&A OBS3+ 0.34 mab 5 min, OBS dual range at 0-250 

and 0-1000

Wetlabs 25 cm transmissometer 1.50 mab 15 min

SBE Microcat CT 1.82 mab 5 min

Paroscientific Pressure Sensor 1.55 mab 15 min

TJR09S1T Southern 

Tripod

RDI 1200 kHz ADCP 2.02 mab Currents at 5 min, waves at 2 hr 

Sontek ADV-O 0.67 mab Currents at 15 min, waves at 60 

min, downward looking

D&A OBS3 1.48 mab 15 min, OBS at medium gain 

setting

Wetlabs 25 cm transmissometer 1.50 mab 15 min

SBE Microcat CT 1.64 mab 5 min

Paroscientific Pressure Sensor 1.56 mab 15 min

1

 – sensor depths are shown in meters below the water surface (mbw) and sensor heights are 

shown in meters above the bed (mab). 

Acoustic Doppler Velocimeters (ADV)

An ADV measures current speed and direction in three directions (u, v, and w) at a single 

point within a small sampling volume by using the Doppler principle to calculate velocity along 

three axes. This study utilized Sontek/YSI, Inc., ocean versions, or “ADV-O,” which operate at 5 

MHz and measure velocities in a sample volume of ~2 cm3 located ~18 cm from the acoustic 

transmitter. The data were logged using Sontek Hydra data loggers, which also logged data from 

two other sensors (typically a transmissometer and an OBS). The ADV-Os were sampled for 

both mean currents and directional wave spectra. 

Optical Backscatter Sensors (OBS)

An OBS measures turbidity by sending a beam of infrared light into the water and then 

measuring the quantity of light that is reflected back to its sensor from suspended particles. 

Suspended-sediment concentration can then be determined if the sensor is calibrated for the 

sediment in suspension. Two models of D&A Instruments’ OBSs were used, single channel 
20

OBS3s and dual channel OBS3+s. Tables 8 and 9 include the gain settings for each OBS3 sensor 

(high, medium, or low). 

Light Transmissometers

A transmissometer measures the transmission of red collimated light (650 nm 

wavelength) from an LED along a fixed path through the water. WET Labs C-Star 

transmissometers with either 10-cm or 25-cm pathlengths were used. 

Conductivity-Temperature (CT) and Conductivity-Temperature-Depth (CTD) Recorders

Conductivity-temperature (CT) sensors measure and record water temperature and 

conductivity, from which salinity can be calculated using the 1978 Practical Salinity Scale 

(Unesco, 1981). Conductivity-temperature-depth (CTD) sensors also include a pressure sensor to 

measure water depth by using the hydrostatic assumption. Seabird Electronics (SBE) sensors 

(both SBE-37 MicroCAT and a SBE-16 SeaCAT) were used in this study. 

Oceanographic Data Processing

Data from the oceanographic sensors were processed using standards recommended by 

the instrument manufacturers. Processed time-series of these data are available in appendix 8. A 

description of the data processing and file formats follows. 

Data-File Identifiers

Data files were produced for either individual instruments or groups of related 

instruments from each oceanographic platform. Data files were uniquely identified by both the 

mooring identification number (mooring ID) and information about the instrument(s) and file 

type. First, a five-part mooring ID was assigned to each mooring and tripod. The mooring ID 

also can be used to identify and/or locate data records in the USGS Woods Hole Science Center 

time-series data management system (Montgomery and others, 2008). Each part of the mooring 

ID represents unique characteristics of the station: the first three characters describe the project 

(“TJR” for Tijuana River Demonstration Project ), the next two characters describe the project 

year (“08” or “09”), the next character describes the general location (for example, “N” for 

northern, “C” for central, “S” for southern), the next character is the platform number at that site 

(“1” or “2”), and the next character represents the station type (“T” for tripod or TRBM and “S” 

for surface buoy). For example, the mooring ID for the central tripod during Phase I of the 

Demonstration was “TJR08C1T.” Data files are labeled first by mooring ID, second by 

instrument number and code, and lastly by the file-type extension. For example, the data file 

from the microcat CT sensor (“mc”), which was the second instrument (“02”) on tripod 

described above was denoted “TJR08C1T02mc.nc”. A complete list of instrument codes is 

provided in appendix 8. 

Raw data files downloaded from each instrument were translated from the manufacturerspecific data format into the netCDF data-file format using toolboxes developed in Matlab 

software specific to each instrument. The netCDF data-file format, developed by the Unidata 

Corporation (http://www.unidata.ucar.edu/software/netcdf/), is a compact binary format 

compatible with most computer systems, which stores both the data and the metadata in the file. 

The USGS uses the EPIC conventions for organizing and naming oceanographic data variables 

(http://www.epic.noaa.gov/epic/document/convention.htm). These data were processed using 

quality-control procedures developed for all USGS Woods Hole Science Center oceanographic 

data. Files generated during the first processing step (which involved conversion to engineering 

units and quality assurance calculations) were stored in netCDF format with .cdf suffixes. Final 
21

versions (after application of calibration coefficients, coordinate transformations, rotation to 

geographic coordinates, and averaging of good data) were stored in netCDF format with .nc 

extensions. All of the final statistics data are in EPIC-compliant netCDF format. Burst-data files 

also are in netCDF format, but are not EPIC-compliant because they use an added dimension 

(sample number) not used by the EPIC convention. 

Time

Times are reported in Universal Time (UT, equivalent to Greenwich Mean Time, GMT). 

Drift of instrument clocks was checked by comparing instrument times with accurate times from 

either the GPS or clocks synchronized with the National Institute of Standards and Technology 

in Boulder, Colorado (http://tf.nist.gov/) before and after deployments. The observed offsets 

were small compared to the sample intervals, so instrument times in this data set were not 

adjusted. 

Time is recorded in the netCDF files as two variables named time1 and time2, in 

compliance with EPIC standards, to allow precise storage of time in integer format. Time1 is the 

Julian day, where midnight on May 23, 1968 = 2440000 and time2 is the elapsed time on that 

day, in milliseconds since midnight. Thus, time in Julian days is computed as 

time1+time2/(1,000x3,600x24). 

Current Meter Data

Instrument Orientations 

Each of the ADVs and ADCPs had internally mounted flux-gate compasses. These were 

calibrated prior to deployment according to manufacturer’s recommendations. Raw ADCP data 

were recorded in beam coordinates. Data from the ADVs were recorded in instrument 

coordinates (referred to here as x, y, z coordinates) and later rotated into geographic coordinates 

using burst-median values for heading, pitch, and roll. All data were then rotated to true 

geographic coordinates (u, v, and w, where positive is toward east, north, and up) by using 

instrument compasses and tilt sensors and correcting for local magnetic variation (13.8oE). 

Acoustic Doppler Current Meter (ADCP) Data 

ADCP data were processed according to standard USGS procedures by using ADCP 

Tools, a collection of Matlab routines written to read in and process raw ADCP data and create 

netCDF files of the raw and processed data. The toolbox is described in USGS Open-File Report 

00–458 (Côté and others, 2011). Raw data files from the ADCPs were converted to netCDF 

format and checked for clock accuracy by comparing in-and-out-of-water times to the mooring 

log and by checking for linear time progression. Data were despiked, with gaps replacing bad 

data points. The clock, ADCP calibrations, and internal compass were compared to nearby 

instruments for consistency. Data from the four beams were compared in pairs for symmetry and 

checked for high-intensity reflections indicative of fish or other beam obstructions. Bad values 

were masked both manually and automatically and, where possible, a three-beam solution was 

used to fill in gaps caused by a compromised beam. Data above the water surface were masked; 

because the water depth at the site varies with the stage of the tide, there are periods where some 

bins above the water surface are retained within the file. Data collected before the instrument 

was on the seafloor or after recovery were trimmed off. Finally, the data from beam coordinates 

were rotated into geographic coordinates. The final processed versions of these data were stored 

in EPIC-compliant format. 
22

Acoustic Doppler Velocimeter (ADV) Data 

The ADVs were set to record velocities in instrument coordinates, which were rotated 

into earth coordinates using data from the internal compass and tilt sensor. In addition to 

velocities, the ADV logged data on the amplitude and correlation of the return signal, sound 

speed, range to boundary, compass and tilt, pressure (from an external Paroscientific Digiquartz 

pressure gauge connected to the ADV), and the external optical sensors. Data from each ADV 

(and the attached external sensors) was logged by an individual Sontek Hydra datalogger and 

stored in binary format. The data in these files were processed using a series of Matlab routines 

in the Hydratools toolbox developed by the USGS (Martini and others, 2005). 

Optical Backscatter Sensor (OBS) Data 

The Sontek Hydra data logger converted raw OBS voltage measurements to counts with a 

14-bit analog-digital converter. Counts were converted to volts (a linear conversion) during 

processing so that the data could be calibrated to sediment concentration from laboratory-derived 

calibration coefficients. The data are available in the .nc file for the instrument to which the OBS 

was connected. 

Transmissometer Data 

The Sontek Hydra data loggers also logged transmissometer data in counts; a linear 

conversion was necessary to convert counts to volts. The Seabird SeaCAT and the RBR 

Brancker loggers, however, logged the raw voltage. The transmissometer data can be presented 

either as percentage of light transmission (from 0 to 100, the former being completely occluded) 

or in terms of beam attenuation in units of 1/m (utilizing another linear conversion with the 

instrument pathlength). The advantage of presenting the data as 1/m is that values increase as the 

suspended load increases, and these values are independent of the light pathlength. The final data 

are available in the .nc file for the instrument with which the transmissometer was deployed 

(ADV, PCADP, or Seacat). 

MicroCAT (MC) 

Software provided by SeaBird Electronics was used to convert the time series of raw 

conductivity measurements recorded by the MicroCATs into salinity. The SeaBird software also 

was used to calculate water density from the temperature and salinity measurements. The data 

were converted to ASCII format and then translated to netCDF. Data were despiked and gaps 

were filled by interpolation where possible. The clock and calibrations were compared to nearby 

instruments for consistency. Processed versions of these data files are available in EPICcompliant netCDF format. 

Additional Data-Collection Resources

Additional data from the study area were collected by agencies unassociated with this 

project, and these data are available from the collecting agencies. These data sources and their 

links are identified below. Because the USGS and its partners did not collect these data, 

information about the accuracy or availability of these data cannot be provided here. 

Furthermore, although the Web-based links listed below were current at the time of publication 

of this report, they may be modified or removed in the future. 

Weather and Hydrology

Ocean and meteorological-condition data collected during the Demonstration Project are 

available through NOAA’s National Data Buoy Center (NDBC), the Scripps Institution of 

Oceanography’s Coastal Data Information Program (CDIP), and the International Boundary 
23

Water Commission (IBWC). The NDBC (http://www.ndbc.noaa.gov/) provides weather and 

ocean observations from numerous stations within the region, including the following buoys: 

Station 46086–San Clemente Basin, California (32.491° N, 118.034° W), 

Station 46232–Point Loma South, California (32.530° N, 117.431° W), and 

Station 46231–Mission Bay, California (32.748° N, 117.370° W). 

The NDBC also provides land-based weather-station data, including Station TIQC1–Oneonta 

Slough, Tijuana River Reserve, California (32.568° N, 117.131° W), which is owned and 

maintained by the National Estuarine Research Reserve System. 

During the Demonstration Project, the CDIP program (http://cdip.ucsd.edu/) operated a 

directional wave buoy near the study area. Directional wave data from this buoy are available 

from the CDIP Web site under Station 155–Imperial Beach Nearshore, California (32.5695° N, 

117.1691° W). The Imperial Beach Nearshore buoy was decommissioned in January 2010. 

Water-discharge data for the Tijuana River were collected at the United States-Mexico 

International Border at Station 11-0133.00 by the IBWC. These data are are tabulated and 

available from the Water Data Web site of the IBWC 

(http://www.ibwc.state.gov/Water_Data/rtdata.htm). 

Beach Topographic Mapping

The USGS funded the SIO Southern California Beach Processes Study (SCBPS) 

(http://cdip.ucsd.edu/SCBPS/) to do topographic mapping of the study area beach for the 

duration of the 2008–2009 Demonstration Project. Unfortunately, the SIO group was not able to 

collect topographic data for the duration of the Demonstration Project. The data collected are 

available at the SCBPS Web site (http://cdip.ucsd.edu/SCBPS/?nav=data). 

References Cited

Côté, J.M., Hotchkiss, F.A., Martini, M., and Denham, C.R., 2011, Acoustic Doppler Current 

Profiler (ADCP) data processing system manual: U.S. Geological Survey Open-File 

Report 00–458, v. 4, 51 p. (also available at: http://pubs.usgs.gov/of/2000/of00-458/). 

Farnsworth, K.L., and Warrick, J.A., 2007, Sources, dispersal, and fate of fine sediment supplied 

to coastal California: U.S. Geological Survey Scientific Investigations Report 2007–

5254, 77 p. 

Flick, R.E., 1993, The myth and reality of southern California beaches: Shore & Beach, v. 61, 

no. 3, p. 3–13. 

Folk, R.L., and Ward, W.C., 1957, Brazos River bar—a study in the significance of grain size 

parameters: Journal of Sedimentary Petrology, v. 27, p. 3–26. 

Fowlera, S.W., 1990, Critical review of selected heavy metal and chlorinated hydrocarbon 

concentrations in the marine environment: Marine Environmental Research, v. 29, no. 1, 

p. 1–64. 

Inman, D.L., 1952, Measures for describing the size distribution of sediments: Journal of 

Sedimentary Petrology, v. 22, no. 3, p. 125–145. 

Inman, D.L., 1976, Summary report of man’s impact on the California coastal zone: Prepared for 

the State of California Department of Navigation and Ocean Development, 150 p. 

Inman, D.L., and Jenkins, S.A., 1999, Climate change and the episodicity of sediment flux of 

small California rivers: Journal of Geology, v. 107, no. 3, p. 251–270. 
24

Kuhn, G.G., and Shepard, F.P., 1984, Sea cliffs, beaches, and coastal valleys of San Diego 

County—Some amazing histories and some horrifying implications: Berkeley, University 

of California Press, 194 p. (also available at http://ark.cdlib.org/ark:/13030/ft0h4nb01z/). 

Martini, M., Sherwood, C., Horwitz, R., Ramsey, A., Lightsom, F., Lacy, J., and Xu, J., 2005, 

Hydratools manual version 1.0, documentation for a MATLAB®-based post-processing 

package for the Sontek Hydra: U.S. Geological Survey Open-File Report 2005–1026 

(also available at: http://pubs.usgs.gov/of/2005/1026/). 

Montgomery, E.T., Martini, M.A., Lightsom, F.L., and Butman, B., 2008, Documentation of the 

U.S. Geological Survey oceanographic time series measurement database: U.S. 

Geological Survey Open-File Report 2007–1194 (also available at:

http://pubs.usgs.gov/of/2007/1194/). 

Noble, M., and Xu, J., 2004, Coastal circulation and transport patterns; The likelihood of 

OCSD’s plume impacting Huntington Beach shoreline: U.S. Geological Survey Open 

File Report 2004–1019, 342 p. (also available at: http://pubs.usgs.gov/of/2004/1019/). 

Olsen, C.R., Cutshall, N.H., and Larsen, I.L., 1982, Pollutant—particle associations and 

dynamics in coastal marine environments—a review: Marine Chemistry, v. 11, no. 6, p. 

501–533. 

Rubin, D.M., Chezar, H., Harney, J.N., Topping, D.J., Melis, T.S., and Sherwood, C.R., 2007, 

Underwater microscope for measuring spatial and temporal changes in bed-sediment 

grain size: Sedimentary Geology, v. 202, no. 3, p. 402–408. 

San Diego Association of Governments (SANDAG), 2012, San Diego Regional Sand Project—

Fact Sheet: San Diego, Calif., SANDAG, 2 p. (also available at: 

http://www.sandag.org/uploads/publicationid_340_1057.pdf). 

Svejkovsky J., Nezlin, N.P., Mustain, N.M., and Kum, J.B., 2010, Tracking stormwater 

discharge plumes and water quality of the Tijuana River with multispectral aerial 

imagery: Estuarine, Coastal and Shelf Science, v. 87, no. 3, p. 387–398. 

Trask, P.D., 1932, Origin and environment of source sediments of petroleum: Houston, Tex., 

Gulf Publishing Co., 323 p. 

Unesco, 1981, The practical salinity scale 1978 and the international equation of state of 

seawater 1980: Technical Paper of Marine Science, v. 36, 25 p. 

Zedler, J.B., Nordby, C.S., and Kus, B.K., 1992, The ecology of Tijuana Estuary—A national 

estuarine research reserve: Washington, D.C., National Oceanic and Atmospheric 

Administration, Office of Coastal Resource Management, Sanctuaries and Reserves 

Division, 104 p. 

Appendixes

Appendix 1 – Sediment grain-size distribution data from the pre-placement 

stockpile. 

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_1/) 

Grain size distribtion data from the stockpile sediment samples are provided in the 

workbook: Appendix_1_Results. There are three sheets within this file: 
25

Progress – A summary of the completion dates for the laboratory methods utilized for 

these analyses. 

Weights – Raw weights and computed weight-based percentages of the sediment samples 

from grain-size sieving. 

SDSZ – The integrated grain-size distribution results for the sediment samples. Results 

are presented in the weight-based percentage of sample in 0.25-phi classes. In addition to these 

results, a number of sediment statistics were calculated using the USGS SEDSIZE software. 

Further details about SEDSIZE can be found at http://water.usgs.gov/cgibin/man_wrdapp?sedsize. Grain-size statistics generated by SEDSIZE include: 

-percentage of gravel (>2 mm) by weight, 

-percentage of sand (0.063–2 mm) by weight, 

-percentage of silt (0.004–0.063 mm) by weight, 

-percentage of clay (<0.004 mm) by weight, 

-percentage of mud (combined silt and clay) by weight, 

-various ratios of the grain-size classes described above, and 

-statistical measures of the grain-size distributions made by using techniques suggested 

by Folk and Ward (1957), Inman (1952), and Trask (1932). 

Appendix 2 – Sediment grain-size distribution data from seafloor samples. 

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_2/) 

Grain-size distribtion data from the seafloor sediment samples are provided in two Excel 

spreadsheets, one for each sampling phase of this project (pre-project and Phase II). Seafloor 

samples were not collected during Phase I of the project. The data files are named 

Appendix_2_Results_PhaseIIt and Appendix_2_Results_PreProject. These files have three 

worksheets: 

Progress – A summary of the completion dates for the laboratory methods utilized for these 

analyses. 

Weights – Raw weights and computed weight-based percentages of the sediment samples 

from grain-size sieving. 

SDSZ – The integrated grain-size distribution results for the sediment samples. Results are 

presented in the weight-based percentage of sample in 0.25-phi classes. In addition to 

these results, a number of sediment statistics were calculated using the USGS SEDSIZE 

software. Further details about SEDSIZE can be found at http://water.usgs.gov/cgibin/man_wrdapp?sedsize. Grain-size statistics generated by SEDSIZE include: 

-percentage of gravel (>2 mm) by weight, 

-percentage of sand (0.063–2 mm) by weight, 

-percentage of silt (0.004–0.063 mm) by weight, 

-percentage of clay (<0.004 mm) by weight, 

-percentage of mud (combined silt and clay) by weight, 

-various ratios of the grain-size classes described above, and 

-statistical measures of the grain-size distributions made by using techniques 

suggested by Folk and Ward (1957), Inman (1952), and Trask (1932). 

In addition, the pre-project file includes the following worksheet: 

Sampling_Notes – A summary of the sample dates, sample location (latitude, longitude, 

relative location on the beach), and the laboratory methods utilized for these analyses. 
26

Appendix 3 – Sediment grain-size distribution data from beach samples. 

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_3/) 

Grain-size distribtion data from the beach-sediment samples obtained during the preproject and Phase II of the project are provided in two workbooks named: 

Appendix_3_Results_PhaseII and Appendix_3_Results_PreProject. Both files contain the 

following worksheets: 

Weights – Raw weights and computed weight-based percentages of the sediment samples 

from grain-size sieving. 

SDSZ – The integrated grain-size distribution results for the sediment samples. Results are 

presented in the weight-based percentage of sample in 0.25-phi classes. In addition to 

these results, a number of sediment statistics were calculated using the USGS SEDSIZE 

software. Further details about SEDSIZE can be found at http://water.usgs.gov/cgibin/man_wrdapp?sedsize. Grain-size statistics generated by SEDSIZE include: 

-percentage of gravel (>2 mm) by weight, 

-percentage of sand (0.063–2 mm) by weight, 

-percentage of silt (0.004–0.063 mm) by weight, 

-percentage of clay (<0.004 mm) by weight, 

-percentage of mud (combined silt and clay) by weight, 

-various ratios of the grain-size classes described above, and 

-statistical measures of the grain-size distributions made by using techniques 

suggested by Folk and Ward (1957), Inman (1952), and Trask (1932). 

In addtion, the pre-project file contains the following worksheet: 

Sampling_Notes – A summary of the sample dates, sample locations (latitude, longitude, 

relative location on the beach), and the laboratory methods utilized for these analyses. 

The Phase II file contains the following additional worksheets: 

Progress – A summary of the completion dates for the laboratory methods utilized for these 

analyses. 

Pit Details – Sample location information, including sample depth and along-trench distance. 

Appendix 4 – Suspended-sediment concentration and grain-size 

distribution data from beach-swash samples.

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_4/) 

Suspended-sediment concentration and grain-size distribtion data from the swash-water 

samples are provided in two workbooks named Appendix_4_Results_PhaseI and 

Appendix_4_Results_PhaseII. There are two sheets within these files: 

Weights – Raw weights and computed weight-based percentages of the suspendedsediment samples from grain-size sieving. 

SDSZ – The integrated grain-size distribution results for the fine fractions of the 

suspended-sediment samples. Results are presented in the weight-based percentage of sample in 

0.25-phi classes. In addition to these results, a number of sediment statistics were calculated 

using the USGS SEDSIZE software. Further details about SEDSIZE can be found at 

http://water.usgs.gov/cgi-bin/man_wrdapp?sedsize. Grain-size statistics generated by SEDSIZE 

include: 

-percentage of gravel (>2 mm) by weight, 
27

-percentage of sand (0.063 – 2 mm) by weight, 

-percentage of silt (0.004 – 0.063 mm) by weight, 

-percentage of clay (<0.004 mm) by weight, 

-percentage of mud (combined silt and clay) by weight, 

-various ratios of the grain-size classes described above, and 

-statistical measures of the grain-size distributions made by using techniques suggested 

by Folk and Ward (1957), Inman (1952), and Trask (1932). 

Appendix 5 – Conductivity-temperature depth (CTD) and optical turbidity 

measurements from small vessel water sampling. 

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_5/) 

The CTD data from both Phase I and II of the Demonstration Project are provided in raw 

text files (.cnv files). Each file includes all samples from one CTD cast, including the initial 

samples at the water surface, the downcast, and the upcast. These files are organized by sample 

date, and each complete sampling of the stations is provided in an unique folder. The folder 

names have the following format: CTD_ YYYY_ MM_DD, where: 

YYYY is the year, 

MM is the numerical month, and 

DD is the numerical day of the month. 

Each file within these folders represents the entire CTD cast for one station. The station 

name (for example, C08, D14, and Buoy-N) is given in each file name. 

The downcast CTD data from Phase II of the Demonstration Project also were depth 

averaged using a 0.25 m interval and compiled with station latitude and longitude in structured 

arrays within Matlab (.mat) files. These depth-averaged data are available in the 

Appendix_5_Results_CTD_PhaseII folder. Each file contains a complete sampling of all of the 

stations, which typically encorporates all of the sampling from a single day. Three files are 

available for the September 30, 2009, because the stations were sampled three complete times. 

Within each file the sampling data are stored within a structured array entitled ctdBin that 

includes the following fields: 

name–the original raw data file name, 

station–coastal sampling station, 

varlable–the original CTD sample variables recorded, 

spans–the length of sample record averaged, 

samp_interval–the depth interval in meters for averaging, 

mtime–the Matlab time of the beginning of sampling, 

gtime–the calendar time of the beginning of sampling [year month day hour minute 

second], 

sensors–names of sensors sampled, 

latitude–latitude of station in decimal degrees, 

longitude–longitude of station in decimal degrees, 

tzone–the time zone of sampling, 

timeJ–time of sample in Julian days, 

timeS–time of sample in seconds after the sensor turned on, 

prdM–average pressure of samples in dbar, 

depSM–average depth of samples in meters, 
28

c0S–average conductivity of samples in microSiemens per meter, 

sal00–average salinity of samples in practical salinity units (psu), 

tv290C–average temperature of samples in degrees Celsius, 

density00–average density of of samples in kilograms in cubic meters, 

v0–average voltage of the tramissometer external sensor (channel #0), 

bat–average beam attenuation of the transmissometer sensor in meters-1, 

v2–average voltage of the optical backscatterance external sensor (channel #3), 

flag–‘NaN’ if no data available for averaging, ‘0’ if adequate data for averaging, 

scan–average number of the sequential scan since the CTD was turned on, and 

dep_reg–midpoint of the 0.25-meter depth averaged bins. 

For more information about the .mat file format, please see Mathworks at 

www.mathworks.com. Note that NaN within any of these fields represents ‘not a number’ and is 

utilized for fields in which no data were recorded or available. 

Appendix 6 – Suspended-sediment concentration measurements from 

small vessel water sampling. 

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_6/) 

Suspended-sediment concentration data from the coastal surface-water samples are 

provided in the workbook named Appendix_6_Results. There is one sheet within this file that 

provides the raw weights and computed weight-based percentages of the suspended-sediment 

samples from grain-size sieving. 

Appendix 7 – Remote-sensing imagery. 

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_7/) 

Digital data from the remote-sensing images are provided in the 

Appendix_7_Remote_Sensing_Imagery_PhaseII folder. The raw data files are large, 

approximately 55 MB for the thermal infrared (TIR) images and 110 MB for the red, green, blue 

(RGB) images. Because of these large file sizes, smaller TIFF files of these images are provided 

in the Imagery_Clips folder. These TIFF files are named using the following convention: 

YYYY_MM_DD_XXX, where YYYY is the year, MM is the numeric month, DD is the day of the 

month, and XXX is the image type (‘rgb’ or ‘TIR’). Note that two images were collected on 

September 23, 2009, and these are labeled A and B for the early and late flights, respectively. 

Raw data are provided in the Imagery_ALL folder. Before accessing these data, please 

review the metadata provided for both the RGB data (dmsc_xxxxxx_rgb_metadata.htm) and the 

TIR data (tir_xxxxxx_rgb_metadata.htm). These metadata files have complete information 

about image acquisition and processing. Each individual image has three files: a full resolution 

TIFF file (.tif), a full resolution raster file (.rrd), and an auxiliary information file associated with 

the image (.aux). These files are named with the following convention: 

ZZZ_MMDDYY_XXX.YYY, where ZZZ is the sensor type (‘dmsc’ for the multispectral sensor, 

‘tir’ for the thermal infrared sensor), MM for the numeric month, DD for the day of the month, 

YY for the last two digits of the year (‘09’ for 2009), XXX for the image type (‘rgb’ or ‘tir’), and 

YYY for the file type as noted above. For further information about these images and imagery 

data, see the metadata. 
29

Appendix 8 – Oceanographic data. 

(Files available at 

http://pubs.usgs.gov/of/2012/1083/of2012-1083_appendixes/of2012-1083_appendix_8/) 

The oceanographic data from the tripods and buoys are organized by phase of the 

Demonstration Project and mooring ID. All data from a specific mooring are contained with a 

separate folder. The folder names are the mooring IDs and have the following format: 

PPPYYMMM, where 

PPP is the project (“TJR” for all), 

YY is the final two digits of the year (“08” or “09”), and 

MMM is the mooring number, where 

the first digit is the location (“N” for northern, “C” for central, “S” for southern), 

 the second digit is the mooring number at that location, and 

 the third digit denotes the type of mooring (“T” for benthic tripod, “S” for surface 

buoy). 

The data are stored in the netCDF format as noted above in this report, and metadata and 

information about measurement units and sampling intervals are provided in each file. 

Information about the netCDF file format can be found in Montgomery and others (2008). File 

names have the following format: PPPYYMMMNNFF.nc, where 

PPPYYMMM is the mooring ID as noted above, 

NN is the sequential file number from this mooring (“01”, “02”, etc. to the total number 

of files), and 

FF is the instrument and data type, including: 

 “adv2s-cal” for SonTek/YSI ADV-O current measurements and concurrent OBS 

and/or transmissometer data, 

“aq-cal” for calibrated Nortek AS Aquadopp current meter data, 

“aw-cal” for Nortek AWAC current data and concurrent OBS data, 

 “awWvs-p” for Nortek AWAC directional wave data, 

 “ls-s” for Sequoia Scientific Inc. LISST-100X data, 

 “mc” for Seabird microcat CTD, 

 “nx” for the Falmouth Scientific, Inc. (now part of Teledyne RDI) Non-eXternal 

Inductive Cell (NXIC) CTD, and 

 “wh” for Teledyne RDI ADCP currents.