U.S. Department of the Interior

U.S. Geological Survey

Data Series 745

Prepared in cooperation with Coastal Protection and Restoration Authority of Louisiana, U.S. 

Army Corps of Engineers, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, 

Natural Resources Conservation Service, and National Oceanic and Atmospheric Administration

Classifications for Coastal Wetlands Planning, Protection 

and Restoration Act Site-Specific Projects: 2010

Classifications for Coastal Wetlands 

Planning, Protection and Restoration Act 

(CWPPRA) Site-Specific Projects: 2010

By William R. Jones and Adrienne Garber

Prepared in cooperation with Coastal Protection and Restoration Authority of 

Louisiana, U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, 

U.S. Fish and Wildlife Service, Natural Resources Conservation Service, and 

National Oceanic and Atmospheric Administration

Data Series 745

U.S. Department of the Interior

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

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2013

This and other USGS information products are available at http://store.usgs.gov/

U.S. Geological Survey

Box 25286, Denver Federal Center

Denver, CO 80225

To learn about the USGS and its information products visit http://www.usgs.gov/

1-888-ASK-USGS

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 materials contained within this report.

Suggested citation:

Jones, W.R., and Garber, Adrienne, 2013, Classifications for Coastal Wetlands Planning, Protection and Restoration 

Act (CWPPRA) site-specific projects—2010: U.S. Geological Survey Data Series 745, 8 p. and 10 maps.,

http://pubs.usgs.gov/ds/745/. 
iii

Contents

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

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

Monitoring Program Overview ....................................................................................................................1

Program Description ............................................................................................................................2

Program Goals.......................................................................................................................................4

Project Types Requiring Monitoring ..................................................................................................4

Freshwater Introduction and Diversion ...................................................................................4

Sediment Diversion ....................................................................................................................4

Outfall Management....................................................................................................................4

Marsh Management....................................................................................................................5

Hydrologic Restoration ...............................................................................................................5

Beneficial Use of Dredged Material/Marsh Creation ............................................................5

Shoreline Protection ...................................................................................................................5

Barrier Island Restoration..........................................................................................................5

Vegetative Planting......................................................................................................................5

Sediment and Nutrient Trapping ...............................................................................................5

Methods...........................................................................................................................................................5

Habitat Monitoring ...............................................................................................................................5

Aerial Photography Covering CWPPRA Project Areas .........................................................6

Geospatial Analysis............................................................................................................6

Acquisition of Photography........................................................................................................6

Processing of Imagery................................................................................................................6

Photointerpretive Classification of Imagery............................................................................6

Land-Water Classification.................................................................................................6

Habitat Classification .........................................................................................................7

Use of Reference Areas ......................................................................................................................7

Conclusion.......................................................................................................................................................8

References......................................................................................................................................................8

Figures

1. Map showing locations of Coastal Wetlands Planning, Protection

and Restoration Act projects across coastal Louisiana for which

site-specific 2010 classification maps were produced..........................................................3

Tables

1. Site-specific classification maps for Coastal Wetlands Planning,

Protection and Restoration Act projects across coastal Louisiana, 2010 ..........................2
iv

Conversion Factors

Inch/Pound to SI

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

yard (yd) 0.9144 meter (m)

Area

acre 4,047 square meter (m2

)

acre 0.4047 hectare (ha)

acre 0.4047 square hectometer (hm2

) 

acre 0.004047 square kilometer (km2

)

Volume

cubic yard (yd3

) 0.7646 cubic meter (m3) 
Classifications for Coastal Wetlands Planning, Protection 

and Restoration Act (CWPPRA) Site-Specific Projects: 2010

By William R. Jones1 and Adrienne Garber2

Abstract

The Coastal Wetlands Planning, Protection and 

Restoration Act (CWPPRA) funds over 100 wetland 

restoration projects across Louisiana. Integral to the success of 

CWPPRA is its long-term monitoring program, which enables 

State and Federal agencies to determine the effectiveness of 

each restoration effort. One component of this monitoring 

program is the classification of high-resolution, color-infrared 

aerial photography at the U.S. Geological Survey’s National 

Wetlands Research Center in Lafayette, Louisiana.

Color-infrared aerial photography (9- by 9-inch) is 

obtained before project construction and several times after 

construction. Each frame is scanned on a photogrametric 

scanner that produces a high-resolution image in Tagged 

Image File Format (TIFF). By using image-processing 

software, these TIFF files are then orthorectified and 

mosaicked to produce a seamless image of a project area and 

its associated reference area (a control site near the project that 

has common environmental features, such as marsh type, soil 

types, and water salinities.) The project and reference areas 

are then classified according to pixel value into two distinct 

classes, land and water. After initial land and water ratios have 

been established by using photography obtained before and 

after project construction, subsequent comparisons can be 

made over time to determine land-water change. 

Introduction

In response to accelerated wetland loss in Louisiana, 

in 1989 the State of Louisiana adopted Act 6 (La. revised 

statute [RS] 49:213.1) of the Second Extraordinary Session 

of the Louisiana State Legislature. This State legislation 

was followed by Federal legislation in 1990 when the 

1

U.S. Geological Survey

2

Five Rivers, LLC, for the U.S. Geological Survey

U.S. Congress passed the Coastal Wetlands Planning, 

Protection, and Restoration Act (CWPPRA; Public Law 

101-646, Title III [16 USC 3951]). Together these acts 

have facilitated conservation, restoration, creation, and 

enhancement of coastal wetlands in Louisiana. The agencies 

responsible for designing and implementing coastal 

conservation and restoration projects include the Coastal 

Protection and Restoration Authority (CPRA) of Louisiana, 

U.S. Department of Commerce, U.S. Department of 

Agriculture, U.S. Department of the Interior, U.S. Department 

of the Army, and the U.S. Environmental Protection Agency.

As part of the monitoring program implemented to 

assess the ongoing success of the CWPPRA legislation, 

scientists at the National Wetlands Research Center (NWRC) 

of the U.S. Geological Survey (USGS; U.S. Department of 

Interior) produce land-water and habitat classification maps 

to help assess and document environmental changes related 

to CWPPRA projects. The maps included in the current report 

(table 1) compose the 2010 collection of maps documenting 

data acquired at CWPPRA projects across coastal Louisiana 

(fig. 1). These maps are produced as deliverables to the CPRA 

of Louisiana, which represents the interests of the State. 

Monitoring Program Overview

As part of CWPPRA legislation, an interagency task 

force was created and charged with the development and 

implementation of a comprehensive approach to the longterm conservation and restoration of coastal wetlands. The 

restoration plans developed pursuant to CWPPRA and 

coordinating State legislation specifically require evaluation of 

the effectiveness of each coastal wetlands restoration project 

in achieving long-term solutions to arresting coastal wetlands 

loss. Evaluating these projects required the development of a 

monitoring program to adequately assess their effectiveness. 

The named agencies have a responsibility to the State of 

Louisiana and to the Nation to develop a monitoring program 

that will effectively ensure the best use of State and Federal 

funds for the restoration and conservation of wetlands.
2 Classifications for Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) Site-Specific Projects: 2010

Because the mission of CWPPRA is to provide 

appropriate management plans for the Louisiana coastal zone 

over the next 50–100 years, long-term monitoring protocols 

need to be applied on a regional scale to provide the data 

necessary for effective management and planning. As part of 

the legislation, CWPPRA required that a report containing 

a scientific evaluation of the effectiveness of the restoration 

project be submitted to Congress no more than three years 

after the completion and submission of the restoration plan 

and at least every three years thereafter. CWPPRA has now 

dedicated resources to the monitoring program for 20 years.

Program Description

The CWPPRA Monitoring Program was developed by 

Monitoring Working Group (MWG) by using a broad-based, 

standardized approach. Steyer and others (1992) provide 

a guidance document that can be used to develop projectspecific and basin-wide monitoring plans and cost estimates. 

The monitoring protocols developed by Steyer and Stewart 

(1992) call for broadly categorizing project types, goals, 

and biological variables and standardizing data collection 

methodologies by using a matrix design. The protocols 

were developed by subgroups of technical experts for seven 

categories of monitoring variables, including water quality, 

hydrology, soils and sediments, vegetative health, habitat 

mapping, wildlife, and fisheries. This organization provides 

accessibility to three levels of information—project type, 

category of variable, and variable—that are cross-referenced 

and ranked to guide personnel in the development of 

appropriate monitoring plans. 

The CWPPRA Monitoring Program develops monitoring 

plans and collects data on individual projects on the basis 

of specific project goals and objectives. The framework 

within which the plans are developed is based on a basinlevel approach. Monitoring efforts for all projects within a 

given hydrologic basin are coordinated in order to adequately 

address secondary or cumulative effects of projects.

Monitoring plans for CWPPRA projects are developed 

on the basis of the minimum number of monitoring variables 

necessary to provide sufficient information to determine if 

project goals and objectives are being met. A subset of the 

variables that are essential to any given project includes those 

that generally will be measured for all project types; however, 

some of the highest priority variables may not be monitored 

because of limited availability of funds. According to project 

type, MWG determines which variables are essential in 

judging project effectiveness and which additional variables 

may need to be monitored on the basis of project objectives 

and possible impacts. This list does not preclude other 

variables from being monitored if determined necessary by 

Technical Advisory Group (TAG). 

The importance of a sound quality assurance (QA) 

program is acknowledged by CWPPRA and is addressed 

in the overall program goals. It is specific policy that all 

environmentally related measurements collected by personnel 

of CPRA and USGS NWRC are of known and documented 

quality. This level of assurance is necessary because vast 

quantities of data are collected. Classification of this data will 

ultimately assist in decision making regarding project- and 

program-level effectiveness; therefore, it is critical that it be of 

the highest quality.

Table 1. Site-specific classification maps for Coastal Wetlands Planning, Protection and Restoration Act projects across coastal 

Louisiana,2010.

[Project maps are listed in geographical order from west to east. Each project is named according to the hydrologic basin in which it is located. The following 

abbreviations are for the hydrologic basins of Louisiana, a map of which is available from the Louisiana Coastal Wetlands Planning, Protection and Restoration 

Act Program (n.d.): CS, Calcasieu/Sabine; TV, Teche/Vermilion; PO, Pontchartrain]

Project 

number Project name Year ofclassification

Type of

classification

Size of map,

in inches

CS–27 Black Bayou Hydrologic Restoration 2010

2010

2010

Land-water

Photomosaic

Photomosaic and

Land-water

8.5 by 11 

8.5 by 11

58 by 30

CS–30 GIWW-Perry Ridge West Bank Stabilization 2005 and 2010

2005 and 2010

2010

2010

Land-water

Land-water

Photomosaic

Land-water

34 by 46

11 by 17

11 by 8.5

11 by 8.5

TV–18 Four Mile Canal Terracing and Sediment Trapping 2010

2010

Land-water

Land-water

8.5 by 11

32 by 34

PO–06 Fritchie Marsh Restoration 2010 Land-water 11 by 8.5
CS-27 Black Bayou Hydrologic Restoration 

CS-30 GIWW-Perry Ridge West Bank Stabilization 

TV-18 Four Mile Canal Terracing and Sediment Trapping

PO-06 Fritchie Marsh Restoration

Lake 

Pontchartrain

Vermilion

Bay

Gulf of Mexico

White 

Lake

Atchafalaya Bay

0 50 

0 50 100 KILOMETERS

Figure 1. Locations of Coastal Wetlands Planning, Protection and Restoration Act projects across coastal Louisiana for which site-specific 2010 clasproduced. (See table 1 for project naming conventions and further information on associated map products.)
4 Classifications for Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) Site-Specific Projects: 2010

Program Goals

Monitoring of projects implemented from the CWPPRA 

restoration plan must result in the following products:

• “An evaluation of the effectiveness of each coastal 

wetlands restoration project in achieving longterm solutions to arresting coastal wetlands loss in 

Louisiana” (U.S. Congress, 1990, Sec. 303 [b][4][L]), 

and

• “A scientific evaluation of the effectiveness of the 

coastal wetlands restoration projects carried out 

under the plan in creating, restoring, protecting and 

enhancing coastal wetlands in Louisiana” (U.S. 

Congress, 1990, Sec. 303[b][7]).

In order for the above mandates to be achieved, 

the monitoring efforts must generate results that aid in 

determining the effectiveness of existing projects, the 

beneficial modification of existing projects, and the design 

of future projects. Most importantly, monitoring data 

collected from existing projects must support future decisions 

on selection of projects proposed for creating, restoring, 

protecting, and enhancing the coastal wetlands of Louisiana. 

Comparison of results among projects of similar types is a way 

to determine which projects are most effective in achieving 

long-term solutions to arresting coastal wetlands loss.

The collection, analysis, and interpretation of highquality ecological, hydrological, and climatological data 

are critical steps to the success of monitoring efforts and 

the mission of CWPPRA. These steps are achieved by 

implementing the following practices:

1. Pragmatic data collection methods based on specific 

goals and objectives and developed by using sound 

experimental design, 

2. Unbiased evaluation of data to determine the effectiveness 

of wetland projects, 

3. Documentation and dissemination of project data, and 

4. Evaluation of program effectiveness as the knowledge and 

technology base expands. 

Fulfillment of the mission results in appropriate 

management decisions that ultimately result in the creation, 

restoration, protection, and enhancement of the coastal 

wetlands of Louisiana.

Project Types Requiring Monitoring

Under Act 6 of the Louisiana legislature (La. revised 

statute [RS] 49:213.1) and CWPPRA, all projects were 

categorized into ten types, including freshwater introduction 

and diversions, sediment diversions, outfall management, 

marsh management, hydrologic restoration, beneficial use of 

dredged material/marsh creation, shoreline protection, barrier 

island restoration, vegetative planting, and sediment and 

nutrient trapping.

A critical step in establishing a successful monitoring 

program is defining the goals of the management project. For 

example, a project using dredged material may be built to 

reduce wave energies and consequential physical erosion or 

to develop a new soil and sediment base at a proper elevation 

to restore or maintain vegetated marsh. Each of these projects 

begins with a hypothesis or set of hypotheses related to 

the expected change in physical, biological, or chemical 

variables of the project area. These hypotheses then guide the 

monitoring program as to which variables will be monitored 

and how frequently.

Freshwater Introduction and Diversion

Freshwater introduction and diversion projects are 

designed to introduce fresh water and alluvial material from 

available sources to shallow marsh estuaries. Areas targeted 

for freshwater diversion projects are characterized by saltwater 

intrusion, sediment subsidence, and shoreline erosion. The 

primary goal of these projects is to enhance proximal wetlands 

by increasing the availability of fresh water, nutrients, and 

sediment that will be provided by the freshwater diversions. 

Management of the outfall will route the fresh water through 

the wetlands and provide greater deposition of sediments 

in the marsh to offset subsidence, increase availability of 

nutrients to vegetation, and create a more gradual release of 

fresh water to the benefit of wildlife, fish, and shellfish. 

Sediment Diversion 

Sediment diversions are projects that increase 

deposition—through sediment accretion—of river-borne 

sediment in shallow bay areas that cannot keep pace with 

the rate of subsidence. A small-scale sediment diversion 

project is designed around the concept of natural crevassesplay development. Where a breach occurs in the bank of 

a river, sediment infilling begins within the surrounding 

distributary bays, and crevasse-splay sediment eventually 

becomes subaerial and established with marsh vegetation. 

Large-scale sediment diversions on the Mississippi River are 

designed to be similar to large natural crevasses, such as the 

one at Baptiste Collette, La. The primary goal of the project 

is to create and manage crevasses through the natural levee 

ridges of rivers and major distributaries so that the natural 

land-building process can create emergent and submergent 

aquatic communities critical to the overall productivity of 

the deltaic systems. 

Outfall Management

Outfall management projects are used to maximize the 

benefits of a river diversion project. This technique involves 

regulating water levels and direction of water flow to increase 

the dispersion and retention time of fresh water, nutrients, and 

sediment in the marsh. The water flow may be regulated by a 

combination of gates, locks, weirs, canal plugs, and gaps cut in 

artificial levee banks.
Methods 5

Marsh Management

In marsh management projects, engineered structures 

actively manipulate local hydrology to control water levels 

and salinity, while concurrently allowing ingress and egress 

of marine organisms. Marsh management plans generally 

incorporate existing canal spoil banks, the construction of 

short levees to connect these spoil banks, the installation of 

water control structures, and/or the construction of pumps 

and other control structures to introduce fresh water into the 

managed area and keep out saline water. The main goals of 

marsh management are to minimize the loss of and promote 

the growth of emergent and submergent plant communities 

by reducing salinities, stabilizing water levels, and restricting 

tidal exchange. 

Hydrologic Restoration

Hydrologic restoration projects typically are designed 

to reestablish former hydrologic pathways and flow regimes, 

with the goal of redistributing fresh water to influence 

water levels and salinity. Specifically, hydrologic restoration 

projects tend to reduce rapid tidal fluctuations and improve 

freshwater retention. These manipulations of the local 

hydrology aid in the reestablishment of emergent and 

submergent plant communities. 

Beneficial Use of Dredged

Material/Marsh Creation

Open-water bodies and navigational channels are 

often sources of dredged sediment material that could be 

beneficially used to create vegetated wetlands or to restore 

areas of deteriorating marsh. Sediment can be pumped 

into confined or nonconfined areas to a height conducive 

to marsh development. Once the dredged material settles, 

growth of emergent vegetation can be promoted. 

Shoreline Protection

Shoreline protection projects use structural and 

nonstructural measures, such as breakwaters, bulkheads, 

revetments, longyard tubes, wave-damping fences, and 

levees, to reduce wave energies and erosive action. Critical 

shoreline areas threatened with hydrological breaches can 

be protected to prevent wave erosion and water exchange 

from jeopardizing the physical integrity of the shoreline 

and adjacent marshes. Vegetation can be incorporated into 

the shoreline protection design to create habitat as well as 

provide an additional erosion buffer. 

Barrier Island Restoration

Barrier islands provide protection to back-barrier bays, 

estuaries, and marshes. This protection includes reducing 

effects of erosion, wind, and wave energies; dissipation of 

storm surges; and prevention of saltwater intrusion. Over

the last century, the barrier islands of Louisiana have been 

reduced by approximately 40 percent, resulting in loss of 

habitat and protection for the coastal mainland. Barrier 

island restoration projects, which include creation of barrier 

islands or augmentation of existing islands, are needed to 

reestablish this natural protective zone. The objectives of 

these projects are to increase the height and width of the 

barrier island and close any shoreline breaches by using 

dredged materials and vegetation. 

Vegetative Planting

Vegetative planting projects are designed to introduce 

suitable plant species into deteriorating marsh areas and 

along eroding shorelines to provide a buffer against erosive 

wave action. Vegetative plantings also provide many other 

functions, such as sediment stabilization, sediment trapping, 

and habitat value. 

Sediment and Nutrient Trapping

Sediment and nutrient trapping projects use structural 

devices such as brush fences or earthen berms to reduce wave 

energies, promote the deposition of suspended sediment, 

and increase water clarity. Project-type goals are to reduce 

erosion of windward marsh edges, promote the growth of 

emergent vegetation, and increase the overall productivity 

of the area.

Methods

High-resolution, color-infrared aerial photography is 

acquired for each CWPPRA project several times during its 

life span. When acquisition is complete, all photography is 

reviewed for complete coverage, tone and quality. Once the 

photography is accepted, it is then rectified and mosaicked to 

provide a seamless image of the project area. All rectification 

meets or exceeds the horizontal National Mapping Accuracy 

Standards for a given scale. 

Habitat Monitoring 

Aerial photography and digital imagery are the primary 

mapping mediums for habitat monitoring. Over 100 

wetland restoration projects across Louisiana are funded 

by CWPPRA, and for each project there is an established 

schedule for photography acquisition. Acquisition and 

classification of aerial photography are conducted by 

scientists at the USGS NWRC in Lafayette, La. 
6 Classifications for Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) Site-Specific Projects: 2010

Aerial Photography Covering CWPPRA

Project Areas

The level of effort needed to establish baseline 

conditions, as described in each site-specific monitoring plan, 

differ depending on the project type. All of the restoration 

projects for which photography is collected require horizontal 

controls to be established in the field by using the Global 

Positioning System (GPS) for georeferencing. Georeferences 

are used for the development of project base maps, 

photograph rectification, and replication of mapping for future 

trend analyses. 

Geospatial Analysis

A coding scheme is used to identify the type of project, 

the project name, the type of data, the date the data were 

collected, and the location where the data were collected for 

each sample. The location will be provided in either latitude/

longitude or UTM coordinates. These steps are needed to 

ensure that sufficient documentation exists for verification of 

data accuracy. Data coding is the responsibility of Geoscience 

Specialists and oversight will verify that all data are properly 

coded to ensure compatibility with the CWPPRA Regional 

GIS Data Base.

All spatial data conforms to an Executive Order dated 

11 April 1994, describing standardized methods of data 

acquisition and access. The proper coding of spatial data is 

the responsibility of the Supervisory Geographer and GIS 

Specialist to ensure compatibility with the CWPPRA Regional 

GIS Data Base.

Acquisition of Photography

Analog aerial photographs are acquired by using the 

Zeiss RMK camera (Carl Zeiss AG, Oberkochen, Germany) 

at various scales depending on the project size, as follows: 

1:6,000 [200 acres or less], 1:12,000 [200 to 20,000 acres], 

and 1:24,000 [over 20,000 acres]. Project areas for which 

aerial photographs must be collected are identified by July 1 

each year, and photographs are acquired during late fall (prior 

to senescence) in order to obtain peak biomass for emergent 

marsh. In the event that conditions arise whereby photography 

cannot be obtained during this period, plans are made to 

acquire the photography during the next fall season. When 

data for a successive year are to be collected for a project, 

arrangements are made to collect the data for that year on a 

date that is as close as possible to the date/season data were 

collected in previous years. 

Because afternoon weather conditions (such as 

afternoon thunderstorms, haze, and cloud cover) are often 

uncertain, personnel of a contracting company will take 

vertical photographs, free of clouds, between 10:00 a.m. 

and 3:00 p.m. to minimize shadowing. The sun angle 

must not be less than 45 degrees. Photographic images of 

marsh vegetation and open water are acquired by using 

a stabilized camera mounted on the aircraft. The scale of 

the photography is held as close as possible to the required 

scales for all photos. A 60 percent end lap and 20 percent 

side lap are required for the photography, which allows the 

photointerpreter to map the images in stereo. GPS navigation 

with digital readout in the airplane cabin is the minimum 

accepted. The contracting personnel acquire high quality 

transparency film for the project. A minimum of two 9- by 

9-inch frames are acquired at the beginning of each flightline 

to reduce flightline syndrome on usable photography. All 

duplicate transparencies are individually made by using an 

automatic dodging printer that reduces color differences 

between the original and the duplicates.

Processing of Imagery

The mosaicking and orthorectification of aerial 

photography is outsourced to a subcontractor who uses 

proprietary software to provide scientists of USGS NWRC 

with orthorectified deliverables. All rectification meets or 

exceeds horizontal National Mapping Accuracy Standards for 

a given scale. 

The mensuration procedure is part of the rectification 

process and is performed in two separate phases. The first 

phase is to transfer control points from a Digital Orthophoto 

Quarter Quadrangle (DOQQ) to the new imagery. The X 

and Y coordinates for the image are determined by using 

the DOQQ, and the Z coordinate is determined by using a 

Digital Elevation Model (DEM) that is downloaded from 

U.S. Geological Survey (2010). The DEMs correspond to 

specified areas that are being photointerpreted. A sufficient 

number of points (usually 10-20) are transferred to interpret 

perimeter images and some interior images. The second phase 

is to transfer common points between adjacent photographs, 

both in-line and cross-strip. Typically, nine points are 

transferred between photos. Initial estimates of the ground 

coordinates and estimates of the elevation of these points are 

determined by the DEM. Once the control and pass points 

are measured, an aerotriangulation is performed by using the 

measurement data and the initial estimates of ground point 

coordinates, aircraft position, and orientation. The results 

of the aerotriangulation (AT) are examined, the outliers are 

eliminated, additional points are added (if necessary), and 

the AT is repeated until a satisfactory result is achieved. The 

images are then orthorectified and mosaicked.

Photointerpretive Classification of Imagery

An important component of the CWPPRA monitoring 

program is the classification (by land-water and by habitat) of 

aerial photography by scientists at the USGS NWRC. 

Land-Water Classification

Each time high-resolution, color-infrared photography 

is acquired, a land-water classification is conducted. An 
Methods 7

unsupervised classification is performed by using Leica 

(ERDAS Imagine, Norcross, Georgia) software. When 

performing the unsupervised classification process, maximum 

iterations are set to 30, and the convergence threshold is set at 

0.980. Depending on the color balance, tone, and other aspects 

of the photography, the number of classes is set between 

50 and 100. If it is determined that the maximum iterations 

have been reached before the convergence threshold is 

achieved, the maximum iterations will be increased to ensure 

the convergence threshold is achieved. This procedure results 

in a thematic raster image with 50–100 different classes, 

depending upon the range of pixel values. These individual 

classes are then interpreted to be either land or water based 

upon photointerpretation. Ancillary datasets from 1998 

through 2010 are used to help classify areas that are difficult 

to identify. The file is then manually edited to correct any 

misclassified pixels. The finished classification is recoded into 

the two classes, land and water. All areas characterized by 

emergent vegetation, wetland forest, scrub-shrub, or uplands 

are classified as land, while open water, aquatics and mud flats 

are classified as water. Occasionally, a third class—flooded 

lands—is used when hurricanes or severe environmental 

impacts have imposed special mapping characteristics 

which may indicate a landscape that is in transition. Several 

challenges are associated with the land-water interpretation 

process. Primarily, land-water classifications are often 

complicated by the presence of floating aquatic vegetation that 

occurs throughout the freshwater systems of coastal Louisiana 

and that is sometimes difficult to differentiate from emergent 

marsh. Other challenges include tidal fluctuations and water 

movement from strong winds, which may result in flooding 

and inundation of emergent marsh during certain conditions. 

Compensating for these events is difficult but possible by 

using other sources of imagery to verify marsh conditions 

for other dates in time. After completion of the classification 

process, the GIS specialist will perform a quality assurance 

(QA) self-check of the results. In addition, a second GIS 

specialist will perform a final, in-house quality control (QC) 

review to assure accuracy and data integrity. In addition, a 

final external review is also performed by personnel of the 

CPRA. Difficult areas wherein the classification remains in 

question are referred to a photointerpreter for final review. 

Habitat Classification

All photointerpretation of habitat adheres to protocols 

and standards used by the U.S. Fish and Wildlife’s National 

Wetlands Inventory (NWI) Program. The NWI classification 

system is outlined in the “Classification of Wetlands and 

Deepwater Habitats of the United States” (Cowardin and 

others, 1979). For habitat classification, certain types of 

restoration projects (such as vegetative plantings or shoreline 

protections) may only require aerial photography, while others 

(for example, hydrologic restoration or marsh management) 

require detailed habitat mapping or land-water classification 

in order to assess restoration success or failure. The basic 

goal of habitat mapping is to provide consistency across 

products by using the NWI classification system. Use of this 

classification system also ensures that wetland habitat changes 

are accurately and similarly assessed throughout the life of a 

project. For those projects requiring detailed mapping, aerial 

photography is photointerpreted. 

To begin the photointerpretation process, the digital 

mosaic of the project area is brought into ArcMap 

(Environmental Systems Research Institute [ESRI], Redlands, 

California) software. Habitat types are then delineated by 

overlaying project area boundaries onto the imagery and 

editing the features. Ancillary datasets from 1998 through 

2010 are used to help classify areas that may be difficult 

to identify. Imagery of the project area is also viewed in 

stereo, which helps determine vegetation height and proper 

classification. After completion of the classification process, 

the photointerpreter performs a QA self-check of the results. In 

addition, a second photointerpreter performs a final in-house 

QC check to further ensure data accuracy and integrity. After 

scientists of the NWRC have completed QA/QC protocols, the 

data are sent to the CPRA for comment. Personnel of CPRA 

have field experience of the project areas and can give critical 

feedback on the accuracy of the data. If changes are suggested, 

NWRC scientists review the area in question and incorporate 

all data to make changes as necessary. After all reviews 

and questions are answered, the final data product is ready 

for map production, and the map is submitted to an online 

distribution source.

Use of Reference Areas

Monitoring of reference areas in relation to project areas 

provides a means to achieve statistically valid comparisons, 

and is, therefore, the most effective means of evaluating 

project success. 

If appropriate reference areas are available, they 

are always included in the project design to allow for 

interpretation of the influence of temporal and spatial variation 

on projects. When a monitoring project lacks a reference 

area, the difference between mean values obtained before and 

after project creation may be misinterpreted. Long-term mean 

values are often averages that do not adequately represent 

rates or conditions that vary in space or time.

Selection of a reference area is ideally performed before 

project initiation. Reference areas should be ecologically 

similar to the project area yet located far enough away so 

as not to be influenced by the project. Potential reference 

areas can be selected by use of the Wetland Value Assessment 

Methodology (Environmental Work Group, 2006) methods or 

by use of more basic comparisons of structural and functional 

attributes. Appropriate reference areas are more likely to be 

found for smaller project areas.

In many areas of Louisiana, appropriate reference 

areas cannot be identified. In addition, the extent of wetland 

modification (both planned and unplanned) occurring 
8 Classifications for Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) Site-Specific Projects: 2010

in this region often results in the loss of reference areas 

before monitoring efforts are completed. Occasionally, and 

especially in the case of very large projects (for example, 

sediment diversions and freshwater diversions from the 

Mississippi River or watershed projects), it may be difficult to 

select reference areas that adequately reflect the same marsh 

type and function as those being affected by the project. In 

these cases, the following two strategies can be adopted:

• Monitoring before and after project implementation: 

The disadvantages of this strategy include delay in 

implementation, temporal variability, and the inability 

to clearly identify cumulative impacts of the project in 

comparison to unaffected areas. In addition, monitoring 

before and after implementation cannot ensure that 

the same events are being monitored for comparison; 

therefore, interpretation of the results will be difficult. 

Nevertheless, such monitoring does provide some 

indication of project performance and impact.

• Baseline data collection: This step is especially 

important in areas where reference areas cannot 

be selected for monitoring. As a “once only” data 

collection program, such collection does not delay 

project implementation as much as does full-scale 

monitoring before implementation [as in (1)]. In 

addition, this strategy provides a datum against which 

changing biological variables can be compared. In 

some cases, an existing database might be considered 

appropriate as baseline data. In such instances, an 

interagency team of experts or their scientific advisors 

should be convened to evaluate the suitability of the 

existing database for this purpose.

Conclusion

Accelerated wetland loss is a reality in the State of 

Louisiana. When the U.S. Congress passed the Coastal 

Wetlands Planning, Protection and Restoration Act 

(CWPPRA) in 1990, it facilitated a comprehensive approach 

for long-term goals of the conservation, restoration, creation, 

and enhancement of wetlands in Louisiana. The past and 

future success of CWPPRA is dependent upon its monitoring 

program, which is carried out by State and Federal agencies 

to determine the effectiveness of these restoration efforts. 

The collection, classification, and interpretation of highquality ecological, hydrological, and climatological data are 

critical components to the success of the greater mission and 

monitoring efforts for each project. By using color-infrared 

aerial photography to interpret wetland change, detailed 

habitat and land-water classifications are performed to 

determine land-to-water ratios and project success. Because 

the U.S. Congress, through CWPPRA, has dedicated 

resources to this monitoring program for 20 years, there has 

been a stable commitment to the continued development and 

advancement of restoration activities to improve long-term 

wetland restoration throughout coastal Louisiana.

References

Cowardin, L.M., Carter, Virginia, Golet, F.C., and LaRoe, 

E.T., 1979, Classification of wetlands and deepwater 

habitats of the United States: U.S. Fish & Wildlife Service 

FWS/OBS-79/31, accessed April 18, 2012, at http://www.

fws.gov/wetlands/Documents/Classification-of-Wetlandsand-Deepwater-Habitats-of-the-United-States.pdf. 

Environmental Work Group, 2006, Coastal Wetlands Planning, 

Protection and Restoration Act wetland value assessment 

methodology—Introduction: Coastal Wetlands Planning, 

Protection and Restoration Act Program, 4 p., accessed 

May 23, 2012, at http://lacoast.gov/reports/wva/WVA%20

Introduction.pdf. 

Louisiana Coastal Wetlands Planning, Protection and 

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Restoration Act Program Web Site, accessed May 23, 2012, 

at http://lacoast.gov/new/About/Basins.aspx. 

Steyer, G.D., Raynie, R.C., Steller, D.L., Fuller, Deborah, 

and Swenson, Erick, 1995, Quality management plan for 

Coastal Wetlands Planning, Protection, and Restoration Act 

Monitoring Program: Baton Rouge, Louisiana Department 

of Natural Resources, Coastal Restoration Division, OpenFile Series No. 95-01, 97p. (Revised June 2000.)

 U.S. Congress, 1990, Coastal Wetlands Planning, Protection 

and Restoration Act—Public Law 101-646, Title III 

[16 USC 3951]: Washington, D.C., U.S. Government 

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Jones and Garber—Classifications for Coastal Wetlands Planning, Protection and Restoration Act Site-Specific Projects: 2010—Data Series 745