Texas Louisiana Mississippi Alabama Florida

Hurricane Tracks

NGOM Study Area

Hurricane Katrina Landfall

August 29, 2005

Hurricane Gustav Landfall

September 1, 2008

Land Area Change Analysis Following 

Hurricane Impacts in Delacroix, Louisiana, 

2004–2009

By Monica Palaseanu-Lovejoy, Christine Kranenburg, and John C. Brock

Pamphlet to accompany

Scientific Investigations Map 3207

U.S. Department of 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

For product and ordering information:

World Wide Web: http://www.usgs.gov/pubprod

Telephone: 1-888-ASK-USGS

For more information on the USGS—the Federal source for science about the Earth, its 

natural and living resources, natural hazards, and the environment: 

World Wide Web: http://www.usgs.gov

Telephone: 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:

Palaseanu-Lovejoy, M.E., Kranenburg, C.J., Brock, J.C., 2012, Land Area Change Analysis 

Following Hurricane Impacts in Delacroix, Louisiana, 2004–2009, U.S. Geological Survey, Scientific 

Investigations Map 3207, 9 p.
i

Contents

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

Methodology ......................................................................................................................1

Discussion...........................................................................................................................1

Conclusions ........................................................................................................................5

Acknowledgements ..........................................................................................................9

References..........................................................................................................................9

Figures

1. Map of study area. ......................................................................................................1

2. Satellite imagery sources, dates, and extents of imagery used. ......................2

3. Change analysis map 2004–2006. .............................................................................4

4. Highlighted section from figure 3–Hurricane Katrina change analysis. ..........5

5. Change analysis map 2006–2008. .............................................................................6

6. Change analysis map 2008–2009. .............................................................................7

7A. Change analysis map 2004–2009..............................................................................8

7B. Change analysis interpretation. ...............................................................................9

Tables

1. Independent and dependent variable predictors for fractional-water maps ..3

2. Evaluation indices for maximum Kappa coefficient of agreement. ...................3
Land Area Change Analysis Following Hurricane Impacts in Delacroix, Louisiana, 2004–2009

1Jacobs Technology, contracted to U.S. Geological Survey, 2U.S. Geological Survey

By Monica Palaseanu-Lovejoy,

1 Christine Kranenburg,1and John C. Brock2

Scientific Investigations Map 3207Pamphlet accompanies map

790000790000

800000800000

810000810000

820000820000

3280000

3280000

3290000

3290000

3300000

3300000

3310000

3310000790000

790000

800000800000

810000810000

820000820000

3280000

3280000

3290000

3290000

3300000

3300000

3310000

3310000790000

790000

800000800000

810000810000

820000820000

3280000

3280000

3290000

3290000

3300000

3300000

3310000

3310000

790000790000

800000800000

810000810000

820000820000

3280000

3280000

3290000

3290000

3300000

3300000

3310000

3310000

0 5 10 Miles

0 5 10 Kilometers

0 5 10 Miles

0 5 10 Kilometers

0 5 10 Miles

0 5 10 Kilometers

Change Analysis Interpretation Mar. 2004 Sept. 2006 Mar. 2008 Nov. 2009

Land Land Land Land

Water Land Land LandLand Water Land LandWater Water Land LandLand Land Water LandWater Land Water Land

Land Water Water LandWater Water Water Land

Land Land Land WaterWater Land Land WaterLand Water Land WaterWater Water Land Water

Land Land Water WaterWater Land Water WaterLand Water Water Water

Water Water Water Water

Unchanged land (41.37%)Permanent land Katrina (3.25%)Temporary water Katrina (1.48%)Drained fields after 2006 (0.55%)Water-level fluctuation 2008 (1.32%)Vegetation seasonality (0.69%)Drainage after 2008 (1.18%)New land Gustav (0.75%)New water Gustav (1.39%)Erosion Gustav (0.74%)Post-storms flooding/seasonality (0.97%)Drainage in 2008 (0.74%)Dead vegetation, after 2006 (0.84%)Temporary new land Katrina (0.92%)Permanent new water Katrina (8.17%)Unchanged water (35.63%)

Sept. 2006 Mar. 2008

Land LandWater LandLand WaterWater Water

Change Analysis Interpretation

Unchanged land areas (46.75%)New land areas (3.75%)New water areas (3.76%)Unchanged water areas (45.73%)

Land Change Analysis 2004–2006:Hurricane Katrina (Aug. 2005)

Land Change Analysis 2006–2008:pre-Hurricane Gustav (Sept. 2008)

Land Change Analysis 2008–2009:Hurricane Gustav (Sept. 2008)

Land Change Analysis 2004–2009

M

Image sources:Base maps derived from USGS Landsat imagery 2004, 2006, 2008, and 2009 30 meter pixel resolutionProjected using WGS 84 datum and Universal Transverse Mercator (UTM ) Zone 15 NorthLongitude of Central meridian: -93.00000

ar. 2004 Sept. 2006

Land LandWater LandLand WaterWater Water

Unchanged land areas (44.92%)New land areas (5.60%)New water areas (11.81%)

Unchanged water areas (37.67%)

Change Analysis Interpretation Nov. 2009

Land LandWater LandLand WaterWater Water

Change Analysis Interpretation

Unchanged land areas (46.67%)New land areas (3.94%)New water areas (3.84%)Unchanged water areas (45.56%)

Mar. 2008

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

April 2012

Northern Gulf of Mexico (NGOM) study area showing the track of hurricanes Gustav and Katrina in relation to the land change study area of this map.

Mississippi Texas Louisiana Alabama Florida

Hurricane TracksNGOM Study Area

Hurricane Katrina LandfallAugust 29, 2005

Hurricane Gustav LandfallSeptember 1, 2008
Land Area Change Analysis Following Hurricane 

Impacts in Delacroix, Louisiana, 2004–2009

By Monica Palaseanu-Lovejoy1, Christine Kranenburg1, and John C. Brock2

Introduction 

In this study, we estimated the changes in land and 

water coverage of a 1,208-square-kilometer area surrounding 

Delacroix, Louisiana (fig. 1), that was impacted by hurricanes 

Katrina (Aug. 29, 2005) and Gustav (Sept. 1, 2008). The 

objective of this study is twofold: (1) to provide pre- and 

post-Hurricane Katrina and pre- and post-Hurricane Gustav 

moderate resolution 30-meter (m) fractional-water maps 

based upon multiple source images, and (2) to quantify land 

and water coverage changes due to the recent hurricanes. 

Tropical Storm (TS) Cindy also moved over the study area 

on July 6, 2005, less than 2 months before Hurricane Katrina 

impacted the area. Thus, any effects from TS Cindy will be 

included in the changes attributed to Hurricane Katrina in the 

following analysis. Although TS Cindy took a more direct path 

across the study area, the peak wind speed was only 50 knots, 

compared to 110 knots for Hurricane Katrina.

Methodology

The U.S. Geological Survey (USGS) Earth Resources 

Observation and Science (EROS) Center provided the 

following imagery for this project: three QuickBird images 

and four Landsat 5 Thematic Mapper (TM) scenes for Path 22, 

Row 39. One Geoeye-1 image was provided by the National 

Geospatial-Intelligence Agency (NGA). Figure 2 shows 

imagery dates and extents.

The aim of this study is to improve estimates of wetland 

land loss in Delacroix, La., due to extreme storms impacting 

the region between 2004 and 2009. The estimates developed in 

this study are based on change-detection-mapping analysis that 

incorporates pre- and post-landfall (Hurricanes Katrina and 

Gustav) fractional-water classifications using a combination 

of high-resolution (< 5 m) QuickBird and Geoeye-1 images, 

and medium-resolution (30 m) Landsat images. The fractionalwater maps are the result of regression-tree modeling in which 

the dependent variables are derived from high-resolution 

imagery and the independent variables from 30-m resolution 

Landsat imagery. The continuous fractional-water maps are 

classified into land and water categories using the maximum 

Kappa coefficient as an optimizer. Palaseanu-Lovejoy 

and others (2010) provide details on the fractional-water 

methodology.

The list of independent and dependent variables that were 

useful predictors for the final maps selected for each year 

is shown in table 1. The optimum threshold and associated 

accuracy metrics derived from each year’s selection point 

dataset are shown in table 2.

Discussion

The Delacroix region is composed of a relatively 

unmanaged (few artificial water diversions present) marsh in 

the central and eastern sections that is bounded by residential 

and agricultural areas to the north and west. Each of these 

distinct land-use types responds to, and recovers differently 

from, an extreme storm event. Land/water changes detected 

after an extreme storm event reflect both permanent and 

temporary changes and are affected by both natural and 

artificially controlled drainage, land-recovery projects, and 

the time elapsed since the storm impact. These changes are 

superimposed on a very dynamic environment in which 

land/water architecture is influenced by seasonality and 

water levels (microtidal fluctuation, precipitation, watermanagement practices). For this study, we consider permanent Figure 1. Map showing location of study area.

1

Jacobs Technology, contracted to the U.S. Geological Survey, 2U.S. Geological Survey

Hurricane Tracks

EXPLANATION

Louisiana Mississippi Louisiana

0 10 20 40 Miles

0 10 20 40 Kilometers Hurricane Katrina landfall

August 29, 2005

Hurricane Gustav landfall

September 1, 2008

Study Area
2

Figure 2. Sources, dates, and extents of satellite imagery used.

 High resolutionQuickbird - (04/04/2004) YellowQuickbird - (09/29/2006) Color Infrared (CIR)Quickbird - (11/07/2007) PurpleGeoeye-1 - (11/16/2009) Greyscale Moderate resolutionLandsat 5 - (03/12/2004)Landsat 5 - (09/26/2006)Landsat 5 - (03/23/2008)Landsat 5 - (11/05/2009)

Lake Borgne

EXPLANATION

0 5 10 Kilometers

0 5 10 Miles
new water areas to be those new water areas that appear 

after a storm and persist through time. They are the result of 

direct removal of wetlands by storm surge and appear mostly 

connected to existing bodies of open water, but also emerge in 

marsh-fringing areas.

Temporary new water bodies are usually the result 

of flooding and water entrapment in impounded areas, 

removal or scouring of floating and submerged vegetation, 

or are caused by water-level fluctuation due to tidal or 

meteorological variations between images. Temporary new 

water bodies usually revert to their original classification 

(land) after a suitable period of recovery.

Land gain in the Delacroix area is mostly transitory 

and is the effect of storm-debris deposition, displacement of 

aquatic vegetation to different locations, drainage, seasonality, 

or nitrate nutrient input. Most of the land gain observed along 

rivers, canals, and beaches is a direct result of variations in 

water levels caused by tidal or meteorological influences.

Hurricane Katrina made landfall on the eastern border of 

the Delacroix study area on August 29, 2005. Many of the new 

water areas (11.81 percent) created by this hurricane formed 

around existing bodies of open-water. (fig. 3).

Extensive marsh scarring is evident in the numerous 

elongated finger-like new water features in the west-central 

part of the study area (fig. 3). At present, it is difficult to 

distinguish between flooded marsh and marsh removed by 

storm surge. The new land areas (5.60 percent) are largely 

due to vegetation seasonality, drainage, or possible nitrate 

pollution from the adjacent agricultural areas to the west or 

the golf course to the north. Scarring, vegetation seasonality, 

displacement, and probable nitrate pollution are apparent 

in Big Mar, the impounded pond, and its vicinity in the 

northwestern part of the study area (fig. 3, highlighted in 

purple; fig. 4). Individual changes cannot be confirmed as 

transitory or permanent until later in the time series.

Between September 2006 and March 2008, no extreme 

storm events impacted the area. The changes that occurred 

represent normal variability in a very dynamic environment 

and were due to vegetation seasonality and water-level 

fluctuation (tidal and meteorological) (fig. 5). Most of the new 

3

Year Idependent variable Dependent variable

2004 Landsat bands: 1 to 6 Water Index: PCA

Texture: Homogeneity (bands 1 to 6)

Principal Components: 2 to 6

Water Index: Braud

2006 Landsat bands: 1 to 6 Water Index: Braud

(sum(VIS)-sum(IR))/(sum(VIS)+sum(IR)) Texture: Entropy (bands 1 to 6)

Principal Components: 2 to 6

Water Index: GNDWI

2008 Landsat bands: 1 to 6 Water Index: GNDWI

(b4-b2)/(b4+b2) Texture: Variance (bands 1 to 6)

Independent Components (log): 1 to 3

2009 Landsat bands: 1 to 6 Water Index: GNDWI

(b4-b2)/(b4+b2) Texture: Contrast (bands 1 to 6)

Principal Components: 2 to 6

Water Index: GNDWI

Table 1. Independent and dependent variable predictors for fractional-water maps. 

Year Threshold PCC PCC water PCC land Kappa AUC Commission Ommission

2004 40 97.75 96.88 98.63 95.50 99.52 1.37 3.12

2006 35 99.64 99.52 99.76 99.29 99.73 .24 .48

2008 40 98.10 99.10 97.24 96.33 99.54 2.71 .91

2009 51 99.31 99.46 99.14 98.62 99.52 .78 .54

Table 2. Evaluation indices for maximum Kappa coefficient of agreement. 

 [Abbreviation of spectral bands and acronyms used: b1, blue; b2, green; b4, IR, infrared; 

VIS, visible bands; PCA, principal components; ICA, independent components; GNDWI, 

green normalized difference water index.]

PCC-percent correctly classified, AUC-area under the curve. All values are percentages.
4

Figure 3. Change analysis map 2004–2006—Hurricane Katrina.

790000 800000 810000 820000

790000 800000 810000 820000

3280000 3290000 3300000 3310000

3280000 3290000 3300000 3310000

Unchanged land areas (44.92%)

New land areas (5.60%)

New water areas (11.81%)

Unchanged water areas (37.67%)

Mar. 2004 Sept. 2006 Change Analysis Interpretation

Land Land

Water Land

Land Water

Water Water

UTM Easting

UTM Northing

Projected using the WGS 84 datum and the Universal Transverse Mercator (UTM) Zone 15N coordinate system.

Base maps derived from USGS Landsat imagery 2004 and 2006.

0 5 10 Kilometers

0 5 10 Miles
water areas (3.76 percent) that developed between September 

2006 and March 2008 are the result of aquatic vegetation loss 

due to seasonality, while the new land areas (3.75 percent) are 

mainly the result of water-level fluctuations and drainage.

Hurricane Gustav made landfall on September 1, 2008, 

approximately 80 to 100 kilometers (km) west of the study 

area and had minimal impact compared to that of Hurricane 

Katrina. Most post-Hurricane Gustav new water (3.84 

percent) and new land (3.94 percent) areas (fig. 6) are more 

comparable to those in the March 2008 change analysis map 

(fig. 5) in both magnitude and spatial distribution than to those 

in the Hurricane Katrina change analysis map (fig. 3). This 

indicates that these changes are more closely related to the 

environment’s natural variability than to Hurricane Gustav 

(fig. 6). This interpretation is supported by analysis of the time 

series change in the Delacroix area, from 2004 to 2009 (fig. 

7).

The interpretation of figure 7 involves determining the 

classification (land or water) of each pixel of the study area 

for each year’s imagery. The change analysis interpretation is 

based on the change in class of a particular pixel through time. 

For example, if a pixel is classified as land in 2004, changes 

to water in 2006 and remains water in 2008 and 2009, it is 

assigned to the class “Permanent new water due to Katrina.” 

A pixel that toggles between water in Spring 2004 imagery, 

land in Fall 2006 imagery, back to water in Spring 2008 and 

then back to land in Fall 2009 is attributed to vegetation 

seasonality. The left half of figure 7B indicates the 16 possible 

classification combinations over a 4-image set.

Time series change analysis reveals the permanent 

changes due to Hurricane Katrina, namely the permanent 

new water (8.17 percent) and permanent new land areas 

(3.25 percent) (fig. 7B). Temporary fluctuations in land/water 

classification due to seasonality, drainage, flooding, and 

water-level oscillations are perceptible as well. Collectively, 

these leave only 0.75 percent as new land areas and 1.39 

percent as new water areas due to Hurricane Gustav, and these 

categories include both permanent and temporary changes. 

A further 0.74 percent of the area then changed from water 

in March 2004 to land in September 2006 and March 2008 

reverted to water after Hurricane Gustav.

Spatially, a clear pattern emerges in which marshes in 

the east and southeast of the study area are almost unaffected; 

damage then gradually increases to the north and west, up to 

and until the boundary with the agricultural/urban areas. This 

trend closely follows the salinity gradient of the marshes in 

the study area. Saline marshes robustly withstood the effects 

of the hurricanes despite being closer to the eye of Katrina 

than the brackish and intermediate marshes farther inland. 

Howes and others (2010) attribute this robustness of highsalinity marshes, relative to their fresher counterparts, to their 

deeper root systems and higher shear strength of the soil on 

which they reside. Fresh marshes display a highly sinusoidal 

land-loss trend-line, indicating the variation is dominated 

by short-term vegetation seasonality and meteorological 

conditions, which conceal hurricane impacts. 

Conclusions

Most of the permanent new water areas (8.17 percent) 

due to Hurricane Katrina occur around existing bodies of open 

water and in marsh fringing areas, but they are also present 

in historically stable areas. The presence of scarring in stable 

marshes is discernible as newly formed, elongated fingerlike ponds, especially in the central-western part of the study 

area. Storm-debris deposition, small reclamation projects and 

permanent drainage can result in small new land areas, but 

5

Figure 4. Highlighted section from figure 3—Hurricane Katrina change analysis.

A. 2004 color infrared composite imagery. B. 2006 panchromatic imagery. C. 2004–2006 change analysis.

New land areas New water areas

796000

796000

797000

797000

798000

798000

799000

799000

800000

800000

801000

801000 796000 797000 798000 799000 800000 801000

796000 797000 798000 799000 800000 801000 796000 797000 798000 799000 800000 801000

796000 797000 798000 799000 800000 801000

3303000 3304000 3305000 3306000 33070003303000 3304000 3305000 3306000 3307000

3303000 3304000 3305000 3306000 33070003303000 3304000 3305000 3306000 33070003303000 3304000 3305000 3306000 33070003303000 3304000 3305000 3306000 3307000
6

Figure 5. Change analysis map 2006–2008—no storm events.

790000

790000

800000

800000

810000

810000

820000

820000

32800003280000

3290000

3290000

33000003300000

3310000

3310000

Change Analysis Interpretation

Unchanged land areas (46.75%)

New land areas (3.75%)

New water areas (3.76%)

Sept. 2006

Land

Water

Land

Water

Mar. 2008

Land

Land

Water

Water Unchanged water areas (45.73%)

UTM Easting

UTM Northing

Projected using the WGS 84 datum and the Universal Transverse Mercator (UTM) Zone 15N coordinate system.

Base maps derived from USGS Landsat imagery 2006 and 2008.

0 5 10 Kilometers

0 5 10 Miles
7

Figure 6. Change analysis map 2008–2009—Hurricane Gustav.

790000 800000 810000 820000

790000 800000 810000 820000

3280000 3290000 3300000 3310000

3280000 3290000 3300000 3310000

Mar. 2008 Nov. 2009

Land

Water

Land

Water

Land

Land

Water

Water

Change Analysis Interpretation

Unchanged land areas (46.67%)

New land areas (3.94%)

New water areas (3.84%)

Unchanged water areas (45.56%)

UTM Easting

UTM Northing

Projected using the WGS 84 datum and the Universal Transverse Mercator (UTM) Zone 15N coordinate system.

Base maps derived from USGS Landsat imagery 2008 and 2009.

0 5 10 Kilometers

0 5 10 Miles
8

790000

790000

800000

800000

810000

810000

820000

820000

32800003280000

32900003290000

33000003300000

33100003310000

UTM Easting

UTM Northing

Figure 7. Change analysis (A) map 2004–2009 and (B) interpretation chart. 

Projected using the WGS 84 datum and the Universal Transverse Mercator (UTM) Zone 15N coordinate system.

0 5 10 Kilometers

0 5 10 Miles

Base maps derived from USGS Landsat imagery 2004, 2006, 2008 and 2009.

A
land gain along waterways and beaches is considered to be the 

result of temporary variations in water levels caused by tidal 

or meteorological influences.

Saline marshes suffered far less hurricane damage 

than their fresher counterparts. In fresh marsh vegetation, 

seasonality has a considerable effect on land-loss variation, 

obscuring hurricane impacts. 

Estimation of permanent losses (or gains) due to 

Hurricane Gustav cannot be made until the transitory impacts 

are identified and quantified. However, it is expected that the 

permanent losses will be relatively small, probably less than 

1 percent of the area. Overall, 77 percent of the area remained 

unchanged between 2004 and 2009, and over 11 percent of 

the area was changed permanently by Hurricane Katrina (both 

land gain and land loss). Less than 3 percent was affected, 

either temporarily or permanently, by Hurricane Gustav.

Acknowledgments

The USGS St. Petersburg Coastal and Marine Science 

Center acknowledges the support and assistance of the 

USGS Land Characterization team at the Earth Resources 

Observation and Science (EROS) Center, in Sioux Falls, South 

Dakota, and the USGS National Wetlands Research Center, in 

Baton Rouge, La., in the development of this dataset.

References

Howes, N.C., FitzGerald, D.M., Hughes, A.J., Georgiou, I.Y., 

Kulp, M.A., Miner, M.D., Smith, J.M., and Barras, J.A., 

2010, Hurricane-induced failure of low salinity wetlands. 

Proceedings of the National Academy of Sciences, v. 107 

no. 32, p. 14014-14019. 

Palaseanu-Lovejoy, M.E., Kranenburg, C.J., and Brock, J.C., 

2010, Land area change and fractional-water maps in the 

Chenier Plain, Louisiana, following Hurricane Rita, (2005): 

U.S. Geological Survey, Scientific Investigations Map 3141, 

6 p. pamphlet.

9

Mar. 2004 Sept. 2006 Mar. 2008 Nov. 2009 Change Analysis Interpretation

Land Land Land Land

Water Land Land Land

Land Water Land Land

Water Water Land Land

Land Land Water Land

Water Land Water Land

Land Water Water Land

Water Water Water Land

Land Land Land Water

Water Land Land Water

Land Water Land Water

Water Water Land Water

Land Land Water Water

Water Land Water Water

Land Water Water Water

Water Water Water Water

Unchanged land (41.37%)

Permanent land Katrina (3.25%)

Temporary water Katrina (1.48%)

Drained fields after 2006 (0.55%)

Water-level fluctuation 2008 (1.32%)

Vegetation seasonality (0.69%)

Drainage after 2008 (1.18%)

New land Gustav (0.75%)

New water Gustav (1.39%)

Erosion Gustav (0.74%)

Post-storms flooding/seasonality (0.97%)

Drainage in 2008 (0.74%)

Dead vegetation, after 2006 (0.84%)

Temporary new land Katrina (0.92%)

Permanent new water Katrina (8.17%)

Unchanged water (35.63%)

Figure 7. Change analysis (A) map 2004–2009 and (B) interpretation chart. ---Continued

B
Palaseanu, M.E., Kranenburg, C.J., Brock, J.C.–Land Area Change Analysis Following Hurricane Impacts in Delacroix, Louisiana, 2004–2009. Pamphlet to SIM 3207