2012 ASPRS Conference presentation in Sacramento California. This paper describes the use of remote sensing data, GIS habitat mapping, and environmental sensitivity analysis methods to map selected coastal and seafloor features. These technologies are employed to develop an efficient means of determining and mapping nearshore and seafloor features warranting environmental protection. The application of remote sensing techniques to high-resolution aerial or satellite imagery may be utilized to identify and delineate near-shore and coastal features and perform habitat classifications. These data can be used to produce Environmental Sensitivity Index (ESI) maps, thematic maps, and statistical summaries (areal and linear dimensions) of habitat type which may support Environmental Impact Assessments (EIAs), Environmental Impact Studies (EISs), Baseline Environmental Baseline Surveys (EBSs), monitoring plans, and spill contingency planning. This rapid assessment and mapping approach gives a time-efficient and cost-effective means to identify and map environmentally sensitive features within a large and environmentally complex geographical area. This paper additionally presents the development and application of an environmental impact mitigation plan based on a combination of the ESI analysis and habitat mapping data. This combined technical approach is a practical means to minimize environmental impact while meeting the scientific, engineering and logistic constraints of coastal and marine development activities.

1. IMAGERY INTERPRETATION FOR
COASTAL AND MARINE SPATIAL
PLANNING
Prepared for:
2012 ASPRS Conference
Keith B. VanGraafeiland,
Stephen T. Viada,
M. John Thompson,
Brian Balcom,
and
George Mcleod

2. Acknowledgments
Anadarko Petroleum Corporation (APC)
• John Peffer
• Mario Rassul
• Karina Pena

3. Purpose
• Remote Sensing Data
– satellite imagery
– side-scan sonar
• GIS habitat mapping
– Imagery classification
– Imagery interpretation
• Environmental sensitivity analysis methods
– Identify features and areas of concern for
avoidance and to minimize environmental impacts

4. • These data can be used to produce:
– Environmental Sensitivity Index (ESI) maps,
– thematic maps, and
– statistical summaries (areal and linear
dimensions) of habitat type
• Support:
– Environmental Impact Assessments (EIAs),
– Environmental Impact Studies (EISs),
– Baseline Environmental Baseline Surveys (EBSs),
– monitoring plans, and
– Spill contingency planning.

5. CASE STUDY
Northern Mozambique,
Africa
• A 2D and 3D geophysical
survey program was
proposed within shallow
waters of the Quirimbas
Archipelago, Mozambique
Study purpose:
• Locate seafloor features
warranting environmental
protection from seismic
operations
• Develop a mitigation plan to
minimize potential
environmental impact

6. Study Objectives
1. Characterize and map marine habitats
2. Identify physical areas of concern
3. Develop a mitigation plan
4. Implement a field survey to delineate
areas of environmental concern
• Environmental Impact Assessment
(EIA), with an approved environmental
impact mitigation plan
• Environmental Management Plan
(EMP)

7. Characterization and Mapping of
Shallow Water Marine Habitats
• Mangrove-dominated communities
• Submerged aquatic vegetation
• Bare sand and mud substrates
• Shallow and emergent hard substrates
• Shallow and emergent coral
communities
• Deepwater coral communities
Objective 1

8. A set of high resolution remote sensing
(satellite imagery) tiles of the coastal and
nearshore waters of the project area were
used to create a georeferenced mosaic
Habitat categories were identified and coded as
colored polygons, creating a georeferenced
habitat map

9. Environmental Sensitivity Index (ESI)
methods were used to determine the
relative sensitivity of each identified
habitat category
Habitat Sensitivity Analysis
Objective 2
Sources of environmental impact included
• seismic sound pressure waves
• physical contact with receiver cables and
autonomous receivers

10. Potential Levels of Impact Severity
Impact Severity Consequence
Negligible
Negligible or little harm to sensitive resources, with reversible effects
Little or no environmental exposure
Minor
Low, minor environmental impact
Exposure limited to immediate site
Moderate
Medium, moderate environmental impact
Incident potentially contaminating local resources
Significant
Major environmental impact (see text below)
Environmental incident resulting in contamination of local resources
Catastrophic
Catastrophic disaster, major environmental impact
Major environmental incident causing significant regional damage to the environment
Scale of Environmental Sensitivity
1
Negligible
2
Minor
3
Moderate
4
Significant
5
Catastrophic
Severity of Impact
––––––––►

11. Objective 3
From the ESI results, an impact mitigation
strategy was designed to avoid or
minimize potential impacts to sensitive
marine resources and habitats
Develop a Mitigation Plan for the Protection of
the Identified Areas of Concern
Mitigation measures consisted of acoustic
exclusion zones (“buffer zones”),
considering proposed activity scenarios

12. Objective 4
A field survey was designed and
implemented to accurately and
efficiently identify and delineate areas
that met sensitive habitat criteria
Field Survey
Field Survey Methods
• a preliminary mapping
survey of selected segments
with digital side-scan sonar
• visual assessment
(groundtruthing) of selected
seafloor features by divers

13. Survey Data Analysis
Image showing sand
waves with seagrasses
and macroalgae
Image showing dense
seagrass beds
on soft substrate

14. Survey Data Analysis
The processed sonar
data swath was
superimposed on the
satellite mosaic for
interpretation
Each proposed seismic
survey trackline was
superimposed on the
corresponding satellite
mosaic

15. Survey Data Analysis
Results obtained
from
groundtruthing
selected targets
provided
supportive
information for
seafloor
interpretation
Selected
groundtruth
targets were
plotted, and areas
meeting selection
criteria were
provided a buffer
of 75 m
The final product
comprised a
color-coded
overlay of the
surveyed trackline
segment

16. Survey Results
• 250 line km were surveyed
• 90 km were in water depths <2 m
• 42 km were designated as sensitive habitat
• 118 km did not contain sensitive habitat or were
too deep to survey

17. Conclusions
• Sensitive shallow water habitats were
mapped within the project area
• Acoustic exclusion areas (buffers) for
selected resources were implemented
The methods provide a practical and
efficient means to characterize and
map seafloor habitats within large
geographic areas, and may be applied
to other activity scenarios and
geographic areas