International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B3, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
IMAGE FUSION APPLIED TO SATELLITE IMAGERY FOR THE IMPROVED
MAPPING AND MONITORING OF CORAL REEFS: A PROPOSAL
M. Gholoum ?, D. Bruce ?, S. Al Hazeam 5
* School of Natural and Built Environments, Barbara Hardy Institute, University of South Australia, GPO Box 2471,
Adelaide, SA, 5001, Australia - (ghomm001, David.Bruce)(gunisa.edu.au
? Aquaculture, Fisheries and Marine Environmental Department, Kuwait Institute for Scientific Research, P O Box:
1638, 22017 Al-Salmyah Eie shpzeem@kisr.edu.kw
OMMISSION
KEY WORDS: Image Fusion, Coral Reef, Hyperion, WorldView 2, Environmental Management, Image Classification
ABSTRACT
A coral reef ecosystem, one of the most complex marine environmental systems on the planet, is defined as biologically diverse and
immense. It plays an important role in maintaining a vast biological diversity for future generations and functions as an essential
spawning, nursery, breeding and feeding ground for many kinds of marine species. In addition, coral reef ecosystems provide
valuable benefits such as fisheries, ecological goods and services and recreational activities to many communities. However, this
valuable resource is highly threatened by a number of environmental changes and anthropogenic impacts that can lead to reduced
coral growth and production, mass coral mortality and loss of coral diversity. With the growth of these threats on coral reef
ecosystems, there is a strong management need for mapping and monitoring of coral reef ecosystems. Remote sensing technology
can be a valuable tool for mapping and monitoring of these ecosystems. However, the diversity and complexity of coral reef
ecosystems, the resolution capabilities of satellite sensors and the low reflectivity of shallow water increases the difficulties to
identify and classify its features.
This paper reviews the methods used in mapping and monitoring coral reef ecosystems. In addition, this paper proposes improved
methods for mapping and monitoring coral reef ecosystems based on image fusion techniques. This image fusion techniques will be
applied to satellite images exhibiting high spatial and low to medium spectral resolution with images exhibiting low spatial and high
spectral resolution. Furthermore, a new method will be developed to fuse hyperspectral imagery with multispectral imagery. The
fused image will have a large number of spectral bands and it will have all pairs of corresponding spatial objects. This will
potentially help to accurately classify the image data. Accuracy assessment use ground truth will be performed for the selected
methods to determine the quality of the information derived from image classification. The research will be applied to the Kuwait's
southern coral reefs: Kubbar and Um Al-Maradim.
1. REVIEW OF PREVIOUS METHODS
A Coral Reef Ecosystem (CRE) is one of the most complex
environmental systems on the planet, and is defined as
biologically diverse and immense (Connell, 1978; Porter and
Tougas, 2001). This ecosystem has been called the rainforest of
the marine world as it is home to many known marine species
(Bryant et al, 1998). Coral reefs are important ecosystems to
many people around the world (Moberg and Folke, 1999;
Nurlidiasari, 2004). They play an important role in maintaining
a vast biological diversity and genetic library for future
generations (Moberg and Folke, 1999). They function as
essential spawning, nursery, breeding and feeding ground for
many kinds of marine species such as fish, marine turtles,
worms, molluscs, crustaceans and sponges (Moberg and Folke,
1999). CRE provides valuable benefits, particularly to local
communities who depend on these resources for their livelihood
(Nurlidiasari, 2004). Moreover, CRE serves as physical and
natural barriers for oceanic currents and waves, protecting
coastlines from erosion and creating suitable environments for
other ecosystems such as mangroves and seagrass beds (Moberg
and Folke, 1999; UNEP, 2006).
This valuable resource, however, is highly threatened by a
number of environmental changes and anthropogenic impacts
such as natural disturbances, overfishing, pollution and tourism
(Johannes and Riepen, 1995; Moberg and Folke, 1999). These
impacts can lead to reduced coral growth and production, mass
coral mortality and loss of coral diversity (Eghtesadi-Araghi,
2011).
Information on the health of coral reef ecosystem status is
essential for conservation and sustainable utilization. Currently,
there is a limited knowledge on the condition and community
assemblage composition of coral reef ecosystems (Knowlton
and Jackson, 2008). With the growing threats of climate
change, natural phenomena and anthropogenic impacts on CRE,
there is a strong management need for the more accurate
mapping and monitoring of these systems (Dekker et al, 2001).
In the past three decades, researchers have witnessed rapid
development of advanced sensors and data processing
methodologies in order to advance the understanding of Earth's
environment, specifically coral reef ecosystem (Mumby and
Edwards, 2002; Andréfouét et al, 2003; Eakin et al, 2010).
Remote sensing technology, such as airborne and satellite
sensors, can potentially provide more accurate classification of
coral reef ecosystem, in a shorter period of time and in a more
cost effective manner than via in situ surveys (Eakin et al,
2010). Airborne hyperspectral sensors have been used to
uniquely identify and map coral reef ecosystems (Clark et al,
1997; Mumby et al, 1998). They have the advantage over data
from satellite sensors because the user has influence on the
mission in terms of time schedules, calibration measurements,
flight line arrangements, spectral and spatial resolutions, and
selecting acceptable weather conditions (Cetin, 2004). Mumby
pr
