video transects surveys to monitor the damage. Passive and active remote sensing,
in various combination with direct in-water damage assessment using photo or
video, have now become part of a common portfolio of tools to successfully assess
damage from ship groundings and monitor recovery over space and time.
15.3.4 Monitoring Temporal Changes
The previous case studies have shown how remote sensing can be used to provide
maps of coral reef properties at specific points in time with defined levels of detail
and areal extent. The logical extension of these applications is to reproduce the
maps of reef extent, geomorphic zonation, benthic communities, fish habitat, etc.,
at different dates and then map and quantify the nature of changes observed within
the coral reef over time. This feeds into one of the key requirements for science
and management: defining what is there and how it is changing over time.
Prior chapters have clearly demonstrated the ability of remote sensing to be
used at an operational level by government agencies, private companies and NGOs
for mapping the extent of reefs, biophysical composition and processes within
reefs, and the physical-biological oceanographic and meteorological parameters
affecting reef extent and growth. The majority of the satellite and airborne image
datasets collected to produce these maps can just as readily obtain repeat coverage
of the same area. This enables reef scientists to map changes in reef composition,
physical features and controlling processes to assess: the type and nature of
changes occurring; the level of natural variations and disturbances; and the direct
or indirect impact of human actions and management decisions (Jupp et al. 1985;
Dustan et al. 2001; Andréfouët and Riegel 2004; Knudby et al. 2007). While
mapping changes in reef extent, composition or habitat has predominantly been
completed using two successive dates of images, research applications are
emerging for mapping these features from long time series of satellite images,
aerial photography and field survey data. Below are two general examples of
image change and trend detection studies used for understanding and managing
reefs. The first example focuses on changes in characteristics mapped between two
successive dates, and the second application covers a longer time series of multiple
(100–1,000 s dates) images.
There are relatively few publications in the peer-reviewed literature covering
operational mapping of changes in coral reefs between two successive dates. Most
of the published studies report results from the map producer’s point of view,
focusing on the techniques used, levels of accuracy obtained, and inference of the
natural or human processes that produced the observed changes. The most commonly reported examples have been for geomorphic zones and benthic communities, mainly using Landsat Thematic Mapper and now higher spatial resolution
multispectral satellites (e.g., Dustan et al. 2001; Andréfouët et al. 2001, 2005b;
Palandro et al. 2003, 2008; Andréfouët 2008; Knudby et al. 2009). These studies
have primarily focused on the context of assessing impacts of disturbances such as
420
S. Jupiter et al.
in various combination with direct in-water damage assessment using photo or
video, have now become part of a common portfolio of tools to successfully assess
damage from ship groundings and monitor recovery over space and time.
15.3.4 Monitoring Temporal Changes
The previous case studies have shown how remote sensing can be used to provide
maps of coral reef properties at specific points in time with defined levels of detail
and areal extent. The logical extension of these applications is to reproduce the
maps of reef extent, geomorphic zonation, benthic communities, fish habitat, etc.,
at different dates and then map and quantify the nature of changes observed within
the coral reef over time. This feeds into one of the key requirements for science
and management: defining what is there and how it is changing over time.
Prior chapters have clearly demonstrated the ability of remote sensing to be
used at an operational level by government agencies, private companies and NGOs
for mapping the extent of reefs, biophysical composition and processes within
reefs, and the physical-biological oceanographic and meteorological parameters
affecting reef extent and growth. The majority of the satellite and airborne image
datasets collected to produce these maps can just as readily obtain repeat coverage
of the same area. This enables reef scientists to map changes in reef composition,
physical features and controlling processes to assess: the type and nature of
changes occurring; the level of natural variations and disturbances; and the direct
or indirect impact of human actions and management decisions (Jupp et al. 1985;
Dustan et al. 2001; Andréfouët and Riegel 2004; Knudby et al. 2007). While
mapping changes in reef extent, composition or habitat has predominantly been
completed using two successive dates of images, research applications are
emerging for mapping these features from long time series of satellite images,
aerial photography and field survey data. Below are two general examples of
image change and trend detection studies used for understanding and managing
reefs. The first example focuses on changes in characteristics mapped between two
successive dates, and the second application covers a longer time series of multiple
(100–1,000 s dates) images.
There are relatively few publications in the peer-reviewed literature covering
operational mapping of changes in coral reefs between two successive dates. Most
of the published studies report results from the map producer’s point of view,
focusing on the techniques used, levels of accuracy obtained, and inference of the
natural or human processes that produced the observed changes. The most commonly reported examples have been for geomorphic zones and benthic communities, mainly using Landsat Thematic Mapper and now higher spatial resolution
multispectral satellites (e.g., Dustan et al. 2001; Andréfouët et al. 2001, 2005b;
Palandro et al. 2003, 2008; Andréfouët 2008; Knudby et al. 2009). These studies
have primarily focused on the context of assessing impacts of disturbances such as
420
S. Jupiter et al.