Field et al. (2008) utilized SHOALS LiDAR data combined with NOAA aerial
photographs from the island of Molokai to study shallow-water coral reef development and response to sedimentation. The study area included a 40 km fringing
coral reef located on the southern coast of the island of Molokai in the main
Hawaiian Islands. Molokai’s south shore is well protected from storm surge and
wave energy and this has allowed for the development of one of the largest
continuous fringing reefs in Hawaii. In addition, the steep terrestrial slopes and
extensive runoff of upland soils has impacted coral reefs along the south shore.
The fusion of aerial photography (2D) and bathymetric LiDAR (3D) were supplemented with in situ observations to infer linkages between the morphological
patterns in reef structure and the coastal processes that shaped this reef tract. For
instance, the LiDAR data highlighted a pronounced channel in the fringing reef off
the coast that was formed from stream erosion during a period of lower sea-level
(Fig. 6.9; Field et al. 2008; Storlazzi et al. 2008).
Fig. 6.9 The coastal area at Palaau is characterized by an extensive mud and salt flat (1) that
formed from heavy flooding and run-off in the early 1900s and an extensive mangrove forest (2)
that was started in 1903 to curb the heavy sediment run-off. The elongated structure (3) east of the
mangroves is a shrimp farm. The reef at Palaau is dissected by a meandering channel (4) that
resulted from erosion during a period of lower sea-level ([12,000 years ago). Note that the reef is
not breached at the end of the channel (5), possibly because the water flowed through the porous
reef rather than over it. East of the channel the reef flat is a broad, barren surface (6) covered by
thin deposits of muddy sand. The middle part of the reef is characterized by large pits (7), which
likely result from extensive, long-term karstic dissolution by fresh water flowing through the reef
(adapted from Field et al. 2008, courtesy USGS)
6 LiDAR Applications
159
photographs from the island of Molokai to study shallow-water coral reef development and response to sedimentation. The study area included a 40 km fringing
coral reef located on the southern coast of the island of Molokai in the main
Hawaiian Islands. Molokai’s south shore is well protected from storm surge and
wave energy and this has allowed for the development of one of the largest
continuous fringing reefs in Hawaii. In addition, the steep terrestrial slopes and
extensive runoff of upland soils has impacted coral reefs along the south shore.
The fusion of aerial photography (2D) and bathymetric LiDAR (3D) were supplemented with in situ observations to infer linkages between the morphological
patterns in reef structure and the coastal processes that shaped this reef tract. For
instance, the LiDAR data highlighted a pronounced channel in the fringing reef off
the coast that was formed from stream erosion during a period of lower sea-level
(Fig. 6.9; Field et al. 2008; Storlazzi et al. 2008).
Fig. 6.9 The coastal area at Palaau is characterized by an extensive mud and salt flat (1) that
formed from heavy flooding and run-off in the early 1900s and an extensive mangrove forest (2)
that was started in 1903 to curb the heavy sediment run-off. The elongated structure (3) east of the
mangroves is a shrimp farm. The reef at Palaau is dissected by a meandering channel (4) that
resulted from erosion during a period of lower sea-level ([12,000 years ago). Note that the reef is
not breached at the end of the channel (5), possibly because the water flowed through the porous
reef rather than over it. East of the channel the reef flat is a broad, barren surface (6) covered by
thin deposits of muddy sand. The middle part of the reef is characterized by large pits (7), which
likely result from extensive, long-term karstic dissolution by fresh water flowing through the reef
(adapted from Field et al. 2008, courtesy USGS)
6 LiDAR Applications
159