HULHULE-MALE’ BRIDGE PROJECT

EIA for the proposed Hulhule-Male’ Bridge Project
maximum flow during the drastic falling of tide reduces to 25,307 m 3 /s from 26,271 m 3 /s, it
decreases about 4%.
6.1.3 Construction impacts on scouring, silting and coastal erosion
The Maldives islands and reefs, including the project area are formed through variations in the
sea level and due to ocean dynamics in the past 10,000 years. Its modern geomorphologic
system is the result of stable marine biological process and sedimentary processes occurring
within relatively stable hydrodynamic conditions. It is the product of biological processes and
sedimentary processes adapting to the dynamic conditions. Therefore, from the perspective of
natural evolution, the islands, reefs and atolls are relatively stable.
The base structure on both Male’ and Hulhule is its reef. It has solidified over hundreds of
thousands of years of coral accumulation. The present reef structure is the result of vertical
growth over the last 10,000 years. Similarly, the seabed within Gaadhoo Koa consists of a layer
of loose sand sitting on top of solidified reef structure dating back to the Pleistocene. Under
these circumstances, surface scouring of sand is unlikely to erode the underlying reef structure
both the reef slope and channel seabed.
The coastal environment of the coral islands are highly dynamic and can respond to
hydrodynamic changes by making significant changes to the beach size and location. The
proposed project is being carried out in a region where almost all island coastlines have been
protected through coastal engineering. In particular, the island of Male’ and Hulhule island have
their entire shoreline within the vicinity of the project site, protected using breakwaters. The only
exception is a relatively protected artificial beach. Therefore, it is unlikely that the project will
have any significant impact on coastal erosion.
Another characteristic of the coral islands and their beaches are their ability to grow through the
sand produced from the reef system. This process requires a number of factors but a critical
component is the wave processes operating around the reef. The proposed piers are located on a
reef slope where waves are generated. Reduction in wave energy and sediment transportation
patterns will deprive the island of the required sediments. However, as noted before, Male’
Island does not have a natural beach and therefore any effects on the waves not have a
significant effect on the island beach system.
This report uses the relatively simple semi-empirical and semi-theoretical approach which is
tested by engineering practice to calculate the annual silting impacts on the channel bed after
construction. According to simulated results, back-silting area is mainly on both sides of bridge
line. The back-silting strength near the bridge approach and the pier of main bridge has the heist
siltation, with a local maximum back-silting about 0.30 m/a. The back-silting strength at the
Prepared by: CDE Consulting & China Shipping Environment Technology
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