Academic Articles -- ޢިލްމީ ލިޔުންތަކުގެ ޖަމާ
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Item Environmental impact assessment report for the proposed housereef protection measures Chaaya Reef Ellaidhoo, North Ari Atoll, Maldives(2011-01) SandcaysThis report addresses the environmental concerns of the proposed immediate measures for the protection of South-West corner of the Chaaya Reef Ellaidhoo, located at eastern rim of the North Ari Atoll. In addition to immediate measures, long term monitoring, planning and mitigation has also been incorporated into the project. Chaaya Reef Ellaidhoo is 300 m long and 280 wide with a total land area at 55,626 m2 covered with common vegetation found in Maldives. The total built up area is recorded at 7,060 m2 (12.7% of total land area). The house reef of Ellaidhoo is considered to be one of the famous and attractive dive spots in Maldives. The island is one of the first resorts in the Maldives and has several coastal developments including offshore breakwaters, seawalls, jetties and water bungalows. There is no beach around the island except south west corner of the island and small isolated patches of beach. The beach formation at south-west corner of the island is severely transformed into tombolos and salients due to the several coastal structures present, including the harbour being located on this side. Consequently, almost every bit of sand on the beaches of Ellaidhoo has accreted in this area over the years, especially during the Northeast monsoon of each year, which is the peak tourist season, resulting in the loss of sand from the island beach system through openings in the offshore breakwater made of cement/concrete and coral rubble. Almost every diver complains about the heavy down pour of sand from this area, which happens to be the area in which the Dive School is located. They say it is like a raining of snowing with sand down there. Therefore, the Dive School, has been hoping for a solution to this growing concern and it is in a dire situation needing an immediate solution along with a long term management strategy. The proposed project is targeted to improve this serious situation. The proposed project involves two basic steps: first to remove or recycle the sand that has accumulated in the area over the past several years and then to correct the tombolo/salient formation and outflow of sand into reef flat at seaward side of the existing segmented offshore breakwaters at south-west corner of the island. Since a lot of sand has been deposited and the rate of accretion is high, manual removal of sand would not be useful. A machine-based approach is necessary and two such approaches have been proposed: one is to use sand pump and the other is to use an excavator to pump or move (recycle) the sand to another location. The sand pump is preferable given that the resort is operational resort and closing the area would not be possible as the area is the primary public area of the resort. If an excavator were to be used, the sand moving has to be done at night without disturbing the guests, which would be quite challenging. Therefore, the primary option is to use a sand pump in the location to recycle the sand. Although improving the offshore breakwaters in the area to minimize tombolo formation is the next step it is not any less important than the first step of moving the sand. For this, it is proposed to cut off sections of some of the longer breakwater barricades to improve flow and completely cut off the tombolos. However, this may mean that the sand will flow further towards the harbour area where sand will accumulate and find its way onto the reef again through the long breakwater in the harbour. Therefore, it would be necessary to ensure that sand removed from this area is recycled in such a way that the sand does not accrete only in this area. Therefore, retention structures such as headlands or groynes would be required in areas where the recycled sand would be placed. This will form the third most important component of the project. An estimated volume of about 4,500m3 of sand will be removed from the tombolos formed in the lee of the breakwaters at south-west corner of the island which will be used to nourish the eroded shoreline around the island, as the sand is part of the sand budget moving around the island. In order to create stable beaches in nourished areas, it may be necessary to remove the existing seawalls which tend to wash away the sand with the reflection of waves off its surface. The reef top just behind the offshore breakwaters is found not healthy with sand spits, rubbles and dead corals. However, the reef slope or edge of the reef is found with rich composition of fish communities and live corals. In the south west reef zone surveyed indicated with 30% of rubbles, 18% of dead corals and 14% sand cover. Live corals including Acropora digigate and Acropora Tabulae are at 9% and 13% respectively. At south east zone more than 40% found with dead corals and 28% of coral algae with 16% of live coral cover indicate the reef top is not healthy. At eastern zone the reef was found with 66% dead corals along with 18% coral algae. At north east reef zone 39% dead corals along with 34% of live corals were found including digitates and tabulae corals. Compared to reef areas surveyed south east reef zone found healthier compared to other sites. Sand cover is highest at south-west and south zone of the reef. The tombolo/salient formation and resultant sand flow onto the reef at south-west corner as discussed is the main issue that has been highlighted and also indicated by aerial photography and the results of the surveys. In order to carry out an in-depth examination of the situation of sand cover at seaward side of existing offshore breakwaters at south-west corner, an open dive was made by a certified diver in the EIA survey team along with a diver from Chaaya Reef Ellaidhoo. Approximately 18m deep dive to reef slope behind the breakwaters / jetty at south west corner of the island was made during data collection. The overall environmental impacts of the project have been assessed using appropriate matrices and the results indicated that the proposed project had net positive impact. Given that the project has major socio-economic and more importantly environmental benefits, it is recommended to allow the project to proceed as proposed. Environmental monitoring recommended for the project includes the monitoring of the shorelines and beach at project site before, during and after the proposed improvements and continuous monitoring of the shoreline and long shore as well as offshore currents around the island and bathymetry in the area. Annual monitoring reports have to be submitted to the Environmental Protection Agency during the monitoring period.Item Environmental impact assessment : proposed reclamation and coastal protection at SH. Komandoo(2011-04) SandcaysThis report addresses the environmental concerns of the proposed reclamation and coastal protection in Komandoo in Shaviyani Atoll. The primary objective of the project is to protect the island coastline, improve the coastal environment and at the same time increase land area to the greatest possible extent thereby addressing the current land shortage issues experienced by the island community. Komandoo is the smallest in size of about 9 hectares but the second most populated island in Shaviyani Atoll with a current population of about 1,800 people. As part of the coastal improvements under the project, the existing small harbour on the eastern side will be shifted offshore from its current location providing harbour front area and increasing the space for boat building and maintenance and other industrial activities. The east harbour re-development works include construction of jetty quaywall, breakwater, revetment and land reclamation to shift the harbour further out of the existing east shoreline of the island. This east harbour, however, fosters limited use in the northeast monsoon and complements the recently developed harbour on the south of the island. There are two options proposed for the coastal protection for the area from the north east to the northwest of the island. One option is to have the beach reclaimed to nearly the edge of the reef and protected by a revetment and the other option is to have breakwater segments in this area and set back the beach from the breakwaters to allow the formation of some length of beach after reclamation. During consultations with the community a unanimous decision was made by some community members in a meeting with the newly elected council members to have beach in at least one part of the island. As such the area on the west or southwest and southeast near the new harbour of the island has been discussed with preference given to the location on the west or southwest of the island. It was believed that the sand dredged from the redevelopment harbour on the east side will not be sufficient to cover area that has been proposed for reclamation. In order to cater for this the lagoon and channel to the south of the island was surveyed and investigated for the location of possible sand borrowing spot. It was found that due to the existing natural hydrodynamics around the island the sand seems to be safely dredged from this south location as continuous sand deposition from natural process of wave action exist in this area. Furthermore, the reef in this area seems to relatively dormant from the previous harbour constructions activities near this area. Hence, minimal adverse environment impacts are expected in considering this location as potential borrow area. The observations made around the island in the context of the extent of damage to the protection structures that currently exist, it was concluded that there impact of the waves and the elevation of the water levels seems to be sever and higher respectively on the south west side of the island. Hence, the suggested height of 1.4m for the breakwater in the south west area seems to be inadequate as the water levels seems to be elevated and caused breaching of the existing protection walls and resulted in extensive damage. These existing elevated water levels can be attributed to the atoll geomorphology and sea bed levels near and offshore surrounding areas. Another observation from the severity of the damage to the existing revetment suggests that material used for the coastal protection works for the new developments have to be more thoroughly addressed. The proposed geotextile bag construction does seem to be adequate at least in this area to able to combat the impact of the wave and current induced forces on any protection structure place in this location. Furthermore, some of the senior citizens on the island expressed a lot of apprehension towards the proposed use of geotextile containers/bags for the breakwaters and revetments of the island. The overall design seems to be appropriate, however, in terms of the structures and proposed dredge sand extraction zones, there are some areas around the island where the current proposed design needs to be modified and these are set out in the alternatives recommended. The beach areas especially on the north side of the island has fair bit of pollution in the lagoon due to dumping of island waste in this area and a solution needs to be provided for the management of the solid waste on the island. In addition, the reclamation activities in the project cover some of the sea out falls placed on the island and recommendations are made for the extension of these pipelines. Another aspect to be considered is the possibilities of flooding during rainy season due to the proposed reclamation encompassing nearly the entire existing beach line. Suggestions are made to improve drainage for the island after the reclamation activity is completed. Substantial raw data is available from research actives carried out on the surrounding lagoon of Komandoo Island and these are suggested to be used as baseline information for establishing environmental monitoring activities for the island. It is thus advised to use drogue studies and water quality studies of the island lagoon be carried out at least for two years from the time of commencement of the project. It is suggested that the monitoring programme will encompass the socio economic impacts including positive and negative responses of the recipient community towards the different aspects of the project during and post project implementation. The Environment Protection Agency is to be furnished with annual monitoring reports for the set monitoring period. The overall environmental impacts of the project have been assessed using appropriate matrices and the results indicated that the proposed project has net positive impacts. Given that the project has several socio-economic benefits and few negative environmental impacts, it is recommended to allow the project to proceed as proposed. The recommended alternatives are also considered appropriate given the need to protect the island from the ever present threat of damage to coastal structures and the need for additional land. In fact, the environmental impacts of the project are relatively mild in considering the net socio-economic benefits and the existing and cumulative impacts on the environment.Item Initial environmental examination (IEE) for beach nourishment : Soneva Gili Resort and Spa, North Malé Atoll(2010-09-01) SandcaysThis report addresses the environmental concerns of the proposed beach nourishment in Soneva Gili Resort and Spa. The primary objective of the project is to recover eroded beach by pumping sand from already excavated areas nearshore. The project encompasses sand pumping using a six or 8 inch sand pump mounted on a barge. The borrow sites for the proposed beach nourishment will be in the western side lagoon. The beach on the eastern side is severely eroded. The beach on Soneva Gili has been maintained through regular beach nourishment. However, this activity has been stopped by the Tourism Ministry recently as beach nourishment is an activity that requires environmental clearance as per the EIA Regulations of the Maldives. Due to the importance attached with beach as beach is one of the main elements of the tourism product of the Maldives, the Environmental Protection Agency has decided to allow temporary clearance for beach nourishment followed by a detailed assessment of shore protection measures. This Initial Environmental Examination (IEE) has been carried out in order to get temporary clearance for a one-time nourishment of the beaches of Soneva Gili. A detailed environmental assessment will be undertaken as soon as possible to ensure compliance as well as to manage the island beaches in a manner in which it has the least impact on the physical and biological environment of the island and requires least interventions. Sand pumping from nearshore locations has the potential to aggravate erosion as the borrow pits can become sediment sinks over a considerable period of time. If borrow areas are too close to the shore, the impact on the island shoreline and the erosion of the nourished beaches would be quite rapid. Therefore, it is recommended to keep the borrow areas as far as possible from the beach. The other possible impact would be the growth hindered patch corals within the lagoon. However, there are no coral patches within the lagoon which may be affected by the proposed beach nourishment activity. Given that biological resources are not directly affected, aesthetic concerns are of importance in the proposed project. Therefore, in order to maintain the aesthetic value of the beach and enhance the socio-economic benefits of the proposed project, it is important that immediate beach nourishment is undertaken. At the same time, it is necessary to ensure that all environmental concerns of future shore protection or beach enhancement activities are clearly established so as to minimize environmental impacts of such activities.