Murray, A BradChambers, Joseph2016-04-292016-04-292016-04-29https://hdl.handle.net/10161/11938Coastal Dynamics of Sumber Sari Coast Bali, Indonesia and Implications for Environmental Management By Joe Chambers Advisor: Dr. Brad Murray Executive Summary People from around the world visit Bali Island, Indonesia for its sandy coastlines, mountainous tropical forests and distinctive culture. Approximately three million tourists (not including Indonesian nationals) visited Bali in 2013, constituting its primary economic resource (Atmodjo 2013) and affirming its reputation as an international vacation destination. In addition, the ministry of tourism hopes to achieve a 15% increase in foreign arrivals by 2019, suggesting Bali is unlikely too see any curb in growth in the near future (Rachman 2015). The southern tourist hubs of Bali such as Kuta Beach, Seminyak and Nusa Dua have witnessed rapid growth since the 1970s. The rapid increase in development coupled with essentially non-existent regulatory framework or coastal zone management plans results in the degradation of the beach environment (Onaka 2012). Lead causes of erosion in the tourist hubs include sediment mining, coral mining and the increased construction of dams. Recent nourishment and shoreline maintenance activities within island tourism hubs highlight the need for revisions to regulatory framework and availability of technical information regarding coastal geomorphology. To receive a building permit within Bali, signatures granting permission are required from government leaders at the village-community level. Community level environmental leaders thus hold the potential to make more sound choices when it comes to developing the their coastline. The interplay between development and shoreline erosion is significant to the Balinese people because to them a beach provides more than economic benefits–it also plays a significant role in cultural and religious activities. Sumber Sari Village located in the Melaya district of Bali exhibits sparse tourism, yielding appeal to outside development. In this project, I assesses the coastal dynamics of Sumber Sari coast by use of historical satellite imagery, beach sediment analyses and field observations to comprehend sediment sources, pathways and sinks—factors that dictate a shoreline’s equilibrium state. A health assessment of the community’s beach shoreline--the community's most valuable asset—could enable community leaders to manage this asset sustainably. Given the results, I also address questions put forth by community members and possible investor(s) regarding what they perceive as solutions to an eroding shoreline (specifically the use of groins adjacent to beach properties and the potential of a beach nourishment project). To provide comparative analyses, beach grains from Sumber Sari are compared to non-native fill sand from a resort beach. Information on the non-native fill sand suggests how its introduction to Sumber Sari could affect the geomorphology of the coast. Initial inferences suggest three possibilities for a sediment source: rocky headland, coral reef or coastal stream. Results of my analyses indicate that beach sediments at the Sumber Sari beach originate inland and enter the beach environment via coastal streams, and are then transported northward via alongshore transport, all of which occurs over a relatively short time period. Aerial photographs suggest the coast remains in an equilibrium state—the shore does not appear to be accreting or eroding at a discernable rate. However, a reduction in sediment load within the coastal stream by way of damming, diversions, increased withdrawals or significant lad use change would likely result in the significant changes to the coast within a relatively short period of time. The construction of groynes adjacent to beachfront properties will create a sand deficit on the north side of the structure, given the northward direction of net alongshore transport. Likewise, a nourishment project utilizing sediment similar to that of the non-native sand sample would create a groin effect due to the differences in grain size and its effects on fall velocity and thus alongshore transport. The short residence time of beach sediments implies a reduction in sediment load to the coast would result in rapid erosion. If community level managers intend to maintain the longevity of their shoreline, it is of utmost importance that the influx of sediment remains unchanged, to avoid the need for ongoing beach nourishment, as occurs on other parts of the island. An expensive large-scale endeavor, nourishment projects are not solution but only treatments for an eroding shoreline. In a developing country such as Indonesia, there exists a serious opportunity cost for undergoing such an intensive unsustainable projects. These funds could be utilized for needs in education and public services. With a better understanding of local coastal dynamics, community leaders hold the power to apply sound coastal and riparian zoning practices, possibly initiating a paradigm shift for the island, providing a lasting impact on how the island perceives sustainable coastal management.en-USBali, sediment load, coastal dynamics, beaches, IndonesiaMaster's project