Figure 5 - Coral reef and Seagrass Mapping in shallow waters of Ninh Hai – Ninh Thuan from VNREDSAT1 image base on BRI (le ) and DII (right) methods
Conclusion VNREDSAT1 is a very good resource for mapping seagrass beds and coral reefs on the Ninh Hai coast with a good overall accuracy of 72.38% and a Kappa coefficient of 0.56 using the DII method. This resource promises to be an efficient tool for the management and conserva on of underwater ecosystems in Vietnam. The total area of seagrass beds along the coasts of My Hoa – Thai An Ninh Thuan waters comprises 275.22 (ha). The total area of coral reefs comprises 772.45ha and is located along the coast on the outer parts of the seagrass area. It needs more research to determine, how deep the VNREDSAT1 image could map the coral reefs on the Ninh Hai coast
Acknowledgments We would like to thank the Vietnam Na onal project of “Building oceanographic data from VNREDSAT-1 on Ninh Thuan - Binh Thuan province for sustainable marine economic development” Project code: VT/UD-07/14-15 (supervised by Dr. Nguyen Huu Huan), belonging to Vietnamese Space Technology Program, which provided the budget and the en re survey data for this study. References Dai NH (2011): Seagrass in Vietnam. In: Seagrasses: resource status and trends in Indonesia, Japan, Malaysia, Thailand and Vietnam. Seizando-Shoten, Tokyo. Lyzenga DR (1981): Remote sensing of bo om reflectance and water a enua on parameters in shallow water using aircra and Landsat data Internaonal journal of remote sensing 2:71-82 doi:10.1080/01431168108948342. Nagelkerken I, van der Velde G, Gorissen MW, Meijer GJ, Van’t Hof T, den Hartog C (2000): Importance of Mangroves, Seagrass Beds and the Shallow Coral Reef as a Nursery for Important Coral Reef Fishes, Using a Visual Census Technique Estuarine, Coastal and Shelf Science 51:31-44 doi:h p:// dx.doi.org/10.1006/ecss.2000.0617 Sagawa T, Boisnier E, Komatsu T, Mustapha KB, Ha our A, Kosaka N, Miyazaki S (2010): Using bo om surface reflectance to map coastal marine areas: a new applica on method for Lyzenga’s model Interna onal journal of remote sensing 31:3051-3064 doi:10.1080/01431160903154341. UNEP (2007): Coral Reefs Demonstra on Sites in the South China Sea. UNEP/GEF/SCS Technical Publica on No.5. Yang D, Yang Y, Yang C, Zhao J, Sun Z (2011): Detec on of seagrass in op cal shallow water with Quickbird in the Xincun Bay, Hainan province, China Image Processing, IET 5:363-368 doi:10.1049/iet-ipr.2009.0392
Research communica ons - NF-POGO alumni Dr. Suriyan Saramul Lecturer, Chulalongkorn University, Thailand Wikipage: h p://www.nf-pogo-alumni.org/~Suriyan+Saramul
Surface current in the inner Gulf of Thailand revealed by land-based remote sensing ntroduc on Coastal environmental issues, such as oil spills and marine debris, are crucial problems that exist in many countries, and especially the developing countries. Such issues will directly impact marine organisms, for example, the oil slicks will block the sunlight to penetrate through the water, causing phytoplankton to be unable to photosynthesize. When an oil tanker crashes at sea, it is difficult to project the oil trajectories if there is no real me surface current observa on or opera onal oceanography system in the area. Moreover, real me current observa on, such as the one using oceanographic buoys, is costly and requires a lot of buoys in order to observe the spa al circula on pa ern of a large area. Remote sensing techniques are being developed to measure ocean surface proper es such as SST (sea surface temperature), SSH (sea surface height) and SSS (Sea Surface salinity). In addi on, land-based remote sensing, e.g. high frequency radar (HF Radar), is developed to measure the surface current and wave characteris cs of coastal areas. Surface currents obtained from HF Radar are es mated based on the Doppler shi of the radio signal that transmits from the sta on and receives the back sca ering signal (see more detail about HF Radar in Joseph (2014)). This technique gives a good spa al and temporal distribu on pa ern of surface currents. Since 2011, the Thai Meteorological Department (TMD) and Geo-Informa cs and Space Technology Development Agency (GISTDA) has implemented the HF Radar system to measure surface currents and wave characteris cs in Thailand waters.
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Contact us: tedwango10@gmail.com, info@nf-pogo-alumni.org, lilian.krug@nf-pogo-alumni.org NANO website: www.nf-pogo-alumni.org
