Authors

Anh Bui Khanh Van 1*

Affiliations

1 Ho Chi Minh City University University of Natural Resources and Environment; bkvanh@hcmunre.edu.vn; bkvanh2020@gmail.com

*Corresponding author: bkvanh2020@gmail.com; Tel.: +84–908836115

Abstracts

Can Gio Mangrove Biosphere Reserve provide many ecosystem services, such as provisioning, regulating, cultural, and supporting services for the urban areas as well as wildlife of suburban areas in Ho Chi Minh City and the nearby ecosystems. Therefore, it is important to monitor and evaluate the changing of mangrove forest cover in the long term. In this study, the Normalized Difference Vegetation Index - NDVI at 10 m resolution from 2015 to 2023 of Can Gio was obtained from the Copernicus Sentinel-2 database using Google Earth Engine - GEE. Subsequently, NDVIs statistic were computed by R to assess the slope of NDVI changing with p-value significance in Can Gio. The results indicated that NDVI values typically range from -0.4 to +0.8 and vary annually. It is evident that NDVIs values from 2015 to 2020 are marginally higher than those recorded between 2021 and 2023. The degradation in average NDVI from 2015 to 2023 was rationally deducible either from the downsizing of mangrove forest areas or the degradation of the mangrove forest. However, the annual NDVI statistic revealed there were areas with an acceleration of NDVI in comparison with the destruction of NDVI areas from 2015 to 2023. Linear regression effectively models continuous processes like deposition or erosion. However, to evaluate other factors such as discrete human-made or sporadic impacts, alternative statistical models should be considered

Keywords

Normalized Difference Vegetation Index - NDVI; The Copernicus Sentinel-2 database; Can Gio; Spatial and temporal pattern.

Cite this paper

Anh, B.K.V. Evaluation of the Can Gio Vegetation Index Changing by the Sentinel-2 Datasets from 2015 to 2023. J. Hydro-Meteorol. 2024, 18, 24-37.

References

1. Shigeyuki, B.  Studies in Can Gio mangrove biosphere reserve, Ho Chi Minh City, Viet nam. International Society for Mangrove Ecosystems (ISME), 2014, 6, pp. 63.

2. Vinh, T.V.; Marchand, C.; Linh, T.V.K.; Jacotot, A.; Nho, N.T.; Allenbach, M. Soil and aboveground carbon stocks in a planted tropical mangrove forest (Can Gio, Vietnam. Chapter 12 in Wetland Carbon and Environmental Management, Wiley. 2021, pp. 229–245. doi: 10.1002/9781119639305.ch12.

3. Torell, M.; Salamanca, A.M. Wetlands Management in Vietnam’s Mekong Delta: An Overview of the Pressures and Responses. Environmental Science, Geography, 2003, pp. 1–19.

4. Vien, N.N.; Le, T.Q. Erosion and Accretion in Can Gio Mangroves. in Studius in Can Gio Mangrove Biosphere Reserve, HCMC, Viet Nam. Int. Soc. Mangrove Ecosyst. 2014, V6, 31–36.

5. Hoan, H.D.; Kiet, B.N.T.; Binh, C.H.; Quy, P.V. Monitoring Riverbank Erosion in Can Gio mangroves. In Studius in Can Gio Mangrove Biosphere Reserve, HCMC, Viet Nam, 2014, V6, 37–43.

6. Vien, N.N.; Le, S.V.; Miyagi, T.; Baba, S.; Chan, H.T. An Overview of Can Gio District and Mangrove Biosphere Reserve. 2014. ISSN 0919-2646 V6.

7. Sugara, et al. Utilization of Sentinel-2 Imagery in Mapping the Distribution and Estimation of Mangroves’ Carbon Stocks in Bengkulu City. Geosfera Indonesia 2022, 7(3), 219. Doi:10.19184/geosi.v7i3.30294.

8. Hirata, Y.; Tabuchi, R.; Patanaponpaiboon, P.; Poungparn, S.; Yoneda, R.; Fujioka, Y. Estimation of aboveground biomass in mangrove forests using high-resolution satellite data. J. For. Res. 2014, 19(1), 34–41. Doi:10.1007/s10310-013-0402-5.

9. Vu, T.T.P.; Pham, T.D.; Saintilan, N.; Skidmore, A.; Luu, H.V.; Vu, Q.H.; Le, N.N.; Nguyen, H.Q.; Matsushita, B. Mapping Multi-Decadal Mangrove Extent in the Northern Coast of Vietnam Using Landsat Time-Series Data on Google Earth Engine Platform. Remote Sens. 2022, 14, 4664. https://doi.org/10.3390/rs14184664.

10. Meneses-Tovar, C. NDVI as indicator of degradation. Unasylva 238, 2011, 62(2), 39–46.

11. Le, H.T.; Tran, T.V.; Gyeltshen, S.; Nguyen, C.P.T.; Tran, D.X.; Luu, T.H.; Duong, M.B. Characterizing Spatiotemporal Patterns of Mangrove Forests in Can Gio Biosphere Reserve Using Sentinel-2 Imagery. Appl. Sci. 2020, 10, 4058. https://doi.org/10.3390/app10124058.

12. Schmid, J.N. Using Google Earth Engine for Landsat NDVI time series analysis to indicate the present status of forest stands. Thesis for: Bachelor of Science, 2017, pp. 33. doi: 10.13140/RG.2.2.34134.14402/6.

13. Townsend, J.T. Theoretical analysis of an alphabetic confusion matrix*. Percept Psychophys 1971, 9, 40–50.

14. Kuhnert, M.; Voinox, A.; Sppelt, R. Comparing raster map comparison algorithms for spatial modelling and analysis.  Photogramm Eng. Remote Sens. 2005, 71(8), 975–984.

15. Mchugh, M.L. Interrater reliability: the kappa statistic.

16. Ehsan, S.; Kazem, D. Analysis of land use-land covers changes using normalized difference vegetation index (NDVI) differencing and classification methods. Afr. J. Agric. Res. 2013, 8(37), 4614–4622. Doi:10.5897/ajar11.1825.

17. Nguyen, T.P.C.; Le, T.H.; Nguyen, T.O.; Le, C.L.; Ha, T.C. Vegetation Indices for Spatio-Temporal Analysis of the Quality of Can Gio Mangrove for Biodiversity and Conservation. Proceeding of the IOP Conference Series: Earth and Environmental Science, Institute of Physics. 2023, 1247(1), 012003. Doi: 10.1088/1755-1315/1247/1/012003.

18. Lap, Q.K.; Luong, V.N.; Hong, X.T.; Tu, T.T.; Thanh, K.T.P. Evaluation of mangrove rehabilitation after being destroyed by chemical warfare using remote sensing technology: A case study in can gio mangrove forest in mekong delta, southern Vietnam. Appl. Ecol. Environ. Res. 2021, 19(5), 3897–3930. Doi: 10.15666/aeer/1905_38973930.

19. Nguyen, H.H.; Quang, P.D.; Nguyen, V.D.; Linh, D.V.K.; Manh, N.K. Management of forest resources and environment estimation of mangrrove carbon stocks using Sentinel 2a and field-based data in Tien Lang district, Hai Phong city.  Manage. Forest Resour. Environ. 2020, 10, 48–58.

20. Nguyen, S.T.; Bui, T.X.; Chau, D.T. Monitoring mangrove forest changes from multi-temporal Landsat Data in Can Gio Biosphere Reserve, Viet Nam. Wetlands 2016, 212, 635–640. Doi: 10.1007/s13157-016-0767-2.