Impacts of Future Flood Risks to Agricultural Land Use and Human Settlements in the Western Mekong Delta of Vietnam
Abstract
In an effort to protect the Mekong River, agricultural ecosystems, and the larger hydrological system of the Mekong Delta from rising sea levels, the government of Viet Nam has implemented precautions to preserve the freshwater status of its Delta. These precautions, including government-funded sluice gates and farmer-supported irrigation wells, have had unintended consequences, including increased fertilizer and human waste pollution in the Mekong River. A reliance upon ground wells for irrigation and drinking water has also increased, leading to ground subsidence that is combined with subsidence caused by rising sea levels due to climate change. The Mekong Delta is home to extensive river and canal networks are crucial for agricultural production, particularly rice paddy, and are impacted by increased flood risk. For this analysis, we combined 30 m Landsat 8 Operational Land Imager (OLI) Normalized Difference Water Index (NDWI), 30 m Shuttle Radar Terrain Mapping (SRTM) digital elevation data, 30 m Global Cropland Product from Thenkabil et al. (2012) and Teluguntla et al. (2014), and human settlement location data from the Humanitarian Data Exchange (2018) in Google Earth Engine and ESRI ArcMap to analyze and visualize current and future flooding risks to agricultural fields and human settlements, including many rural communities. We modeled 2017 extreme flood levels in the western Mekong, focusing on An Giang and Đồng Tháp provinces and surrounding areas, and estimated what extreme flood levels will look like in 2050 given sea level rise predicted by Erban et al. (2016). A list of threatened agricultural fields and human communities was created. We estimate 9,420 km2 of predominantly rice paddy agriculture in the Mekong Delta in Viet Nam are now more likely to be at risk from extreme flooding given human and climate change-caused ground subsidence.
Citations Erban, L.E., Gorelick, S.M. and Zebker, H.A., 2014. Groundwater extraction, land subsidence, and sea-level rise in the Mekong Delta, Vietnam. Environmental Research Letters, 9(8), p.084010. doi:10.1088/1748-9326/9/8/084010. Human Data Exchange, 2018. Version 1.21.6, Online: https://data.humdata.org/. Thenkabail P.S., Knox J.W., Ozdogan, M., Gumma, M.K., Congalton, R.G., Wu, Z., Milesi, C., Finkral, A., Marshall, M., Mariotto, I., You, S. Giri, C. and Nagler, P. 2012. Assessing future risks to agricultural productivity, water resources and food security: how can remote sensing help?. Photogrammetric Engineering and Remote Sensing, August 2012 Special Issue on Global Croplands: Highlight Article. 78(8): 773-782. Teluguntla, P., Thenkabail, P.S., Xiong, J., Gumma, M.K., Giri, C., Milesi, C., Ozdogan, M., Congalton, R., Tilton, J., Sankey, T.R., Massey, R., Phalke, A., and Yadav, K. 2014. Global Cropland Area Database (GCAD) derived from Remote Sensing in Support of Food Security in the Twenty-first Century: Current Achievements and Future Possibilities. Chapter 7, Vol. II. Land Resources: Monitoring, Modelling, and Mapping, Remote Sensing Handbook edited by Prasad S. Thenkabail.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMGC51G0870H
- Keywords:
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- 0402 Agricultural systems;
- BIOGEOSCIENCESDE: 1630 Impacts of global change;
- GLOBAL CHANGEDE: 1640 Remote sensing;
- GLOBAL CHANGEDE: 6309 Decision making under uncertainty;
- POLICY SCIENCES