Cycle 5 (2015 Deadline)
GIS and remote sensing application for assessment of land degradation in the Lower Mekong River Basin
PI: Quyet Vu (email@example.com), Soils and Fertilizers Research Institute
U.S. Partner: John Bolten, National Aeronautics and Space Administration (NASA), Goddard Space Flight Center
Project Dates: December 2016 - November 2018
Land and forest are being overexploited in the Lower Mekong River Basin (LMB) due to the pressure of rapid economic development and high population growth. These factors may impact the functions and services of land ecosystems, including biomass productivity. Because human livelihoods in the LMB still rely strongly on agricultural production, land degradation will be a significant issue for development strategies. In tropical regions, poverty and land degradation are often part of a downward spiral: poverty and economic marginalization lead to overexploitation of land resources, resulting in land degradation, which then leads to more serious poverty. To combat land degradation, policy makers often need information to identify areas of most intense degradation in order to plan strategic interventions. The specific objectives of this project include
The map of land degradation hotspots to be created may help researchers and policy makers identify locations in the LMB where more detailed actions may be required. Through project activities, team members will improve their research capacity and knowledge regarding applications of geographic information systems (GIS) and remote sensing (RS) for assessing natural resources. Land degradation is also linked with biodiversity loss and climate change at the global and local levels, so this project should also help to serve as a reference database for further studies on climate change impacts, adaptation, and mitigation of emissions from land use in the agriculture, land cover, and forestry sectors. The project team will be supported by U.S. partner Dr. Bolten, who has experience in remote sensing research in the same region. He and other NASA colleagues will check the Vietnamese researchers’ analyses and calculations of geospatial data and contribute their expertise to other project activities, including technical workshops and joint publications.
- Producing a map of geospatial biomass productivity decline for the LMB (Vietnam, Laos, Cambodia, and Thailand), using long-term biomass productivity trends as a proxy for land degradation;
- Differentiating human-induced land degradation from climate-driven signals by examining the temporal correlation between long-term biomass productivity trends and climate data; and
- Identifying potential underlying processes (population density, soil/terrain conditions, and land-cover types) that affect land degradation.
|The team introduces the project to the local research community.||Key team members review available maps and satellite images.|
Summary of Recent Activities
In the second and third quarters of 2017, Dr. Vu and his team focused on compiling and analyzing data to address the main objectives of their project: (1) identifying and tracking trends in biomass decline during the period 1982 through 2015 and (2) separating out human-induced land degradation from climate-driven signals. They analyzed trends in the Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) for the Lower Mekong River Basin (LMB) and calculated the annual climatic research unit time series (CRU TS) for temperature and rainfall from 1982-2015. The annual mean GIMMS NDVI (period 1982 - 2015) was calculated and clipped, or matched, with the boundary of research area (including administrative boundaries of Vietnam, Laos, Cambodia and Thailand extracted from the Database of Global Administrative Areas - GADM). Dr. Vu’s team then analyzed the spatio-temporal trend of inter-annual mean NDVI over 34 years. The next step was to correlate trends in the vegetation index with data on annual rainfall to try to identify places where precipitation changes were affecting the vegetation and places where human-induced land degradation was the main factor in the vegetation changes. In general, the team has achieved their planned milestones as of the end of the first year of the project, and in the coming year they will continue similar data compilation and analysis but at a finer resolution and over a shorter period (2001-2016).
The PI and his group have prepared a manuscript summarizing their first year’s results, which is entitled “Analyzing the trend of AVHRR NDVI time-series to identify the hotspots of land degradation in the Lower Mekong River Basin countries.” They will present their work at the GIS conference Water Resources Security and Climate Change 2017, which will be held at Quy Nhon University, Vietnam, November 30 – December 2, 2017. Plans for sending team members to the United States for training in Year 1 were delayed due to the busy schedule of their U.S. partner, but they are working to find a feasible time for the visit in early 2018. Meanwhile, Dr. Vu will also be serving as co-PI on a new project entitled “Developing and promoting market-based agroforestry and forest rehabilitation options for northwest Vietnam,” funded by the Australian Centre for International Agricultural Research (ACIAR) through the World Agroforestry Centre (ICRAF). He is co-leading Objective 2 on the project, “To understand suitability of different agroforestry options in relation to different contexts, and create linkages to markets and government programs and policies to scale up adoption.” This new effort fits in well with the PEER-funded project, as the data collected and analyzed for spatial analysis on the PEER project can also be used for identifying current status and tracking previous trends of land use and land cover in the study areas of the new project. The climate data can also serve as a reference source for land evaluation to identify the suitability levels of crops and trees that might be planted at various sites.
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