Mapping Deforestation
Using Land Cover and Vegetation Continuous Fields to highlight land cover changes.
National Geographic Style Map
The southeastern Asian country of Cambodia continues to struggle with extensive loss of its forests. In 2013, Dr. Matthew Hansen and colleagues found that Cambodia lost nearly 12,600 square kilometers of forest from 2000 to 2012. This ranked fifth worldwide for the time period (Hansen et al. 2013). Since 2012, Cambodia has continued to experience forest loss at alarming rates, loss that has extended even into the country’s national parks and protected areas. Large scale vegetation loss, or gains, can be monitored using Earth observation land data products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on-board the Terra satellite. Data products like these are archived and distributed free of charge by NASA’s Land Processes Distributed Active Archive Center (LP DAAC). Specifically, data products that contain variables such as Land Cover Classification ( MCD12Q1.006 ) and Percent Tree Cover ( MOD44B.006 ) can provide information on vegetation change through time going back to the year 2000.
The MODIS Vegetation Continuous Fields data product (MOD44B.006) contains separate data layers that describe the Earth’s surface as percent tree cover, percent non-tree vegetation, or percent bare.
This image shows percent tree cover for March 6, 2001, over Cambodia. The data represent the percent of each pixel covered by tree canopy ranging from 0% (light green) to 100% (dark green).
This image shows percent tree cover for March 6, 2018, over the same geographic area. The data represent the percent of each pixel covered by tree canopy ranging from 0% (light green) to 100% (dark green).
International Geosphere-Biosphere Progamme (IGBP) land cover classification for 2001 using MCD12Q1.006. The MCD12Q1 Version 6 data product is derived using supervised classifications of MODIS Terra and Aqua reflectance data. Pay special attention to the several forest classifications (green) in eastern Cambodia.
IGBP land cover classification (MCD12Q1.006) for 2009. Both urban growth and deforestation are evident. Notice the capital city of Phnom Penh and its growth outward (red).
IGBP land cover classification (MCD12Q1.006) for 2018. These images show the growth of urban areas (red) and the change in forest cover (green) from 2001 through 2018.
Forest loss in Cambodia is largely driven by the replacement of forest stands with rubber tree plantations and urban growth (Deipart & Sem, 2015). An area hit particularly hard by the clearing of forests for commercial rubber tree plantations has been the province of Ratanakiri in the Northeast part of the country. Using the International Geosphere-Biosphere Programme (IGBP) land cover classification layer from the MCD12Q1.006 product, we can see that forest loss is extensive throughout Ratanakiri from 2001 to 2018, and that even the protected Virachey National Park is experiencing losses as well.
IGBP land cover classification (MCD12Q1.006) displayed over the province of Ratanakiri in northeastern Cambodia for the year 2001. As you scroll through the images, notice the forest retreating northward.
IGBP land cover classification (MCD12Q1.006) over Ratanakiri Province, Cambodia, for 2009. The loss of evergreen needleleaf forest is evident.
IGBP land cover classification (MCD12Q1.006) for Ratanakiri Province, Cambodia, for 2018. The change in forest cover (green) from 2001 is drastic.
Percent Tree Cover (MOD44.006) over Ratanakiri Province, Cambodia, for 2001.
Percent Tree Cover (MOD44.006) for 2018 over Ratanakiri Province, Cambodia, shows the drastic change in canopy from 2001 to 2018.
Additionally, due to Cambodia’s geographic location, it has become a major supplier of construction products to China. The non-profit U.S.-based Forest Trends (2015) reported that exports of rosewood (a highly sought after and valuable luxury timber product) to China increased by 1,250% between 2000 and 2015. In recent years, Cambodia has taken steps to quell the deforestation, among them the suspension of the country’s logging concessions around 2002; however, those suspensions have not had the positive impact that was projected, and timber extraction still exists through economic land concessions (ELCs) for agro-industrial plantations (Forest Trends 2015).
Products like MOD44B.006 and MCD12Q1.006 can be accessed via NASA's Application for Extracting and Exploring Analysis Ready Samples (AppEEARS) and can be used to better understand our changing landscapes.
References
Header image by Vladimir Mokry
For a list of references and data cited, click here (PDF, 77 kB).
Geo-narrative created by Jared Beck, KBR Inc., contractor to the U.S. Geological Survey
For more information, please contact:
USGS Earth Resources Observation and Science (EROS) Center
Sioux Falls, South Dakota 57198
Work performed under USGS contract G15PC00012 for LP DAAC
LP DAAC Work Performed under NASA contract NNG14HH33I.
All images by U.S. Geological Survey unless otherwise noted.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
