IRRI scientists publish article on using satellites to map a wide range of rice environments in Asia

Providing accurate, timely, and detailed information on staple crops like rice is the basis for food security policies. This is especially important in Asia where rapid changes in rice sector policies, market preferences, land use, water availability, and climate are occurring simultaneously.  Since 2012, IRRI has been collaborating with partners in Europe and Asia on the RIICE (Remote Sensing based Information and Insurance for crops in Emerging economies) project to build in-country capacity to use satellite information for rice crop monitoring in Cambodia, India, Indonesia, Philippines, Thailand, and Vietnam.

In November, IRRI scientists Dr. Andrew Nelson, Dr. Tri Setiyono and colleagues published the first major scientific output from RIICE, Towards an Operational SAR-Based Rice Monitoring System in Asia: Examples from 13 Demonstration Sites across Asia in the RIICE Project. The study is the largest of its kind and was conducted in collaboration with Sarmap, Philippine Rice Research Institute, ICALRD (Indonesia), TNAU (India), GISTDA (Thailand), TRD (Thailand), Can Tho University (Vietnam), IMHEN (Vietnam), CARDI (Cambodia), GIZ-India, SDC-Cambodia and SDC-Vietnam. The article focuses on the use of Synthetic Aperture Radar (SAR) imagery which is highly suitable for detecting lowland rice, especially in tropical and subtropical regions, where pervasive cloud cover in the rainy seasons prevents the use of optical imagery. Hence, the study shows how a simple, robust, and rule-based classification algorithm can be used to map rice areas using regularly acquired, multi-temporal SAR imagery across a wide range of rice environments in Asia.

The paper presents rice monitoring results from 13 study sites across six countries. Project partners conducted more than 1,900 in-season site visits across 228 monitoring locations in the study sites and a further 1,300 field observations were made for accuracy assessment. Some 1.6 million hectares of rice areas were mapped with classification accuracy at field level between 85% and 95%.
The article recommends that the time is right for the development of national scale rice crop observation systems using this technology.  New satellite platforms such as Sentinel-1, ALOS-PALSAR-2 and RISAT-1 can provide free or low cost imagery over Asia which can be analyzed using RIICE technologies to provide monthly information on rice area, planting dates, yield estimates, and the impact of calamities like tropical storms and drought.   Such information would support governments in planning and policymaking, and other stakeholders such as crop insurance or disaster response units. It will also help IRRI and other research partners in better understanding current and future trends in rice production for better targeted research.

Better information for food security in a changing climate is essential as highlighted recently by the UN:

“Data are the lifeblood of decision-making and the raw material for accountability. Without high-quality data providing the right information on the right things at the right time; designing, monitoring and evaluating effective policies becomes almost impossible.” A World that Counts – UN Data Revolution, November 2014  

IRRI—through RIICE Phase II (2015-2018)—is committed to working with national partners to ensure that the capacity to use this technology is developed in-country. The aim is to provide governments and other stakeholders with national scale information on the rice crop that will ultimately benefit both rice producers and consumers.  RIICE Phase I has been supported by SDC and the Global Rice Science Partnership.

View publication | http://www.mdpi.com/2072-4292/6/11/10773
Read more about the RIICE project |  http://www.riice.org

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International Rice Research Institute (IRRI)
Philippine Rice Research Institute (PhilRice)
Indonesian Center for Agricultural Land Resources Research and Development (ICALRD)
Tamil Nadu Agricultural University (TNAU)
Geo-Informatics and Space Technology Development Agency (GISTDA)
Thailand Rice Department (TRD)
Can Tho University (CTU)
Institute of Meteorology, Hydrology and Environment (IMHEN)
Cambodian Agricultural Research and Development Institute (CARDI)
Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ)
Swiss Agency for Development and Cooperation (SDC)

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