Space to Village: SERVIR-Himalaya fusing satellite-based observations with community forestry in Nepal

Forested areas are important to our planet's health because they take in large amounts of carbon and release oxygen. When forests are removed or degraded, less carbon is taken from the atmosphere, and the result is increased carbon emissions – which may hasten climate change and increase its impact. Primarily for these reasons, an initiative called REDD+, which stands for Reducing Emissions from Deforestation and forest Degradation, provides funds for tropical countries in proportion to their efforts to protect their forests and reduce greenhouse gas emissions, particularly CO₂.

Countries that have engaged with REDD+ need accurate information about their forests' extents and compositions (i.e., biomass) to assess carbon stores and develop forest conservation strategies. A major challenge, however, of awarding funds for positive changes in forest carbon stock is the identification of an accurate, reliable, and cost-efficient way to monitor forest change. 

As part of a project toward supporting REDD+ efforts and similar initiatives, SERVIR-Himalaya and its host organization, the International Centre for Integrated Mountain Development (ICIMOD), are performing a wall-to-wall assessment of Nepal’s forest carbon stocks. The project team is drawing upon (1) community-based forest monitoring that provided annual carbon measurements of hundreds of field plots, and (2) satellite-based assessments using many gigabytes of public domain satellite data. The team is integrating methods such as ground-based repeat photography (Figure 1), low-cost GPS-based data collection, and visual analysis of high-resolution satellite-based repeat images. 

Above: Repeat photographs of Charikot, Dolakha District, show the exact picture of development on the ground over time and the return of forests in the region. (Source: HELVETAS Swiss Intercooperation Nepal)

“Under SERVIR, we are collecting field data and integrating it with satellite data to develop a 30 m biomass map for all of Nepal,” explains Hammad Gilani, who leads the SERVIR-Himalaya/ICIMOD biomass mapping effort* in Nepal.

Through SERVIR/ICIMOD, Gilani connected with Dr. Ramakrishna Nemani, Dr. Sangram Ganguly, and Dr. Gong Zhang of NASA Ames Research Center (ARC). The ARC scientists had experiences to share in biomass mapping of the state of California. Gilani is working with the three researchers, learning how to apply similar methods using satellite data to assess carbon stocks in Nepal. Currently, community and state owned monitoring systems on the ground in Nepal are responsible for assessing and monitoring forest degradation and forest biomass. The country’s community forests are managed by Community Forest User Groups (CFUGs), and community forestry is recognized as a successful model for conserving forests, raising awareness among local people, and decentralizing forest governance practices. 

The CFUGs measure plot-level forest stock annually. While such monitoring of community forests is essential to assess positive and negative changes in biomass, field measurements and photographs can provide information on only a small area at a time and are quite labor intensive.

Remote sensing data from Earth observation satellites are a key input for scaling up ground-based assessments to a national level. They offer the advantages of a "big-picture" views of large areas – such as entire community forests – over different time periods, repeated data collection, and a digital format that allows for fast processing of large amounts of data. 

For example, in Figure 3, repeat satellite images (IKONOS [2002] and GeoEye-1 [2009 and 2012]) over selected community forests in the Kayar Khola watershed of the Chitwan District in Nepal clearly demonstrate how one can visually interpret and quantify the number and sizes of tree crowns, revealing impressive improvement of forest cover in the community forests.

Above: Improvement in forest cover in selected community forests, Kayar Khola watershed, Chitwan

The SERVIR/ICIMOD project is helping to fuse community-based monitoring with a satellite-based approach, providing the tools and methods for the quantification of community forests using medium to high resolution satellite images. The easily readable, repeat satellite images help CFUGs detect losses and gains in their forests’ biomass. And the satellite-based change measurements, integrated with annual measurements from community based permanent field plots, enhance the accuracy of biomass assessments for the entire community forest area.

In summary, integrating remote sensing observations with ground-based carbon assessments by local communities can improve efficiency of assessing and monitoring forest carbon. Local communities in Nepal are committed to REDD+ and to further improving forest conservation. High-resolution satellite images can complement their efforts by validating and supplementing their observations.

Notes:

*The biomass mapping effort is a collaboration of SERVIR/ICIMOD with the Biospheric Science Branch at NASA Ames Research Center. An online web application is under construction.