Using open-source remote sensing data and tools to monitor forest carbon in Bangladesh

15 Jun 2022
training visualising SAR data
A participant at the training visualising SAR data in a GIS environment (Photo: Utsav Maden/ICIMOD)

As storehouses for carbon, forests need to be conserved in order for effective climate mitigation to be achieved. In this regard, forest conservation is also essential for countries aiming to meet the emission goals and targets set by international protocols and agreements.

However, conducting conventional forest inventories and field-based measurements to quantify carbon stocks or estimate forest biomass is resource-intensive, time-consuming, and costly. Remote sensing tools can help overcome these problems. A viable option is synthetic aperture radar (SAR) remote sensing, which is equipped with cloud-penetrating capabilities. SAR can effectively measure and monitor forest biomass and forest carbon at national scales, particularly in tropical regions.

Forest carbon monitoring efforts in Bangladesh

The Bangladesh Forest Department (BFD) is working on establishing an accurate baseline of aboveground forest carbon in the country to help monitor future changes in forest carbon. This will also help Bangladesh avail of opportunities from REDD+, a global instrument for climate mitigation that requires participating countries to provide accurate carbon stock estimates for economic incentives.

Our SERVIR-HKH Initiative, a joint partnership between USAID, NASA and ICIMOD, has been supporting the BFD in adopting new technologies like SAR to monitor forest cover and estimate forest carbon, and training them in their use. We are also working with the BFD in customizing the Regional Land Cover Monitoring System (RLCMS) to cater to Bangladesh’s national needs.

presents on microwave remote sensing technology
Rajesh Bahadur Thapa, Science and Data Lead, ICIMOD, presents on microwave remote sensing technology at the training (Photo: Utsav Maden/ICIMOD)

SAR training for foresters

In March 2022, we organized a training for 11 BFD professionals – three of them women – at the department campus in Dhaka on the use of SAR for measuring and monitoring forest carbon. As a resource person, I was delighted to be part of a capacity building programme that enables individuals and institutions to adopt and implement Earth observation technology in their daily work.

Over the course of five days, we provided theoretical and practical knowledge of SAR data and its applications in estimating aboveground forest biomass and forest carbon. The training introduced microwave remote sensing, polarimetric SAR and its benefits, the different SAR missions, and SAR applications used in aboveground forest biomass estimation. Its practical sessions focused on installing the required software and providing participants with a walkthrough on downloading SAR data – Sentinel 1A and ALOS PALSAR mosaic datasets from open access hubs.

Later, we delved into using open SAR data, software, and tools; image pre-processing, stacking, and visualization; image colour interpretation with field data; information extraction, interpretation, and analysis; and building a forest carbon model. While a few of the participants knew the basics of remote sensing (RS) and Geographic Information System (GIS) prior to the training, they had not been able to use such knowledge in their daily work. Some participants had worked with remote sensing data. However, SAR was completely new for them.

Bringing participants of different age groups, academic and professional backgrounds, and varied technical skills and competencies on the same page was a bit challenging. However, participants actively engaged in all sessions, exhibited a high level of enthusiasm, and contextualized the learning from the training in their real work. Furthermore, they sought solutions to such problems. An active learning atmosphere and plenty of interactions with and among participants helped clear concepts further.

Speaking to the value SAR adds to remotely monitoring forest carbon data, Md. Tauhidor Rahaman, a forester, said, “Obtaining cloud-free data is a real limitation in remote sensing analysis. SAR can help overcome this and could enable a new era of forest management in Bangladesh.”

how to download SAR data from open access hubs
Sajana Maharjan, Remote Sensing and Geo-information Analyst, talking about how to download SAR data from open access hubs (Photo: Utsav Maden/ICIMOD)

Going forward

We plan to organise a follow-on training for our 11 participants to discuss the results obtained from their study and improve the forest carbon model further. Towards the end of the March 2022 training, we had formed four groups, with each undertaking one using BFD’s forest inventory data. The groups have agreed to communicating with the resource persons for any additional guidance they might need. We look forward to taking this work further in Bangladesh.

five-day training at the BFD campus in Dhaka, Bangladesh
Participants and resource persons of the five-day training at the BFD campus in Dhaka, Bangladesh (Photo: Utsav Maden/ICIMOD)



Sajana Maharjan

Remote Sensing and Geoinformation Analyst