Tracking Forests from Space

This year’s Climate and Society class is out in the field (or lab or office) completing a summer internship or thesis. They’ll be documenting their experiences one blog post at a time. Read on to see what they’re up to.

Credit: Stephen Thomas/Flickr

By Yixing Zhu, C+S ’15

What can you see from space? Ed Lu, the science officer from Expedition Seven aboard the International Space Station, states that people can see an awful lot from space: ocean, desert, forest, glaciers; even things as small as a road, harbor and ships.

And with rapid development of better sensors and remote sensing techniques, people have access to ever more information through the remote sensing images including monitoring forests. Today, scientists are developing an index to assess the healthiness, density and size of forests in Indonesia. They share the images and analysis results in Global Forest Watch (GFW).

Indonesia is one of the countries that scientists are paying much closer attention to not only because Indonesia has a large rainforest but also because Indonesia is the world’s third largest emitter of greenhouse gases, driven in large part by deforestation, peatland degradation and forest fires. People cut down trees for economic interest, and they also develop peatland for urbanization. Forest fires that are deliberately lit by farmers or timber and oil palm plantation owners destroy millions of acres of rainforest.

On the other hand, forests feed millions of plants and animals, which provide economic value and ecosystem services that support the daily life of more than 60 million Indonesians. That means land use change has both ecological and social impact. More than $400 million was lost because of deforestation directly while there are still more than $550 million in economic losses due to the human health and water and air pollution due to deforestation.

There were more than 2 billion tons of carbon dioxide (CO2) released because of the deforestation and land use change in 2007. In comparison, the CO2 emitted due to energy production, agriculture and waste was only 400 million tons.

Continuous monitoring of forest degradation is an important tool in identifying and tracking threats to forests and delineating vulnerable forests at a regional scale.

I am working with GFW to developed remote sensing capabilities and protocols to continuously monitor fires, and eventually other types of forest degradation. Remote sensing can detect the change of land use, especially forest and grassland by looking at their density or health using  different vegetation indices. Comparing the distribution, density and health of forests during the last 20 years, deforestation can be detected and people can figure out the relationship between greenhouse gas and land use change.

With little environmental knowledge, people cannot understand the complicated raw data. That’s why I’m helping develop a new website with maps that make the change in tree cover clearer. Images and graphs are a method to help general public access useful information in a short amount time and decision makers come to clearer decisions.

Credit: Global Forest Watch

In the map above, the purple color represents the tree cover gain while the pink areas are the places that tree cover loss has taken place over the last 10 years. This map provides a visible signal for the decision maker. The northwest part of Indonesia is one hot spot for land use change. Therefore, the Indonesian government has taken several actions to reduce the deforestation and increase forest cover. All the environmental workers and many stakeholders in Indonesia’s forests are trying to take actions to reach the goal to reduce greenhouse gas emissions 26 percent by 2020.

In addition to decision makers, GFW is trying to also connect the general public with forest data. GFW has developed an SMS tool to provide real-time alerts. Once the satellite gets the signal of high temperature, it will text or email an alert to the forest guard and fire station. Thus, people can be aware of bad fire conditions and avoid undue economic losses. Besides the website, social media like Twitter and Facebook also help keep people informed about what’s happening in their neck of the woods.