Ashoka Trust for Research in Ecology and the Environment

Muneeswaran Mariappan, Ph.D., Coordinator, Ecoinformatics Lab, Ashoka Trust for Research in Ecology and the Environment (ATREE)
Ashoka Trust for Research in Ecology and the Environment (ATREE)
Tools Used
Google Earth Engine

The challenge and the organization

For more than 20 years, Ashoka Trust for Research in Ecology and the Environment (ATREE) has done research in India related to conservation, resource management and sustainable development.

The group has long had an interest in preserving one of India's most important protected areas, the Kalakkad Mundanthurai Tiger Reserve (KMTR) in the South Western Ghats in the southern Indian state of Tamil Nadu. KMTR, made up of wet forests on high elevations and dry forests in the foothills, is known for its abundance of animals and rare plants. The reserve is extremely biodiverse, and is home to 77 species of mammals, 273 species of birds, 81 species of reptiles, 37 species of amphibians, 33 species of fish, and many species of plants.

In 2007, ATREE implemented a conservation intervention program in KMTR to decrease local villagers' dependency on the forests for fuel and to build community awareness about the value of biodiversity. Ten years after that, it took on another challenge -- to provide the site specific and precise forest type information that scientists and policy makers need in order to protect the tigers and elephants living on the preserve.

How they did it

The key to protecting tigers and elephants is understanding their habitats. “Our goal is to provide basic information about the types of vegetation on the reserve,” says Muneeswaran Mariappan, Ph.D., Coordinator, Ecoinformatics Lab, for ATREE. “That can then be combined with climate data, field data, socioeconomic information and more to understand the landscape and environment, and create policies to protect endangered animals.”

However, it is difficult to map the composition and ranges of the different types of forests, grasslands, and savannas in KMTR because the reserve is covered by clouds year-round, and satellite images cannot adequately display the landscape.

Mariappan uses Google Earth Engine’s public data catalog and analysis capabilities. He starts with multiple satellite images of KMTR. On the images, areas of the reserve are clear or partially clear on some days, and cloud-covered on others. Using Google Earth Engine, he stitches together the images across the entire reserve, and uses a masking algorithm to remove the cloud cover.

Next, he merges the cloud-free images for several seasons, for example, the summer and fall. Vegetation varies according to the season, so combining images in this way ensures the most accurate representation possible. Finally, using analysis tools in Google Earth Engine, Mariappan is building a highly accurate map of forests, grasslands, savannas and bodies of water on the reserve.


Using Google Earth Engine, ATREE is creating an accurate, comprehensive map of the KMTR’s vegetation and forests, providing the information policy makers need to protect tigers and elephants. The final report and analysis will be shared with the forest department of Tamilnadu. The department will then design policies, such as for wildlife monitoring and anti-poaching, to protect tigers, elephants and other wildlife and flora.

ATREE is also using Google Earth Engine for an interdisciplinary project studying how to optimize the sustainable use of forests while minimizing the impacts of emerging zoonotic diseases such as the fatal, tick-borne Kyasanur Forest Disease.

Mariappan cites Google Earth Engine as one of ATREE’s most important research tools for these projects and others. “Google Earth Engine is a great tool for doing the remote sensing analysis that agencies and policy makers need in order to protect endangered wildlife, preserve habitats and promote conservation, resource management and sustainable development,” he says. “We simply couldn’t create the kind of maps that provide the detailed information we need without it.”