In NISAR run-up, scientists to study forest biomass in select regions

Bengaluru: As the NASA-Isro Synthetic Aperture Radar (NISAR) programme picks pace with a series of pre-launch data validation exercises, Isro has commissioned scientists to undertake a project to assess forest biomass in three regions – Shivamogga in Karnataka, Nilambur in Kerala, and Hoshangabad in Madhya Pradesh.

The parameters measured in these regions, which include tree species, tree height and girth, canopy density, and wood and soil moisture, will be used to calibrate and validate data from the regions as mapped by NISAR.

NISAR, a low earth orbit observatory with a dual-frequency radar system jointly developed by NASA and Isro, is designed to map the entire globe in 12 days. It can generate high-resolution data that track changes in the earth’s ecosystems, from ice mass to vegetation to ocean levels, and natural hazards like earthquakes and tsunamis. The space agencies are planning a 2024 launch for the mission.

Led by Girish Gopinath, associate professor and head of remote sensing and GIS at the Kerala University of Fisheries and Ocean Studies (KUFOS), the scientists will collect Lidar (Light Detection and Ranging, a remote-sensing tool to study the earth’s surface), optical and in situ data over forest inventory plots in the three regions.

The first phase of the KUFOS-led project involved the validation of ground truth data from the regions. In January, Isro’s Space Applications Centre (SAC) in Ahmedabad approved the second phase, on a budget of Rs 44 lakh.

The ground-measured data and drone-based Lidar and optical data from the inventory plots will be used to validate one of NISAR’s key science products – the forest Above Ground Biomass or the total mass of living matter within a given unit of forest area.

Stimulating new research

Under the NISAR utilisation programme, SAC has identified multiple areas of engagement with India’s scientific community that include calibration and validation of data and science products from NISAR. Estimating forest biomass and carbon sequestration potential of Indian forests is one of the identified research areas.

“This is part of a global exercise aimed at validating NISAR data across areas of application. The team will function as a nodal agency for the work being done in South India. In the first phase, we used one-hectare plots to study the forest biomass; in the second phase, we will be working on plots with varied measurements, like 2.5 km x 3 km and 3 km x 5 km,” Gopinath, principal investigator of the project, told DH.

U Surendran, principal scientist at the Centre for Water Resources Development and Management, Kozhikode, and K A Sreejith, principal scientist at the Kerala Forest Research Institute, are co-investigators in the project.

The scientists pitch the research as an exercise that can significantly advance the understanding of forest ecosystems and hydrology. Gopinath said the team would monitor forest biomass in the identified regions for over 10 years.