Center of Studies in Resources Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India.
AICTE NEAT, Ministry of Education, Govt. of India, Ranchi, 834 004, Jharkhand, India.
Environ Monit Assess. 2022 Nov 4;195(1):71. doi: 10.1007/s10661-022-10657-w.
Forests absorb atmospheric carbon and hence play a vital role in carbon sequestration and climate regulation. Recent research emphasizes developing technology and methods to understand the carbon sequestration potential in various forest ecosystems. Forest stand height estimation is one of the crucial parameters in allometry that estimates forest biomass. An attempt is made in this study to map forest stand height in tropical and sub-tropical forests in India using recently launched spaceborne LiDAR platforms Ice Cloud and Elevation Satellite (ICESat-2) and Global Ecosystem Dynamics Investigation (GEDI). A geostatistical kriging approach is used to interpolate the forest stand height, and the generated stand height surface is validated using ground truth samples. The results showed that GEDI data performed better with an RMSE of 3.99 m and 2.62 m in tropical forests than the ICESat-2 data, which showed an RMSE of 5.71 m and 5.08 m, respectively. A similar pattern was observed in sub-tropical forests where GEDI modelled stand height outperformed ICESat-2 modelled stand height. This analysis demonstrates the potential of existing spaceborne LiDAR platforms in interpolating forest stand height at different forest types. Also, the research emphasizes the necessity of a high density of LiDAR footprints spread in both across- and along-track directions for accurate interpolation of forest stand height.
森林吸收大气中的碳，因此在碳封存和气候调节方面发挥着至关重要的作用。最近的研究强调开发技术和方法来了解各种森林生态系统的碳封存潜力。林分高度估计是树木测高学中估计森林生物量的关键参数之一。本研究试图利用最近发射的星载激光雷达平台——冰云和地面高度卫星（ICESat-2）和全球生态系统动力学调查（GEDI）——来绘制印度热带和亚热带森林的林分高度图。使用地质统计学克里金插值方法来插值林分高度，并使用地面真值样本验证生成的林分高度面。结果表明，与ICESat-2 数据相比，GEDI 数据在热带森林中的 RMSE 分别为 3.99 米和 2.62 米，表现更好，而 ICESat-2 数据的 RMSE 分别为 5.71 米和 5.08 米。在亚热带森林中也观察到类似的模式，其中 GEDI 建模的林分高度优于 ICESat-2 建模的林分高度。该分析表明现有的星载激光雷达平台在不同森林类型的林分高度插值方面具有潜力。此外，研究还强调了在沿迹和交叉迹方向上分布高密度激光雷达足迹对于准确插值林分高度的必要性。
