Forest Structure Retrieval from Ecosar P-Band Single-Pass Interferometry

EcoSAR is a single-pass (dual antenna) digital beamforming, P-band radar system that is designed for remote sensing of dense forest structure. Forest structure retrievals require the measurement related to the vertical dimension, for which several techniques have been developed over the years. These techniques use polarimetric and interferometric aspects of the SAR data, which can be collected using EcoSAR. In this paper we describe EcoSAR system in light of its interferometric capabilities and investigate forest structure retrieval techniques

Estimating mangrove tree biomass and carbon content: A comparison of forest inventory techniques and drone imagery

Published: 22 January 2020Mangroves provide many ecosystem services including a considerable capacity to sequester and store large amounts of carbon, both in the sediment and in the above-ground biomass. Assessment of mangrove above-ground carbon stock relies on accurate measurement of tree biomass, which traditionally involves collecting direct measurements from trees and relating these to biomass using allometric relationships. We investigated the potential to predict tree biomass using measurements derived from unmanned aerial vehicle (UAV), or drone, imagery. This approach has the potential to dramatically reduce time-consuming fieldwork, providing greater spatial survey coverage and return for effort, and may enable data to be collected in otherwise hazardous or inaccessible areas. We imaged an Avicennia marina (grey mangrove) stand using an RGB camera mounted on a UAV. The imaged trees were subsequently felled, enabling physical measurements to be taken for traditional biomass estimation techniques, as well as direct measurements of biomass and tissue carbon content. UAV image-based tree height measurements were highly accurate (R2 = 0.98). However, the variables that could be measured from the UAV imagery (tree height and canopy area) were poor predictors of tree biomass. Using the physical measurement data, we identified that trunk diameter is a key predictor of A. marina biomass. Unfortunately, trunk diameter cannot be directly measured from the UAV imagery, but it can be predicted (with some error) using models that incorporate other UAV image-based measurements, such as tree height and canopy area. However, reliance on second-order estimates of trunk diameter leads to increased uncertainty in the subsequent predictions of A. marina biomass, compared to using physical measurements of trunk diameter taken directly from the trees. Our study demonstrates that there is potential to use UAV-based imagery to measure mangrove A. marina tree structural characteristics and biomass. Further refinement of the relationship between UAV image-based measurements and tree diameter is needed to reduce error in biomass predictions. UAV image-based estimates can be made far more quickly and over extensive areas when compared to traditional data collection techniques and, with improved accuracy through further model-calibration, have the potential to be a powerful tool for mangrove biomass and carbon storage estimation.Alice R. Jones, Ramesh Raja Segaran, Kenneth D. Clarke, Michelle Waycott, William S. H. Goh and Bronwyn M. Gillander

Toward a Blue Economy : A Pathway for Sustainable Growth in Bangladesh

This report aims to synthesize the current theory and practice of the blue economy concept to govern economic activity linked to the ocean, and to provide a framework for the Government of Bangladesh to analyze its potential. With the peaceful resolution of maritime boundary disputes with its neighbors in 2012 and 2014, the Government has recently defined the ocean space under its jurisdiction and prioritized its use as a key source of future economic growth. The Government has prioritized the use of these spaces as a key source of future growth. However, a number of questions remain in embarking on a policy planning process to achieve Bangladesh’s blue economy aspirations, including measures of the current economic uses of the ocean space, the identification of clear targets for sustainable growth of the use of this space, and a policy pathway to get there. Described as an economic frontier, the term “ocean economy” applies collectively to ocean based industry activities and the assets, goods, and services of marine ecosystems. Ocean ecosystems provide the natural capital inputs that combine with produced and human capital to underpin the ocean economy.The concept of a “blue economy” emerged in 2012 as countries around the world have grappled with the twin trends of accelerating growth in the ocean economy and change in the underlying ecosystems. A “blue economy” aims for a balance between economic opportunities and the environmental limitations of using the ocean to generate wealth. Few documents exist to describe how countries can transition their ocean economies toward a blue economy, despite much discussion since 2012. This report fills that gap by offering a conceptual framework to guide policy-makers in Bangladesh in proposing specific reforms, by illustrating the economic activities of the ocean economy together with the underlying natural capital, as well as other types of capital. The framework suggests entry points for policy reforms to change the flow of inputs from ocean ecosystems to the ocean economy over time, or conversely to reduce outputs from economic activity (such as pollution) that may impact the functioning of ocean ecosystems. The report also synthesizes principles that may help guide such policy reforms. Most importantly, the report summarizes the information base needed for the Government of Bangladesh to set realistic targets for a blue economy development pathway and monitor progress