Vorosmarty, Charles: CUNY (Project Lead)
Project Funding:
2017 - 2020
NRA: 2016 NASA: Interdisciplinary Research in Earth Science
Funded by NASA
Abstract:
South and Southeast Asia (SSEA) is a region of rapid environmental change, driven by growing urbanization, widespread expansion of water engineering, and agricultural
intensification. These processes drive changes in the region’s watershed dynamics, impair rivers, and translate impacts downstream through pathways that ultimately compromise coastal water quality. While eutrophication and hypoxia are documented as major challenges along many of the world's coastlines, our understanding of hypoxia risk across SSEA is much more limited. Our domain of analysis runs along the coast from south India to the east coast of Vietnam, a known focal point for rapid and intensifying anthropogenic change.
Recent improvements in remote sensing, GIS, data assimilation, and synthesis demonstrate that many of the human-driven changes unfolding across inland and coastal ecosystems are today detectable and manifest themselves as coastal zone eutrophication and hypoxia. We extend ongoing work to develop an integrated framework capable of analyzing these phenomena. While this project’s main technical goal is to develop a surveillance system that employs multiple platform and multi-resolution sensors, our scientific motivation is to test the hypothesis that the landmass bearing the most rapid human development is the most important driver of coastal eutrophication and hypoxia across SSEA. We further hypothesize that wetland area loss and human-controlled patterns of inundation amplify the rates of coastal water quality deterioration. Three major advancements are targeted, to: (i) establish and analyze within-basin and coastal zone geographies for bioactive constituents and resulting coastal zone hypoxia risk; (ii) develop the PlumeWatch Assessment Data and Toolkit to estimate hypoxia risk profiles for use by both researchers and stakeholders, and (iii) prepare a Science Requirements document to NASA to help guide future planning for eutrophication and hypoxia monitoring based on remote sensing and other coastal monitoring assets.
We begin with a focus on two test basins (Krishna/Godavari & Mekong). These systems are emblematic of the major forces at work transforming modern river basin-coastal zone complexes, and to which we can apply our process models depicting land-to-ocean dynamics that give rise to eutrophication. From the process knowledge gained, we next extend analysis to the larger region using empirical risk models trained on the high-resolution case study systems. This extension enables us to create time-varying maps revealing hotlines of coastal risk based on the combination of remote sensing, integrated regional upland basin water and nutrient flux modeling, as well as in situ river and ocean observations. The study team has worked consistently toward this end and forwarded interdisciplinary perspectives, having developed models and data processing systems for regional-to-continental scale hydrology, suspended sediment transport, and fluvial delivery of bioactive nutrients to the coastal zone. Members of the study team are also pioneering remote sensing techniques to operationally monitor wetlands state as well as coastal water quality.
Emphasis will be placed on environmental and ecological change, using SAR (archived PALSAR, contemporary Sentinel-1 and PALSAR-2) and optical (archived and contemporary Landsat, Sentinel-2) remote-sensing. NASA and other agencies remote sensing assets will be used for detailed, spatially-explicit assessment of coastal land cover change, wetland loss, and changing inundation dynamics and their accompanying impacts
on coastal hypoxia risk. Results will be communicated to the larger community through the online data PlumeWatch dashboard.
Publications:
D'Sa, E. J., Tzortziou, M., Liu, B. 2023. Extreme events and impacts on organic carbon cycles from ocean color remote sensing: Review with case study, challenges, and future directions. Earth-Science Reviews. 243, 104503. DOI: 10.1016/j.earscirev.2023.104503
More details may be found in the following project profile(s):
