Final Report: Ecological Assessment of Generalized Littoral Environments Decision-Support System (EAGLE/OS)

EPA Grant Number: R835193
Title: Ecological Assessment of Generalized Littoral Environments Decision-Support System (EAGLE/OS)
Investigators: Muller-Karger, Frank Edgar , Chen, F. Robert , McCarthy, Matthew , Mendez-Lazaro, Pablo , Otis, Daniel
Institution: University of South Florida , University of Puerto Rico - Medical Sciences Campus
EPA Project Officer: Hiscock, Michael
Project Period: June 1, 2012 through August 14, 2014 (Extended to May 31, 2016)
Project Amount: $750,000
RFA: Extreme Event Impacts on Air Quality and Water Quality with a Changing Global Climate (2011) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Water Quality , Climate Change , Air , Water

Objective:

This study was focused on using novel applications of satellite products to examine water quality, land use and land use change in estuaries in the Gulf of Mexico and Puerto Rico. In addition, demographic variables and environmental data were used in San Juan, Puerto Rico to assess climate change on dengue outbreaks and create an mapped index of heat vulnerability among census tracts within the city.

One main focus of this study was to utilize satellite data from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) sensor flown on the Terra satellite to examine suspended sediment dynamics in the estuaries of the Gulf of Mexico and Puerto Rico. MODIS has provided a time-series of satellite remote sensing observations at relatively high temporal resolution (near-weekly or better at tropical and sub-tropical latitudes) and high spatial resolution (250 m pixels and coarser). The data used for coastal turbidity observations are well calibrated and have relatively high sensitivity. Specifically, we generated time-series of water quality indices based on remote-sensing reflectance measurements at 645 nm [Rrs(645)] using MODIS Band 1. The basic assumption is that sediments suspended near the water surface provide a signal in this red band, and that this signal can be measured from space distinctly from effects due to constituents in the atmosphere such as aerosols or reflection of light from the benthos.

Additionally, land cover changes in the Florida watersheds of Tampa Bay (1976-2011), Sarasota Bay (1985-2011), and Charlotte Harbor (1984-2011) over the past four decades were examined along with precipitation and wind observations to help understand causes of long-term changes in turbidity within the respective estuaries.

A third objective of this research was to use satellite products and meteorological data to analyze both climate change effects on dengue fever transmission in San Juan, Puerto Rico as well as the risk of high temperature in particular locations by creating heat maps of the city of San Juan. Heat Vulnerability Index (HVI) maps were developed using images collected by satellite-based remote sensing combined with census data. Land surface temperature was assessed using images from the Thermal Infrared Sensor (TIRS) flown on the Landsat 8 satellite sensor. Social determinants (e.g., age, economic level, level of education and social isolation, disability, health insurance coverage) were analyzed by Census Tract.

Summary/Accomplishments (Outputs/Outcomes):

  • Overall, estuaries in Texas, Louisiana, and Alabama were found to have much higher apparent turbidity (higher Rrs(645)) levels than those in Florida.
  • Estuaries in TX, LA, and AL also had much higher ranges of the seasonal cycle of Rrs(645) than FL estuaries.
  • In all Gulf of Mexico estuaries, variance in time-series of Rrs(645) was found to be significantly explained by wind speed.
  • River discharge was found to be a significant explanatory variable of variance of Rrs(645) in Mobile Bay.
  • Due to the presence of two large rivers (the Alabama and Tombigbee), Mobile Bay has by far the highest freshwater inflow of any of the estuaries in this study, so the fact that river discharge is significant here is not surprising.
  • Both rivers are controlled by locks and dams, so management of flow from these rivers has implications for suspended sediment concentrations in Mobile Bay.
  • Land cover and water quality show a relationship in Tampa Bay from scales spanning local river mouths to the entire estuary. The long-term decrease in turbidity and chlorophyll concentration shows a strong negative correlation with developed land percent cover. There was no clear long-term change in precipitation between the 1970s and the 2000s, but the trend in water quality may have also been in part driven by a small decrease in average annual wind speed over the study period.
  • A heat vulnerability index was created for San Juan Bay using data from the Landsat 8 satellite sensor and 27 demographic variables and 4 exposure variables.

Conclusions:

The utility of satellite products to investigate the coastal zone is rapidly advancing. Using novel approaches to correct for atmospheric effects and combining datasets in unique ways, we can begin to get a better understanding of ecosystems, how they function and the services they provide. However, existing satellite sensors lack key capabilities in terms of spatial resolution and revisit times. To fully understand coastal estuaries and their associated ecosystem and ecosystem services, we need to characterize short-term changes in the functional biodiversity and biogeochemical cycles of these coastal and wetland ecosystems, from canopy to benthos, and trace these changes to their underlying environmental influences. This requires an observation-based approach that covers coastal and inland aquatic ecosystems in a repeated, synoptic manner. Space-borne sensing systems can provide this capability, supported by coordinated in situ calibration and product validation activities. The design requires high temporal resolution (weekly or better), medium spatial resolution (30 m pixels at nadir to complement Landsat-class sensors), and highly sensitive, ocean-color radiometric quality, high resolution spectroscopy with Visible and Short-Wave IR bands (order of 10 nm or better) to assess both atmospheric correction parameters and land vegetation composition.


Journal Articles on this Report : 1 Displayed | Download in RIS Format

Other project views: All 6 publications 2 publications in selected types All 2 journal articles
Type Citation Project Document Sources
Journal Article Mendez-Lazaro P, Muller-Karger FE, Otis D, McCarthy MJ, Pena-Orellana M. Assessing climate variability effects on dengue incidence in San Juan, Puerto Rico. International Journal of Environmental Research and Public Health 2014;11(9):9409-9428. R835193 (2013)
R835193 (2014)
R835193 (Final)
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  • Abstract from PubMed
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  • Full-text: MDPI-Full Text PDF
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  • Relevant Websites:

    Institute for Marine Remote Sensing Website (IMaRS) Exit

    EPA data portal and viewer with IMaRS turbidity and chlorophyll-a products from Puerto Rico

    Progress and Final Reports:

    Original Abstract
    2012 Progress Report
    2013 Progress Report
    2014 Progress Report