Case Studies

Human and Animal Health Case Studies
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Applying SeaWiFS Data to Monitoring Harmful Algal Blooms
The Challenge
Marine planktonic algae, or phytoplankton, are essential elements of the marine environment, but some species are detrimental, forming harmful algal blooms (HABs). Toxic HAB species, such as the dinoflagellate Gymnodinium breve (G. breve), cause “red tides” that can harm fish and wildlife, cause illness in humans, and have a significant economic impact. Sampling HABs effectively is a difficult problem because of the large areas of ocean they may cover and the logistical costs of traditional sampling. Improved monitoring of HABs would increase understanding of the inception of HABs and the conditions that promote their growth. Rapid identification of HABs is essential for state managers to protect public health. Satellite imagery of ocean color has the potential to provide information on the distribution and abundance of HABs at high frequency and with suitable spatial and temporal resolution. Read more

Satellite and Aerial Remote Sensing for Monitoring Coastal Sewage Discharge
The Challenge
Coastal pollution from sewage effluent is a major problem in southern California and other U.S. coastal regions. Inadequate containment may result in beach closings and long-term pollution with significant health and economic impacts. In southern California, beach closures during the tourist season result in the loss of millions of dollars of revenue to local businesses. In some cases, cities or their sanitation districts may be fined appreciable sums for lack of compliance. Monitoring discharges is essential for U.S. coastal sanitation districts that operate under the jurisdiction of an Environmental Protection Agency (EPA) permit process. Renewal of permits is dependent on evidence of compliance derived from regular field monitoring of physical and biological properties. Most sampling is done only on a weekly or monthly basis because of the high costs of field sampling. This schedule leaves large gaps when the sanitation districts and other agencies may lack information on the trajectories of wastewater plumes. Read more

Controlling Schistosomiasis in Africa
Schistosomiasis is a snail-borne disease. The ability to identify this health threat and monitor the disease enables public health officials to take preventive measures (e.g., vector control). Often the identification of infected human hosts and vector snails depends on labor-intensive ground survey methods for data collection. This method introduces inconsistencies that lead to inaccuracies. By contrast, satellite remote-sensing methods make it possible to obtain standardized data over large geographic areas (Abdel-Rahman et al., 2001). As a result there is increasing interest in these methods for health-related applications. Read more

A Continent-wide Application - Mapping Malaria Risk in Africa (MARA) Project
The Mapping Malaria Risk in Africa (MARA) project maps malaria risk using in situ data on malaria occurrence in combination with spatial modeling to predict the geographic distribution, seasonality, and endemicity (peculiarity to a locality or region) of the disease. The project uses the GIS to evaluate location and risk and to disseminate information to national and international decision-makers.
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A Continent-wide Application - The Famine Early Warning System Network
FEWS NET is a network of 17 African countries working with partners to address food security issues (Chapter 3). FEWS NET operates on the principle that gradually unfolding natural disasters influencing food security give decision-makers time to prepare and take preventive action.
A range of data and information sources is used by FEWS NET including continent-wide, 10-day NDVI (Chapter 6) and rainfall estimates from NOAA and European satellites, ground-based meteorological data, data on crop and rangeland conditions, commodity pricing data and agricultural production data (Chopak, 2000). FEWS NET handles a large volume of data, and has developed automated processing and analysis tools for routine operations. Read more