Landsat data to support pesticide exposure assessment

Landsat data to support pesticide exposure assessment

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US: The recent US Geological Survey policy offering Landsat satellite data at no cost provides researchers new opportunities to explore relationships between environment and health.

A group of researchers, namely Susan K Maxwell, Matthew Airola, John R Nuckols, have published their findings in International Journal of Health Geographics 2010. The complete article is available as a provisional PDF. The purpose of this study was to examine the potential for using Landsat satellite data to support pesticide exposure assessment in California.

Researchers collected a dense time series of 24 Landsat 5 and 7 images spanning the year 2000 for an agricultural region in Fresno County. They intersected the Landsat time series with the California Department of Water Resources (CDWR) land use map and selected field samples to define the phenological characteristics of 17 major crop types or crop groups.

They found the frequent overpass of Landsat enabled detection of crop field conditions (for example, bare soil, vegetated) over most of the year. However, images were limited during the winter months due to cloud cover.

Many samples designated as single-cropped in the CDWR map had phenological patterns that represented multi-cropped or non-cropped fields, indicating they may have been misclassified.

Rsearchers found the combination of Landsat 5 and 7 image data would clearly benefit pesticide exposure assessment in this region by
1) providing information on crop field conditions at or near the time when pesticides are applied, and
2) providing information for validating the CDWR map.
The Landsat image time-series was useful for identifying idle, single-, and multi-cropped fields.

Source: 7th Space