Sept. 18, 2015 -- A new interactive mapping tool from the U.S. Geological Survey (USGS) provides predicted concentrations for 108 pesticides in streams and rivers across the nation and identifies which streams are most likely to exceed water-quality guidelines for human health or aquatic life.
Citizens and water managers can create maps showing where pesticides are likely to occur in local streams and rivers and evaluate the likelihood of concentrations exceeding water-quality guidelines. The predictions can also be used to design cost-effective monitoring programs.
"Because pesticide monitoring is very expensive, we cannot afford to directly measure pesticides in all streams and rivers," said William Werkeiser, USGS Associate Director for Water. "This model can be used to estimate pesticide levels at unmonitored locations to provide a national assessment of pesticide occurrence."
The online mapping tool is based on a USGS statistical model -- referred to as Watershed Regression for Pesticides, or WARP -- which provides key statistics for thousands of streams, including the probability that a pesticide may exceed a water-quality benchmark and the reliability of each prediction.
The WARP model estimates concentrations using information on the physical and chemical properties of pesticides, agricultural pesticide use, soil characteristics, hydrology, and climate.
The model used by the mapping tool is based on data from USGS monitoring of pesticides in streams across the nation since 1992 as part of the National Water-Quality Assessment (NAWQA) Program. Since 1991, NAWQA has been a primary source of nationally consistent data and information on the quality of the Nation’s streams and groundwater.
See also:
"New online USGS tool tracks nutrients, sediment in waterways across nation"
"USGS studies 2015 low snowpack, river flows to forecast future droughts"
###
