USGS

Estimation of Agricultural Pesticide Use in Drainage Basins Using Land Cover Maps and County Pesticide Data

By Naomi Nakagaki and David M. Wolock

 

U.S. GEOLOGICAL SURVEY

Open-File Report 2005-1188

Sacramento, California 2005


ONLINE ONLY

National Water-Quality Assessment Program


Complete accessible text of report (4.08 MB PDF)

To view PDF documents, you must have the Adobe Acrobat Reader (free from Adobe Systems) installed on your computer.

 

(download free copy of Acrobat Reader).

Abstract

    A geographic information system (GIS) was used to estimate agricultural pesticide use in the drainage basins of streams that are studied as part of the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program. Drainage basin pesticide use estimates were computed by intersecting digital maps of drainage basin boundaries with an enhanced version of the National Land Cover Data 1992 combined with estimates of 1992 agricultural pesticide use in each United States county. This report presents the methods used to quantify agricultural pesticide use in drainage basins using a GIS and includes the estimates of atrazine use applied to row crops, small-grain crops, and fallow lands in 150 watersheds in the conterminous United States. Basin atrazine use estimates are presented to compare and analyze the results that were derived from 30-meter and 1-kilometer resolution land cover and county pesticide use data, and drainage basin boundaries at various grid cell resolutions. Comparisons of the basin atrazine use estimates derived from watershed boundaries, county pesticide use, and land cover data sets at different resolutions, indicated that overall differences were minor. The largest potential for differences in basin pesticide use estimates between those derived from the 30-meter and 1-kilometer resolution enhanced National Land Cover Data 1992 exists wherever there are abrupt agricultural land cover changes along the basin divide. Despite the limitations of the drainage basin pesticide use data described in this report, the basin estimates provide consistent and comparable indicators of agricultural pesticide application in surface-water drainage basins studied in the NAWQA Program.

CONTENTS

Abstract

Introduction

Background

Purpose and Scope

Acknowledgments

GIS Datasets

Drainage Basin Boundaries

Land Cover

30-Meter Resolution

1-Kilometer Resolution

County Agricultural Pesticide Use

Estimating Agricultural Pesticide Use in Drainage Basins

Basin Pesticide Use Estimated from the 1-Kilometer Resolution Land Cover Dataset

Steps to Generate a 1-Kilometer Resolution Pesticide Use Grid

Steps to Estimate the Basin Pesticide Use Using a 1-Kilometer Resolution Pesticide Use Grid

Basin Pesticide Use Estimated from the 30-Meter Resolution Land Cover Dataset

Results

Which Resolution is the Most Appropriate for Estimating Agricultural Pesticide Use in Drainage Basins?

Limitations of the Agricultural Pesticide Use Estimates in Drainage Basins

Other Applications of the Methods

Future Directions

Summary

Endnotes

References Cited


Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Acrobat Reader 6.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.

 



Water Resources of California



FirstGov button  Take Pride in America button