Applying a statewide geospatial leaching tool forassessing soil vulnerability ratings foragrochemicals across the contiguous UnitedStates

Seo Jin Ki, Chittaranjan Ray, Mohamed M. Hantush

Research output: Contribution to journalArticlepeer-review

Abstract

A large-scale leaching assessment tool not only illustrates soil (or groundwater) vulnerability in unmonitored areas, but also can identify areas of potential concern for agrochemical contamination. This study describes the methodology of how the statewide leaching tool in Hawaii modified recently for use with pesticides and volatile organic compounds can be extended to the national assessment of soil vulnerability ratings. For this study, the tool was updated by extending the soil and recharge maps to cover the lower 48 states in the United States (US). In addition, digital maps of annual pesticide use (at a national scale) as well as detailed soil properties and monthly recharge rates (at high spatial and temporal resolutions) were used to examine variations in the leaching (loads) of pesticides for the upper soil horizons. Results showed that the extended tool successfully delineated areas of high to low vulnerability to selected pesticides. The leaching potential was high for picloram, medium for simazine, and low to negligible for 2,4-D and glyphosate. The mass loadings of picloram moving below 0.5m depth increased greatly in northwestern and central US that recorded its extensive use in agricultural crops. However, in addition to the amount of pesticide used, annual leaching load of atrazine was also affected by other factors that determined the intrinsic aquifer vulnerability such as soil and recharge properties. Spatial and temporal resolutions of digital maps had a great effect on the leaching potential of pesticides, requiring a trade-off between data availability and accuracy. Potential applications of this tool include the rapid, large-scale vulnerability assessments for emerging contaminants which are hard to quantify directly through vadose zone models due to lack of full environmental data.

Original languageEnglish (US)
Pages (from-to)107-118
Number of pages12
JournalWater Research
Volume77
DOIs
StatePublished - Jun 5 2015

Keywords

  • Agrochemical contamination
  • Chemical leaching tool
  • Diffuse pollution
  • National soil vulnerability maps
  • Subsurface processes
  • Tier 1 assessment

ASJC Scopus subject areas

  • Ecological Modeling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

Fingerprint

Dive into the research topics of 'Applying a statewide geospatial leaching tool forassessing soil vulnerability ratings foragrochemicals across the contiguous UnitedStates'. Together they form a unique fingerprint.

Cite this