Dataset Identification:
Resource Abstract:
- description: This dataset is one of eight datasets produced by this study. Four of the datasets predict the probability of
detecting atrazine and(or) desethyl-atrazine (a breakdown product of atrazine) in ground water in Colorado; the other four
predict the probability of detecting elevated concentrations of nitrate in ground water in Colorado. The four datasets that
predict the probability of atrazine and(or) desethyl-atrazine (atrazine/DEA) are differentiated by whether or not they incorporated
atrazine use and whether or not they incorporated hydrogeomorphic regions. The four datasets that predict the probability
of elevated concentrations of nitrate are differentiated by whether or not they incorporated fertilizer use and whether or
not they incorporated hydrogeomorphic regions. Each of the eight datasets has its own unique strengths and weaknesses. The
user is cautioned to read Rupert (2003, Probability of detecting atrazine/desethyl-atrazine and elevated concentrations of
nitrate in ground water in Colorado: U.S. Geological Survey Water-Resources Investigations Report 02-4269, 35 p., http://water.usgs.gov/pubs/wri/wri02-4269/)
to determine if he(she) is using the most appropriate dataset for his(her) particular needs. This dataset specifically predicts
the probability of detecting elevated concentrations of nitrate in ground water in Colorado with hydrogeomorphic regions included
and fertilizer use not included. The following text was extracted from Rupert (2003). Draft Federal regulations may require
that each State develop a State Pesticide Management Plan for the herbicides atrazine, alachlor, metolachlor, and simazine.
Maps were developed that the State of Colorado could use to predict the probability of detecting atrazine/DEA in ground water
in Colorado. These maps can be incorporated into the State Pesticide Management Plan and can help provide a sound hydrogeologic
basis for atrazine management in Colorado. Maps showing the probability of detecting elevated nitrite plus nitrate as nitrogen
(nitrate) concentrations in ground water in Colorado also were developed because nitrate is a contaminant of concern in many
areas of Colorado. Maps showing the probability of detecting atrazine/DEA at or greater than concentrations of 0.1 microgram
per liter and nitrate concentrations in ground water greater than 5 milligrams per liter were developed as follows: (1) Ground-water
quality data were overlaid with anthropogenic and hydrogeologic data by using a geographic information system (GIS) to produce
a dataset in which each well had corresponding data on atrazine use, fertilizer use, geology, hydrogeomorphic regions, land
cover, precipitation, soils, and well construction. These data then were downloaded to a statistical software package for
analysis by logistic regression. (2) Relations were observed between ground-water quality and the percentage of land-cover
categories within circular regions (buffers) around wells. Several buffer sizes were evaluated; the buffer size that provided
the strongest relation was selected for use in the logistic regression models. (3) Relations between concentrations of atrazine/DEA
and nitrate in ground water and atrazine use, fertilizer use, geology, hydrogeomorphic regions, land cover, precipitation,
soils, and well-construction data were evaluated, and several preliminary multivariate models with various combinations of
independent variables were constructed. (4) The multivariate models that best predicted the presence of atrazine/DEA and elevated
concentrations of nitrate in ground water were selected. (5) The accuracy of the multivariate models was confirmed by validating
the models with an independent set of ground-water quality data. (6) The multivariate models were entered into a geographic
information system and the probability GRIDS were constructed.; abstract: This dataset is one of eight datasets produced by
this study. Four of the datasets predict the probability of detecting atrazine and(or) desethyl-atrazine (a breakdown product
of atrazine) in ground water in Colorado; the other four predict the probability of detecting elevated concentrations of nitrate
in ground water in Colorado. The four datasets that predict the probability of atrazine and(or) desethyl-atrazine (atrazine/DEA)
are differentiated by whether or not they incorporated atrazine use and whether or not they incorporated hydrogeomorphic regions.
The four datasets that predict the probability of elevated concentrations of nitrate are differentiated by whether or not
they incorporated fertilizer use and whether or not they incorporated hydrogeomorphic regions. Each of the eight datasets
has its own unique strengths and weaknesses. The user is cautioned to read Rupert (2003, Probability of detecting atrazine/desethyl-atrazine
and elevated concentrations of nitrate in ground water in Colorado: U.S. Geological Survey Water-Resources Investigations
Report 02-4269, 35 p., http://water.usgs.gov/pubs/wri/wri02-4269/) to determine if he(she) is using the most appropriate dataset
for his(her) particular needs. This dataset specifically predicts the probability of detecting elevated concentrations of
nitrate in ground water in Colorado with hydrogeomorphic regions included and fertilizer use not included. The following text
was extracted from Rupert (2003). Draft Federal regulations may require that each State develop a State Pesticide Management
Plan for the herbicides atrazine, alachlor, metolachlor, and simazine. Maps were developed that the State of Colorado could
use to predict the probability of detecting atrazine/DEA in ground water in Colorado. These maps can be incorporated into
the State Pesticide Management Plan and can help provide a sound hydrogeologic basis for atrazine management in Colorado.
Maps showing the probability of detecting elevated nitrite plus nitrate as nitrogen (nitrate) concentrations in ground water
in Colorado also were developed because nitrate is a contaminant of concern in many areas of Colorado. Maps showing the probability
of detecting atrazine/DEA at or greater than concentrations of 0.1 microgram per liter and nitrate concentrations in ground
water greater than 5 milligrams per liter were developed as follows: (1) Ground-water quality data were overlaid with anthropogenic
and hydrogeologic data by using a geographic information system (GIS) to produce a dataset in which each well had corresponding
data on atrazine use, fertilizer use, geology, hydrogeomorphic regions, land cover, precipitation, soils, and well construction.
These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Relations were
observed between ground-water quality and the percentage of land-cover categories within circular regions (buffers) around
wells. Several buffer sizes were evaluated; the buffer size that provided the strongest relation was selected for use in the
logistic regression models. (3) Relations between concentrations of atrazine/DEA and nitrate in ground water and atrazine
use, fertilizer use, geology, hydrogeomorphic regions, land cover, precipitation, soils, and well-construction data were evaluated,
and several preliminary multivariate models with various combinations of independent variables were constructed. (4) The multivariate
models that best predicted the presence of atrazine/DEA and elevated concentrations of nitrate in ground water were selected.
(5) The accuracy of the multivariate models was confirmed by validating the models with an independent set of ground-water
quality data. (6) The multivariate models were entered into a geographic information system and the probability GRIDS were
constructed.
Citation
- Title Raster dataset showing the probability of elevated concentrations of nitrate in ground water in Colorado, hydrogeomorphic
regions included and fertilizer use estimates not included..
-
- creation Date
2018-06-08T10:59:08.593426
Resource language:
Processing environment:
Back to top:
Metadata data stamp:
2018-08-06T23:01:31Z
Resource Maintenance Information
- maintenance or update frequency:
- notes: This metadata record was generated by an xslt transformation from a dc metadata record; Transform by Stephen M. Richard, based
on a transform by Damian Ulbricht. Run on 2018-08-06T23:01:31Z
Metadata contact
-
pointOfContact
- organisation Name
CINERGI Metadata catalog
-
- Contact information
-
-
- Address
-
- electronic Mail Address cinergi@sdsc.edu
Metadata language
eng
Metadata character set encoding:
utf8
Metadata standard for this record:
ISO 19139 Geographic Information - Metadata - Implementation Specification
standard version:
2007
Metadata record identifier:
urn:dciso:metadataabout:87a42e71-6f9f-4c09-ada2-841fea25a118
Metadata record format is ISO19139 XML (MD_Metadata)