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Water-resources data for the 2004 water year for North Carolina
consist of records of stage, discharge, water quality for streams;
stage and contents for lakes and reservoirs; precipitation; and
ground-water levels and water quality of ground water. Volume 1
contains discharge records for 217 gaging stations; stage and
contents for 58 lakes and reservoirs; stage only records for 22
gaging stations; elevations for 9 stations; water quality for 39
gaging stations and 5 miscellaneous sites, and continuous water
quality for 35 sites; and continuous precipitation at 127 sites.
Volume 2 contains ground-water-level data from 161 observation
wells, ground-water-quality data from 38 wells, continuous water
quality for 7 sites and continuous precipitation at 7 sites.
Additional water data were collected at 51 sites not involved in
the systematic data-collection program, and are published as
miscellaneous measurements in Volume 1. The collection of
water-resources data in North Carolina is a part of the National
Water-Data System operated by the U.S. Geological Survey in
cooperation with State, municipal, and Federal agencies.
Weather and climate are strong drivers of population dynamics,
plant and animal spatial distributions, community interactions, and
ecosystem states. Information on local weather and climate is
crucial in interpreting trends and patterns in the natural
environment for resource management, research, and visitor
enjoyment. This document describes the weather and climate
monitoring program at the Channel Islands National Park (fig. 1),
initiated in the 1990s. Manual and automated stations, which
continue to evolve as technology changes, are being used for this
program. The document reviews the history of weather data
collection on each of the five Channel Islands National Park
islands, presents program administrative structure, and provides an
overview of procedures for data collection, archival, retrieval,
and reporting. This program overview is accompanied by the 'Channel
Islands National Park Remote Automated Weather Station Field
Handbook' and the 'Channel Islands National Park Ranger Weather
Station Field Handbook'. These Handbooks are maintained separately
at the Channel Island National Park as 'live documents' that are
updated as needed to provide a current working manual of weather
and climate monitoring procedures. They are available on request
from the Weather Program Manager (Channel Islands National Park,
1901 Spinnaker Dr., Ventura, CA 93001; 805.658.5700). The two Field
Handbooks describe in detail protocols for managing the four remote
automated weather stations (RAWS) and the seven manual Ranger
Weather Stations on the islands, including standard operating
procedures for equipment maintenance and calibration; manufacturer
operating manuals; data retrieval and archiving; metada collection
and archival; and local, agency, and vendor contracts.
The computer program PHAST (PHREEQC And HST3D) simulates
multicomponent, reactive solute transport in three-dimensional
saturated groundwater flow systems. PHAST is a versatile
groundwater flow and solute-transport simulator with capabilities
to model a wide range of equilibrium and kinetic geochemical
reactions. The flow and transport calculations are based on a
modified version of HST3D that is restricted to constant fluid
density and constant temperature. The geochemical reactions are
simulated with the geochemical model PHREEQC, which is embedded in
PHAST. Major enhancements in PHAST Version 2 allow spatial data to
be defined in a combination of map and grid coordinate systems,
independent of a specific model grid (without node-by-node input).
At run time, aquifer properties are interpolated from the spatial
data to the model grid; regridding requires only redefinition of
the grid without modification of the spatial data. PHAST is
applicable to the study of natural and contaminated groundwater
systems at a variety of scales ranging from laboratory experiments
to local and regional field scales. PHAST can be used in studies of
migration of nutrients, inorganic and organic contaminants, and
radionuclides; in projects such as aquifer storage and recovery or
engineered remediation; and in investigations of the natural
rock/water interactions in aquifers. PHAST is not appropriate for
unsaturated-zone flow, multiphase flow, or density-dependent flow.
A variety of boundary conditions are available in PHAST to simulate
flow and transport, including specified-head, flux
(specified-flux), and leaky (head-dependent) conditions, as well as
the special cases of rivers, drains, and wells. Chemical reactions
in PHAST include (1) homogeneous equilibria using an
ion-association or Pitzer specific interaction thermodynamic model;
(2) heterogeneous equilibria between the aqueous solution and
minerals, ion exchange sites, surface complexation sites, solid
solutions, and gases; and
The United States Geological Survey (USGS) is a scientific agency
of the United States government. The scientists of the USGS study
the landscape of the United States, its natural resources, and the
natural hazards that threaten it. The agency lives by its motto:
"Science for a changing world." The USGS publishes technical
reports, data series, investigation results, and procedural
documents for internal USGS use and the general public. These
publications include titles like Lithium Use in Batteries, Sound
Data Management, and Groundwater Qualities Across the Nation.
A new analytical method for the determination of elements in
filtered aqueous matrices using inductively coupled plasma-mass
spectrometry (ICP-MS) has been implemented at the U.S. Geological
Survey National Water Quality Laboratory that uses
collision/reaction cell technology to reduce molecular ion
interferences. The updated method can be used to determine elements
in filtered natural-water and other filtered aqueous matrices,
including whole-water, biota, sediment, and soil digestates. Helium
or hydrogen is used as the collision or reaction gas, respectively,
to eliminate or substantially reduce interferences commonly
resulting from sample-matrix composition. Helium is used for
molecular ion interferences associated with the determination of
As, Co, Cr, Cu, K, Mg, Na, Ni, V, W and Zn, whereas hydrogen is
used for Ca, Fe, Se, and Si. Other elements that are not affected
by molecular ion interference also can be determined simply by not
introducing a collision/reaction gas into the cell. Analysis time
is increased by about a factor of 2 over the previous method
because of the additional data acquisition time in the hydrogen and
helium modes. Method detection limits for As, Ca, Co, Cr, Cu, Fe,
K, Mg, Na, Ni, Se, Si (as SiO2), V, W, and Zn, all of which use a
collision/reaction gas, are 0.06 microgram per liter (?g/L) As,
0.04 milligram per liter (mg/L) Ca, 0.02 ?g/L Co, 0.02 ?g/L Cr,
0.04 ?g/L Cu, 1 ?g/L Fe, 0.007 mg/L K, 0.009 mg/L Mg, 0.09 mg/L Na,
0.05 ?g/L Ni, 0.04 ?g/L Se, 0.03 mg/L SiO2, 0.05 ?g/L V, 0.03 ?g/L
W, and 0.04 ?g/L Zn. Most method detection limits are lower or
relatively unchanged compared to earlier methods except for Co, K,
Mg, Ni, SiO2, and Tl, which are less than a factor of 2 higher.
Percentage bias for samples spiked at about one-third and
two-thirds of the concentration of the highest calibration standard
ranged from -8.1 to 7.9 percent for reagent water, -14 to 21
percent for surface water, and -16 to 16 percent for ground water.
The percen
The United States Geological Survey (USGS) is a scientific agency
of the United States government. The scientists of the USGS study
the landscape of the United States, its natural resources, and the
natural hazards that threaten it. The agency lives by its motto:
"Science for a changing world."
This report documents the addition of shared node Local Grid
Refinement (LGR) to MODFLOW-2005, the U.S. Geological Survey
modular, transient, three-dimensional, finite-difference
ground-water flow model. LGR provides the capability to simulate
ground-water flow using one block-shaped higher-resolution local
grid (a child model) within a coarser-grid parent model. LGR
accomplishes this by iteratively coupling two separate MODFLOW-2005
models such that heads and fluxes are balanced across the shared
interfacing boundary. LGR can be used in two-and three-dimensional,
steady-state and transient simulations and for simulations of
confined and unconfined ground-water systems. Traditional one-way
coupled telescopic mesh refinement (TMR) methods can have large,
often undetected, inconsistencies in heads and fluxes across the
interface between two model grids. The iteratively coupled
shared-node method of LGR provides a more rigorous coupling in
which the solution accuracy is controlled by convergence criteria
defined by the user. In realistic problems, this can result in
substantially more accurate solutions and require an increase in
computer processing time. The rigorous coupling enables sensitivity
analysis, parameter estimation, and uncertainty analysis that
reflects conditions in both model grids. This report describes the
method used by LGR, evaluates LGR accuracy and performance for two-
and three-dimensional test cases, provides input instructions, and
lists selected input and output files for an example problem. It
also presents the Boundary Flow and Head (BFH) Package, which
allows the child and parent models to be simulated independently
using the boundary conditions obtained through the iterative
process of LGR.
The United States Geological Survey (USGS) is a scientific agency
of the United States government. The scientists of the USGS study
the landscape of the United States, its natural resources, and the
natural hazards that threaten it. The agency lives by its motto:
"Science for a changing world." The USGS publishes technical
reports, data series, investigation results, and procedural
documents for internal USGS use and the general public. These
publications include titles like Lithium Use in Batteries, Sound
Data Management, and Groundwater Qualities Across the Nation.
The Kendall-Theil Robust Line software (KTRLine-version 1.0) is a
Visual Basic program that may be used with the Microsoft Windows
operating system to calculate parameters for robust, nonparametric
estimates of linear-regression coefficients between two continuous
variables. The KTRLine software was developed by the U.S.
Geological Survey, in cooperation with the Federal Highway
Administration, for use in stochastic data modeling with local,
regional, and national hydrologic data sets to develop
planning-level estimates of potential effects of highway runoff on
the quality of receiving waters. The Kendall-Theil robust line was
selected because this robust nonparametric method is resistant to
the effects of outliers and nonnormality in residuals that commonly
characterize hydrologic data sets. The slope of the line is
calculated as the median of all possible pairwise slopes between
points. The intercept is calculated so that the line will run
through the median of input data. A single-line model or a
multisegment model may be specified. The program was developed to
provide regression equations with an error component for stochastic
data generation because nonparametric multisegment regression tools
are not available with the software that is commonly used to
develop regression models. The Kendall-Theil robust line is a
median line and, therefore, may underestimate total mass, volume,
or loads unless the error component or a bias correction factor is
incorporated into the estimate. Regression statistics such as the
median error, the median absolute deviation, the prediction error
sum of squares, the root mean square error, the confidence interval
for the slope, and the bias correction factor for median estimates
are calculated by use of nonparametric methods. These statistics,
however, may be used to formulate estimates of mass, volume, or
total loads. The program is used to read a two- or three-column
tab-delimited input file with variable names in the first row and
The United States Geological Survey (USGS) is a scientific agency
of the United States government. The scientists of the USGS study
the landscape of the United States, its natural resources, and the
natural hazards that threaten it. The agency lives by its motto:
"Science for a changing world." The USGS publishes technical
reports, data series, investigation results, and procedural
documents for internal USGS use and the general public. These
publications include titles like Lithium Use in Batteries, Sound
Data Management, and Groundwater Qualities Across the Nation.
This report documents work at the U.S. Geological Survey (USGS)
National Water Quality Laboratory (NWQL) to validate enzymatic
reduction, colorimetric determinative methods for nitrate + nitrite
in filtered water by automated discrete analysis. In these
standard- and low-level methods (USGS I-2547-11 and I-2548-11),
nitrate is reduced to nitrite with nontoxic, soluble nitrate
reductase rather than toxic, granular, copperized cadmium used in
the longstanding USGS automated continuous-flow analyzer methods
I-2545-90 (NWQL laboratory code 1975) and I-2546-91 (NWQL
laboratory code 1979). Colorimetric reagents used to determine
resulting nitrite in aforementioned enzymatic- and
cadmium-reduction methods are identical. The enzyme used in these
discrete analyzer methods, designated AtNaR2 by its manufacturer,
is produced by recombinant expression of the nitrate reductase gene
from wall cress (Arabidopsis thaliana) in the yeast Pichia
pastoris. Unlike other commercially available nitrate reductases we
evaluated, AtNaR2 maintains high activity at 37 C and is not
inhibited by high-phenolic-content humic acids at reaction
temperatures in the range of 20 C to 37 C. These previously
unrecognized AtNaR2 characteristics are essential for successful
performance of discrete analyzer nitrate + nitrite assays
(henceforth, DA-AtNaR2) described here. Method detection levels (or
limits; MDL) estimated for standard- and low-level DA-AtNaR2
nitrate + nitrite methods were 0.02 milligrams nitrogen per liter
(mg-N/L) and 0.002 mg-N/L, respectively, which are comparable to
2010 NWQL long-term MDLs of the continuous-flow analyzer,
cadmium-reduction methods (henceforth, CFA-CdR) they replace.
Typically, reagent-water blanks for standard- and low-level
DAAtNaR2 nitrate + nitrite methods are one half MDL or less.
Nitrate + nitrite concentration differences for between-day
replicates were 3 percent or less at or above 5 times the MDL and
were as great as 35 percent near the MDL. Typically, nitrate
The United States Geological Survey (USGS) is a scientific agency
of the United States government. The scientists of the USGS study
the landscape of the United States, its natural resources, and the
natural hazards that threaten it. The agency lives by its motto:
"Science for a changing world." The USGS publishes technical
reports, data series, investigation results, and procedural
documents for internal USGS use and the general public. These
publications include titles like Lithium Use in Batteries, Sound
Data Management, and Groundwater Qualities Across the Nation.
The United States Geological Survey (USGS) is a scientific agency
of the United States government. The scientists of the USGS study
the landscape of the United States, its natural resources, and the
natural hazards that threaten it. The agency lives by its motto:
"Science for a changing world." The USGS publishes technical
reports, data series, investigation results, and procedural
documents for internal USGS use and the general public. These
publications include titles like Lithium Use in Batteries, Sound
Data Management, and Groundwater Qualities Across the Nation.
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