Geology topics

Nancy T. Baker

Publications and source records attributed to Nancy T. Baker.

At least 19 recordsLinked to original sources

USGS2026

Sediment vulnerability ranking for river basins across the contiguous U.S. using integrated biophysical and social-ecological data

Nearly half of streams and rivers in the United States (U.S.) have fair to poor conditions for aquatic ecosystem health as declared by the U.S. Environmental Protection Agency, and sediment was identified as a primary factor impairing these waterbodies. We rank sediment vulnerability using physical, ecological, and socioeconomic datasets in 163 4-digit Hydrologic Unit Codes within 18 regions across the contiguous U.S. based on the National Hydrography Dataset. We refer to sediment vulnerability as the potential for excess sediment to adversely impact social-ecological aspects of streams and rivers. Metrics were organized into six variable groups: (1) geomorphic setting, (2) modeled sediment and phosphorus, (3) hydrologic conditions, (4) anthropogenic factors and land use, (5) socioeconomic considerations, and (6) measures of ecosystem sensitivity. Correlations and principal component analysis were used to reduce and select metrics that explained the highest variability across basins. Results from the regional analysis identify basins with higher sediment vulnerability in each region, whereas national results identify hotspots of highly ranked basins in the Midwest and the central U.S. with a concentration of moderately to highly ranked basins in the south-central and southwestern U.S. Indicators of socioeconomic and ecological vulnerability integrated with physical drivers of sediment production help identify important gaps in sediment monitoring and research.

contiguous United States↗

USGS2025

Gaps in water quality modeling of hydrologic systems

This review assesses gaps in water quality modeling, emphasizing opportunities to improve next-generation models that are essential for managing water quality and are integral to meeting goals of scientific and management agencies. In particular, this paper identifies gaps in water quality modeling capabilities that, if addressed, could support assessments, projections, and evaluations of management alternatives to support ecosystem health and human beneficial use of water resources. It covers surface water and groundwater quality modeling, dealing with a broad suite of physical, biogeochemical, and anthropogenic drivers. Modeling capabilities for six constituents (or constituent categories) are explored: water temperature, salinity, nutrients, sediment, geogenic constituents, and contaminants of emerging concern. Each constituent was followed through the coupled atmospheric-hydrologic-human system, with prominent modeling gaps described for a diverse array of relevant inputs, processes, and human activities. Commonly identified modeling gaps primarily fall under three types: (1) model gaps, (2) data gaps, and (3) process understanding gaps. In addition to potential solutions for addressing specific individual modeling limitations, some broad approaches (e.g., enhanced data collection and compilation, machine learning, reduced-complexity modeling) are discussed as ways forward for tackling multiple gaps. This gap analysis establishes a framework of diverse approaches that may support improved process representation, scale, and accuracy of models for a wide range of water quality issues.

Water↗

USGS2025

Ranking river basins for stream temperature research and monitoring in the contiguous United States

There is a need to prioritize research and data collection in river basins by integrating information from environmental, ecological, and socioeconomic datasets to maintain acceptable water quality for human uses and ecosystem health. Multiple anthropogenic and natural stressors are responsible for driving changes in stream temperatures that can alter ecosystems and degrade water quality. These stressors are variable spatially and temporally, which can be challenging for prioritizing monitoring and research. In this study, an evaluation of variables related to stream temperature was performed for 163 candidate basins of the contiguous United States to highlight potential focal areas. Thirty variables were combined in six components: anthropogenic forcing, natural forcing, climate change, ecological sensitivity, socioeconomic sensitivity, and data availability. The components were incorporated into three themes: vulnerability of streams to thermal change, vulnerability of ecosystems, and vulnerability of communities. By evaluating each theme separately, patterns of vulnerability and potential resiliency were identified as well as consistency in ranks within the themes. For example, results of the national scale ranking indicated the Southern California Coastal basin (within California-Nevada region) was the highest-ranking priority in vulnerability of streams to thermal change and vulnerability of ecosystems. The analysis also identified vulnerable basins with gaps in monitoring. For example, the Missouri-Oahe basin (within the Northern High Plains region) was the highest-ranking priority for vulnerable communities with limitations in data availability. The ranking approach provides insight into basins that are resilient and are ideal candidates for monitoring and research.

Journal of Hydrology↗

USGS2024

Prioritizing US Geological Survey science on salinization and salinity in candidate and selected priority river basins

The US Geological Survey (USGS) is selecting and prioritizing basins, known as Integrated Water Science basins, for monitoring and intensive study. Previous efforts to aid in this selection process include a scientifically defensible and quantitative assessment of basins facing human-caused water resource challenges (Van Metre et al. in Environmental Monitoring and Assessment , 192(7), 458 2020). In the present work, we explore this ranking process based on water quality considerations, specifically salinity and salinization. We selected top candidate basins to study salinity and salinization issues in 18 hydrologic regions that include 163 candidate basins. Our prioritization is based on quantitative assessment of sources of salinity, drivers of change, and receptors that must respond to those sources and drivers. Source terms represented in the prioritization include geology, depth to brackish groundwater, stream conductivity, chloride in precipitation, urban and agricultural land use, application of road salt as a deicer, and irrigation. Drivers represented in prioritization include changes in chemical weathering as a result of changes in rainwater chemistry. Receptors include measures of water stress, measurements of stream ecological health, and socioeconomic factors. In addition, we present research activities for the USGS on salinity and salinization that can be pursued in these basins including assessment of sources, pathways, and loadings; predicting and understanding changes in sources, peaks, and trends; understanding the components of salinity and mobilization of contaminants; understanding the relationship between salinization and changing ecosystems; and developing knowledge on the causes and distribution of groundwater salinity, brackish water resources, and challenges related to desalination.

Enviornmental Monitoring and Assessment↗

USGS2022

Green infrastructure in the Great Lakes—Assessment of performance, barriers, and unintended consequences

The Great Lakes Basin covers around 536,393 square kilometers, and the Great Lakes hold more than 5,400 cubic miles of water, accounting for more than 20 percent of the world’s fresh surface water supply. The Great Lakes provide a source of drinking water to tens of millions of people in Canada and the United States and support one of the most diverse ecosystems in the world. Increasing urbanization combined with aging infrastructure and more extreme storm events because of changing weather patterns creates stormwater management challenges for communities across the Great Lakes region. A variety of green infrastructure (GI) practices, designed to decrease runoff and improve water quality, have been implemented throughout the region in response to these challenges; however, implementation often remains limited to local efforts and with little coordination among various levels of government because of, at least in part, a lack of clear standards for stormwater, limited funding, and a general uncertainty in the type and expected performance of these practices. City planners, engineers, and political leaders often see GI investment as riskier than other alternatives despite studies that determined, in most cases, practices can either reduce or not affect costs. This report summarizes selected published reports and data sources from studies done in Great Lakes states and compares the measured effects of various GI practices and their applicability in different settings around the Great Lakes. By summarizing selected published reports and data sources from studies done in Great Lakes states, this report provides foundational information for U.S. Geological Survey scientists and their local and national partners to assess the ability of GI to reduce stormwater runoff in Great Lakes urban areas. GI includes a variety of stormwater management techniques designed to mimic natural hydrologic processes like infiltration and evapotranspiration, which can decrease the volume of water running into sewers and streams. It can also improve water quality by trapping sediment, nutrients, and other contaminants. A variety of landscape practices can be incorporated into urban areas as GI, but the discussion here is limited to vegetated basins, vegetated channels, permeable pavement, urban tree canopy, and green roofs. Other types of GI, such as downspout disconnection, rainwater harvesting, and wet and dry detention basins were not included because hydrologic function and associated components are not widely monitored or evaluated in literature.

Illinois, Indiana, Michigan, Minnesota, New York, ↗

USGS2021

Nutrient and suspended-sediment concentrations in the Maumee River and tributaries during 2019 rain-induced fallow conditions

Above average precipitation from October 2018 through July 2019 in the Maumee River (R.) Basin resulted in 29% of cropland left fallow, providing a glimpse of potential effects from decreased nutrient application. Ongoing monitoring at 15 water-quality sites on the Maumee R. upstream from Defiance enabled comparison with 2017, which was hydrologically similar to 2019 in precipitation and streamflow. In 2019, nitrate (as nitrogen; NO 3 -N) for March-July was significantly less than previous years (2015–2018), but the response for phosphorus (P) was more complicated. Relative to 2017, total P (TP) was lower at 7 of 15 sites, but higher at 7, reflecting higher suspended sediment (SS). Dissolved P (DP) was generally lower, but less different than NO 3 ; DP was higher at 3 sites. DP-P:NO 3 -N was generally higher in 2019, DP-P:TP was lower, and there was less TP relative to SS. Overall, less P was in the system in 2019. However smaller streams showed a large range of difference between 2019 and 2017 for all constituents, indicating variability in land management and physiography. In contrast, all constituents were lower in 2019 in larger (>5000 km 2 ) streams, including the Maumee R. near Defiance, where the difference in NO 3 (−37%) exceeded that for TP (−16%), DP (−10%), and SS (−20%). Differences in these relations among N, P, and SS indicate that P was available from legacy sources that are more difficult to distinguish during typical agricultural production years and that some material from 2019 was stored in the system upstream from the largest sites.

Indiana, Ohio↗

USGS2020

Causal factors for pesticide trends in streams of the United States: Atrazine and deethylatrazine

Pesticides are important for agriculture in the United States, and atrazine is one of the most widely used and widely detected pesticides in surface water. A better understanding of the mechanisms by which atrazine and its degradation product, deethylatrazine, increase and decrease in surface waters can help inform future decisions for water-quality improvement. This study considers causal factors for trends in pesticide concentration in streams in the United States and models the causal factors, other than use, in structural equation models. The structural equation models use a concomitant trend in corn and a latent variable model indicating moisture supply and management. The moisture supply and management latent variable incorporates long-term moisture conditions in the individual watersheds by using the Palmer Hydrologic Drought Index; human influence on the hydrologic cycle through the percent of the watershed drained by tile drains in 2012; and the base-flow contribution to streamflow, using the base-flow index. The structural equation models explain 77% and 38% of the variability in atrazine and deethylatrazine trends, respectively, across the conterminous United States. The models highlight future water-quality challenges, particularly in tile-drained settings where fall precipitation and heavy precipitation are increasing.

Journal of Environmental Quality↗

USGS2020

Influence of land use and region on glyphosate and aminomethylphosphonic acid in streams in the USA

Glyphosate is the most widely used herbicide in the United States for agricultural and non-agricultural weed control. Many studies demonstrate possible effects of glyphosate and its degradate AMPA on human and ecological health. Although glyphosate is thought to have limited mobility in soil, it is found year-round in many rivers and streams throughout the world in both agricultural and developed environments. It is vitally important to continue to increase the knowledge base of glyphosate use, distribution, transport, and impacts on human health and the environment. Here we show that glyphosate and AMPA are found in nearly all of 70 streams throughout the United States at concentrations far below human health or ecological benchmarks, with less occurrence in the Northeast and that undeveloped land, classified as such by land use near the sampling station, has lower concentrations compared to other types of land. Results also show that sites with large watersheds tend to have more AMPA than glyphosate and the opposite is true for small watersheds. Travel times and opportunity for glyphosate to degrade to AMPA and for reservoirs of AMPA to grow are greater in large watersheds. Factors that promoted quick movement of glyphosate to streams, such as subsurface tile or storm drains, sewers, overland flow from developed landscapes, and arid landscapes were associated with sites that had greater concentrations of glyphosate compared to AMPA. These results contribute contemporary information and generalized interpretations adding to the knowledge base of the fate of glyphosate on a national scale and provide a springboard for further exploration of technical processes controlling transport to streams.

Science of the Total Environment↗

USGS2018

Agriculture — A river runs through it — The connections between agriculture and water quality

Sustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and longterm economic, social, and environmental benefits that make a difference to the lives of the almost 400 million people projected to live in the United States by 2050. In 1991, Congress established the U.S. Geological Survey National Water-Quality Assessment (NAWQA) to address where, when, why, and how the Nation’s water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has been a leading source of scientific data and knowledge used by national, regional, state, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs. Plans for the third decade of NAWQA (2013–23) address priority water-quality issues and science needs identified by NAWQA stakeholders, such as the Advisory Committee on Water Information and the National Research Council, and are designed to meet increasing challenges related to population growth, increasing needs for clean water, and changing land-use and weather patterns. This report is one of a series of publications, The Quality of Our Nation’s Waters , which describes major findings of the NAWQA Project on water-quality issues of regional and national concern and provides science-based information for assessing and managing the quality of our groundwater resources. Other reports in this series focus on occurrence and distribution of nutrients, pesticides, and volatile organic compounds in streams and groundwater, the effects of contaminants and stream-flow alteration on the condition of aquatic communities in streams, and on the quality of groundwater from private domestic and public supply wells. Each reports builds toward a more comprehensive understanding of the quality of regional and national water resources. All NAWQA reports are available online ( https://water.usgs.gov/nawqa/bib/ ). We hope this publication will provide you with insights and information to meet your water-resource needs and will foster increased citizen awareness and involvement in the protection and restoration of our Nation’s waters. The information in this report is intended primarily for those interested or involved in resource management and protection, conservation, regulation, and policymaking at the regional and national levels.

Circular↗

USGS2016

Contrasting nitrogen fate in watersheds using agricultural and water quality information

Surplus nitrogen (N) estimates, principal component analysis (PCA), and end-member mixing analysis (EMMA) were used in a multisite comparison contrasting the fate of N in diverse agricultural watersheds. We applied PCA-EMMA in 10 watersheds located in Indiana, Iowa, Maryland, Nebraska, Mississippi, and Washington ranging in size from 5 to 1254 km 2 with four nested watersheds. Watershed Surplus N was determined by subtracting estimates of crop uptake and volatilization from estimates of N input from atmospheric deposition, plant fixation, fertilizer, and manure for the period from 1987 to 2004. Watershed average Surplus N ranged from 11 to 52 kg N ha −1 and from 9 to 32% of N input. Solute concentrations in streams, overland runoff, tile drainage, groundwater (GW), streambeds, and the unsaturated zone were used in the PCA-EMMA procedure to identify independent components contributing to observed stream concentration variability and the end-members contributing to streamflow and NO 3 load. End-members included dilute runoff, agricultural runoff, benthic-processing, tile drainage, and oxic and anoxic GW. Surplus N was larger in watersheds with more permeable soils (Washington, Nebraska, and Maryland) that allowed greater infiltration, and oxic GW was the primary source of NO 3 load. Subsurface transport of NO 3 in these watersheds resulted in some removal of Surplus N by denitrification. In less permeable watersheds (Iowa, Indiana, and Mississippi), NO 3 was rapidly transported to the stream by tile drainage and runoff with little removal. Evidence of streambed removal of NO 3 by benthic diatoms was observed in the larger watersheds.

Indiana, Iowa, Maryland, Nebraska, Mississippi, Wa↗

USGS2015

Estimated agricultural pesticide use for Southeast Stream-Quality Assessment, 2014

Introduction One of the goals of the U.S. Geological Survey (USGS) Southeast Stream-Quality Assessment (SESQA) is to characterize contaminants at perennial-stream sites throughout the southern Piedmont and southern Appalachian Mountains. The evaluation of pesticide inputs from agricultural sources will aid in that characterization. Methods used for calculating county-level pesticide use documented in this report are from methods developed and described by Thelin and Stone (2013) and Baker and Stone (2015). Two methods for calculating estimated pesticide use (EPest) rates—EPest-low and EPest-high—were applied in this study to estimate a probable range in the annual amounts of pesticide used for agriculture in 2014. To calculate watershed-level estimates, county-level use was proportionally allocated to agricultural land within each watershed. Concentrations of 262 pesticide compounds were estimated and compiled for subsequent analysis by the USGS National Water Quality Assessment Program, Southeast Stream-Quality Assessment. This report provides estimates of annual agricultural use of 262 pesticide compounds for counties and selected watersheds in parts of eight southeastern States for 2014. Estimates of county- and watershed-level annual agricultural pesticide use are provided as downloadable, tab-delimited files for both EPest-high and EPest-low.

Alabama, Georgia, Kentucky, North Carolina, South ↗

USGS2015

Preliminary estimates of annual agricultural pesticide use for counties of the conterminous United States, 2013

Summary This report provides preliminary estimates of annual agricultural use of 387 pesticide compounds in counties of the conterminous United States in 2013, compiled by means of methods described in Thelin and Stone (2013) and Baker and Stone (2015). U.S. Department of Agriculture county-level data for harvested-crop acreage were used in conjunction with proprietary Crop Reporting District-level pesticide-use data to estimate county-level pesticide use. Where Crop Reporting District data were not available or were incomplete, estimated pesticide use values were calculated with two different methods, resulting in a low and a high estimate based on different assumptions about missing survey data (Thelin and Stone, 2013). Preliminary estimates in this report are expected to be revised upon availability of updated crop acreages in the 2017 Agricultural Census, to be published by the U.S. Department of Agriculture in 2019. Estimates of annual agricultural pesticide use are provided as downloadable, tab-delimited files, which are organized by compound, year, state Federal Information Processing Standard (FIPS) code, county Federal Information Processing Standard code, and amount in kilograms (kg). The files, listed below, are a continuation of the 1992–2009 and 2008–2012 pesticide-use estimates reported by Stone (2013) and Baker and Stone (2015), respectively: High estimates of county pesticide use, arranged by pesticide name: Table 1. 1-Methyl Cyclopropene through Chlorantraniliprole Table 2. Chlorethoxyfos through Diflufenzopyr Table 3. Dimethenamid through Gibberellic Acid Table 4. Glufosinate through Metiram Table 5. Metolachlor through Propazine Table 6. Propiconazole through Triasulfuron Table 7. Tribenuron Methyl through Zoxamide Low estimates of county pesticide use, arranged by pesticide name: Table 8. 1-Methyl Cyclopropene through Chlorantraniliprole Table 9. Chlorethoxyfos through Diflufenzopyr Table 10. Dimethenamid through Gibberellic Acid Table 11. Glufosinate through Metiram Table 12. Metolachlor through Propazine Table 13. Propiconazole through Triasulfuron Table 14. Tribenuron Methyl through Zoxamide References Cited Baker, N.T., and Stone, W.W., 2015, Estimated annual agricultural pesticide use for counties of the conterminous United States, 2008–12: U.S. Geological Survey Data Series 907, 9 p., accessed July, 12, 2015, at http://dx.doi.org/10.3133/ds907. Stone, W.W., 2013, Estimated annual agricultural pesticide use for counties of the conterminous United States, 1992–2009: U.S. Geological Survey Data Series 752, 1 p., 14 tables Thelin, G.P., and Stone, W.W., 2013, Estimation of annual agricultural pesticide use for counties of the conterminous United States, 1992–2009: U.S. Geological Survey Scientific Investigations Report 2013–5009, 54 p.

Open-File Report↗

USGS2015

Estimated annual agricultural pesticide use for counties of the conterminous United States, 2008-12

Annual county-level pesticide use was estimated for 423 herbicides, insecticides, and fungicides applied to agricultural crops grown in the conterminous United States during 2008–12. For all States except California, pesticide-use data were compiled from proprietary surveys of farm operations located within U.S. Department of Agriculture Crop Reporting Districts (CRDs). Surveyed pesticide-use data were used in conjunction with county annual harvested-crop acres reported by the U.S. Department of Agriculture 2007 and 2012 Censuses of Agriculture and the 2008–11 County Agricultural Production Survey to calculate use rates per harvested-crop acre, or an “estimated pesticide use” (EPest) rate, for each crop by year. County-use estimates were then calculated by multiplying EPest rates by harvested-crop acres for each pesticide crop combination. Use estimates for California were obtained from annual Department of Pesticide Regulation-Pesticide Use Reports. Proprietary surveyed pesticide-use data were not available for all CRDs and years. When pesticide-survey data were unavailable for a CRD in a particular year, EPest extrapolated rates were calculated from adjoining or nearby CRDs to ensure that pesticide use was estimated for all counties where harvested-crop acres were reported. Two estimation methods were used—EPest-low and EPest high—and differed in how they treated situations when a CRD was surveyed and pesticide use was not reported for a particular pesticide-by-crop combination. California pesticide-use estimates were not extrapolated; therefore, EPest-low and EPest-high are the same for counties in California. This data series is a continuation of the 1992–2009 pesticide-use estimates reported by Stone (2013). It is an update of estimates for 2008–9 (Stone, 2013), as well as an update of the 2010–11 preliminary estimates reported by Baker and Stone (2013). EPest values from these compilations (1992–2012) are suitable for making national, regional, and watershed assessments of annual pesticide use. County-level estimates are provided to make it easier to compile watershed assessments; however, users should be aware there is a greater degree of uncertainty in individual county-level estimates when compared to CRD or State-level estimates. This report provides EPest-low and EPest-high annual agricultural pesticide use for counties of the conterminous United States for 423 compounds during 2008–12 in tab-delimited files organized by compound, year, State Federal Information Processing Standard (FIPS) code, county FIPS code, and amount in kilograms (kg). EPest-high county pesticide-use estimates were divided into tables 1 through 7 by pesticide name: Table 1: 2, 4-D through Chlorantraniliprole Table 2: Chlorethoxyfos through Diflufenzopyr Table 3: Dimethenamid through Gibberellic acid Table 4: Glufosinate through Metiram Table 5: Metolachlor through Propazine Table 6: Propiconazole through Triasulfuron Table 7: Tribenuron methyl through Zoxamide EPest-low county pesticide-use estimates were divided into tables 8 through 14 by pesticide name: Table 8: 2, 4-D through Chlorantraniliprole Table 9: Chlorethoxyfos through Diflufenzopyr Table 10: Dimethenamid through Gibberellic acid Table 11: Glufosinate through Metiram Table 12: Metolachlor through Propazine Table 13: Propiconazole through Triasulfuron Table 14: Tribenuron methyl through Zoxamide

Data Series↗

USGS2014

Annual agricultural pesticide use for Midwest Stream-Quality Assessment, 2012-13

This report provides estimates of annual agricultural use of 190 pesticide compounds for counties and selected watersheds of Midwestern States for 2012 and 2013 compiled for subsequent analysis by the National Water-Quality Assessment Program, Midwest Stream-Quality Assessment (MSQA). One of the goals of MSQA is to characterize contaminants at perennial-stream sites throughout the Corn Belt. Evaluating pesticide inputs from agricultural sources will aid in that characterization. Crop acres for selected Midwestern crops were obtained from the Cropland Data Layer of the U.S. Department of Agriculture’s National Agricultural Statistics Service and used in conjunction with GfK Kynetec, Inc. proprietary Crop Reporting District-level pesticide-use data to estimate pesticide use for counties and watersheds. Estimated pesticide use (EPest) values were calculated by using both the “EPest-high” and “EPest-low” methods, the distinction being that there are more counties with estimated pesticide use for EPest-high compared to EPest-low, owing to differing assumptions about missing survey data. County-level and watershed-level estimates of annual agricultural pesticide use are provided as downloadable, tab-delimited files for both EPest-high and Epest-low. Summary graphs of MSQA watershed-level pesticide use for selected crops are also provided.

Data Series↗

USGS2014

Water quality in Indiana: trends in concentrations of selected nutrients, metals, and ions in streams, 2000-10

Water quality in Indiana streams generally improved during the 2000–10 study period, based on trends in selected nutrients, metals, and ions. This study combined water-quality data from the Indiana Fixed Station Monitoring Program (FSMP) with streamflow data from nearby U.S. Geological Survey streamgages. A parametric time-series model, QWTREND, was used to develop streamflow-adjusted constituent concentrations, to adjust for seasonal variance and serial correlation, and to identify trends independent of streamflow-related variability. This study examined 7,345 water samples from 57 FSMP sites for 11 years. Concentration trends were analyzed for 12 constituents—the nutrients nitrate, organic nitrogen, and phosphorus; suspended solids; the metals copper, iron, lead, and zinc; the ions chloride, and sulfate together with hardness as a measure of the calcium carbonate ion; and dissolved solids. Nutrient concentrations in this study generally were too high relative to standards and criteria. The national recommended criteria for the three ecoregions in Indiana were exceeded by more than one-half of the nitrate and most of the phosphorus concentrations. Copper, lead, zinc, chloride, sulfate, and dissolved solids concentrations were in acceptable ranges relative to standards and criteria in more than 97 percent of samples. The two Lake Michigan Basin sites had the highest concentrations and were in a unique statistical group for 10 of the 12 constituents, with concentrations many times higher than the statewide median and higher than the medians of most other basins. The two Ohio River Basin sites had the lowest concentrations and were in a unique statistical group for 6 of the 12 constituents. Statistically significant trends were identified that included 167 downward trends and 83 upward trends. The Kankakee River Basin had the most significant upward trends while the most significant downward trends were in the Whitewater River Basin, the Lake Michigan Basin, and the Patoka River Basin. For most constituents, a majority of sites had significant downward trends. Two streams in the Lake Michigan Basin have shown substantial decreases in most constituents. The West Fork White River near Indianapolis, Indiana, showed increases in nitrate and phosphorus and the Kankakee River Basin showed increases in copper, zinc, chloride, sulfate, and hardness. Upward trends in nutrients were identified at a few sites, but most nutrient trends were downward. Upward trends in metals corresponded with relatively small concentration increases while downward trends involved considerably larger concentration changes. Downward trends in chloride, sulfate, and suspended solids were observed statewide, but upward trends in hardness were observed in the northern half of Indiana.

Indiana↗

USGS2013

Preliminary estimates of annual agricultural pesticide use for counties of the conterminous United States, 2010-11

This report provides preliminary estimates of annual agricultural use of 374 pesticide compounds in counties of the conterminous United States in 2010 and 2011, compiled by means of methods described in Thelin and Stone (2013). U.S. Department of Agriculture (USDA) county-level data for harvested-crop acreage were used in conjunction with proprietary Crop Reporting District (CRD)-level pesticide-use data to estimate county-level pesticide use. Estimated pesticide use (EPest) values were calculated with both the EPest-high and EPest-low methods. The distinction between the EPest-high method and the EPest-low method is that there are more counties with estimated pesticide use for EPest-high compared to EPest-low, owing to differing assumptions about missing survey data (Thelin and Stone, 2013). Preliminary estimates in this report will be revised upon availability of updated crop acreages in the 2012 Agricultural Census, to be published by the USDA in 2014. In addition, estimates for 2008 and 2009 previously published by Stone (2013) will be updated subsequent to the 2012 Agricultural Census release. Estimates of annual agricultural pesticide use are provided as downloadable, tab-delimited files, which are organized by compound, year, state Federal Information Processing Standard (FIPS) code, county FIPS code, and kg (amount in kilograms).

Open-File Report↗

USGS2012

Selected historic agricultural data important to environmental quality in the United States

This report and the accompanying tables summarize some of the important changes in American agriculture in the form of a timeline and a compilation of selected annual time-series data that can be broadly related to environmental quality. Although these changes have been beneficial for increasing agricultural production, some of them have resulted in environmental concerns. The agriculture timeline is divided into four categories (1) crop and animal changes, (2) mechanical changes, (3) biological and chemical changes, and (4) regulatory and societal changes. The timeline attempts to compile events that have had a lasting impact on agriculture in the United States. The events and data presented in this report may help to improve the connections between agricultural activist and environmental concerns.

Data Series↗

USGS2011

Tillage practices in the conterminous United States, 1989-2004: Datasets aggregated by watershed

This report documents the methods used to aggregate county-level tillage practices to the 8-digit hydrologic unit (HU) watershed. The original county-level data were collected by the Conservation Technology Information Center (CTIC). The CTIC collects tillage data by conducting surveys about tillage systems for all counties in the United States. Tillage systems include three types of conservation tillage (no-till, ridge-till, and mulch-till), reduced tillage, and intensive tillage. Total planted acreage for each tillage practice for each crop grown is reported to the CTIC. The dataset includes total planted acreage by tillage type for selected crops (corn, cotton, grain sorghum, soybeans, fallow, forage, newly established permanent pasture, spring and fall seeded small grains, and 'other' crops) for 1989-2004. Two tabular datasets, based on the 1992 enhanced and 2001 National Land Cover Data (NLCD), are provided as part of this report and include the land-cover area-weighted interpolation and aggregation of acreage for each tillage practice in each 8-digit HU watershed in the conterminous United States for each crop. Watershed aggregations were done by overlying the 8-digit HU polygons with a raster of county boundaries and a raster of either the enhanced 1992 or the 2001 NLCD for cultivated land to derive a county/land-cover area weighting factor. The weighting factor then was applied to the county-level tillage data for the counties within each 8-digit HU and summed to yield the total acreage of each tillage type within each 8-digit HU watershed.

Conterminous United States↗