Filters: partyWithName: Barbara J Mahler (X) > Types: Map Service (X)
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Temporal patterns in glyphosate and atrazine concentrations were measured weekly by the U.S. Geological Survey (USGS) during the 2013 growing season in 100 small streams in the Midwestern United States. Concentrations also were measured every 2 days at a subset of 8 of the sites, all located in Missouri. Glyphosate was detected more frequently in urban streams than in agricultural streams, and at concentrations similar to those in streams with high agricultural land use in the watershed. In contrast, atrazine was detected more frequently and at higher concentrations in agricultural streams than in urban streams. This data release provides watershed characteristics and 2013 glyphosate and atrazine compound concentrations...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Corn Belt,
ELISA,
Illinois,
Indiana,
Iowa,
The Edwards aquifer is a karst aquifer system that is a primary water source for a large part of central Texas including the city of San Antonio, Texas. These vector geospatial data represent the geographic extent of the contributing zones for the Northern, Barton Springs, and San Antonio segments of the Edwards aquifer. The contributing zone is defined as the drainage area of the Edwards Plateau that contributes surface water to the Edwards aquifer recharge zone. The recharge zone is where surface water and precipitation infiltrate into the outcrop of the rocks that compose the aquifer (see Ashworth and Hopkins, 1995, and George and others, 2011). References Ashworth, J.B., and Hopkins, Janie, 1995, Aquifers of...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Bandera County,
Bell County,
Bexar County,
Blanco County,
Comal County,
Dissolved pesticides were measured in weekly water samples from 482 wadeable streams in five regions of the United States during 2013-2017, as part of the U.S. Geological Survey's (USGS) Regional Stream Quality Assessment (RSQA). One study was conducted each year, starting with the Midwest (2013), followed by the Southeast Piedmont (2014), Pacific Northwest (2015), Northeast (2016), and Central California Coast (2017). Within each region, 77-100 streams were sampled over 6-14 weeks, followed by ecological surveys of fish, invertebrate and fish communities. The first study (Midwest) is an agricultural-gradient study, where the majority of sites were located along a gradient from undeveloped to 100% agricultural land...
In 2013, the U.S. Geological Survey and the U.S. Environmental Protection Agency characterized water-quality stressors and ecological conditions in 100 wadeable streams across the Midwestern United States. The goal of the study was to determine the relative effects of multiple ecological stressors – contaminants, nutrients, sediment, and habitat – on ecological communities in the streams. The Midwest is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers...
Categories: Data;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Illinois,
Indiana,
Iowa,
Kansas,
Minnestoa,
Karst aquifers—formed when the movement of water dissolves bedrock—are critical groundwater resources in North America. Water moving through these aquifers carves out magnificent caves, sinkholes, and other formations. These formations are home to high concentrations of rare and endangered species, but the hydrological conditions that support these species can change rapidly. Managing these ecosystems into the future requires a better understanding of how climate, hydrology, and karst ecosystems interact. The objective of this project was to determine how species and ecosystems associated with karst might respond to future temperature and precipitation extremes and accompanying changes in groundwater levels and...
Categories: Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: 2012,
CASC,
Completed,
Other Water,
Other Water,
These datasets are one component of the multistressor studies conducted in Midwest streams in 2013 (MSQA) and in Southeast streams in 2014 (SESQA) by the U.S. Geological Survey National Water Quality Assessment Project. High-frequency small-volume autosamplers were deployed at 7 sites each in MSQA and SESQA that collected daily and weekly composite water samples, which were analyzed for 225 pesticides and pesticide degradates. Five of the MSQA autosampler sites were in agricultural watersheds and two in urban watersheds, whereas all seven SESQA autosampler sites were in urban watersheds. The daily and weekly composite samples were compared with results from traditional discrete water samples collected weekly at...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alabama,
Corn Belt,
Georgia,
Illinois,
Indiana,
Dissolved pesticides were measured in weekly water samples from 85 wadeable streams in Central Coastal California over a variable six-week period during March–May, 2017, as part of the California Stream Quality Assessment (CSQA) study conducted by the U.S. Geological Survey's (USGS) Regional Stream-Quality Assessment (RSQA) Project. The 85 streams consisted of 40 urban sites (5–100% urban land in the lower basin), 9 agricultural sites, 24 mixed land-use sites, and 12 undeveloped sites. Water samples were filtered (0.7 micrometers) and analyzed for 253 pesticide compounds by direct-injection liquid chromatography with tandem mass-spectrometry (LC-MS/MS). Two similar LC-MS/MS methods were used: a broad-spectrum (223...
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