Data

The Midwest Stream Quality Assessment is the first of several regional studies that are being conducted as part of the Regional Stream Quality Assessment (RSQA) project, a component of the Cycle 3 National Water Quality Assessment (NAWQA) project. The MSQA was a collaborative study amongst NAWQA, the USGS Columbia Environmental Research Center (CERC), and the USEPA National Rivers and Streams Asse

The Midwest United States 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 (POCIS) in 100 small streams across the Midwest fo

This data release contains environmental and quality control results for chemical, biological, and physical sampling of water and bed sediment from Albemarle Sound and associated tributaries between 2012 and 2014 referenced in USGS OFR 2016-1171. Appendix 1 contains all quality control results to characterize the bias and variability of sampling, handling, and analysis of water, phytoplankton, and

This data release contains the data used to interpret the origin of the shallow lakes in the Khorezm Province, Uzbekistan, and the history of pesticide use around these lakes. The data include 1) lake sediment core data for age dating (cesium-137 and lead-210) for 12 lakes in Uzbekistan, 2) lake sediment core data for loss on ignition (LOI550)for determining organic carbon content of 12 lakes in

The spring 2016 mainland sea otter count began on 1 May and was completed on 11 May. Overall viewing conditions this year were very good, being more favorable than those during the 2015 spring census (3.1 vs. 2.6, where 0=poor, 1=fair, 2=good, 3=very good, and 4=excellent) and contributed to the relatively short duration of the count. The surface canopies of kelp (Macrocystis sp.) were considered

A hydrogeologic framework was constructed to represent the altitudes and thicknesses of hydrogeologic units within the Ozark Plateaus aquifer system (hereinafter referred to as the Ozark system). The Ozark system study area is nearly 70,000 square miles and includes parts of Arkansas, Kansas, Missouri, and Oklahoma. Nine hydrogeologic units were selected for delineation within the Ozark system and

Sediment samples and samples for water-toxicity testing were collected during 2014 from several streams in San Antonio, Texas known locally as the Westside creeks (Alazn, Apache, Martnez, and San Pedro Creeks) and from the San Antonio River. Samples were collected once during base-flow and again after periods of storm-water runoff (post-storm conditions) to determine baseline sediment- and water-q

This USGS Data Release represents the synthetic and real data from hydrologically diverse streams used to test the performance and limitations of the Two-tracer Ratio-based Mixing Model (TRaMM) which uses high-frequency measures of two tracers (A and B) and streamflow to separate total streamflow into water from slowflow and fastflow sources. The ratio between the concentrations of the two tracers

This data release contains spatial data associated the sedimentation survey conducted by the U.S. Geological Survey cfor the Lago La Plata, Toa Alta, Puerto Rico, during March and April 2015 to provide up-to-date information about the relation of pool elevation and storage volume in the reservoir. The survey was conducted in cooperation with the Puerto Rico Aqueduct and Sewer Authority. A total of

The dataset includes specifics on fragments of bullets recovered from shot Belding's ground squirrels from Oregon and California. Ground squirrels were radiographed and then we used ImageJ software to count and measure the area of those bullet fragments. A subset of shot carcasses were then digested and bullet fragments were recovered. Statistical models were developed to predict either the number

Low-altitude (approximately 120 meters above ground level) digital images were obtained from cameras mounted in a fixed-wing unmanned aerial system (UAS) flown from the lawn adjacent to the Coast Guard Beach parking lot on 1 March, 2016. The UAS was a Skywalker X8 operated by Raptor Maps, Inc., contractors to the U.S. Geological Survey (USGS). Two consecutive UAS missions were flown, each with two