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Discrete sample surface-water data for the Sacramento-San Joaquin River Delta

Metadata Updated: October 29, 2025

The goal of this study was to develop a suite of inter-related water quality monitoring approaches capable of modeling and estimating the spatial and temporal gradients of particulate and dissolved total mercury (THg) concentration, and particulate and dissolved methyl mercury (MeHg), concentration, in surface waters across the Sacramento / San Joaquin River Delta (SSJRD). This suite of monitoring approaches included: a) data collection at fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, b) spatial mapping using boat-mounted flow-through sensors, and c) satellite-based remote sensing. The focus of this specific Child Page is to present all field and laboratory-based data associated with discrete surface water samples collected as part of the CMS and boat mapping components of the study.
The data provided in the table herein constitute a collection of field-based and laboratory-based measurements that coincide with the timestamps of samples collected at 33 sites across the Delta. Laboratory-based measurements presented herein were conducted by the U.S. Geological Survey (USGS) Organic Matter Research Laboratory (OMRL) in Sacramento, CA, the USGS Earths System Processes Division (ESPD) microbial biogeochemistry laboratory in Menlo Park, CA, the USGS Reston Stable Isotope Laboratory (RSIL) in Reston, VA and the USGS National Water Quality Laboratory (NWQL) in Denver, CO. The machine-readable (comma separated value, *.csv) file presented herein includes laboratory-based measurements for discrete samples collected from 33 established field sites (sampled repeatedly). In addition, field-based sensor data from continuous measurement platforms (CMS locations or as part of the mapping boat flow-through system) are also included in this discrete sample dataset by ensuring that the field sensor measurements were both spatially and temporally coincident with the physically discrete water sample collected for laboratory analysis.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date September 12, 2025
Metadata Updated Date October 29, 2025

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date September 12, 2025
Metadata Updated Date October 29, 2025
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/usgs-5f45218282ce4c3d122516df
Data Last Modified 2023-02-16T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 2747bb2a-ac7d-40ce-b1ce-943709527ba5
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial -121.8633, 37.8540, -121.1704, 38.7651
Source Datajson Identifier True
Source Hash 17e25d12aa730e126af79cfa0b3082a1b9492949fd3994928b49f9d0dffa7fe5
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -121.8633, 37.8540, -121.8633, 38.7651, -121.1704, 38.7651, -121.1704, 37.8540, -121.8633, 37.8540}

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