Heather M Bragg
Science and Products
Willamette River Basin Dissolved Gas Monitoring Network
USGS total dissolved gas (TDG) data help guide spill and discharge management from dams operated along tributaries of the Willamette River.
Lower Columbia River Dissolved Gas Monitoring Network
USGS total dissolved gas (TDG) data help guide spill and discharge management from dams operated along the lower Columbia River.
North Santiam River Basin Study
The streamflow and water-quality conditions monitored by the USGS in the North Santiam River basin provide valuable information to water resource managers
Investigation of land surface phenology detections in shrublands using multiple scale satellite data
Shrublands occupy about 13% of the global land surface, contain about one-third of the biodiversity, store about half of the global terrestrial carbon, and provide many ecosystem services to a large amount of world's human population and livestock. Because phenology is a sensitive indicator of the response of shrubland ecosystems to climate change...
Peng, Dailiang; Wang, Yan; Xian, George Z.; Huete, Alfredo R; Huang, Wenjiang; Shen, Miaogen; Wang, Fumin; Yu, Le; Liu, Liangyun; Xie, Qiaoyun; Liu, Lingling; Zhang, Xiaoyang Seasonality of acarological risk of exposure to Borrelia miyamotoi from questing life stages of Ixodes scapularis collected from Wisconsin and Massachusetts, USA
Measures of acarological risk of exposure to Ixodes scapularis-borne disease agents typically focus on nymphs; however, the relapsing fever group spirochete, Borrelia miyamotoi can be transmitted transovarially, and I. scapularis larvae are capable of transmitting B. miyamotoi to their hosts. To quantify the...
Han, Seungeun; Hickling, Graham J.; Ogden, Nicholas H.; Ginsberg, Howard S.; Kobbekaduwa, Vishvapali; Rulison, Eric L.; Beati, Lorenza; Tsao, Jean I. Trends in nitrogen, phosphorus, and sediment concentrations and loads in streams draining to Lake Tahoe, California, Nevada, USA
Lake Tahoe, a large freshwater lake of the eastern Sierra Nevada in California and Nevada, has 63 tributaries that are sources of nutrients and sediment to the lake. The Tahoe watershed is relatively small, and the surface area of the lake occupies about 38% of the watershed area (1313 km2). Only about 6% of the watershed is urbanized or...
Domagalski, Joseph L.; Morway, Eric D.; Alvarez, Nancy L.; Hutchins, Juliet; Rosen, Michael R.; Coats, Robert Hydrocarbons to carboxyl-rich alicyclic molecules: A continuum model to describe biodegradation of petroleum-derived dissolved organic matter in contaminated groundwater plumes
Relationships between dissolved organic matter (DOM) reactivity and chemical composition in a groundwater plume containing petroleum-derived DOM (DOMHC) were examined by quantitative and qualitative measurements to determine the source and chemical composition of the compounds that persist downgradient. Samples were collected from a transect down...
Podgorski, David C.; Zito, Phoebe; Kellerman, Anne M.; Bekins, Barbara A.; Cozzarelli, Isabelle M.; Smith, Donald F.; Cao, Xiaoyan; Schmidt-Rohr, Klaus; Wagner, Sasha; Stubbins, Aron; Spencer, Robert G. M. Exposure of an early to middle Noachian valley network in three dimensions on Mars
We document a set of channels in a section of the Martian cratered highlands located between crustal massifs northeast of Hellas Planitia that are visible in cross section and planview >200 m below the surface. The morphometry and spatial distribution of the outcrops provide concrete geological evidence of a dynamic aqueous system in a...
Skinner, James A.; Fortezzo, Corey M.; Mouginis-Mark, Peter J. Weed-suppressive bacteria effects differ in culture compared to in soils and with or without microbial competition and separation of active ingredient
Weed-suppressive bacteria (WSB), specifically the D7 and ACK55 strains of Pseudomonas fluorescens, were previously reported to selectively inhibit growth of invasive annual grasses (IAGs) that have caused severe ecosystem degradation across much of the western US. However, recent studies show highly mixed evidence for WSB effectiveness in...
Lazarus, Brynne E.; Feris, Kevin; Germino, Matthew Complexity of groundwater age mixing near a seawater intrusion zone based on multiple tracers and Bayesian inference
Aquifer flow systems near seawater interfaces can be complicated by density-driven flows and the formation of stagnation zones, which inevitably introduces uncertainty into groundwater age-dating. While age-dating has proved effective to understand the seawater intrusion and aquifer salinization process in coastal aquifers, further efforts are...
Ju, YeoJin; Massoudieh, Arash; Green, Christopher; Lee, Kang-Kun; Kaown, Dugin Movement of synthetic organic compounds in the food web after the introduction of invasive quagga mussels (Dreissena bugensis) in Lake Mead, Nevada and Arizona, USA
Introductions of dreissenid mussels in North America have been a significant concern over the last few decades. This study assessed the distribution of synthetic organic compounds (SOCs) in the food web of Lake Mead, Nevada/Arizona, USA and how this distribution was influenced by the introduction of invasive quagga mussels. A clear spatial...
Goodbred, Steven L.; Rosen, Michael R.; Patino, Reynaldo; Alvarez, David; Echols, Kathy R.; King, Kerensa; Umek, John
Evaluation of the U.S. Geological Survey streamgage network in South Carolina, 2017
The U.S. Geological Survey (USGS) has been monitoring streamflow in South Carolina since the late 1800s. From the beginning, the USGS streamgage network in South Carolina has been dynamic, with streamgages being added or removed depending on their purpose and the availability of funding from Federal, State, and local partners. Streamflow...
Feaster, Toby D.; Kolb, Katharine R.
Chapter A6.2. Dissolved Oxygen
The “National Field Manual for the Collection of Water-Quality Data” (NFM) provides guidelines and procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation’s surface water and groundwater resources. This chapter, NFM A6.2, provides guidance and protocols for the measurement of dissolved...
Estimating flood magnitude and frequency on gaged and ungaged streams in Maine
Accurate estimates of flood frequency and magnitude on rivers and streams in Maine are a key component of effective flood risk management, flood mitigation, and flood recovery programs for the State. Flood-frequency estimates are published here for 148 streamgages in and adjacent to Maine. Equations are provided for users to compute flood-...
Lombard, Pamela J.; Hodgkins, Glenn A.
Physical and chemical stressors on algal, invertebrate, and fish communities in 14 Milwaukee area streams, 2004–2013
In 2004, the U.S. Geological Survey (USGS) began sampling 14 wadable streams in urban or urbanizing watersheds near Milwaukee, Wisconsin. The overall goal of the study is to assess the health of the aquatic communities in the Milwaukee Metropolitan Sewerage District planning area to inform current and future watershed management. In addition to...
Eikenberry, Barbara C. Scudder; Nott, Michelle A.; Stewart, Jana S.; Sullivan, Daniel J.; Alvarez, David A.; Bell, Amanda H.; Fitzpatrick, Faith A.