Laboratory assessment of alternative stream velocity measurement methods.

Understanding streamflow in montane watersheds on regional scales is often incomplete due to a lack of data for small-order streams that link precipitation and snowmelt processes to main stem discharge. This data deficiency is attributed to the prohibitive cost of conventional streamflow measurement methods and the remote location of many small streams. Expedient and low-cost streamflow measurement methods used by resource professionals or citizen scientists can provide scientifically useful solutions to this data deficiency.

Streamflow contributions from tribal lands to major river basins of the United States.

While many studies on tribal water resources of individual tribal lands in the United States (US) have been conducted, the importance of tribal water resources at a national scale has largely gone unrecognized because their combined totals have not been quantified. Thus, we sought to provide a numerical estimate of major water budget components on tribal lands within the conterminous US and on USGS hydrologic unit codes (HUC2) regions. Using existing national-scale data and models, we estimated mean annual precipitation, evapotranspiration, excess precipitation, streamflow, and water use for the period 1971-2000.

Environmental Air Sampling Near Burn Pit and Incinerator Operations at Bagram Airfield, Afghanistan.

Objective: This study presents environmental air samples collected at a US military installation with a solid waste disposal facility (SWDF) containing a burn pit from 2005 through 2012 and compared these results with occupational (breathing zone) samples.

Methods: Particulate matter (PM) environmental samples were collected as part of the installation monitoring program. Service Members in four security positions were monitored for PM and acrolein occupational exposures.

Occupational exposures among personnel working near combined burn pit and incinerator operations at Bagram Airfield, Afghanistan.

Occupational air samples were collected at Bagram Airfield Afghanistan for security forces (SF) stationed at the perimeter of the solid waste disposal facility that included a burn pit, air curtain destructors, and solid waste and medical waste incinerators. The objective of the investigation was to quantify inhalation exposures of workers near the disposal facility. Occupational air sample analytes included total particulates not otherwise specified (PNOS), respirable PNOS, acrolein and polyaromatic hydrocarbons (PAH).

Distinguishing sources of ground water recharge by using delta2H and delta18O.

Stable isotope values of hydrogen and oxygen from precipitation and ground water samples were compared by using a volumetrically based mixing equation and stable isotope gradient to estimate the season and location of recharge in four basins. Stable isotopes were sampled at 11 precipitation sites of differing elevation during a 2-year period to quantify seasonal stable isotope contributions as a function of elevation. Supplemental stable isotope data collected by the International Atomic Energy Association during a 14-year period were used to reduce annual variability of the mean seasonal stable isotope data.

Electrical resistance sensors record spring flow timing, Grand Canyon, Arizona.

Springs along the south rim of the Grand Canyon, Arizona, are important ecological and cultural resources in Grand Canyon National Park and are discharge points for regional and local aquifers of the Coconino Plateau. This study evaluated the applicability of electrical resistance (ER) sensors for measuring diffuse, low-stage (<1.0 cm) intermittent and ephemeral flow in the steep, rocky spring-fed tributaries of the south rim.