New Mexico Geological Society Annual Spring Meeting — Abstracts

Snow pack dominated rivers and streams across the Southwestern United States have been feeling the effects of global climate change, which mainly include increasing temperatures and decreasing amounts of precipitation, especially precipitation in the form of snow. Over the past 50 years the Jemez River regions has experienced a 2oF increase in ambient air temperature, as well as a 40% decrease in stream discharge. Spanning roughly 129 km and contributing more than 50,000,000 cubic meters of water to the Rio Grande River annually, the Jemez River is the largest tributary to the Middle Rio Grande Basin. Further complicating matters, the surrounding geology of the Jemez River is of volcanic origin which is responsible for the many hydrothermal springs and seeps in the area, which allow for introduction of heavy metals, especially arsenic into the Jemez River. A 72-study was conducted to determine how total and dissolved arsenic concentrations fluctuate diurnally, and also to determine what physiochemical and site parameters dictate the fluctuations. The study demonstrates that the arsenic concentrations fluctuated up to 60% between night and day, and that a variety of physiochemical parameters, including dissolved oxygen, pH, conductivity, and stream discharge are closely correlated to the fluctuation in arsenic, and also fluctuate diurnally, providing insight to long term changes that the river may experience in the future due to climate change impacts. As the regional climate changes with a continual increase in temperature and decreased precipitation, it is highly probable that arsenic concentrations will rise in the river; possibly high enough to impact downstream users and the water quality of the Rio Grande River.