Overcast
Overcast
62.6 °F
August 23, 2014
River Reporter Facebook pageTRR TwitterRSS Search Login
news

Groundwater study underway in Upper Delaware

Temperature mapping is being conducted using an emerging technology capable of achieving high-precision measurements every minute along the entire length of optical fiber cables that are placed on the riverbed. The mapping allows for understanding groundwater/surface-water interaction at spatial and temporal scales difficult to achieve with conventional methods.


The project is designed to look at the distribution of groundwater as it discharges to the Delaware River. “The people who live here and fish here know to a large extent where the groundwater is focused,” said Rosenberry. “They know that groundwater is discharging to the river, but they probably don’t think about what it means. We do. This is the kind of work that USGS does all across the country.

“As a country, about 40% of the water we consume comes from groundwater. In rural areas, that percentage is much larger. The concern is that as we use more groundwater to supply our homes and infrastructure, there may be less groundwater discharging to the river. So at times when the river temperature is very warm, the fish and the animals that live in the substrate may become stressed.”

USGS staff have also been sampling the chemistry of several small hand-augured wells that they installed in the river bed and along the shore to determine the chemical inputs to the river. Several wells with sensors inside will continue to collect data every 20 minutes throughout the year.

Gathering such data now establishes a baseline against which changes can be measured in the future. “It’s not just people who make use of groundwater,” said Rosenberry. “It’s also the natural environment. Animals that live in the substrate, macroinvertebrates and plants — there are many microenvironments that rely on this. We don’t always think about that. This kind of work will set a baseline we can compare to years from now.”

The USGS produces numerous reports for the public in addition to those for its scientific colleagues. Two of particular relevance to this topic can be seen at http://pubs.er.usgs.gov/publication/cir1186 and http://pubs.er.usgs.gov/publication/cir1139.