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The Massachusetts Division of Fisheries and Wildlife has been studying brook trout populations in Cape Cod groundwater-fed river systems for decades. Recently, a notable reduction in trout population in the Santuit River sparked the concern of several groups, including the Wampanoag Tribe. Brook trout population dynamics may be tied to water quality and temperature changes, which are both impacted by spatially preferential groundwater discharge to the river. The streambed interface temperature and near-surface geophysical data compiled in this data release were collected in summer 2018 as part of a larger effort to characterize the spatial distribution of groundwater discharge zones, and exchanges with surface water,...
Quantification of mobile/less-mobile porosity dynamics at the sediment/water interface is critical to predicting contaminant storage, release, and transformation processes. Zones in groundwater flow-through lakes where lake water recharges the aquifer can strongly control aquifer water quality. Less-mobile porosity has previously been characterized in aquifers using flow path scale (10's of m+) tracer injections which are analyzed using numerical models. Methodology was recently developed to couple geoelectric measurements (bulk electrical conductivity, EC), which are directly sensitive to less-mobile ionic tracer exchange processes, with pumped fluid EC tracer data over time. If the fluid EC concentration history...
When water is pumped slowly from saturated sediment-water inteface sediments, the more highly connected, mobile porosity domain is prefferentially sampled, compared to less-mobile pore spaces. Changes in fluid electrical conductivity (EC) during controlled downward ionic tracer injections into interface sediments can be assumed to represent mobile porosity dynamics, which are therefore distinguished from less-mobile porosity dynamics that is measured using bulk EC geoelectrical methods. Fluid EC samples were drawn at flow rates similar to tracer injection rates to prevent inducing preferential flow. The data were collected using a stainless steel tube with slits cut into the bottom (USGS MINIPOINT style) connected...
Heat is used as a tracer for a variety of physical hydrogeological process. Several types of instruments are used to measure the temperature of surface water and saturated sediments. In the Quashnet River we have been using methods that include: infrared, individual logging thermistors, and fiber-optic distributed temperature sensing. The latter type of data (FO_DTS) are described and presented here.
A continuous resistivity profiling (CRP) survey was conducted in a 1.2-mile reach of the Similkameen River upstream of Enloe Dam in December 2021 in Washington State. The survey was performed to characterize the resistivity of the water column and subbottom materials using the CRP method. The survey consisted of eight longitudinal profiles roughly equivalent in length and conducted in the right, left and center of the channel. In this survey, a 100-m cable with 11 electrodes spaced 10 m apart and outfitted with floatation aids was towed behind a boat at speeds of 1-1.5 m/s and data were collected using the dipole-dipole array type. In this configuration, two electrodes nearest the boat transmitted electric current...
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