The temperature and surface geophysical data contained in this release have primarily been collected to support groundwater/surface water methods development, and to characterize the hydrogeological controls on native brook trout habitat. All data have been collected since 2010 along the Quashnet River corridor located on Cape Cod, MA, USA. Cape Cod is a peninsula in southeastern coastal Massachusetts, USA, composed primarily of highly permeable unconsolidated glacial moraine and outwash deposits. The largest of the Cape Cod sole-source aquifers occupies a western (landward) section of the peninsula, and is incised by several linear valleys that drain groundwater south to the Atlantic Ocean via baseflow-dominated streams. Strong groundwater discharge to the Quashnet River supports a relatively stable flow regime, as monitored by USGS gage 011058837, located at the downstream end of typical field research focus areas. The lower Quashnet River emerges from a narrow sand and gravel valley to a broader area with well-defined lateral floodplains. Historical cranberry farming practices, abandoned in the 1950s, have modified the stream corridor as described by: Barlow, P. M. and Hess, K. M.: Simulated Hydrologic Responses of the Quashnet River Stream-Auquifer System to Proposed Ground-Water Withdrawals, Cape Cod, Massachusetts, U.S. Geol. Surv. Rep. 93-4064, 51, 1993. The Massachusetts Division of Fisheries and Wildlife has been monitoring brook trout populations in the Quashnet River since 1988 and movement since 2007. Groundwater influence on stream temperature is pronounced, particularly over the 2-km reach above the USGS gage, below which stream stage is tidally affected.

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, fiber-optic distributed temperature sensing, and individual logging thermistors. The latter type of data (thermistor) are described and presented here.

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.

Heat is used as a tracer for a variety of physical hydrogeological process. For ongoing studies related to groundwater/surface water exchange, temperatures of streambed sediment along the bank, in drainage ditches, and in the river were measured using handheld thermal infrared (FLIR Systems, Inc) cameras and thermocouple (Digi-Sense, Inc) probes. Thermal surveys of the Quashnet river were completed from August 14 to August 25, 2017. Zones of spatially-preferential groundwater discharge were identified as cold anomalies in summer, reflecting the influence from groundwater temperatures of approximately 11 degrees Celsius.

In summer in Massachusetts, USA, preferential groundwater discharge zones are often colder than adjacent streambed areas that do not have substantial discharge. Therefore, discharge zones can efficiently be identified and mapped over space using heat as a tracer. This data release contains fiber-optic distributed temperature sensing (FO-DTS) data collected along the streambed interface of the main channel and tributaries of the upper Quashnet River, within approximately 1 km of Johns Pond, from June 14 to June 20, 2020. For these deployments a Salixa XT-DTS control unit (Salixa Ltd, Hertfordshire, UK) was used, and measurements were made over several day increments at 0.508 m linear resolution. Specific locations for collected data are located within the data files, and additional details are contained in the ‘readme’ files within each zipped data directory. Measured data in the form of Salixa instrument files are located in the 'Raw' data directory, including data collected along lengths of optical fiber that were not installed in the streams. The 'Processed' data directory contains data that have been aggregated from the original machine output files, spatially trimmed, and georeferenced. Additionally, simple summary streambed interface temperature statistics (mean, max, min, standard deviation) are listed by streambed location.

Common offset ground penetrating radar (GPR) data were collected to image near surface streambed structure. These data are to be used in conjunction with fiber-optic distributed temperature sensing (FO-DTS) and electromagnetic imaging (EMI) data. The combined dataset represents point in time mapping of preferential groundwater discharge points (FO-DTS) and the bed structure that controls where these points are located (GPR, EMI).

Fiber-optic distributed temperature sensing (FO-DTS) cables were deployed along the sediment/water interface to map high spatial resolution temperature variations along the streambed. These variations are used to detect zones of groundwater discharge. Data are to be used in conjunction with electromagnetic imaging (EMI) and ground penetrating radar (GPR) data. The combined dataset represents point in time mapping of preferential groundwater discharge points (FO-DTS), and the bed structure that controls where these points are located (GPR, EMI).

This data set includes dissolved oxygen (DO) and specific conductivity (SpC) data collected in both the surface water and shallow streambed at the Quashnet River, Mashpee, USA from 2014-16. This data was collected to better understand groundwater discharge to the river and associated brook trout habitat. DO was typically near saturation in surface water and some groundwater, but is reduced in streambed zones that may be influenced by buried peat lenses. SpC was used as an indicator of groundwater flowpath dynamics, and lower values were generally associated with higher DO.

Impervious surfaces such as paved roads, parking lots, and building roofs can affect the natural streamflow patterns and ecosystems of nearby streams. This data set summarizes the percent of impervious surface for hydrologic units in Massachusetts using a newly available statewide 1-m binary raster dataset of impervious surface for 2005. A hydrologic unit consists of all or part of a drainage basin, or an area of coastal drainage. Hydrologic units subdivide large drainage basins into discrete, non-overlapping areas. This is one of three data layers in this data series publication.

The U.S. Geological Survey (USGS), in cooperation with the Air Force Civil Engineer Center (AFCEC), has compiled Geographic Information Systems (GIS) datasets. The spatial data layers provided in this data release are hydrography data derived from high-resolution lidar digital elevation models (DEM). They include a hydroline polyline shapefile used to hydro-enforce the high-resolution lidar DEM; a stream network centerline polyline shapefile derived from the hydro-enforcement that shows stream location; a sub-basin polygon shapefile derived from the hydro-enforcement representing watershed areas for all stream network centerline polylines; a flow direction raster, predicting the direction of flow based on direction of steepest drop; and a flow accumulation raster, predicting the number of upstream cells flowing into each one-meter cell. Field verification was conducted for locations where the high-resolution lidar digital elevation models were unclear on hydraulic connection. Photographs were captured to confirm the conveyance of flow. The datasets are provided in separate child items.