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At least 37 records · Page 2Linked to original sources
USGS2019

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir Drainage Area, Rhode Island, Water Year 2017

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir drainage area, the U.S. Geological Survey, in cooperation with the Providence Water Supply Board, collected streamflow and water-quality data at the Scituate Reservoir and tributaries. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance were used to calculate loads of chloride and sodium during water year 2017 (October 1, 2016, through September 30, 2017) for tributaries to the Scituate Reservoir, Rhode Island. Streamflow was measured or estimated by the U.S. Geological Survey following standard methods at 23 streamgages; 14 of these streamgages are equipped with instrumentation capable of continuously monitoring water level, specific conductance, and water temperature. Water-quality samples were collected by the Providence Water Supply Board at 36 sampling stations, which also include the 14 continuous-record streamgages maintained by the U.S. Geological Survey, during water year 2017 as part of a long-term sampling program; all stations are in the Scituate Reservoir drainage area. Water-quality data collected by the Providence Water Supply Board are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields (loads per unit area) of selected water-quality constituents for water year 2017. The Ponaganset River, which is the largest tributary to the reservoir and was monitored by the U.S. Geological Survey, contributed a mean streamflow of 29 cubic feet per second to the reservoir during water year 2017. For the same period, annual mean streamflows measured (or estimated) for the other monitoring stations in this study ranged from about 0.44 to about 20 cubic feet per second. Together, tributaries equipped with instrumentation capable of continuously monitoring specific conductance transported about 3,100 metric tons of chloride and 1,900 metric tons of sodium to the Scituate Reservoir during water year 2017; chloride yields for the tributaries ranged from 16 to 140 metric tons per square mile, and sodium yields, from 10 to 80 metric tons per square mile. At the stations where water-quality samples were collected by the Providence Water Supply Board, the medians of the median concentrations were 25.3 milligrams per liter for chloride, 0.002 milligram per liter as nitrogen for nitrite, 0.10 milligram per liter as nitrogen for nitrate, 0.05 milligram per liter as phosphate for orthophosphate, 1,200 colony forming units per 100 milliliters for total coliform bacteria, and 14 colony forming units per 100 milliliters for Escherichia coli ( E. coli ). The medians of the median daily loads of chloride, nitrite, nitrate, orthophosphate, total coliform, and E. coli bacteria were 230 kilograms per day, 17 grams per day, 860 grams per day, 690 grams per day, 84,000 million colony forming units per day, and 1,200 million colony forming units per day, respectively. The medians of the median yields of chloride, nitrite, nitrate, orthophosphate, total coliform, and E. coli bacteria were were 87 kilograms per day per square mile, 6.1 grams per day per square mile, 280 grams per day per square mile, 260 grams per day per square mile, 44,000 million colony forming units per day per square mile, and 655 million colony forming units per day per square mile, respectively.

Rhode Island↗
USGS2019

Effect of corolla slitting and nectar robbery by the Eastern Carpenter Bee (Hymenoptera: Apidae) on fruit quality of Vaccinium corymbosum, L.; (Ericales: Ericaceae).

Eastern carpenter bees, Xylocopa virginica (L.) (Hymenoptera: Apidae), are among the most abundant native bee visitors to highbush blueberry, Vaccinium corymbosum L., flowers in the northeastern United States, and they sometimes display corolla-slitting behavior to rob nectar. We studied foraging behavior of X. virginica on 14 blueberry cultivars in an experimental planting in Rhode Island, and assessed factors related to slitting frequency, and the effects of slitting on fruit set and blueberry quality. Among 14 cultivars in bloom, an average of 35% (range 16–67%) of flowers were slit in 2017, and 39% (range 20–62%) in 2018. Factors that affected the proportion of corollas slit included cultivar, anther length, flower volume, and number of days in bloom at or above 15°C. Corolla slitting did not affect fruit set. Average weight and percent soluble solids of fruit resulting from slit and non-slit corollas did not differ significantly in two early- ( ‘ Bluehaven ’ , ‘ Earliblue ’ ), two mid- ( ‘ Collins ’ , ‘ Bluecrop ’ ), and two late-season ( ‘ Herbert ’ , ‘ Lateblue ’ ) ripening cultivars in 2017. In 2018, average fruit weight and percent soluble solids resulting from slit and non-slit flowers did not differ significantly in most cultivars, but slit corollas resulted in berries with greater mass in two cultivars, ‘ Bluehaven ’ and ‘ Collins ’ . ‘ Collins ’ fruit from non-slit corollas had a significantly higher percentage of soluble solids at maturity than fruit from slit corollas in 2018. Corolla slitting and nectar robbery by X. virginica did not have a significant negative effect on fruit quality under the described growing conditions and pollinator community.

Rhode Island↗
USGS2019

The bee fauna of coastal Napatree Point and two inland sites in southern Rhode Island

We surveyed the bee fauna at Napatree Point, a coastal barrier beach in southwestern Rhode Island, using bee-bowl and netting samples, and compared results to bee-bowl samples at 2 inland sites. We collected a total of 53 species and morphospecies at Napatree Point, including 5 likely Rhode Island state records and several coastal dune and sand-nesting species that were not found inland. The comparative bee-bowl samples (colored bowls with soapy water placed at the sites to collect visiting bees) captured 35 species at Napatree Point and 66 at the inland sites (which included 6 likely state records, 2 shared with Napatree). The Napatree fauna shared numerous species with the inland sites, but overall species composition differed substantially. Both Napatree and inland sites showed greatest bee activity and species richness in spring. During spring, the most common bees at Napatree were twig- and cavity-nesting species such as Ceratina dupla and Osmia simillima , and the wood-nesting Lasioglossum oblongum , while the most abundant bees inland were the soil-nesting Andrena nasonii and Augochlorella aurata . Netting samples differed from bee-bowl samples in that they captured larger species and species foraging at flowers distant from the bee-bowl transects, but they missed several diminutive species that were captured by bee bowls. Use of 2 sampling methods, therefore, provided a broader view of the bee fauna than would have been possible with a single collection method.

Rhode Island↗
USGS2018

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir Drainage Area, Rhode Island, Water Year 2016

As part of a long-term cooperative program to monitor water quality within the Scituate Reservoir watershed, the U.S. Geological Survey in cooperation with the Providence Water Supply Board collected streamflow and water-quality data at the Scituate Reservoir and tributaries. Streamflow and concentrations of chloride and sodium estimated from records of specific conductance were used to calculate loads of chloride and sodium during water year (WY) 2016 (October 1, 2015, through September 30, 2016) for tributaries to the Scituate Reservoir, Rhode Island. Streamflow was measured or estimated by the U.S. Geological Survey following standard methods at 23 streamgages; 14 of these streamgages are equipped with instrumentation capable of continuously monitoring water level, specific conductance, and water temperature. Water-quality samples were collected by the Providence Water Supply Board at 34 sampling stations that also include 14 continuous-record streamgages maintained by the U.S. Geological Survey during WY 2016 as part of a long-term sampling program; all stations are in the Scituate Reservoir drainage area. Water-quality data collected by the Providence Water Supply Board are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields (loads per unit area) of selected water-quality constituents for WY 2016. The largest tributary to the reservoir, the Ponaganset River, which was monitored by the U.S. Geological Survey, contributed a mean streamflow of 18 cubic feet per second to the reservoir during WY 2016. For the same period, annual mean streamflows measured (or estimated) for the other monitoring stations in this study ranged from about 0.27 to about 12 cubic feet per second. Together, tributaries equipped with instrumentation capable of continuously monitoring specific conductance transported about 2,100,000 kilograms of chloride and 1,300,000 kilograms of sodium to the Scituate Reservoir during WY 2016; chloride and sodium yields for the tributaries ranged from 14,000 to 95,000 kilograms per square mile and from 8,600 to 56,000 kilograms per square mile, respectively. At the stations where water-quality samples were collected by the Providence Water Supply Board, the medians of the median concentrations were 27.9 milligrams per liter for chloride, 0.002 milligram per liter as nitrogen for nitrite, 0.13 milligrams per liter as nitrogen for nitrate, 0.07 milligram per liter as phosphate for orthophosphate, and 700 and 10 colony forming units per 100 milliliters for total coliform bacteria and Escherichia coli ( E. coli ), respectively. The medians of the median daily loads of chloride, nitrite nitrogen, nitrate nitrogen, orthophosphate, and total coliform and E. coli bacteria were 170 kilograms per day, 8.9 grams per day, 570 grams per day, 320 grams per day, 41,000 million colony forming units per day, and 680 million colony forming units per day. The medians of the median yields of chloride, nitrite nitrogen, nitrate nitrogen, orthophosphate, total coliform, and E. coli bacteria were 53 kilograms per day per square mile, 4.7 grams per day per square mile, 130 grams per day per square mile, 165 grams per day per square mile, 23,000 million colony forming units per day per square mile, and 340 million colony forming units per day per square mile, respectively.

Rhode Island↗
USGS2018

Flood-inundation maps for the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island

A series of 15 digital flood-inundation maps was developed for a 10.2-mile reach of the Pawtuxet River in the municipalities of West Warwick, Warwick, and Cranston, Rhode Island, by the U.S. Geological Survey (USGS), in cooperation with the Rhode Island Emergency Management Agency and the U.S. Army Corps of Engineers. The coverage of the maps extends downstream from Natick Pond dam near State Route 33/Providence Street bridge in West Warwick to the mouth of the river at Pawtuxet Cove (Broad Street bridge) on the border between Cranston and Warwick, R.I. A one-dimensional step-backwater hydraulic model created and calibrated for the Federal Emergency Management Agency Flood Insurance Studies for Kent and Providence Counties in 2015 was updated for this study. The updated hydraulic model reflects the removal of the Pawtuxet Falls dam during 2011 and the raised elevation of a levee surrounding the Warwick Sewer Authority wastewater treatment facility during 2014–17. The hydraulic model was calibrated by using the current (2018) stage-discharge relation at the USGS Pawtuxet River at Cranston, Rhode Island, streamgage (01116500) and documented high-water marks from the March 31, 2010, flood, which had a peak flow greater than the estimated 0.2-percent annual exceedance probability floodflow. The hydraulic model was used to compute water-surface profiles for 15 flood stages at 1-foot (ft) intervals referenced to the USGS Pawtuxet River at Cranston, Rhode Island, streamgage (01116500) and ranging from 8.0 ft (15.2 ft, North American Vertical Datum of 1988), which is the National Weather Service Advanced Hydrologic Prediction Service flood category “action stage,” to 22.0 ft (29.2 ft, North American Vertical Datum of 1988), which is the maximum stage of the stage-discharge relation at the streamgage and exceeds the National Weather Service Advanced Hydrologic Prediction Service flood category “major flood stage” of 13.0 ft. The simulated water-surface profiles were combined with a geographic information system digital elevation model derived from light detection and ranging (lidar) data with a 1.0-ft vertical accuracy to create flood-inundation maps. The flood-inundation maps depict estimates of the areal extent and depth of flooding corresponding to 15 selected flood stages at the streamgage. The flood-inundation maps depict only riverine flooding and do not depict any tidal backwater or coastal storm surge that might occur in the lower part of the river reach. The flood-inundation maps can be accessed through the USGS Flood Inundation Mapping Science website at https://water.usgs.gov/osw/flood_inundation . Near-real-time stages and discharges at the Pawtuxet River streamgage can be obtained from the USGS National Water Information System at https://waterdata.usgs.gov/ . The National Weather Service Advanced Hydrologic Prediction Service provides flood forecasts of stage for this site (CRAR1) at https:/water.weather.gov/ahps/ . The availability of flood-inundation maps referenced to current and forecasted water levels at the USGS Pawtuxet River at Cranston, Rhode Island, streamgage (01116500) can provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, and postflood recovery efforts. The flood-inundation maps are nonregulatory but provide Federal, State, and local agencies and the public with estimates of the potential extent of flooding during flood events.

Rhode Island↗
USGS2018

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir Drainage Area, Rhode Island, water year 2015

Streamflow and concentrations of sodium and chloride estimated from records of specific conductance were used to calculate loads of sodium and chloride during water year (WY) 2015 (October 1, 2014, through September 30, 2015) for tributaries to the Scituate Reservoir, Rhode Island. Streamflow and water-quality data used in the study were collected by the U.S. Geological Survey and the Providence Water Supply Board. Streamflow was measured or estimated by the U.S. Geological Survey following standard methods at 23 streamgages; 14 of these streamgages are equipped with instrumentation capable of continuously monitoring water level, specific conductance, and water temperature. Water-quality samples were collected at 36 sampling stations by the Providence Water Supply Board and at 14 continuous-record streamgages by the U.S. Geological Survey during WY 2015 as part of a long-term sampling program; all stations are in the Scituate Reservoir drainage area. Water-quality data collected by the Providence Water Supply Board are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields (loads per unit area) of selected water-quality constituents for WY 2015. The largest tributary to the reservoir (the Ponaganset River, which was monitored by the U.S. Geological Survey) contributed a mean streamflow of 25 cubic feet per second to the reservoir during WY 2015. For the same time period, annual mean streamflows measured (or estimated) for the other monitoring stations in this study ranged from about 0.38 to about 14 cubic feet per second. Together, tributaries (equipped with instrumentation capable of continuously monitoring specific conductance) transported about 1,500,000 kilograms of sodium and 2,400,000 kilograms of chloride to the Scituate Reservoir during WY 2015; sodium and chloride yields for the tributaries ranged from 8,000 to 54,000 kilograms per square mile and from 12,000 to 91,000 kilograms per square mile, respectively. At the stations where water-quality samples were collected by the Providence Water Supply Board, the medians of the median concentrations were the following: for chloride, 29.5 milligrams per liter; for nitrite, 0.002 milligrams per liter as nitrogen; for nitrate, 0.05 milligrams per liter as nitrogen; for orthophosphate, 0.08 milligrams per liter as phosphate; and for total coliform bacteria and Escherichia coli , 440 and 20 colony forming units per 100 milliliters, respectively. The medians of the median daily loads (and yields) of chloride, nitrite, nitrate, orthophosphate, and total coliform and Escherichia coli bacteria were 170 kilograms per day (79 kilograms per day per square mile), 14 grams per day (5.2 grams per day per square mile), 670 grams per day (190 grams per day per square mile), 640 grams per day (210 grams per day per square mile), 18,000 million colony forming units per day (7,600 million colony forming units per day per square mile), and 1,200 million colony forming units per day (810 million colony forming units per day per square mile), respectively.

Rhode Island↗
USGS2016

Streamflow, water quality and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2014

Streamflow and concentrations of sodium and chloride estimated from records of specific conductance were used to calculate loads of sodium and chloride during water year (WY) 2014 (October 1, 2013, through September 30, 2014) for tributaries to the Scituate Reservoir, Rhode Island. Streamflow and water-quality data used in the study were collected by the U.S. Geological Survey and the Providence Water Supply Board in the cooperative study. Streamflow was measured or estimated by the U.S. Geological Survey following standard methods at 23 streamgages; 14 of these streamgages are equipped with instrumentation capable of continuously monitoring water level, specific conductance, and water temperature. Water-quality samples were collected at 37 sampling stations by the Providence Water Supply Board and at 14 continuous-record streamgages by the U.S. Geological Survey during WY 2014 as part of a long-term sampling program; all stations are in the Scituate Reservoir drainage area. Water-quality data collected by the Providence Water Supply Board are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields (loads per unit area) of selected water-quality constituents for WY 2014. The largest tributary to the reservoir (the Ponaganset River, which was monitored by the U.S. Geological Survey) contributed a mean streamflow of 23 cubic feet per second to the reservoir during WY 2014. For the same time period, annual mean streamflows measured (or estimated) for the other monitoring stations in this study ranged from about 0.35 to about 14 cubic feet per second. Together, tributaries (equipped with instrumentation capable of continuously monitoring specific conductance) transported about 1,200,000 kilograms of sodium and 2,100,000 kilograms of chloride to the Scituate Reservoir during WY 2014; sodium and chloride yields for the tributaries ranged from 7,700 to 45,000 kilograms per year per square mile and from 12,000 to 75,000 kilograms per year per square mile, respectively. At the stations where water-quality samples were collected by the Providence Water Supply Board, the median of the median chloride concentrations was 24 milligrams per liter, median nitrite concentration was 0.002 milligrams per liter as nitrogen (N), median nitrate concentration was 0.01 milligrams per liter as N, median orthophosphate concentration was 0.07 milligrams per liter as phosphate, and median concentrations of total coliform bacteria and Escherichia coli were 320 and 20 colony forming units per 100 milliliters, respectively. The medians of the median daily loads (and yields) of chloride, nitrite, nitrate, orthophosphate, and total coliform and Escherichia coli bacteria were 62 kilograms per day (42 kilograms per day per square mile), 19 grams per day (6.1 grams per day per square mile), 79 grams per day (36 grams per day per square mile), 380 grams per day (150 grams per day per square mile), 13,000 million colony forming units per day (8,300 million colony forming units per day per square mile), and 1,000 million colony forming units per day (470 million colony forming units per day per square mile), respectively.

Rhode Island↗
USGS2015

Sea-floor morphology and sedimentary environments in southern Narragansett Bay, Rhode Island

Multibeam echosounder data collected by the National Oceanic and Atmospheric Administration along with sediment samples and still and video photography of the sea floor collected by the U.S. Geological Survey were used to interpret sea-floor features and sedimentary environments in southern Narragansett Bay, Rhode Island, as part of a long-term effort to map the sea floor along the northeastern coast of the United States. Sea-floor features include rocky areas and scour depressions in high-energy environments characterized by erosion or nondeposition, and sand waves and megaripples in environments characterized by coarse-grained bedload transport. Two shipwrecks are also located in the study area. Much of the sea floor is relatively featureless within the resolution of the multibeam data; sedimentary environments in these areas are characterized by processes associated with sorting and reworking. This report releases bathymetric data from the multibeam echosounder, grain-size analyses of sediment samples, and photographs of the sea floor and interpretations of the sea-floor features and sedimentary environments. It provides base maps that can be used for resource management and studies of topics such as benthic ecology, contaminant inventories, and sediment transport.

Rhode Island↗
USGS2015

Hydrologic conditions in Rhode Island during water year 2014

Hydrologic data and conditions throughout Rhode Island during water year 2014 are presented in this report. Stream discharge and groundwater level conditions varied geographically across the State. Ten streamgages reached record-low minimum monthly mean discharges during the year, and a record-high maximum groundwater level was observed at one groundwater well.

Rhode Island↗
USGS2015

Scientific information in support of water resource management of the Big River area, Rhode Island

The Rhode Island Water Resources Board (RIWRB) is concerned that the demand for water may exceed the available public water supply in central and southern Rhode Island. Although water is often assumed to be plentiful in Rhode Island because of abundant rainfall, an adequate supply of water is not always available everywhere in the state during dry periods. Concerns that water demand may exceed supply are greatest during the summer, when lower water levels and increased drought potential combine with seasonal increases in peak water demand (Rhode Island Water Resources Board, 2012). High summer water demands are due to increases in outdoor water use, such as lawn watering and agricultural irrigation, and to increased summer population in coastal areas. Water-supply concerns are particularly acute in central and southern Rhode Island, where groundwater is the primary source of drinking water. The Big River and Mishnock River Basins are subbasins of the South Branch of the Pawtuxet River Basin in central and southern Rhode Island. These basins—referred to together as “the Big River area” for the purposes of this report—are undeveloped relative to other nearby areas and provide a potential source of high-quality public drinking water for central and southern Rhode Island. After the severe drought of the 1960s, the State of Rhode Island acquired land in the Big River area with the intention of building a water-supply reservoir. The reservoir was not built because of concerns over potential environmental impacts and projected statewide water-supply needs (U.S. Environmental Protection Agency, 1989). The land acquired for the reservoir (13.4 mi 2 ), called the Big River Management Area (BRMA), is currently managed by the RIWRB as a future source for public water supply and as open space. In the 1980s, the RIWRB began to consider whether the BRMA could supply water from its aquifers (groundwater). Groundwater withdrawals for public or other water-supply needs can alter the hydrologic conditions and ecologic communities of surrounding rivers, lakes, and wetlands by removing water from these systems. Consequently, the RIWRB was interested in determining optimal amounts of groundwater that could be withdrawn from the BRMA for public supply while minimizing the effects on rivers, lakes, streams, and wetlands that also rely on this water. For nearly two decades, the RIWRB has conducted a series of cooperative studies with the U.S. Geological Survey (USGS). The goals of these studies have been to (1) evaluate and characterize the water resources of the BRMA and the greater Big River area, and (2) identify sustainable levels of groundwater use that would minimize effects on water resources. This fact sheet describes the major findings of those studies.

Rhode Island↗
USGS2015

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2013

Streamflow and concentrations of sodium and chloride estimated from records of specific conductance were used to calculate loads of sodium and chloride during water year (WY) 2013 (October 1, 2012, through September 30, 2013) for tributaries to the Scituate Reservoir, Rhode Island. Streamflow and water-quality data used in the study were collected by the U.S. Geological Survey (USGS) or the Providence Water Supply Board (PWSB) in the cooperative study. Streamflow was measured or estimated by the USGS following standard methods at 23 streamgages; 14 of these streamgages are equipped with instrumentation capable of continuously monitoring water level, specific conductance, and water temperature. Water-quality samples were collected at 37 sampling stations by the PWSB and at 14 continuous-record streamgages by the USGS during WY 2013 as part of a long-term sampling program; all stations are in the Scituate Reservoir drainage area. Water-quality data collected by the PWSB are summarized by using values of central tendency and are used, in combination with measured (or estimated) streamflows, to calculate loads and yields (loads per unit area) of selected water-quality constituents for WY 2013. The largest tributary to the reservoir (the Ponaganset River, which was monitored by the USGS) contributed a mean streamflow of 30 cubic feet per second (ft 3 /s) to the reservoir during WY 2013. For the same time period, annual mean1 streamflows measured (or estimated) for the other monitoring stations in this study ranged from about 0.45 to about 19 ft 3 /s. Together, tributaries (equipped with instrumentation capable of continuously monitoring specific conductance) transported about 1,300,000 kilograms (kg) of sodium and 2,100,000 kg of chloride to the Scituate Reservoir during WY 2013; sodium and chloride yields for the tributaries ranged from 8,600 to 58,000 kilograms per square mile (kg/mi 2 ) and from 14,000 to 97,000 kg/mi 2 , respectively. At the stations where water-quality samples were collected by the PWSB, the median of the median chloride concentrations was 18 milligrams per liter (mg/L), median nitrite concentration was 0.002 mg/L as nitrogen (N), median nitrate concentration was less than 0.01 mg/L as N, median orthophosphate concentration was 0.128 mg/L as phosphate, and median concentrations of total coliform bacteria and Escherichia coli ( E. coli ) were 330 and 15 colony-forming units per 100 milliliters (CFU/100mL), respectively. The medians of the median daily loads (and yields) of chloride, nitrite, nitrate, orthophosphate, and total coliform and E. coli bacteria were 100 kilograms per day (kg/d; 50 kilograms per day per square mile [kg/d/mi 2 ]), 10 grams per day (g/d; 5.1 grams per day per square mile [g/d/mi 2 ]), 73 g/d (28 g/d/mi 2 ), 720 g/d (320 g/d/mi 2 ), 21,000 colony-forming units per day (CFU×10 6 /d; 8,700 CFU×10 6 /d/mi 2 ), and 1,000 CFU×10 6 /d (510 CFU×10 6 /d/mi 2 ), respectively.

Rhode Island↗
USGS2015

Areas contributing recharge to production wells and effects of climate change on the groundwater system in the Chipuxet River and Chickasheen Brook Basins, Rhode Island

The Chipuxet River and Chickasheen Brook Basins in southern Rhode Island are an important water resource for public and domestic supply, irrigation, recreation, and aquatic habitat. The U.S. Geological Survey, in cooperation with the Rhode Island Department of Health, began a study in 2012 as part of an effort to protect the source of water to six large-capacity production wells that supply drinking water and to increase understanding of how climate change might affect the water resources in the basins. Soil-water-balance and groundwater-flow models were developed to delineate the areas contributing recharge to the wells and to quantify the hydrologic response to climate change. Surficial deposits of glacial origin ranging from a few feet to more than 200 feet thick overlie bedrock in the 24.4-square mile study area. These deposits comprise a complex and productive aquifer system. Simulated areas contributing recharge to the production wells covered a total area of 0.63 square miles for average well withdrawal rates from 2007 through 2011 (total rate of 583 gallons per minute). Simulated areas contributing recharge for the maximum well pumping capacities (total rate of 3,700 gallons per minute) covered a total area of 2.55 square miles. Most simulated areas contributing recharge extend upgradient of the wells to morainal and upland till deposits and to groundwater divides. Some simulated areas contributing recharge include small, isolated areas remote from the wells. Relatively short groundwater traveltimes from recharging locations to discharging wells indicated that the wells are vulnerable to contamination from land-surface activities; median traveltimes ranged from 3.5 to 8.6 years for the production wells examined, and 57 to 91 percent of the traveltimes were 10 years or less. Land cover in the areas contributing recharge includes a substantial amount of urban and agriculture land use for five wells adjacent to the Chipuxet River; for one well adjacent to a tributary stream, land use is less developed. The calibrated groundwater-flow model provided a single, best representation of the areas contributing recharge to a production well. The parameter variance-covariance matrix from model calibration was used to create parameter sets that reflect the uncertainty of the parameter estimates and the correlation among parameters to evaluate the uncertainty associated with the predicted contributing areas to the wells. A Monte Carlo analysis led to contributing areas expressed as a probability distribution that differed from a single deterministic contributing area. Because of the effects of parameter uncertainty, the size of the probabilistic contributing areas for both average and maximum pumping rates was larger than the size of the deterministic contributing areas for the wells. Thus, some areas not in the deterministic contributing area might actually be in the contributing area, including additional areas of urban and agricultural land use that has the potential to contaminate groundwater. Additional areas that might be in the contributing area included recharge originating near the pumping wells that have relatively short groundwater-flow paths and traveltimes. At the maximum pumping rates, areas associated with low probabilities extended long distances along groundwater divides in the uplands remote from the wells. Climate projections for the Chipuxet River and Chickasheen Brook Basins from downscaled output from general circulation models indicate that mean annual temperature might increase by 4.7 degrees Fahrenheit and 8.0 degrees Fahrenheit by the late 21st century (2070–99) compared with the late 20th century (1970–99) under scenarios of lower and higher emissions of greenhouse gases, respectively. By the late 21st century, winter and spring precipitation is projected to increase by 12 to 17 percent, summer precipitation to increase by about the same as mean annual precipitation (8 percent), and fall precipitation to decrease by 5 percent for both emission scenarios compared with the late 20th century. Soil-water-balance simulations indicate that, although precipitation is expected to increase in three seasons, only in winter do precipitation increases exceed actual evapotranspiration increases. Recharge is projected to decrease in fall and generally change little in spring and summer. By the late 21st century, winter recharge is expected to increase by 13 percent for the lower emissions scenario and by 15 percent for the higher emissions scenario. In fall, recharge is projected to diminish by 13 percent for the lower emissions scenario and by 24 percent for the higher emissions scenario. Although recharge is projected to change seasonally in the 21st century, mean annual recharge changes minimally. Soil moisture is projected to decrease in the 21st century from spring through fall because of increases in potential evapotranspiration, and in fall because of decreases in precipitation in addition to increases in potential evapotranspiration. By the late 21st century, soil moisture for the lower emissions scenario is expected to decrease by 11 percent in summer and 15 percent in fall, and for the higher emissions scenario, decrease by 23 percent for both seasons. These decreases in soil moisture during the growing season might have implications for agriculture in the study area. Predicted changes in the magnitude and seasonal distribution of recharge in the 21st century increase simulated base flows and groundwater levels in the winter months for both emission scenarios, but because of less recharge in the fall and less or about the same recharge in the preceding months of spring and summer, base flows and groundwater levels in the fall months decrease for both emission scenarios. October has the largest base flow and groundwater level decreases. By the late 21st century, base flows at the Chipuxet River in October are projected to decrease by 9 percent for the lower emissions scenario and 18 percent for the higher emissions scenario. For a headwater stream in the upland till with shorter groundwater-flow paths and lower storage properties in its drainage area, base flows in October are projected to diminish by 28 percent and 42 percent for the lower and higher emissions scenarios by the late 21st century. Groundwater level changes in the uplands show substantial decreases in fall, but because of the large storage capacity of stratified deposits, water levels change minimally in the valley. By the late 21st century, water levels in large areas of upland till deposits in October are projected to decrease by up to 2 feet for the lower emissions scenario, whereas large areas decrease by up to 5 feet, with small areas with decreases of as much as 10 feet, for the higher emissions scenario. For both emission scenarios, additional areas of till go dry in fall compared with the late 20th century. Thus projected changes in recharge in the 21st century might extend low flows and low water levels for the year later in fall and there might be more intermittent headwater streams compared with the late 20th century with corresponding implications to aquatic habitat. Finally, the size and location of the simulated areas contributing recharge to the production wells are minimally affected by climate change because mean annual recharge, which is used to determine the contributing areas to the production wells, is projected to change little in the 21st century.

Rhode Island↗
USGS2015

Water-quality trends in the Scituate reservoir drainage area, Rhode Island, 1983-2012

The Scituate Reservoir is the primary source of drinking water for more than 60 percent of the population of Rhode Island. Water-quality and streamflow data collected at 37 surface-water monitoring stations in the Scituate Reservoir drainage area, Rhode Island, from October 2001 through September 2012, water years (WYs) 2002-12, were analyzed to determine water-quality conditions and constituent loads in the drainage area. Trends in water quality, including physical properties and concentrations of constituents, were investigated for the same period and for a longer period from October 1982 through September 2012 (WYs 1983-2012). Water samples were collected and analyzed by the Providence Water Supply Board, the agency that manages the Scituate Reservoir. Streamflow data were collected by the U.S. Geological Survey. Median values and other summary statistics for pH, color, turbidity, alkalinity, chloride, nitrite, nitrate, total coliform bacteria, Escherichia coli ( E. coli ), and orthophosphate were calculated for WYs 2003-12 for all 37 monitoring stations. Instantaneous loads and yields (loads per unit area) of total coliform bacteria and E. coli , chloride, nitrite, nitrate, and orthophosphate were calculated for all sampling dates during WYs 2003-12 for 23 monitoring stations with streamflow data. Values of physical properties and concentrations of constituents were compared with State and Federal water-quality standards and guidelines and were related to streamflow, land-use characteristics, varying classes of timber operations, and impervious surface areas. Tributaries in the Scituate Reservoir drainage area for WYs 2003-12 were slightly acidic (median pH of all stations equal to 6.1) and contained low median concentrations of chloride (22 milligrams per liter [mg/L]), nitrate (0.01 mg/L as nitrogen), nitrite (0.001 mg/L as nitrogen), and orthophosphate (0.02 milligrams per liter as phosphorus [mg/L as P]). Turbidity and alkalinity values also were low with medians of 0.57 nephelometric turbidity units and 5.1 mg/L as calcium carbonate, respectively. Total coliform bacteria and E. coli were detected in most samples from all stations, but median concentrations were generally low-43 colony-forming units per 100 milliliters (mL) and 15 colony-forming units per 100 milliliters, respectively. Median values of several physical properties and median concentrations of several constituents correlated positively with the percentages of developed land and negatively with the percentages of forest cover in the drainage areas above the monitoring stations. Median concentrations of chloride correlated positively with the percentages of impervious land use in the subbasins of monitoring stations, likely reflecting the effects of deicing compounds applied to roadways during winter maintenance. Median concentrations of alkalinity also correlated positively with the percentage of impervious land use, which may be related to the deterioration of fabricated structures containing calcium carbonate. Median values of color correlated positively with the percentage of wetland area in the subbasins of monitoring stations, reflecting the natural sources of color in tributaries. Streamflows were negatively correlated with turbidity and concentrations of total coliform bacteria and E. coli, possibly reflecting seasonal patterns in which relatively high values of these properties and constituents occur during warmer low-flow conditions late in the water year. Similar seasonal patterns were observed for pH, alkalinity, and color. Negative correlations between concentrations of chloride and streamflow also were significant, indicating that deicing salts from roadways and other impervious surfaces that lack direct connection to the tributaries are likely infiltrating to the groundwater and discharging to some of the tributaries late in the water year. While salt-laden runoff directly enters some of the tributaries at roadway crossings, most of the roadway runoff infiltrates into the adjacent berms throughout the drainage area. Statistically significant correlations were not identified between various degrees of tree-canopy reduction caused by timber operations in the subbasins and median values or concentrations of water-quality properties. Loads and yields of chloride, nitrate, nitrite, orthophosphate, and bacteria varied at monitoring stations in the Scituate Reservoir drainage area in WYs 2003-12. Loads generally were greater at stations in the Barden Reservoir and the Regulating Reservoir Subbasins that have larger drainage areas than in subbasins with smaller drainage areas. Subbasin yields of fecal-indicator bacteria and orthophosphate generally were largest in the Westconnaug Reservoir Subbasin, and subbasin yields for chloride, nitrate, and nitrite were largest in the Moswansicut Reservoir Subbasin in the northeastern part of the drainage area. Upward trends in pH were identified for nearly half of the monitoring stations for WYs 1983-2012 and may reflect regional reductions in acid precipitation. Many upward trends in alkalinity also were identified for both the WYs 1983-2012 and for WYs 2003-12 periods and are likely related to the natural weathering of structures containing concrete or, in some cases, the application of lime or fertilizers on agriculture lands. Significant trends in chloride concentrations at most stations during WYs 1983-2012 were upward; however, results for WYs 2003-12 substantiate few significant upward trends and, in a few cases, downward trends were identified in several tributary drainage areas.

Rhode Island↗
USGS2014

Character, distribution, and ecological significance of storm wave-induced scour in Rhode Island Sound, USA

Multibeam bathymetry, collected during NOAA hydrographic surveys in 2008 and 2009, is coupled with USGS data from sampling and photographic stations to map the seabed morphology and composition of Rhode Island Sound along the US Atlantic coast, and to provide information on sediment transport and benthic habitats. Patchworks of scour depressions cover large areas on seaward-facing slopes and bathymetric highs in the sound. These depressions average 0.5-0.8 m deep and occur in water depths reaching as much as 42 m. They have relatively steep well-defined sides and coarser-grained floors, and vary strongly in shape, size, and configuration. Some individual scour depressions have apparently expanded to combine with adjacent depressions, forming larger eroded areas that commonly contain outliers of the original seafloor sediments. Where cobbles and scattered boulders are present on the depression floors, the muddy Holocene sands have been completely removed and the winnowed relict Pleistocene deposits exposed. Low tidal-current velocities and the lack of obstacle marks suggest that bidirectional tidal currents alone are not capable of forming these features. These depressions are formed and maintained under high-energy shelf conditions owing to repetitive cyclic loading imposed by high-amplitude, long-period, storm-driven waves that reduce the effective shear strength of the sediment, cause resuspension, and expose the suspended sediments to erosion by wind-driven and tidal currents. Because epifauna dominate on gravel floors of the depressions and infauna are prevalent in the finer-grained Holocene deposits, it is concluded that the resultant close juxtaposition of silty sand-, sand-, and gravel-dependent communities promotes regional faunal complexity. These findings expand on earlier interpretations, documenting how storm wave-induced scour produces sorted bedforms that control much of the benthic geologic and biologic diversity in Rhode Island Sound.

Rhode Island↗
USGS2014

Relative humidity and activity patterns of Ixodes scapularis (Acari: Ixodidae)

Laboratory studies have shown clear relationships between relative humidity (RH) and the activity and survival of Ixodes scapularis Say (blacklegged tick). However, field studies have produced conflicting results. We examined this relationship using weekly tick count totals and hourly RH observations at three field sites, stratified by latitude, within the state of Rhode Island. Records of nymphal tick abundance were compared with several RH-related variables (e.g., RH at time of sampling and mean weekly daytime RH). In total, 825 nymphs were sampled in 2009, a year of greater precipitation, with a weighted average leaf litter RH recorded at time of sampling of 85.22%. Alternatively, 649 nymphs were collected in 2010, a year of relatively low precipitation, and a weighted average RH recorded at time of sampling was 75.51%. Negative binomial regression analysis of tick count totals identified cumulative hours <82% RH threshold as a significant factor observed in both years (2009: P = 0.0037; 2010: P < 0.0001). Mean weekly daytime RH did not significantly predict tick activity in either year. However, mean weekly daytime RH recorded with 1-wk lag before sample date was a significant variable ( P = 0.0016) in 2010. These results suggest a lag effect between moisture availability and patterns of tick activity and abundance. Differences in the relative importance of each RH variable between years may have been due to abnormally wet summer conditions in 2009.

Rhode Island↗
USGS2014

Adverse moisture events predict seasonal abundance of Lyme disease vector ticks (Ixodes scapularis)

Background : Lyme borreliosis (LB) is the most commonly reported vector-borne disease in north temperate regions worldwide, affecting an estimated 300,000 people annually in the United States alone. The incidence of LB is correlated with human exposure to its vector, the blacklegged tick ( Ixodes scapularis ). To date, attempts to model tick encounter risk based on environmental parameters have been equivocal. Previous studies have not considered (1) the differences between relative humidity (RH) in leaf litter and at weather stations, (2) the RH threshold that affects nymphal blacklegged tick survival, and (3) the time required below the threshold to induce mortality. We clarify the association between environmental moisture and tick survival by presenting a significant relationship between the total number of tick adverse moisture events (TAMEs - calculated as microclimatic periods below a RH threshold) and tick abundance each year. Methods : We used a 14-year continuous statewide tick surveillance database and corresponding weather data from Rhode Island (RI), USA, to assess the effects of TAMEs on nymphal populations of I. scapularis . These TAMEs were defined as extended periods of time (>8 h below 82% RH in leaf litter). We fit a sigmoid curve comparing weather station data to those collected by loggers placed in tick habitats to estimate RH experienced by nymphal ticks, and compiled the number of historical TAMEs during the 14-year record. Results : The total number of TAMEs in June of each year was negatively related to total seasonal nymphal tick densities, suggesting that sub-threshold humidity episodes >8 h in duration naturally lowered nymphal blacklegged tick abundance. Furthermore, TAMEs were positively related to the ratio of tick abundance early in the season when compared to late season, suggesting that lower than average tick abundance for a given year resulted from tick mortality and not from other factors. Conclusions : Our results clarify the mechanism by which environmental moisture affects blacklegged tick populations, and offers the possibility to more accurately predict tick abundance and human LB incidence. We describe a method to forecast LB risk in endemic regions and identify the predictive role of microclimatic moisture conditions on tick encounter risk.

Rhode Island↗
USGS2014

Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2012

Streamflow and concentrations of sodium and chloride estimated from records of specific conductance were used to calculate loads of sodium and chloride during water year (WY) 2012 (October 1, 2011, through September 30, 2012), for tributaries to the Scituate Reservoir, Rhode Island. Streamflow and water-quality data used in the study were collected by the U.S. Geological Survey (USGS) or the Providence Water Supply Board (PWSB). Streamflow was measured or estimated by the USGS following standard methods at 23 streamgages; 14 of these streamgages were equipped with instrumentation capable of continuously monitoring water level, specific conductance, and water temperature. Water-quality samples were collected at 37 sampling stations by the PWSB and at 14 continuous-record streamgages by the USGS during WY 2012 as part of a long-term sampling program; all stations were in the Scituate Reservoir drainage area. Water-quality data collected by the PWSB were summarized by using values of central tendency and used, in combination with measured (or estimated) streamflows, to calculate loads and yields (loads per unit area) of selected water-quality constituents for WY 2012. The largest tributary to the reservoir (the Ponaganset River, which was monitored by the USGS) contributed a mean streamflow of about 26 cubic feet per second (ft 3 /s) to the reservoir during WY 2012. For the same time period, annual mean1 streamflows measured (or estimated) for the other monitoring stations in this study ranged from about 0.40 to about 17 ft 3 /s. Together, tributaries (equipped with instrumentation capable of continuously monitoring specific conductance) transported about 1,100,000 kilograms (kg) of sodium and 1,900,000 kg of chloride to the Scituate Reservoir during WY 2012; sodium and chloride yields for the tributaries ranged from 8,700 to 51,000 kilograms per square mile (kg/mi 2 ) and from 14,000 to 87,000 kg/mi 2 , respectively. At the stations where water-quality samples were collected by the PWSB, the median of the median chloride concentrations was 19 milligrams per liter (mg/L), median nitrite concentration was 0.002 mg/L as nitrogen (N), median nitrate concentration was less than 0.01 mg/L as N, median orthophosphate concentration was 0.06 mg/L as phosphorus, and median concentrations of total coliform and Escherichia coli (E. coli) bacteria were 43 and 16 colony forming units per 100 milliliters (CFU/100mL), respectively. The medians of the median daily loads (and yields) of chloride, nitrite, nitrate, orthophosphate, and total coliform and E. coli bacteria were 200 kilograms per day (kg/d) (71 kilograms per day per square mile (kg/d/mi 2 )); 15 grams per day (g/d) (5.4 grams per day per square mile (g/d/mi 2 )); 100 g/d (38 g/d/mi 2 ); 500 g/d (260 g/d/mi 2 ); 4,300 million colony forming units per day (CFUx10 6 /d) (1,500 CFUx10 6 /d/mi 2 ); and 1,000 CFUx10 6 /d (360 CFUx10 6 /d/mi 2 ), respectively.

Rhode Island↗
USGS2014

Hydrologic Drought Decision Support System (HyDroDSS)

The hydrologic drought decision support system (HyDroDSS) was developed by the U.S. Geological Survey (USGS) in cooperation with the Rhode Island Water Resources Board (RIWRB) for use in the analysis of hydrologic variables that may indicate the risk for streamflows to be below user-defined flow targets at a designated site of interest, which is defined herein as data-collection site on a stream that may be adversely affected by pumping. Hydrologic drought is defined for this study as a period of lower than normal streamflows caused by precipitation deficits and (or) water withdrawals. The HyDroDSS is designed to provide water managers with risk-based information for balancing water-supply needs and aquatic-habitat protection goals to mitigate potential effects of hydrologic drought. This report describes the theory and methods for retrospective streamflow-depletion analysis, rank correlation analysis, and drought-projection analysis. All three methods are designed to inform decisions made by drought steering committees and decisionmakers on the basis of quantitative risk assessment. All three methods use estimates of unaltered streamflow, which is the measured or modeled flow without major withdrawals or discharges, to approximate a natural low-flow regime. Retrospective streamflow-depletion analysis can be used by water-resource managers to evaluate relations between withdrawal plans and the potential effects of withdrawal plans on streams at one or more sites of interest in an area. Retrospective streamflow-depletion analysis indicates the historical risk of being below user-defined flow targets if different pumping plans were implemented for the period of record. Retrospective streamflow-depletion analysis also indicates the risk for creating hydrologic drought conditions caused by use of a pumping plan. Retrospective streamflow-depletion analysis is done by calculating the net streamflow depletions from withdrawals and discharges and applying these depletions to a simulated record of unaltered streamflow. Rank correlation analysis in the HyDroDSS indicates the persistence of hydrologic measurements from month to month for the prediction of developing hydrologic drought conditions and quantitatively indicates which hydrologic variables may be used to indicate the onset of hydrologic drought conditions. Rank correlation analysis also indicates the potential use of each variable for estimating the monthly minimum unaltered flow at a site of interest for use in the drought-projection analysis. Rank correlation analysis in the HyDroDSS is done by calculating Spearman’s rho for paired samples and the 95-percent confidence limits of this rho value. Rank correlation analysis can be done by using precipitation, groundwater levels, measured streamflows, and estimated unaltered streamflows. Serial correlation analysis, which indicates relations between current and future values, can be done for a single site. Cross correlation analysis, which indicates relations among current values at one site and current and future values at a second site, also can be done. Drought-projection analysis in the HyDroDSS indicates the risk for being in a hydrologic drought condition during the current month and the five following months with and without pumping. Drought-projection analysis also indicates the potential effectiveness of water-conservation methods for mitigating the effect of withdrawals in the coming months on the basis of the amount of depletion caused by different pumping plans and on the risk of unaltered flows being below streamflow targets. Drought-projection analysis in the HyDroDSS is done with Monte Carlo methods by using the position analysis method. In this method the initial value of estimated unaltered streamflows is calculated by correlation to a measured hydrologic variable (monthly precipitation, groundwater levels, or streamflows from an index station identified with the rank correlation analysis). Then a pseudorandom number generator is used to create 251 six-month-long flow traces by using a bootstrap method. Serial correlation of the estimated unaltered monthly minimum streamflows determined from the rank correlation analysis is preserved within each flow trace. The sample of unaltered streamflows indicates the risk of being below flow targets in the coming months under simulated natural conditions (without historic withdrawals). The streamflow-depletion algorithms are then used to estimate risks of flow being below targets if selected pumping plans are used. This report also describes the implementation of the HyDroDSS. The HyDroDSS was developed as a Microsoft Access® database application to facilitate storage, handling, and use of hydrologic datasets with a simple graphical user interface. The program is implemented in the database by using the Visual Basic for Applications® (VBA) programming language. Program source code for the analytical techniques is provided in the HyDroDSS and in electronic text files accompanying this report. Program source code for the graphical user interface and for data-handling code, which is specific to Microsoft Access® and the HyDroDSS, is provided in the database. An installation package with a run-time version of the software is available with this report for potential users who do not have a compatible copy of Microsoft Access®. Administrative rights are needed to install this version of the HyDroDSS. A case study, to demonstrate the use of HyDroDSS and interpretation of results for a site of interest, is detailed for the USGS streamgage on the Hunt River (station 01117000) near East Greenwich in central Rhode Island. The Hunt River streamgage was used because it has a long record of streamflow and is in a well-studied basin with a substantial amount of hydrologic and water-use data including groundwater pumping for municipal water supply.

Rhode Island↗