Geology topics

Research about Massachusetts

Source-linked reports with geographic coverage including Massachusetts.

At least 19 recordsLinked to original sources

USGS2026

Forecasting marsh resilience in the Plum Island Estuary: Integrating uncertainty to inform coastal management

Salt marshes provide critical ecosystem services yet face increasing threats from accelerated relative sea-level rise (SLR). The long-term persistence of these habitats depends on their ability to vertically accrete and laterally migrate into adjacent uplands. Predicting the location and viability of these future marsh corridors is therefore a primary challenge for coastal managers; one often hindered by uncertainties in future water levels and topographic data accuracy, particularly in vegetated wetlands where light detection and ranging (lidar) data systematically overestimate elevation. This study applies an uncertainty-informed modeling framework to forecast marsh resilience in the Plum Island Estuary, Massachusetts. We integrated the Sea Level Affecting Marshes Model (SLAMM) with a Monte Carlo error analysis, generating an ensemble of bias-corrected digital elevation models (DEMs) alongside three probabilistic SLR scenarios (Intermediate, Intermediate High, High) through 2100. We synthesized these simulations into a “marsh fate” classification map to distinguish between resilient core habitats, vulnerable zones requiring intervention, and likely migration corridors. While the marsh platform exhibits resilience under Intermediate scenarios, a critical tipping point emerges under the High SLR scenario. In this case, accelerating inundation overwhelms accretion capacities, driving a landscape-scale regime shift. By integrating the interacting uncertainties of SLR trajectories and initial marsh elevation, we project 2100 net marsh coverage outcomes ranging from a 10.5% gain to a 23.2% loss. These results demonstrate that incorporating elevation uncertainty is essential for detecting non-linear threshold behaviors that deterministic models often miss. The resulting framework empowers managers with a spatially explicit tool to prioritize land acquisition and restoration efforts in the face of climate uncertainty.

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USGS2026

A methods framework for evaluating measurement consistency across spectrometers for multispectral uncrewed aerial system vegetation mapping applications

The U.S. Geological Survey collects remote sensing data to support national scientific assessments of natural resources, hazards, and landscape change. Spectrometers and spectroradiometers are essential for gathering point-based spectral measurements used in applications such as uncrewed aerial systems (UAS) multispectral image calibration, validation, and analysis. Evaluating how different instruments perform in laboratory and field environments helps determine whether they provide consistent, interoperable measurements. Such verification can expand access to spectral ground data during UAS operations by allowing scientists to use alternative instruments when budgets, logistics, or field conditions limit options. We propose and test a methodological framework for evaluating spectrometers for measurement consistency during UAS multispectral vegetation mapping applications. There are three central evaluation components to the framework: laboratory, field, and relative to UAS multispectral imagery. By evaluating the instruments in both relatively controlled and uncontrolled environments, we thoroughly examine measurement consistency and when/why measurements may differ. We opportunistically selected two instruments for a case study in a coastal marsh setting: a compact laboratory spectrometer we modified for field use and a field-ready spectroradiometer. The instruments produced consistent measurements in both environments. We found differences between the field spectra and UAS spectra that likely reflect the perspectives of ground vs. aerial data and indicate that further radiometric calibration may be needed.

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USGS2026

Escaping the density trap: Estuarine connectivity supports juvenile river herring growth

Alewife ( Alosa pseudoharengus ) and blueback herring ( A. aestivalis ) require connectivity among freshwater, estuarine, and marine environments to complete their life cycle. Impediments to watershed connectivity are major drivers of population declines along the eastern United States, where physical barriers and low-flow conditions can inhibit or delay juvenile outmigration, limiting access to productive estuarine nursery habitats. Because juvenile growth strongly influences early survival and recruitment, understanding how connectivity to estuaries shapes growth across nursery habitats is critical but remains poorly understood. We evaluated juvenile river herring growth across connected lake, river, and estuary habitats in three coastal Massachusetts watersheds from 2021 to 2023. Juvenile fish and water quality were sampled throughout each summer, and sagittal otoliths were used to estimate growth rates. Juvenile growth was enhanced in downstream estuarine habitats where connectivity was intact and in-lake juvenile densities were high, as observed in the Weymouth Back River watershed. In contrast, growth limitations occurred in a high-density system with restricted passage, where juveniles occupied shallow, eutrophic river reaches in the Mystic River watershed. Growth rates were similar between lake and estuarine habitats in a low-density system (Essex River watershed), indicating that estuarine benefits to growth are context dependent. Together, these results demonstrate that connectivity to estuarine habitats can alleviate density-dependent growth constraints, but that barriers and delayed outmigration to estuaries can limit these benefits. Maintaining or restoring functional freshwater–estuarine connectivity is therefore critical for sustaining juvenile production and provides a clear management priority for municipalities, state and federal agencies, and watershed managers working to restore river herring populations in fragmented coastal systems.

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USGS2026

3D Elevation Program—Massachusetts

Using 3D Elevation Program data, a modern illustration of each State's landscape showcases its elevation differences in vivid detail. Each State has been consistently adjusted and colorized according to its highest and lowest elevations, accentuating differences even in States with low relief. To further emphasize landforms, shaded relief has been added on top of the elevation colors.

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USGS2026

Ecogeomorphologic response of a tidally restricted salt marsh to tidal restoration and sea-level rise

Diked marshes with decades of restricted tidal flow exhibit fundamentally altered hydrologic and ecologic dynamics that result in limited vertical accretion, land subsidence, and underdeveloped tidal channels. These changes complicate marsh restoration efforts and constrain the marsh's ability to build elevation in response to future sea levels. In this study, we developed an integrated hydrodynamic and marsh accretion model to conduct the first assessment of the restoration potential of a diked marsh in response to reintroduction of tidal flow and sea-level rise (SLR). We applied our model to evaluate changes in biomass production in the Herring River estuary, Cape Cod, MA, USA—which has experienced significant ecological shifts due to more than a century of tidal restriction—in response to a range of SLR scenarios, tidal flow conditions, management interventions, and biomass production rates through 2100. We found that with restoration of tidal flow, the simulated marsh extent expanded in areas with efficient drainage, increasing biomass production by up to 4.4 times. However, when SLR was imposed, parts of the marsh gradually transitioned to open water, leading to a decline in marsh coverage from 19% to as low as 12%. Management interventions aimed at enhancing marsh elevation and improving the drainage capacity of tidal channels slowed marsh loss, supporting marsh area through 2100. Our findings provide insight into the key drivers of marsh resilience and loss, and our approach can be applied across tidally restricted and restored systems to develop targeted, adaptive restoration strategies that achieve desired ecological outcomes.

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USGS2026

PFAS mixture composition and internal exposure profiles shape biological responses under field-realistic exposure

Per- and polyfluoroalkyl substances (PFAS) occur as complex mixtures, yet mixture-dependent biological effects under environmentally realistic exposure conditions remain poorly understood. We conducted multiyear (2018, 2019, 2021) continuous-flow, field-based exposures of male fathead minnows ( Pimephales promelas ) using a low-PFAS reference well (REF; sum of measured PFAS (∑PFAS) 0.1–0.2 μg L –1 ) and PFAS-contaminated groundwater from a fire-training area (FTA) at Joint Base Cape Cod, Massachusetts. Dilution treatments enabled separation of concentration and mixture effects. Groundwater from well FTA1 was perfluorooctanesulfonate (PFOS) dominated (∑PFAS 10–31 μg L –1 ), whereas groundwater from well FTA2 had higher concentrations and was enriched in perfluorooctanoate (PFOA) and diverse precursors (∑PFAS ∼ 80 μg L –1 ). Despite comparable plasma ∑PFAS and PFOS in FTA1–100% and FTA2–50% on day-7, cumulative mortality reached approximately 35% in FTA2–50% and 17% in FTA2–100%, and secondary sex trait expression was reduced by approximately 65–80% relative to REF, whereas sperm motility effects were mixture- and time-dependent. Plasma PFAS profiles were dominated by perfluorohexanesulfonate (PFHxS), PFOS, and sulfonamide precursors. Liver transcriptomics from REF-acclimated fish revealed robust disruption of metabolic, mitochondrial, and endocrine pathways that link PFAS mixture chemistry and internal exposure profiles to organismal outcomes, and testis transcriptomics provided complementary insight into reproductive impairment. These results indicate that PFAS mixture composition and internal exposure profiles, including precursor-associated differences, are important determinants of ecotoxicological outcomes under field-realistic conditions.

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USGS2026

A 2.5 km movement by a potentially ill white-tailed deer along Nantasket Beach in suburban Massachusetts, USA

White-tailed deer ( Odocoileus virginianus ) ecology has received significant research attention, yet there is a need for further synthetic work on the species across environmental contexts and research areas. Opportunistic natural history accounts can help identify new conceptual links and research directions by offering new observations and ideas, synthesizing context from the literature, and highlighting gaps in understanding. We provide an opportunistic account of a 2.5 km movement of a white-tailed deer walking, wading, and swimming along Nantasket Beach in a suburban context in Massachusetts, USA. The deer displayed behaviors that could potentially be reflective of trauma, disorientation, or illness, including possibly symptomatic head movements and crouching behavior. The behavior of the deer may also have been influenced by the coastal and suburban context in which the observation took place. Our account explores swimming, deer behavior, and possible illness in a coastal, suburban context. We highlight the need for additional research on the ecology and management of white-tailed deer, including swimming and disease in coastal, marine, and developed contexts, and intersections across these areas.

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USGS2026

An automated geographic information system-based hydraulic modeling tool for developing preliminary culvert designs for stream crossings in Massachusetts

Introduction Currently (2026), many of the about 25,000 roadway crossing structures over rivers and streams in Massachusetts are undersized. Undersized culverts and bridges can be detrimental to fish and wildlife movement, habitat continuity, and the health of aquatic organisms. Undersized culverts also can lack the resiliency needed to withstand large floods, which could be worsened by potential increases in flood magnitude and frequency due to climate change. Improving culvert and bridge designs for stream crossing projects may improve aquatic organism passage, stream continuity, and resiliency during future floods by decreasing upstream overbank flooding, road flooding and erosion, and degradation of aquatic habitat. The U.S. Geological Survey (USGS), Massachusetts Department of Environmental Protection (MassDEP), and University of Massachusetts Amherst began a series of cooperative studies in July 2019 to develop an automated geographic information system (GIS) hydraulic modeling tool for preliminary culvert designs for stream crossings. The USGS plans to provide preliminary culvert designs in the web-based StreamStats application, which enables municipalities and engineers to view potential designs and related information for stream crossing replacement projects in Massachusetts. This application can (a) provide information on hydrology, hydraulics, and ecological conditions at stream crossing sites, (b) provide users with potential culvert designs to improve aquatic organism passage and flood resiliency, and (c) assist MassDEP in implementing the Massachusetts Wetlands Protection Act regulations for stream crossing projects.

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USGS2026

Pre-restoration sediment budget of a tidally restricted estuary reveals potential for landward transport

Unnatural tidal restrictions are common features in estuaries, often arising from agricultural practices, road construction, or drainage activities. Restrictions tend to attenuate tides landward of the structure but can induce more complex effects in the seaward direction, including modification of natural geomorphic processes. The Herring River Estuary is the site of the largest salt marsh restoration effort in the northeast United States. We deployed a suite of instruments over one year to identify the role of tidal and atmospheric processes on sediment dynamics. We find 6.2·10 6 kg yr -1 of sediment is exported from the system through its only channel; this seaward-directed flux indicates that the seaward Wellfleet Harbor is not a sediment source for the Herring River Estuary. The sediment floodebb differential is landward above the tidal restriction, producing a divergent, transgressive embayment. The mudflats are the primary source of this sediment, eroding at rates of 0.1 and 5.3 cm yr -1 at the shallow and deep stations, respectively. Sediment is resuspended on the mudflats during wind events and exported from the system when landward-directed winds produced a seaward return flow. Ebb-dominated tides also yield net sediment export during calm periods. Once the tidal restriction is removed, the areas landward of the restriction may become a large sediment sink. It is possible that sediment from the embayment between the mouth and the restriction begins to move landward rather than seaward, but it is unlikely that Wellfleet Harbor would supply additional sediment. Therefore, as the subsided salt marshes landward of the tidal restriction begin to accrete sediment, it would most likely come at the expense of the seaward channel bottoms, mudflats, and salt marsh shorelines described in this study. In partitioning the sediment budget to geomorphic processes, this work presents a significant advance in the understanding of the linkage between a tidally restricted estuary and its seaward embayment. As tidal restriction removal becomes a more common restoration practice, the understanding of pre-removal baseline conditions becomes important for developing conceptual models of post-removal geomorphic evolution.

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USGS2026

Low streamflows in Massachusetts: Variability over space and time and relations with climatic and basin variables

Streamflows in Massachusetts have set record lows in recent years despite generally wetter conditions than during the drought of the 1960s, and the reasons for this are not known. To analyse potential drivers of low streamflows in Massachusetts, six low-flow metrics were computed at 107 streamgages. These metrics represent low-flow magnitude, magnitude normalized to median flows, and duration. Multiple linear regressions were used to analyse the variability of low flows over space and time. Potential explanatory variables were computed using climatic, land use, water use, and basin data. For all low-flow metrics, the ratio of precipitation to potential evapotranspiration (P/PET) in July–August explained the most variability, with decreasing P/PET largely explained by lower precipitation. Water/wetland area was a significant explanatory variable in all the normalized-magnitude and duration models, with greater area associated with lower normalized magnitudes and with shorter durations of low flows. Human influence (characterized by development, population, water use, and artificial water storage) had mixed effects. Trends from 1983 to 2022 in summer P/PET and human influence have been strongest in the eastern part of the state where the strongest decreases in flows are observed. Low flows in Massachusetts seem to be driven by a combination of low summer precipitation and human effects, though the specific mechanisms of human influence on flow likely vary between basins.

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USGS2026

PFAS from a discrete-event terrestrial source migrates with groundwater to intertidal seepages

Groundwater transport of per- and polyfluoroalkyl substances (PFAS) from terrestrial sources to marine coastal ecosystems is a topic of growing recognition, though with few published field studies. Furthermore, most research on PFAS fate and transport dynamics has focused on source areas with long histories like fire training and manufacturing facilities; the effect of single PFAS dispersal events to the coastal environment is not well documented. We have assessed PFAS mobility in groundwater to intertidal seepages from two discrete, adjacent tanker-truck rollover events that occurred in 1997 and 2000 where aqueous film forming foams (AFFF) were applied to suppress fuel vapors. Using a combination of groundwater-flow and particle-track modeling, geophysical field characterization, and chemical sampling, we found substantial concentrations of PFAS (up to 530.5 ng/L), mainly perfluorooctane sulfonate (PFOS), in groundwater discharging to a shoreline along an embayment used for swimming and recreational shellfish harvesting. The general groundwater trajectory to the embayment was predicted by numerical particle tracking. The highest concentrations of PFAS were found in discharges near the landward side of the intertidal zone. The discharges had variable salinity at the time of sampling. Our research generated the finding that even in areas of strong, preferential groundwater discharge at low tide, there was tidal “pumping” of ocean water into the aquifer sediments during higher tides. Therefore, there are likely to be continuously variable salinity conditions at similar seepage interfaces that have not been broadly considered in previous conceptual models of PFAS fate and transport.

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USGS2026

Tracking baseflow supply dynamics using SWOT data from small groundwater-dominated lakes

In situ surface-water monitoring strategies are biased towards larger perennial streams and lakes and are generally not designed to track mechanisms of baseflow supply contributed by the dynamic storage of aquifers. Additionally, small (< 1 km 2 ) groundwater-influenced lakes and wetlands globally have little in situ monitoring infrastructure. We explored the utility of remotely sensed Surface Water Ocean Topography Satellite (SWOT) data, collected from 2023 onward, to characterise the seasonal and multi-year water-level trends of groundwater flow-through kettle lakes distributed across the permeable sediments of eastern Massachusetts, USA. This analysis indicated that water levels for kettle lakes with areas down to approximately 0.05 km 2 are resolvable in the study area. Our examination of 17 kettle lakes found that SWOT water-surface elevation data closely tracked groundwater levels in adjacent monitoring wells where available, including the timing of seasonal patterns (highest levels generally in late spring), although there was some variation between years and there was a substantial lag in the timing of high water levels for a lake located downgradient from a 30-m-thick vadose zone. Furthermore, SWOT-observed water-level increases in kettle lakes tracked with baseflow increases in two adjacent groundwater-dominated streams, as would be expected from increased hydraulic gradients. Unlike spectral remote sensing, SWOT data are generally not affected by cloud cover, resulting in a potential for groundwater-dominated lakes to be sentinels of dynamic storage patterns, including identification of baseflow drought lags, which are currently ill-defined hydrological processes. SWOT monitoring of groundwater-influenced surface waters shows potential for augmenting existing monitoring wells and streamgages as continuous monitors of groundwater levels and baseflow supply in permeable terrain.

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USGS2026

Chronic wasting disease (CWD) knowledge, risk perception, and management acceptance are influenced by media engagement and trust among deer hunters in Massachusetts

Prior to wildlife disease emergence, public outreach campaigns can improve disease-related knowledge and increase the likelihood that stakeholders accept potential management actions. One wildlife disease of particular interest is chronic wasting disease (CWD), which is spreading across the United States but has not been detected in Massachusetts. We conducted a survey of deer hunters ( n = 7,419) in Massachusetts to: (1) explore media channel usage and source trust, and (2) assess the relationship among CWD knowledge, risk perception, management acceptability, and state wildlife agency trust. We found that channel usage and source trust varied by socio-demographic factors. We also found that engagement with popular channels and trust in accurate sources were positively correlated with CWD knowledge. CWD risk perception mediated the relationship between knowledge and management acceptance, and trust was positively associated with management acceptance. Collectively, our results indicate a mixed-media campaign by state wildlife agencies could improve CWD management acceptance.

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USGS2026

Groundwater–surface water exchange at a New England salt marsh: The interplay between tidal pumping at multiple frequencies and terrestrial groundwater discharge

Groundwater–surface water exchange plays a fundamental role in the transport of energy and solutes in coastal salt marshes, which are positioned at an intersection between terrestrial and marine hydrologic environments. Hydraulic gradients in shallow marsh sediments continuously change due to tidal water level variations that alternately flood and drain the marsh platform, often superimposed on terrestrial groundwater drainage. We use timeseries data from Vertical Temperature Profiler and Conductivity-Temperature-Depth instruments to investigate the space–time patterns of groundwater–surface water exchange at a hillslope-adjacent fringing salt marsh on the Herring River in Wellfleet, MA. Analyses of data acquired from September to December 2023 demonstrate that time-averaged exchange rates systematically vary from recharge near the tidal channel to saline groundwater discharge towards the upland fringe and systematically decrease during the transition from summer to winter conditions. Exchange rates were continuously modulated by tides, including high-frequency compound and harmonic components generated by non-linear interactions as the astronomical tide propagated into the estuary. The exchange rate sensitivity to tidal forcing decreased with both frequency and distance from the tidal channel, consistent with the lateral diffusion of pore pressure perturbations through the high permeability layer underlying the surficial, low permeability peat. We find that tidal loading of the marsh sediments is a two-stage process consisting of direct, instantaneous loading during inundation and indirect, time delayed loading via lateral diffusion of pore pressure variations in-between inundation intervals. The combination of terrestrial groundwater entering the marsh through the high permeability layer beneath the peat, seawater flooding the marsh platform during inundation, and tidally induced pore pressure variations diffusing into the marsh generates a complex space–time exchange pattern, including bi-directional exchange at tidal periods, with poorly understood but important implications for biogeochemical processes in the marsh sediments and constituent fluxes to the coastal ocean.

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USGS2026

No detection of Batrachochytrium salamandrivorans after non-native salamander putative pet release in Massachusetts, USA

The disease caused by the amphibian chytrid fungus Batrachochytrium salamandrivorans (Bsal) has caused mass mortality of salamanders across Europe (Stegen et al. 2017; amphibians are not known to be susceptible to the disease (Martel et al. 2014). Bsal puts North American amphibian biodiversity at risk (Martel et al. 2014; Gray et al. 2015) despite imports of potentially infected amphibians (USFWS 2016; WAPTR 2018; Grear et al. 2021). Recently, the U.S. has announced the finalization of the 2016 interim rule to the Lacey Act (USFWS 2016) to restrict imports of all species of salamanders from 20 genera to the list of injurious amphibians and has added 16 genera to the injurious amphibian list in a new interim rule in response to updated research on salamander susceptibility to Bsal infection (USFWS 2025). A large-scale survey across the USA failed to detect Bsal in over 10,000 individuals (Waddle et al. 2020), and ongoing efforts by North American colleges and universities are similarly conducting Bsal surveillance without more recent detection (e.g., Hyman and Hill 2024). Concerned amphibian and disease specialists nevertheless are preparing for a Bsal invasion into North America (Grant et al. 2017; Olson et al.2024). Despite the initial survey results, the risk of Bsal incursion into North America remains due to broad host susceptibility of North American amphibian species (Gray et al. 2023). The major driver of Bsal introduction risk in the U.S. is expected to be captive amphibian release (Cunningham et al. 2015; Grear et al. 2021). Bsal primarily affects salamanders but anuran species can also be vectors (e.g., Towe et al. 2021; Monzon et al. 2022; Gray et al. 2023; Olson et al. 2024), increasing the risk of a released amphibian carrying Bsal into the natural environment (Grear et al. 2021). An early survey of pet salamanders in the United States did not detect Bsal (Klocke et al. 2017), but even one animal released with Bsal could have a major effect on local amphibians. Early detection and rapid response can improve host outcomes (Bletz et al. 2024; Gray et al. 2018), but the lack of timely knowledge about unwanted release of non-native pets to natural systems causes inevitable delay. Herein, we describe our experience responding to a report of a released non-native amphibian species, common in the pet trade (Gerson 2012; Maximo et al. 2021). We suggest improvements to early detection and rapid response efforts for amphibians and amphibian disease

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USGS2025

Using multiple lines of evidence to evaluate spatio‐temporal trends in nitrogen loading to a eutrophic estuary

Nitrogen (N) pollution in groundwater in coastal watersheds can have negative impacts on the health of estuaries. West Falmouth Harbor, a shallow lagoon on Cape Cod, MA, USA, has experienced a marked increase in N load since the 1990s due to input from a groundwater aquifer contaminated by a municipal wastewater treatment facility. As part of a broader, long-term research effort to understand the changes to the ecosystem associated with this N input, this study takes an integrative approach at quantifying groundwater N load to the estuary from 1985 through 2024 by combining traditional groundwater well sampling with a wintertime open water mixing model. The latter gives a robust spatially averaged nitrate concentration in discharged groundwater, supplementing the spatial and temporal patterns from the well data. We calculate a conservative estimate for the mean N load to West Falmouth Harbor during peak loading years (2008–2013) of 3.1 mmol m−2 d−1. This then decreased by approximately 25% by 2024 as a result of wastewater treatment improvements and should continue to decline over the next decade. The long-term trends observed in the groundwater well network complement the open water sampling, providing confidence in the accuracy of the latter approach and allowing us to interpolate an estimate of N loading to West Falmouth Harbor back to 1985. This integrative approach to evaluating groundwater inputs to this ecosystem dramatically improves our ability to quantify total N load and can be a powerful tool for studies in groundwater-fed lagoonal estuaries with a short residence time.

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USGS2025

Technical note: A low-cost approach to monitoring relative streamflow dynamics in small headwater streams using time lapse imagery and a deep learning model

Despite their ubiquity and importance as freshwater habitat, small headwater streams are under-monitored by existing stream gage networks. To address this gap, we describe a low-cost, non-contact, and low-effort method that enables organizations to monitor relative streamflow dynamics in small headwater streams. The method uses a camera to capture repeat images of the stream from a fixed position. A person then annotates pairs of images, in each case indicating which image has more apparent streamflow or indicating equal flow if no difference is discernible. A deep learning modeling framework called streamflow rank estimation (SRE) is then trained on the annotated image pairs and applied to rank all images from highest to lowest apparent streamflow. From this result a relative hydrograph can be derived. We found that our modeled relative hydrograph dynamics matched the observed hydrograph dynamics well for 11 cameras at 8 streamflow sites in western Massachusetts. Higher performance was observed during the annotation period (median Kendall's Tau rank correlation of 0.75, with a range of 0.6–0.83) than after it (median Kendall's Tau of 0.59, with range 0.34–0.74). We found that annotation performance was generally consistent across the 11 camera sites and 2 individual annotators and was positively correlated with streamflow variability at a site. A scaling simulation determined that model performance improvements were limited after 1000 annotation pairs. Our model's estimates of relative flow, while not equivalent to absolute flow, may still be useful for many applications, such as ecological modeling and calculating event-based hydrological statistics (e.g., the number of out-of-bank floods). We anticipate that this method will be a valuable tool to extend existing stream monitoring networks and provide new insights on dynamic headwater systems.

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USGS2025

The 3D Elevation Program—Supporting the economy of Massachusetts

Introduction Massachusetts extends from the mountains of the Appalachian system in the west of the State to the sandy beaches and rocky shorelines of the Atlantic coast in the east. Inland topographic data support a wide range of important activities, including geologic mapping, transportation planning, forest and wildlife management, quantifying ecological services, water supply protection, commonwealth-wide infrastructure planning, local site planning, and flood-plain management. Nearshore bathymetry can be used to support coastal portions of the Commonwealth by addressing the combined threats of ocean warming, strong storm surge, and rising sea levels. The maintenance and (or) expansion of Massachusetts ports (for instance, Boston, New Bedford) and Cape Cod sediment management depends upon the accurate mapping of bathymetry and the frequent influx of sediment and redeposition. Critical applications that address the broad range of requirements depend on light detection and ranging (lidar) data that provide a highly detailed three-dimensional (3D) model of the Earth’s surface and aboveground features. The 3D Elevation Program (3DEP) is managed by the U.S. Geological Survey (USGS) in partnership with Federal, State, Tribal, U.S. territorial, and local agencies to acquire consistent lidar coverage at quality level 2 or better to meet the many needs of the Nation and Massachusetts. The status of available and in-progress 3DEP baseline lidar data in Massachusetts is shown in figure 1. 3DEP baseline lidar data include quality level 2 or better, 1-meter or better digital elevation models, and lidar point clouds, and must meet the Lidar Base Specification version 1.2 ( https://www.usgs.gov/3dep/lidarspec ) or newer requirements. The National Enhanced Elevation Assessment identified user requirements and conservatively estimated that availability of lidar data would result in at least $1.23 million in new benefits annually to Massachusetts. The top 10 Massachusetts business uses for 3D elevation data, which are based on the estimated annual conservative benefits of 3DEP, are shown in table 2.

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