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Research about Louisiana

Source-linked reports with geographic coverage including Louisiana.

At least 19 recordsLinked to original sources
USGS2026

Sediment dredging influences the seasonal biomass and community composition of microphytobenthos on a sandy shoal

Microphytobenthos on sand shoals of continental shelves support biogeochemical cycles and trophodynamics and can be affected by sediment dredging. Therefore, our goal was to assess seasonal (spring, summer, fall) microphytobenthic biomass and composition over two years (2021 and 2022) at three areas (reference, relic dredged pit, and new dredged pit) of Ship Shoal off the coast of Louisiana, USA. Surface sediment was collected for algal pigment analysis to estimate microphytobenthic biomass and community composition using high-performance liquid chromatography. The average seasonal biomass ranged from 0.2 to 16.7 μg chlorophyll a g dry sediment −1 across the three regions and was consistently high in the relic dredged pit, with peak biomass during summer 2022. All regions contained benthic diatoms, cyanobacteria, and green algae, with diatoms significantly higher in the reference shoal region compared to the other regions. Benthic cyanobacteria and green algae dominated the biomass in relic pit. Enhanced deposition of organic-rich material in the relic pit, likely drives high seasonal biomass and shifts the community to benthic cyanobacteria and green algae. New and active dredging may suppress biomass despite changes in community composition. Thus, dredging-related changes could impact the autotrophic base of the benthic food web and have potential cascading effects.

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USGS2026

3D Elevation Program—Louisiana

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

The saline groundwater legacy of a large buried coastal paleo-estuary

Elevated groundwater salinity in coastal regions threatens the beneficial use of fresh groundwater. Coastal groundwater management typically focuses on preventing intrusion from modern sources of seawater; however, past geological processes can also leave a legacy of saline groundwater now hidden in the subsurface. Here, multiple extensive airborne electromagnetic surveys provide detailed evidence of residual salinity from a paleo-estuary filling a late Pleistocene incised valley impacting more than 10,000 km 2 that is now hidden beneath coastal Louisiana’s deltaic plain. Our results show that the three-dimensional pattern of saline groundwater beneath Louisiana mimics that of near-surface aquifers surrounding the modern Delaware Bay estuary, fingerprinting the signature of the past drowning of a large, incised valley of the Mississippi River following post-glacial sea-level rise. These findings demonstrate a new framework for understanding legacy sources of saltwater critical for managing stressed water resources along global coastlines.

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USGS2026

High and dry: The persistence of diverse coastal marsh communities depends on available upland area and connection to surrounding waters

Sea-level-rise and alterations to natural hydrology have contributed to coastal land loss. To combat coastal land loss and maintain the ecosystem services provided by marshes, marsh creation has been broadly implemented. Marsh creation projects can be performed in conjunction with the construction of elevated terrestrial ridges that seek to mimic historic delta-formed distributary ridges. Ridges and similar elevated structures, such as those surrounding created marshes, offer the opportunity to sample the ecotones between low marsh and upland areas within a small area. We sampled marsh assemblages on elevation gradients at eight sites in the Louisiana coastal zone. We identified nine marsh communities based on co-occurrence of taxa and abiotic conditions (soil salinity, percent time inundated, soil percent moisture, soil bulk density, and soil pH) with a two-step process of hierarchical clustering and random forest classification. Inundation time and salinity were identified as the most important conditions related to community composition. We used future estimates of coastal elevations based on local relative sea-level-rise estimates to make predictions of community change up to 50 years into the future. Our predictions, meant to serve as generalizations for the coastal region, indicate a near total loss of high-elevation salt marsh communities at the sites sampled. Elevation variation supports diverse marsh communities when water is allowed to flow as in a natural marsh. Hydrology regulates inundation, and by extension, salinity. Evaluating hydrologic exchange can be incorporated into decisions regarding future marsh creation to support marsh health and persistence.

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USGS2026

Expansion trends and impacts of Phragmites australis on the Louisiana Gulf Coast

Invasive plant species pose substantial threats to ecosystem integrity by disrupting ecosystem processes, reducing biodiversity, and complicating restoration and management efforts. Non-native lineages of Phragmites australis are invasive in wetlands across parts of North America, causing declines in the diversity of native wetland plants and disrupting biogeochemical cycles. Despite recognition of these effects, important knowledge gaps remain regarding the spatiotemporal dynamics, environmental drivers, and consequences of Phragmites expansion for native communities. Here, we examined long-term data from the Louisiana Coastwide Reference Monitoring System (CRMS), collected from 2006 to 2023 and spanning 390 sites across nine basins, to quantify basin-specific Phragmites cover trajectories and evaluate their associations with co-occurring native plant cover and soil properties. Louisiana supports both long-established noninvasive and (since ~2000) invasive European P. australis lineages, but CRMS cannot distinguish them; thus, our basin-level trajectories reflect species-level cover dynamics that may integrate lineage-specific turnover. Phragmites dynamics varied markedly among basins over the study period: Phragmites cover decreased in the Mississippi River Delta (initially >25%), whereas the Calcasieu-Sabine, Mermentau, Teche-Vermilion, and Terrebonne basins, each starting with <5%, exhibited positive expansion trends. The remaining four basins maintained low and stable Phragmites cover (<5%) over the study period. These distinct basin-level trajectories may reflect basin-to-basin differences in a hydrogeomorphic setting and associated sediment and nutrient inputs. In basins with positive expansion trends, Phragmites cover was associated with decreases in native plant cover. Overall, Phragmites expansion was positively associated with higher soil nutrients, lower pH, and higher salinity, highlighting key environmental factors that could inform targeted management to prevent or mitigate its expansion. Although Phragmites cover remains low in most basins (<10%), expansion in several basins suggests the value of basin-specific early-warning monitoring to maintain native plant cover and associated ecosystem functions. Our two-step framework offers a transferable monitoring template that integrates Phragmites cover trends (expanding/stable/declining), concurrently measured native plant cover, and key soil and pore-water indicators to flag emerging hotspots and prioritize adaptive management in other estuarine and deltaic systems.

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USGS2026

Local, regional, and coastwide effects of interactions between storms and relative position in tidal frame on Louisiana coastal marshes

Context In coastal wetlands, land area is dynamic in both space and time, and it is crucial to understand the factors that may tip the balance between wetland area loss and gain. Flooding has been shown to be a key regulator of wetland resilience to land loss through effects on vegetation health and productivity. However, the relationship between elevation and land change is complex, likely interacting with lateral processes such as edge erosion to influence land change rates. Objectives We sought to determine the role of storms, major drivers of lateral erosion, to help explain the complex relationships between elevation and land change at multiple spatial scales and improve predictions of wetland loss. Methods We used long-term records of elevation change, water elevation, and surface wind stress together with remotely sensed land-area change datasets to determine the factors that contribute to land loss in Louisiana (USA) coastal wetlands. Results Our results illustrate that wetland elevation alone cannot be used as a predictor of land change. Annual time-integrated wind stress, which we used as an indicator of storminess, is an important predictor of land change and interacts with elevation to impact wetland gain or loss. The data showed high site-level variation, indicating that local factors strongly determine land change. Nonetheless, we were able to identify broad generalities at the larger scales. We found that the interaction of flooding and storminess varied among geographic regions along the coast. In the Delta Plain region of the coast, sites that are frequently flooded (low elevation) were more likely to experience land gain in stormy years and land loss in calm years. Conversely, sites that were frequently drained (high elevation) had greater land loss during stormy years, presumably due to wind-wave erosion. This trend was not observed in the heavily managed Chenier Plain region, where perpetually flooded wetlands gained land during stormy years, likely due to wind-driven drainage of the marsh. Conclusion Together, these results illustrate that models of wetland vulnerability based upon elevation change or storm effects alone are too simple and will not capture observed trends in land change. Incorporating additional factors such as wind stress and management status can improve predictions of coastal wetland loss and our understanding of the mechanisms controlling resilience of these ecosystems.

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USGS2026

Water use in Louisiana, 2020

The U.S. Geological Survey (USGS), in cooperation with the Louisiana Department of Transportation and Development, collected water-withdrawal and water-use data from a 2020 inventory of water withdrawals in Louisiana. In 2020, approximately 8,700 million gallons per day (Mgal/d) of water was withdrawn from groundwater and surface-water sources in Louisiana, which represented a 0.22-percent decrease from 2015. Total groundwater withdrawals were about 1,900 Mgal/d, an increase of 7.1 percent from 2015, and total surface-water withdrawals were about 6,800 Mgal/d, a decrease of 2.1 percent from 2015 to 2020. Total water withdrawals, in million gallons per day, in 2020 for the various categories of use were as follows: public supply, 720; industry, 2,100; power generation, 4,100; rural domestic, 39; livestock, 7.0; rice irrigation, 930; general irrigation, 250; and aquaculture, 590. From 2015 to 2020, Louisiana’s total withdrawals for public supply increased by 1.4 percent, industry decreased by 2.3 percent, power generation decreased by 4.9 percent, rural domestic decreased by 1.2 percent, livestock increased by 11 percent, rice irrigation increased by 13 percent, general irrigation increased by 12 percent, and aquaculture increased by 20 percent. About 51 percent (approximately 960 Mgal/d) of all groundwater withdrawn was from the Chicot aquifer system and 24 percent (approximately 450 Mgal/d) was withdrawn from the Mississippi River alluvial aquifer. Since 2015, withdrawals from the Chicot aquifer system increased by 13 percent, and withdrawals from the Mississippi River alluvial aquifer increased by 18 percent. About 72 percent (4,900 Mgal/d) of all surface water withdrawn was from the Mississippi River main stem. This value represents a 1.1-percent decrease in withdrawals from 2015 to 2020. All water-withdrawal and water-use data presented in this report should be considered estimates. Because of rounding, totals and percentages presented in the tables, figures, and text in the report may differ slightly from totals or percentages calculated individually.

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USGS2026

Hydrological control on soil redox condition and carbon loss of coastal wetland under sea-kevel rise

Coastal wetlands are critical carbon sinks with their biogeochemical and ecological functioning shaped by dynamic hydrological conditions that are increasingly influenced by climate change. A key unresolved question is how hydrologic flow, vegetation response, and rising sea levels interact to regulate soil redox condition and carbon loss in coastal wetlands. Using a field-tested hydrological–biogeochemical–ecological modeling framework, we reveal how the interplay between terrestrial groundwater discharge and tidal fluctuations generates complex groundwater flow patterns at the terrestrial–aquatic interface, and how these patterns modulate soil redox conditions, in turn influencing soil organic matter decomposition and carbon loss. Notably, rising sea levels suppress soil CO 2 emissions while reducing lateral dissolved carbon losses, thereby enhancing litter carbon sequestration under anoxic conditions. As vegetation responds to sea-level rise and carbon inputs diminish, litter carbon subsequently declines. These findings underscore a critical hydrological control on carbon cycling, advancing our understanding of coastal ecosystem resilience in a warming world.

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USGS2026

Small cumulative survival costs of enzootic disease could suppress long-term population size

Fungal pathogens can cause epizootics that result in widespread mortality and rapid population declines in some species. However, even in the absence of high disease-induced mortality, enzootic mycoses could have large-scale impacts on host population dynamics. Here, we examined the effects of ophidiomycosis, an enzootic fungal disease, on a Louisiana snake community over a 3-year period using a multi-state Jolly–Seber model with disease-state misclassification. We did not detect a difference between the average weekly apparent survival probability of uninfected and infected hosts for either Nerodia species or Thamnophis proximus . We also found a strong positive association between snout-to-vent length and weekly apparent survival probability across all species. We found that recruitment of infected hosts was slightly higher than recruitment of uninfected hosts for two of the three species. Population projections suggested divergent trajectories between disease-present and disease-absent scenarios, where disease-absent populations had higher abundance than disease-present populations. Our results highlight that small differences in survival can accumulate over time, as well as the challenges of quantifying population-level impacts of enzootic diseases when survival differences are not readily detected, underscoring the importance of continued long-term monitoring to assess whether ophidiomycosis affects snake population dynamics.

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USGS2026

Modeling carbon fluxes in tidal forested wetlands in the Mississippi river deltaic plain under various hydrologic conditions: Implications for river diversions

Our understanding of the impacts of climate change, sea-level rise (SLR), and freshwater management on the magnitude and variability of carbon fluxes in tidal forested wetlands remains limited. In this study, we applied a process-driven wetland biogeochemistry model, Wetland Carbon Assessment Tool—DeNitrification-DeComposition (WCAT-DNDC) model to explore responses of carbon fluxes in tidal swamp forests to climate change-induced alterations in hydrologic conditions and to predict impacts of planned reintroduction of river flows. We selected twelve sites in three habitats (throughput, relict, degraded) inside the Lake Maurepas swamp forests (Louisiana, USA) to represent various hydrological and salinity regimes. Environmental scenarios included dry, average, and wet conditions, SLR (low and high), and a Mississippi River (MR) diversion. Simulation results showed that the responses of net ecosystem exchange (NEE), net primary productivity (NPP), ecosystem respiration (ER), methane (CH 4 ) and nitrous oxide (N 2 O) emissions in the Lake Maurepas swamp forests varied substantially among sites. However, the overall net carbon uptake capacity of the Lake Maurepas swamp forests was high (NEE: − 1143 to − 1650 g C m −2 yr −1 ), suggesting that Lake Maurepas swamp forests are large carbon sinks. The high net carbon uptake capacity could be significantly affected by climate change induced drought, flooding, and SLR with the bi-directional changes (increase or decrease) depending on the direction and magnitude of the hydrologic regime changes. The response of the net carbon uptake capacity to MR diversion is also bi-directional and site-specific, but enhancement of the capacity of NEE of up to − 1957 g C m 2 yr −1 is possible, implying that MR diversion into the swamp forests could be beneficial in the context of carbon cycling and carbon sequestration.

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USGS2026

Root biomass and productivity in coastal swamp forests of Louisiana (USA)

Coastal swamp forests (CSF) occupy approximately 225,000 ha in Southeastern Louisiana (USA), and across a large percentage of this area, CSF are subjected to sediment starvation, salinity intrusion, and chronic submergence. We assessed root biomass and productivity in nine CSF in Louisiana, and found that root biomass ranged from 420.8 g m −2 to 1712.2 g m −2 to a soil depth of 30 cm. Root biomass generally increased with salinity up to a mean and maximum of 1.8 and 4.3 psu, respectively, deviating from how aboveground biomass typically patterns. Submergence is a likely explanation for this deviation given that fresher sites had long hydroperiods with deeper water than salinized sites. In contrast, root productivity over a single year ranged from 112.1 g m −2 y −1 to 844.1 g m −2 y −1 , but did not relate strongly to salinity. On average, 16–87% of live roots were replaced each year among sites, leading to root longevities of 1.5–6.3 years. Also, root turnover was generally lower at more saline sites and higher from freshwater sites under greater submergence. Periodic water drawdown as a result of management intervention to reduce long-hydroperiod, chronic flooding by re-connecting river or tide to degraded CSF might stimulate root productivity and biomass accrual. Sediment amendment, strategic breaching of levees and gapping, and river water re-introductions are possible management actions.

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USGS2026

Coastal barrier resilience and resistance: Analysis and metrics for characterizing coastal state

Barrier islands are shaped by a variety of short- and long-term environmental processes such as storms and relative sea-level rise. These islands, found along the estuarine-marine interface, provide ecosystem services including storm surge and wave attenuation, erosion protection to inland marshes, habitat for fish and wildlife, and recreation. Natural resource managers require actionable information on how barrier island resilience and resistance changes over time to understand how an island’s current state relates to past conditions and to inform restoration prioritization and implementation. The U.S. Geological Survey and The Water Institute collaborated on a study to develop indicators of resilience and resistance for barrier islands in Louisiana. Here, resilience captures island persistence on yearly to decadal time scales, and resistance captures persistence on event time scales of days to weeks. The indicators fall in two categories: Tier 1 Screening Metrics, that can be readily calculated from available data, are easily interpretable as an evaluation of barrier condition, and provide a high-level snapshot of overall barrier resilience and resistance; and Tier 2 Analysis Metrics, which are detailed metrics that required specialized analysis and interpretation and are more applicable to answering specific questions managers may have about barrier state. The research team derived Tier 1 resilience indicators from subaerial land and vegetation cover calculated from publicly available maps and products based on satellite imagery. By benchmarking the total land and vegetation extent against their respective historical maxima, this metric provides a snapshot of an island’s current state in the context of its long-term trajectory. The research team developed Tier 1 resistance indicators based on subaerial island configuration and water level recurrence as a proxy for evaluating island resistance to storms, which are the primary driver of short-term change. These Tier 1 metrics can be analyzed over time to provide a high-level assessment of how an island’s resistance decreases because of elevation loss or sea-level rise or increases due to restoration or natural recovery. The research team developed Tier 2 resilience and resistance indicators and associated analyses to provide detailed information for specific time periods or applications (e.g., wildlife management). These metrics include habitat coverage from high-resolution maps, which show composition changes over time to capture the evolving resilience of specific habitat types; high tide flooding analysis, which evaluate island area relative to specified flooding thresholds to characterize resistance in the short-term or, if analyzed over time, indicate changes in resilience; and hypsometric curve analysis, which allows managers to evaluate island area changes above their own elevation benchmarks of interest and similarly characterize resistance in the short-term or indicate changes in resilience if assessed over time. The research team calculated Tier 1 metrics of the barrier islands and headlands along the coast of Louisiana for the period of 1984 through 2021 and Tier 2 metrics for select times during that period depending on data available and quality. The results were captured in a report card for each barrier, which also includes an overview of the metrics and their interpretation; a restoration and storm history; and Tier 1 and Tier 2 metric analysis, including benchmarking against coastwide and regional values as well as to an island’s pre-restoration trajectory. These report cards provide a readily digestible synthesis of barrier condition and trajectory that coastal managers can use to support restoration prioritization and other decisions.

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USGS2025

Phytoplankton biomass dynamics in wet (2019) and dry (2023) years in Lake Pontchartrain estuary, Louisiana from Sentinel 2-MSI and PACE-OCI observations

This study provides a comprehensive assessment of phytoplankton biomass dynamics in Lake Pontchartrain, Louisiana, by combining monthly water quality data with multispectral and hyperspectral satellite observations using a machine learning algorithm. A machine learning model based on Variational Autoencoder (VAE), globally applicable, was used to estimate phytoplankton biomass via chlorophyll- a (Chl- a ) from Sentinel 2-MSI and NASA's new hyperspectral mission, PACE-OCI, enabling the first direct comparison between the two sensors. The model performed well in this complex estuarine system, with higher accuracy from PACE-OCI (MAE: 1.48, RMSE: 10.40, slope: 0.87) than Sentinel 2-MSI (MAE: 1.57, RMSE: 11.08, slope: 0.83). This approach enabled continuous high-resolution monitoring of phytoplankton biomass across space and time. Comparative analysis of 2019, a wet year with Bonnet Carré Spillway (BCS) openings, and 2023, a dry year with extremely low riverine inputs, revealed distinct biomass dynamics. In 2019, BCS discharge initially suppressed Chl- a within turbid waters (<5 mg Chl- a m −3 ) but later acted as a nutrient and hydrodynamic driver, transporting nutrients toward the lake outlet and Mississippi coast, promoting high biomass (25–45 mg Chl- a m −3 ) near the entrance. In contrast, dry conditions in 2023 led to more frequent-than-expected high biomass (>35 mg Chl- a m −3 ), persisting in the lake center. Similar spatial patterns were observed again in 2024, revealed for the first time by PACE-OCI. This study demonstrates the value of satellite-derived observations for capturing transient phytoplankton biomass events and highlights the potential of PACE-OCI's hyperspectral capabilities to better distinguish phytoplankton communities and improve understanding of their responses to freshwater inflows and associated processes driving pulses into estuaries.

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USGS2025

Greater white-fronted goose habitat use in Louisiana provides water depth management insights

Numerous waterfowl species have altered their geographic distribution in recent decades. The greater white-fronted goose ( Anser albifrons ) has shifted its wintering distribution from coastal marshes in Texas and Louisiana, USA, to interior landscapes, creating challenges for conservation managers. Although the range shift has been primarily attributed to landscape-scale changes in rice production, effects of fine-scale habitat conditions on greater white-fronted goose habitat use are unknown. Thus, information on fine-scale environmental conditions could provide information to managers working to mitigate effects of the shift. We used global positioning system neck collars to monitor 78 greater white-fronted geese in Louisiana each winter during 2016–2019 and visited all used locations to record vegetation height, water depth, and land cover. We modeled greater white-fronted goose habitat use in 4 regions across Louisiana (central, coastal, north, southwest), and evaluated effects of vegetation height, water depth, land cover, and interactions. In our candidate model set, we included a sampling null, which accounted for differences in sampling frequencies among hunt seasons and diel periods. The top model in the central, coastal, and north regions included water depth, whereas the top model in the southwest region included water depth, vegetation height, and land cover. Parameter estimates and confidence intervals indicated that goose habitat use was higher at sites with >5.1 cm of water compared to dry sites or sites with <5.1 cm of water. In the southwest region, goose habitat use was highest in areas identified as other land cover (e.g., corn, cotton, rye, sugarcane) and lowest in open water. Although Louisiana has substantial anthropogenic food resources in the form of rice agriculture and abundant grazing opportunities afforded by mild winters, our results indicate that wet areas provide better habitat to greater white-fronted geese than dry areas. New agricultural flooding regimes in Louisiana could improve habitat quality and potentially mitigate some effects of the winter distribution shift.

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USGS2025

Assessing survey design for long-term population trend detection in piping plovers

Determining appropriate spatio-temporal scales for monitoring migratory shorebirds is challenging. Effective surveys must detect population trends without excessive or insufficient sampling, yet many programs lack formal evaluations of survey effectiveness. Using data from 2012 to 2019 on Louisiana’s barrier islands (Whiskey, west Raccoon, east Raccoon, and Trinity), we assessed how spatial and temporal scales influence population trend inference for piping plovers ( Charadrius melodus ). Point count data were aggregated to grid sizes from 50 to 200 m and analyzed using Bayesian dynamic occupancy models. We found occupancy and colonization estimates varied by spatial resolution, with space–time autocorrelation common across scales. Smaller islands (east and west Raccoon) yielded higher trend detection power due to better detectability, while larger islands (Trinity and Whiskey) showed lower power. Detectability, more than sampling frequency, drove trend inference. Models incorporating spatial autocorrelation outperformed traditional Frequentist approaches but showed poorer fit at coarser scales. These findings underscore how matching analytical scale to ecological processes and selecting appropriate models can influence predictions. Power analysis revealed that increasing survey frequency may improve inference, especially in low-detectability areas. Overall, our study highlights how careful scale selection, model diagnostics, and survey design can enhance monitoring efficiency and support long-term conservation of migratory shorebirds.

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USGS2025

Advancing the implementation of coastal restoration in Louisiana through a co-production of science framework

Coastal Louisiana faces complex challenges from the compounding effects of coastal land loss and climate change. The State of Louisiana’s Coastal Protection and Restoration Authority (CPRA) and the RESTORE Act Center of Excellence for Louisiana (LA-COE) have adopted a co-production of science framework to help ensure that scientific research funded through the LA-COE supports the research needs of CPRA and the Louisiana Coastal Master Plan (CMP), a large-scale coastal restoration plan that outlines activities needed to restore and protect Louisiana’s coast. In this paper, we describe the co-production of science framework established between the LA-COE, CPRA, and research projects funded by the LA-COE. Through an iterative process, the Louisiana CMP is revised every 6 years with improved model and scientific information. The LA-COE leverages the cyclical nature of the CMP by working with CPRA to identify research needs for each Request for Proposals solicited by the LA-COE. The LA-COE proposal review process is structured to include anonymous CPRA review of projects to promote the production of actionable science, and once funded, multiple mechanisms are in place to support collaboration between researchers and CPRA staff. We highlight these mechanisms and provide examples of four LA-COE-funded projects where co-produced science is being used by CPRA to inform the CMP and its implementation. Finally, we discuss challenges of co-production within the confines of funding requirements and review restrictions, highlighting how the LA-COE continues to adapt to navigate these challenges and enhance the implementation of co-production throughout the research funding lifecycle.

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USGS2025

The 3D Elevation Program—Supporting Louisiana's economy

Introduction Recent and ongoing collections of high-resolution elevation data in Louisiana are providing information that supports improved critical public safety modeling and enables the State to strengthen its efforts to fight the effects of land subsidence and sea-level rise. The availability of current and accurate three-dimensional (3D) elevation data supports numerous business activities, including flood risk management, infrastructure and construction management, coastal zone management, wildlife and habitat management, recreation, agriculture and precision farming, urban and regional planning, water supply and quality assessment, and natural resources conservation. Critical applications that meet the State’s management needs depend on light detection and ranging (lidar) data that provide a highly detailed 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 Louisiana. The status of available and in-progress 3DEP baseline lidar data in Louisiana 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 $6.96 million in new benefits annually to the State. The top 10 Louisiana 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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