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USGS2003

Geographic Information System Tools for Conservation Planning: User's Manual

Public and private land managers desire better ways to incorporate landscape, species, and habitat relations into their conservation planning processes. We present three tools, developed for the Environmental Systems Research Institute?s ArcView 3.x platform, applicable to many types of wildlife conservation management and planning efforts. These tools provide managers and planners with the ability to rapidly assess landscape attributes and link these attributes with species-habitat information. To use the tools, the user provides a detailed land cover spatial database and develops a matrix to identify species-habitat relations for the landscape of interest. The tools are applicable to any taxa or suite of taxa for which the required data are available. The user also has the ability to interactively make polygon-specific changes to the landscape and re-examine species-habitat relations. The development of these tools has given resource managers the means to evaluate the merits of proposed landscape management scenarios and to choose the scenario that best fits the goals of the managed area.

Information and Technology Report↗

USGS2016

The effects of anthropogenic land cover change on pollen-vegetation relationships in the American Midwest

Fossil pollen assemblages provide information about vegetation dynamics at time scales ranging from centuries to millennia. Pollen-vegetation models and process-based models of dispersal typically assume stable relationships between source vegetation and corresponding pollen in surface sediments, as well as stable parameterizations of dispersal and productivity. These assumptions, however, are largely unevaluated. This paper reports a test of the stability of pollen-vegetation relationships using vegetation and pollen data from the Midwestern region of the United States, during a period of large changes in land use and vegetation driven by Euro-American settlement. We compared a dataset of pollen records for the early settlement-era with three other datasets of pollen and forest composition for two time periods: before Euro-American settlement, and the late 20th century. Results from generalized linear models for thirteen genera indicate that pollen-vegetation relationships significantly differ (p < 0.05) between pre-settlement and the modern era for several genera: Fagus, Betula, Tsuga, Quercus, Pinus , and Picea . The estimated pollen source radius for the 8 km gridded vegetation data and associated pollen data is 25–85 km, consistent with prior studies using similar methods and spatial resolutions. Hence, the rapid changes in land cover associated with the Anthropocene affect the accuracy of ecological predictions for both the future and the past. In the Anthropocene, paleoecology should move beyond the assumption that pollen-vegetation relationships are stable over time. Multi-temporal calibration datasets are increasingly possible and enable paleoecologists to better understand the complex processes governing pollen-vegetation relationships through space and time.

Michigan, Minnesota, Wisconsin↗

USGS2014

Multisensor earth observations to characterize wetlands and malaria epidemiology in Ethiopia

Malaria is a major global public health problem, particularly in Sub-Saharan Africa. The spatial heterogeneity of malaria can be affected by factors such as hydrological processes, physiography, and land cover patterns. Tropical wetlands, for example, are important hydrological features that can serve as mosquito breeding habitats. Mapping and monitoring of wetlands using satellite remote sensing can thus help to target interventions aimed at reducing malaria transmission. The objective of this study was to map wetlands and other major land cover types in the Amhara region of Ethiopia and to analyze district-level associations of malaria and wetlands across the region. We evaluated three random forests classification models using remotely sensed topographic and spectral data based on Shuttle Radar Topographic Mission (SRTM) and Landsat TM/ETM+ imagery, respectively. The model that integrated data from both sensors yielded more accurate land cover classification than single-sensor models. The resulting map of wetlands and other major land cover classes had an overall accuracy of 93.5%. Topographic indices and subpixel level fractional cover indices contributed most strongly to the land cover classification. Further, we found strong spatial associations of percent area of wetlands with malaria cases at the district level across the dry, wet, and fall seasons. Overall, our study provided the most extensive map of wetlands for the Amhara region and documented spatiotemporal associations of wetlands and malaria risk at a broad regional level. These findings can assist public health personnel in developing strategies to effectively control and eliminate malaria in the region.

Amhara region↗

USGS2024

Western and McKay's bumble bees occupancy trends and future projections

The Western and McKay's bumble bees, originally petitioned for listing as subspecies of the Western bumble bee (Bombus occidentalis) were previously among the most common western bumble bee species but have declined since the late 1990s (Graves et al. 2021). This report details an occupancy analysis utilizing pre-existing and newly collected bumble bee survey data to evaluate potential mechanisms associated with species trends across their distributions in western North America. In addition to evaluating spatially explicit changes in occupancy trends, we also sought to assess how widespread environmental conditions and stressors influence occupancy. Although changing climate, land cover, pesticides, and pathogens have all been identified as potential mechanisms for declines (Cameron et al. 2011, Kerr et al. 2015, Soroye et al. 2020), previous studies have not tied most climate hypotheses to bumble bee life histories or evaluated combined effects of more than 2 of these mechanisms at multi-state/ multiprovince scales. Using a scenario-based approach across climate models, emissions, and land cover scenarios, we projected future occupancy to mid-century (2050-2059). This analysis was conducted to support the Species Status Assessment (SSA) for Western and Mckay’s bumble bees being administered by the U.S. Fish & Wildlife Service (USFWS).

Report↗

USGS2007

Response of Stream Chemistry During Base Flow to Gradients of Urbanization in Selected Locations Across the Conterminous United States, 2002-04

During 2002-2004, the U.S. Geological Survey's National Water-Quality Assessment Program conducted a study to determine the effects of urbanization on stream water quality and aquatic communities in six environmentally heterogeneous areas of the conterminous United States--Atlanta, Georgia; Raleigh-Durham, North Carolina; Milwaukee-Green Bay, Wisconsin; Dallas-Fort Worth, Texas; Denver, Colorado; and Portland, Oregon. This report compares and contrasts the response of stream chemistry during base flow to urbanization in different environmental settings and examines the relation between the exceedance of water-quality benchmarks and the level of urbanization in these areas. Chemical characteristics studied included concentrations of nutrients, dissolved pesticides, suspended sediment, sulfate, and chloride in base flow. In three study areas where the background land cover in minimally urbanized basins was predominantly forested (Atlanta, Raleigh-Durham, and Portland), urban development was associated with increased concentrations of nitrogen and total herbicides in streams. In Portland, there was evidence of mixed agricultural and urban influences at sites with 20 to 50 percent urban land cover. In two study areas where agriculture was the predominant background land cover (Milwaukee-Green Bay and Dallas-Fort Worth), concentrations of nitrogen and herbicides were flat or decreasing as urbanization increased. In Denver, which had predominantly shrub/grass as background land cover, nitrogen concentrations were only weakly related to urbanization, and total herbicide concentrations did not show any clear pattern relative to land cover - perhaps because of extensive water management in the study area. In contrast, total insecticide concentrations increased with increasing urbanization in all six study areas, likely due to high use of insecticides in urban applications and, for some study areas, the proximity of urban land cover to the sampling sites. Phosphorus concentrations increased with urbanization only in Portland; in Atlanta and Raleigh-Durham, leachate from septic tanks may have increased phosphorus concentrations in basins with minimal urban development. Concentrations of suspended sediment were only weakly associated with urbanization, probably because this study analyzed only base-flow samples, and the bulk of sediment loads to streams is transported in storm runoff rather than base flow. Sulfate and chloride concentrations increased with increasing urbanization in four study areas (Atlanta, Raleigh-Durham, Milwaukee-Green Bay, and Portland), likely due to increasing contributions from urban sources of these constituents. The weak relation between sulfate and chloride concentrations and urbanization in Dallas-Fort Worth and Denver was likely due in part to high sulfate and chloride concentrations in ground-water inflow, which would have obscured any pattern of increasing concentration with urbanization. Pesticides often were detected at multiple sites within a study area, so that the pesticide 'signature' for a given study area - the mixtures of pesticides detected, and their relative concentrations, at streams within the study area - tended to show some pesticides as dominant. The type and concentrations of the dominant pesticides varied markedly among sites within a study area. There were differences between pesticide signatures during high and low base-flow conditions in five of the six study areas. Normalization of absolute pesticide concentrations by the pesticide toxicity index (a relative index indicating potential toxicity to aquatic organisms) dramatically changed the pesticide signatures, indicating that the pesticides with the greatest potential to adversely affect cladocerans or fish were not necessarily the pesticides detected at the highest concentrations. In a screening-level assessment, measured contaminant concentrations in individual base-flow water samples were compared with various water-qual

Scientific Investigations Report↗

USGS2000

Combining accuracy assessment of land-cover maps with environmental monitoring programs

A scientifically valid accuracy assessment of a large-area, land-cover map is expensive. Environmental monitoring programs offer a potential source of data to partially defray the cost of accuracy assessment while still maintaining the statistical validity. In this article, three general strategies for combining accuracy assessment and environmental monitoring protocols are described. These strategies range from a fully integrated accuracy assessment and environmental monitoring protocol, to one in which the protocols operate nearly independently. For all three strategies, features critical to using monitoring data for accuracy assessment include compatibility of the land-cover classification schemes, precisely co-registered sample data, and spatial and temporal compatibility of the map and reference data. Two monitoring programs, the National Resources Inventory (NRI) and the Forest Inventory and Monitoring (FIM), are used to illustrate important features for implementing a combined protocol.

Environmental Monitoring and Assessment↗

USGS1999

The sensitivity of terrestrial carbon storage to historical climate variability and atmospheric CO2 in the United States

We use the Terrestrial Ecosystem Model (TEM, Version 4.1) and the land cover data set of the international geosphere-biosphere program to investigate how increasing atmospheric CO2 concentration and climate variability during 1900-1994 affect the carbon storage of terrestrial ecosystems in the conterminous USA, and how carbon storage has been affected by land-use change. The estimates of TEM indicate that over the past 95 years a combination of increasing atmospheric CO2 with historical temperature and precipitation variability causes a 4.2% (4.3 Pg C) decrease in total carbon storage of potential vegetation in the conterminous US, with vegetation carbon decreasing by 7.2% (3.2 Pg C) and soil organic carbon decreasing by 1.9% (1.1 Pg C). Several dry periods including the 1930s and 1950s are responsible for the loss of carbon storage. Our factorial experiments indicate that precipitation variability alone decreases total carbon storage by 9.5%. Temperature variability alone does not significantly affect carbon storage. The effect of CO2 fertilization alone increases total carbon storage by 4.4%. The effects of increasing atmospheric CO2 and climate variability are not additive. Interactions among CO2, temperature and precipitation increase total carbon storage by 1.1%. Our study also shows substantial year-to-year variations in net carbon exchange between the atmosphere and terrestrial ecosystems due to climate variability. Since the 1960s, we estimate these terrestrial ecosystems have acted primarily as a sink of atmospheric CO2 as a result of wetter weather and higher atmospheric CO2 concentrations. For the 1980s, we estimate the natural terrestrial ecosystems, excluding cropland and urban areas, of the conterminous US have accumulated 78.2 Tg C yr-1 because of the combined effect of increasing atmospheric CO2 and climate variability. For the conterminous US, we estimate that the conversion of natural ecosystems to cropland and urban areas has caused a 18.2% (17.7 Pg C) reduction in total carbon storage from that estimated for potential vegetation. The carbon sink capacity of natural terrestrial ecosystems in the conterminous US is about 69% of that estimated for potential vegetation.

Tellus, Series B: Chemical and Physical Meteorolog↗

USGS2015

Implications of climate and land use change

This chapter relates ecosystem services to climate change and land use. The bulk of the chapter focuses on ecosystem services and steepland land use in the humid Neotropics – what is lost with land-cover changed, and what is gained with various types of restoration that are sustainable given private ownership. Many case studies are presented later in the white paper. The USGS contribution relates to climate change and the role of extreme weather events in land-use planning.

Book chapter↗

USGS1996

Trends in surface-water quality in Connecticut, 1969-88

Surface-water-quality data from selected monitoring stations in Connecticut were analyzed for trend, using the Seasonal Kendall test, for water years 1969-88, 1975-88, and 1981-88. The number of constituents and stations evaluated varied with the different time periods. The 39 monitoring stations included 26 freshwater streams with associated discharge data, 7 tidally affected streams, 4 harbor stations, and 2 surface impoundments. Flow-adjustment procedures were used where possible to minimize the effects of stream- flow variability on trend results. The drainage area of the monitoring stations includes approximately 5,000 mi 2 covering the State of Connecticut and about 11,000 mi 2 in upstream drainage areas outside of the State. Drainage basin size for the freshwater streams ranges from 4.1 mi 2 to 9,660 mi 2 . Land uses in the drainage basins range from undeveloped forested areas to highly urbanized metropolitan areas. During the period covered by the trend study, the State's population has grown, suburban development has increased, agricultural land use has decreased, and wastewater-treatment practices have improved. Increases in specific conductance and in the concentrations of calcium, magnesium, chloride, sulfate, dissolved solids, and total solids were geographically widespread and numerous during water years 1975-88 and indicate a general increase statewide in dissolved constituents in streamflow, both in urbanized and less developed areas. The effects of increasing urbanization, including municipal and industrial wastewater, septic system leachate, nonpoint runoff, and atmospheric deposition of contaminants, are possible causes for these increases. Decreases in turbidity and in the concentrations of total phosphorus, total organic carbon, and fecal coliform bacteria were geographically widespread and numerous during 1975-88. This general decrease in suspended material and bacteria may be attributable to basic improvements in the treatment of municipal and industrial wastewater during the period of record. Decreasing concentrations of total phosphorus may also be related to decreases in agricultural land use and to a decline in the use of detergents containing phosphorus. Detected decreases in total organic carbon and turbidity may have been caused, in part, by changes in sampling or analytical methods. Increases in total nitrogen, total organic nitrogen, and total nitrite-plus- nitrate were geographically widespread and numerous during 1975-88 and appear to indicate effects from both point sources in urbanized basins and nonpoint sources in less developed basins. The number of stations with increasing concentrations of nitrogen constituents was much smaller during 1981-88 than during 1975-88. Decreases in total ammonia nitrogen were detected at 11 stations during 1981-88. Decreases in total ammonia, sometimes paired with increases in total nitrite-plus-nitrate, may result from improvements in wastewater treatment. Increases in the concentration of dissolved oxygen, or dissolved oxygen as a percent of saturation, were geographically widespread and numerous during 1969-88 and 1975-88. Increases were less common during 1981-88. Increases in dissolved oxygen in urbanized basins may be related to major improvements in wastewater treatment during the 1970's and 1980's. The magnitude of the trends detected during 1969-88 may have been affected in part by a change, around 1974, in the model of the instrument used to measure dissolved oxygen in the field. Statewide increases in pH were detected during 1969-88, 1975-88, and 1981-88, in both urbanized and less developed basins. The widespread increases in pH were unexpected, given the relatively acidic quality of precipitation in the region during the study period. Only two decreases in pH were detected, both in relatively undeveloped basins. Increases in pH in urbanized areas may be related to decreasing concentrations of ammonia and to requirements for neutralization of municipal and industrial wastewater.

Connecticut↗

USGS2019

Nutritional status of honey bee (Apis mellifera L.) workers across an agricultural land-use gradient

Land use and habitat quality have emerged as critical factors influencing the health, productivity, and survival of honey bee colonies. However, characterization of the mechanistic relationship between differential land-use conditions and ultimate outcomes for honey bee colonies has been elusive. We assessed the physiological health of individual worker honey bees in colonies stationed across a gradient of agricultural land use to ask whether indicators of nutritional physiology including glycogen, total sugar, lipids, and protein were associated with land-use conditions over the growing season and colony population size the subsequent spring during almond pollination. Across the observed land-use gradient, we found that September lipid levels related to growing-season land use, with honey bees from apiaries surrounded by more favorable land covers such as grassland, pasture, conservation land, and fallow fields having greater lipid reserves. Further, we observed a significant effect of total protein during September on population size of colonies during almond pollination the following February. We demonstrate and discuss the utility of quantifying nutritional biomarkers to infer land-use quality and predict colony population size.

Scientific Reports↗

USGS2018

Persistence-based area prioritization for conservation: Applying occupancy and habitat threats and risks analyses

Effective habitat conservation is predicated on maintaining high levels or increasing local persistence probability of the species it purports to protect. Thus, methodological approaches that improve the inferential value of local persistence are of utmost value to guide conservation planning as they inform area selection processes. Herein we used the painted bunting Passerina ciris, a species of conservation interest in North Carolina, as an illustrative case that combined single-season, single-species occupancy analyses and a threats and risk decision support tool to rank five areas of conservation interest in terms of local persistence probability. We used survey data from two seasons (2008–2009) grouped into 21 natal dispersal sampling units and land-cover data from 12 habitat classes to establish the relationship between local occupancy probability and habitat. Occupancy increased most strongly with increasing amount of maritime forest. Projections to year 2050, relative to year 2000, indicated that a potential loss of maritime forest of 200–1,300 ha, depending on the area of interest. Projected loss was lowest at Bald Head Island–Wilmington (2%) and highest at Camp Lejune (27%). Bald Head Island–Wilmington ranked highest in projected local persistence probability (0.91; 95% confidence interval [CI] = 0.53–0.99), whereas Top Sail–Hammocks Beach Park ranked lowest (0.28; 95% CI = 0.03–0.82). Estimates of local persistence offer decision-makers another criterion to prioritize areas for conservation and help guide efforts aimed at maintaining or enhancing local persistence. These include in situ habitat management, expanding or connecting existing areas of interest. In the future, we recommend the use of multiseason occupancy models, coupled with measures of uncertainty of land-cover projections, to strengthen inferences about local persistence, particularly useful in nonstationary landscapes driven by human activities.

North Carolina↗

USGS2018

Nearshore sediment monitoring for the Stormwater Action Monitoring (SAM) Program, Puget Sound, western Washington

Chemicals such as metals and organics (polychlorinated biphenyl [PCBs], polybrominated diphenyl ethers [PBDEs], polycyclic aromatic hydrocarbons [PAHs], and phthalates) continue to enter Puget Sound, western Washington, from point sources (such as industrial and municipal outfalls) and combined sewer outfalls and non-point sources (such as stormwater runoff). Runoff during storm events has been identified as a major source of contamination entering Puget Sound and has been implicated in the degradation of nearshore habitats and biota. Metals, organic chemicals, and other pollutants are known to accumulate in sediments such as those present along the shoreline of Puget Sound. In addition to chemical contaminants, small plastic particles (known as microplastics), found in marine waters of Puget Sound and suspected of being in aquatic sediments, are a potential concern because they can be ingested by animals and are suspected of transporting sorbed chemicals such as PCBs and metals. The Stormwater Work Group of Puget Sound (SWG) (composed of State and municipal stormwater permittees, and other stakeholders) developed a strategy to address sediment conditions in the nearshore environment of Puget Sound. As part of this strategy, the SWG developed a regional stormwater monitoring strategy designed to inform monitoring requirements in National Pollutant Discharge Elimination System (NPDES) stormwater permits issued by the Washington State Department of Ecology (Ecology). The monitoring program is referred to as the Stormwater Action Monitoring (SAM). The overall focus of the work described in this report is to address one of the goals of SAM, which is to characterize the status, spatial extent, and quality of Puget Sound sediment chemicals in the nearshore urban areas. The nearshore urban areas are defined as areas parallel to established Urban Growth Areas (UGAs) using a spatially balanced probabilistic Generalized Random Tessellation Stratified (GRTS) sampling design. One of the benefits of the GRTS sampling design used for this study is that it allows one to efficiently extrapolate from a relatively small number of sampled nearshore sites to the entire nearshore shoreline within the 2011 defined UGA boundaries of Puget Sound. In addition to characterizing nearshore sediment chemical concentrations, this study also characterized the abundance of microplastics in the nearshore sediment. A total of 41 randomly selected sites were sampled throughout Puget Sound in summer and early autumn of 2016. All sampling sites were located at 6 feet below the Mean Lower Low Water line. The top 2–3 centimeters of sediment were collected using a boat-mounted, pre-cleaned stainless-steel box corer. All chemical samples were sieved to 2 millimeters and placed in appropriate containers for chemical analysis for PCBs, PBDEs, PAHs, phthalates, metals, total organic carbon, and grain size. Pre-sieved sediment samples were stored in glass containers for microplastic analysis. Nearshore sediment chemical concentrations were summarized using numerous statistical approaches to examine the minimum, mean, and maximum concentrations for each of the compounds analyzed and to compare the results to criteria and other nearshore and marine sediment studies. The GRTS sampling design also allowed the authors to assess the percentage of the UGA nearshore environment that did not meet established standards or criteria for each chemical analyzed. Additionally, regression and machine learning statistical analyses were used to examine relations between measured chemical concentrations, and land cover and geologic features at multiple scales within the watersheds adjacent to sampling sites. The influence of marine hydrodynamic factors on nearshore sediment chemical concentrations was statistically evaluated with nonparametric methods by assigning each sampling site to one of five nearshore drift cell types based on its location. The Puget Sound shoreline can be divided into segments, referred to as drift cells, based on the movement of sediment along the shore by waves. Each drift cell type has a unique influence on nearshore sediment transport. The nearshore sediment chemical concentrations for organics and metals generally were low, and in most cases less than Washington State criteria. The concentrations of some PAHs were greater than the criteria, but these exceedances were limited to one or two sites. The results of the probabilistic study design determined that, for the PAHs examined, 96 percent or more of the 1,344 km of shoreline represented by this study had concentrations less than any established criteria. For the remaining organics (PCBs and PBDEs), the probabilistic study design indicates that more than 98 percent of shoreline examined had concentrations less than criteria or proposed standards. For the metals, the results of the study indicate that 100 percent of the nearshore sediment had concentrations less than the criteria. The relations between sediment organic and metal concentrations, and adjacent watershed land cover and the particle size of the samples, were determined to be weakly related. Although weakly related, the particle size of the sediment in a sample typically explained more of the variation in metal concentrations than organics. While the measured watershed attributes adjacent to the sampling sites and sediment size of the samples were weakly related to chemical concentrations, they were significantly related to unique drift cells along the shoreline of Puget Sound known as drift cells. Each drift cell represents a long-term directional transport of sediment from its source to its depositional zone. Sediment chemical concentrations were significantly higher in drift cells with limited sediment movement compared to those with higher sediment transport energy. Microplastics in the nearshore sediment ranged from 0.02 to 0.65 pieces per gram of sediment, with a mean of 0.19 pieces per gram of sediment, and were dominated by small fibers (355–1,000 micrometers). Like chemical concentrations, microplastics concentrations in the nearshore sediment were poorly related to watershed land cover. Although not significantly different, microplastics concentrations generally were higher in the low energy drift cells compared to the high energy drift cells. The results of this study provide a statistically valid status assessment of current nearshore sediment chemical conditions throughout Puget Sound in those areas adjacent to defined UGAs. In addition to the study findings of relatively low concentrations of PCBs, PBDEs, PAHs, phthalates, and metals, the study design provides a statistically valid tool for evaluating changes in these compounds over time if future nearshore sediment assessments are done. Furthermore, the assessment of microplastic abundance represents the first study of its kind that can be used as a benchmark for future evaluations. The results of this study will help inform Ecology in the implementation of monitoring requirements as part of its NPDES stormwater permitting process.

Washington↗

USGS2021

How well do proxy species models inform conservation of surrogate species?

Context Proxy species, which represent suites of organisms with similar habitat requirements, are common in conservation. Landscape Capability (LC) models aim to quantify the spatially-explicit capability of landscapes to support proxy species that represent suites of forest birds. Objectives We evaluated the North Atlantic Landscape Conservation Cooperative (NALCC) proxy models of LC and represented species framework across 13 states in the northeastern United States from Virginia to Maine. We validated a suite of questions related to co-occurrence of proxy and represented species with a compilation of independent datasets. Methods We tested proxy species LC models ability to explain represented species’ occurrences, including using multiple proxies together, and benchmarked against empirical data and land cover type classifications. We tested effect of several factors on predictive ability including relative range overlap and ecological and taxonomic dissimilarity between proxy and represented species. Results LC models performed variably, but represented species occurrences were rarely predicted as accurately as proxy species. Models improved predictions over macrohabitat classifications. Using multiple proxies together occasionally improved predictions of represented species. Considerable range overlap was needed for models to be predictive of represented species. Ecological and taxonomic similarity had no effect on predictive ability. LC models worked similarly to using empirical observations, suggesting shortcomings were because of imperfect surrogacy. Conclusions Conservation proxies as representatives of species groups that are associated with macrohabitats are useful, but empirical data are necessary to evaluate proxy species’ effectiveness. Habitat-based models can provide similar predictive ability as empirical observations of proxies and represent a useful tool in conservation planning.

Landscape Ecology↗

USGS2014

Predicting the effects of climate change on ecosystems and wildlife habitat in northwest Alaska

We used a modeling framework and a recent ecological land classification and land cover map to predict how ecosystems and wildlife habitat in northwest Alaska might change in response to increasing temperature. Our results suggest modest increases in forest and tall shrub ecotypes in Northwest Alaska by the end of this century thereby increasing habitat for forest-dwelling and shrub-using birds and mammals. Conversely, we predict declines in several more open low shrub, tussock, and meadow ecotypes favored by many waterbird, shorebird, and small mammal species.

Alaska↗

USGS2007

A multi-scale segmentation approach to filling gaps in Landsat ETM+ SLC-off images

On 31 May 2003, the Landsat Enhanced Thematic Plus (ETM+) Scan Line Corrector (SLC) failed, causing the scanning pattern to exhibit wedge-shaped scan-to-scan gaps. We developed a method that uses coincident spectral data to fill the image gaps. This method uses a multi-scale segment model, derived from a previous Landsat SLC-on image (image acquired prior to the SLC failure), to guide the spectral interpolation across the gaps in SLC-off images (images acquired after the SLC failure). This paper describes the process used to generate the segment model, provides details of the gap-fill algorithm used in deriving the segment-based gap-fill product, and presents the results of the gap-fill process applied to grassland, cropland, and forest landscapes. Our results indicate this product will be useful for a wide variety of applications, including regional-scale studies, general land cover mapping (e.g. forest, urban, and grass), crop-specific mapping and monitoring, and visual assessments. Applications that need to be cautious when using pixels in the gap areas include any applications that require per-pixel accuracy, such as urban characterization or impervious surface mapping, applications that use texture to characterize landscape features, and applications that require accurate measurements of small or narrow landscape features such as roads, farmsteads, and riparian areas.

International Journal of Remote Sensing↗

USGS2023

Volcanic aquifers of Hawaiʻi—Contributions to assessing groundwater availability on Kauaʻi, Oʻahu, and Maui

The volcanic aquifers of the Hawaiian Islands supply water to 1.46 million residents, diverse industries, and a large component of the U.S. military in the Pacific. Groundwater also supplies fresh water that supports ecosystems in streams and near the coast. Hawaii’s aquifers are remarkably productive given their small size, but the capacity of the islands to store fresh groundwater is limited because each island is surrounded by seawater, and salt water underlies much of the fresh groundwater. The amount of fresh groundwater available for human use from Hawai‘i’s volcanic aquifers is constrained by the consequences of groundwater withdrawal. Restrictions placed on these consequences can translate to limitations on groundwater availability. Changes in recharge resulting from changes in land cover or climate can alter the effect of withdrawals. This study uses numerical models of the volcanic aquifers of the islands of Kaua‘i, O‘ahu, and Maui to quantify the consequences of historical and plausible future withdrawals and changes in recharge. The study compares the results of model simulations of multiple scenarios of historical and projected future withdrawal and recharge. Results of the simulations using the groundwater models of the islands of Kaua‘i, O‘ahu, and Maui have implications for other islands in Hawai‘i. Since the first modern water well was drilled in Hawai‘i in 1879, total groundwater withdrawals on Kaua‘i, O‘ahu, and Maui have risen to nearly 400 million gallons per day. Model simulations indicate that these withdrawals have caused reductions in groundwater discharge to streams and springs, reductions in groundwater discharge to the ocean, changes in subsurface flow between sectors within an island, lowering of groundwater levels, and rise of the interface between fresh water and salt water in the aquifers. Future increases in withdrawals will increase the severity of the consequences. Changes in recharge can alter the effect of withdrawals—increases in recharge can offset the consequences of withdrawals, whereas decreases in recharge can exacerbate the effects of withdrawals. This study quantifies the consequences of withdrawals for past and plausible future circumstances. The models can be used to test other circumstances. Limits placed on the consequences of withdrawals—such as restrictions to protect stream or coastal ecosystems that rely on groundwater discharge and limitations on water-level decline and rise of the freshwater-saltwater interface to protect the productivity of existing wells—can translate to limits on groundwater availability from Hawai‘i’s volcanic aquifers. Setting acceptable limits to the consequences of groundwater withdrawal is also a critical part of assessing groundwater availability. Once these limits are set, numerical models can be used to quantify the amount of water that can be withdrawn within those limits and thereby inform management decisions that seek to balance the need to limit the consequences of groundwater withdrawals with the need to develop water for human use.

Hawaii↗

USGS2019

Predicting the occurrence of chemicals of emerging concern in surface water and sediment across the U.S. portion of the Great Lakes Basin

Chemicals of emerging concern (CECs) are introduced into the aquatic environment via various sources, posing a potential risk to aquatic organisms. Previous studies have identified relationships between the presence of CECs in water and broad-scale watershed characteristics. However, relationships between the presence of CECs and source-related watershed characteristics have not been explored across the Great Lakes basin. Boosted regression tree (BRT) analyses were used to develop predictive models of CEC occurrence in water and sediment throughout 24 U.S. tributaries to the Great Lakes. Models were based on the distribution of both broad-scale and source-related watershed characteristics. Twenty-one upstream watershed characteristics, including land cover, number of permitted point sources, and distance to point sources were used to develop models predicting the probability of CEC occurrence in surface water and bottom sediment. Total accuracy of BRT models ranged from 66% to 94% for both matrices. All 21 watershed characteristics were important predictor variables in at least one surface-water model; twenty were important in at least one bottom-sediment model. Among the model variables, developed land use and distance to point sources were important predictors of the presence of CEC classes in both water and sediment. Although limitations exist, BRT models are one tool available for assessing vulnerability of fisheries and aquatic resources to CEC occurrences.

Great Lakes basin↗

USGS2014

Disentangling the effects of climate and landscape change on bird population trends in the western U.S. and Canada

Changes in climate are often assumed result in changes to species’ ranges, with potential impacts on natural system functioning and ecosystem services. ‘Climate envelope models’, which rely on correlations between climate and species distributions, have been used to predict the future of biodiversity under these assumptions. However, other factors including land-cover, dispersal ability and interspecific competition and facilitation may play an important role in driving species distributions and population trends either alone or in combination with climate. In an ongoing project, we used long-term data on bird distributions and abundance to develop climate envelope and land-use models for 161 species in order to provide a multi-species test of the degree to which climate envelope versus land-use models are useful in predicting species distributions and population trends of birds in forest ecosystems of the western U.S. and Canada. Our results suggest that models describing associations between climatic variables and abundance patterns can be used for some species to predict changes through time, and that changes in climate have already driven shifts in the geographic patterns of abundance of bird populations in western North America. For other species, models using land-use variables including raw remote-sensing variables may provide the best predictions for abundance change. The results of this research showing the reliability of models across multiple species will aid managers in understanding which species are most vulnerable to changes from climate, land-use change and their interaction.

Final Report↗