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At least 991 records · Page 55Linked to original sources

Concepts for monitoring water quality in the Spokane River Basin, northern Idaho and eastern Washington

Numerous environmental studies have been conducted in the Spokane River Basin over the past several decades by government agencies, academic institutions, and environmental engineering firms. Most of these efforts have focused on the environmental effects of more than a century of silver, lead, and zinc mining and oreprocessing activities in the South Fork Coeur d'Alene River valley in northern Idaho. Several studies also have assessed the water quality and potential for eutrophication of Coeur d'Alene and Long Lakes and the Coeur d'Alene, St. Joe, and Spokane Rivers. Because past investigations often were limited in scope and employed different approaches and methods, an integrated understanding of hydrologic, water-quality, and aquatic biological conditions still is lacking for the basin as a whole. Substantial resources are being spent for water-quality and naturalresource management, and for mitigating the adverse environmental effects of past mining activities in the basin. A water-quality monitoring network, integrated with the decision-making processes associated with these efforts, could be of considerable value. The purpose of such a monitoring network is to produce high-quality information on which to base sound water-quality and natural-resource management decisions and to assess the effectiveness of those decisions. A streamflow- and water-quality monitoring infrastructure already exists in the Spokane River Basin. This infrastructure consists of 20 lake-stage and streamflow-gaging stations, representing specific drainages or subdrainages and, in many cases, specific stream reaches or subreaches. These gaging stations are operated by the U.S. Geological Survey (USGS), several of them in cooperation with State and Federal agencies and a private utility company. Extensive streamflow data are available, some dating from the late 1800s. Water-quality data are also available from recent USGS cooperative studies in the Coeur d'Alene Lake watershed. A nutrient load/lake response (eutrophication) model has been developed for Coeur d'Alene Lake. Hydraulic models for estimating streamflow through the low-gradient reaches of the Coeur d'Alene and St. Joe Rivers have been developed. Trace-element concentrations and distributions in sediments in the lower South Fork and main-stem Coeur d'Alene River flood plain and the bed of Coeur d'Alene Lake have been assessed. Trace-element transport models have been developed for the lower Coeur d'Alene River system; estimates of annual load are available from the early 1990's to the present (1998). The USGS is monitoring traceelement concentrations and transport at seven gaging stations in the lower Coeur d'Alene River system and upper Spokane River, in cooperation with the U.S. Environmental Protection Agency. Fish and macroinvertebrate community assessment and tissue contaminant analyses at four Coeur d'Alene and St. Joe River gaging stations will begin in 1998, either as part of the Idaho Surface- Water Quality Ambient Monitoring Network operated by USGS in cooperation with the Idaho Division of Environmental Quality, or for the Northern Rockies Intermontane Basins (NROK) study of the USGS National Water-Quality Assessment (NAWQA) Program. Several gaging stations in the Spokane River Basin are being considered for routine sampling sites for the NROK NAWQA study. Several other sites also will be sampled for contaminants in bed sediment and fish tissue for the NROK study. Combined with appropriate sampling and data interpretation strategies, the existing USGS gaging-station network and data base could provide integrated water-quality information needed for sound environmental and resource-management decisions throughout the Spokane River Basin.

Idaho;Washington↗

Development and use of a habitat gradient model to evaluate wildlife habitat

Ecologists and wildlife managers are increasingly confronted with the problems of predicting the value of surface cover as wildlife habitat and developing management alternatives to offset wildlife values lost because of land-use change. These problems have become urgent and more acute because of increased demand for products from the land and diminished fiscal and manpower resources for obtaining meaningful environmental information for the decision maker. This paper describes a relatively rapid, simple, and quantitative process for evaluating the quality of an area as wildlife habitat.

Transactions of the North American Wildlife and Na↗

Reactive solute-transport simulation of pre-mining metal concentrations in mine-impacted catchments: Redwell Basin, Colorado, USA

With the increased importance of water resources in the western United States and many areas worldwide, the remediation of impacts from historical mining becomes ever more important. A possible process of making decisions about remediation for a catchment might include identification of principal sources of metals in the catchment, classification of the sources as natural or anthropogenic, and simulations to evaluate different options for removal of anthropogenic sources. The application of this process is based on understanding the pre-mining conditions in the catchment, so that remediation goals appropriately correct for the impacts of mining. A field experiment in Redwell Basin, Colorado, provided a setting to demonstrate this process and to evaluate pre-mining concentrations through reactive solute-transport modeling. The field experiment provided spatially detailed stream and inflow samples that were the basis for model calibration. Only two inflows along the study reach were affected by mining or mine exploration. To simulate pre-mining conditions, these inflows were removed from the model calibration; the result was a simulation of the stream with all the non-mining inputs. At a point downstream from the two mining inflows, the simulated pre-mining pH would have been 5.1, up from the measured 3.8. At the higher pH, the streambed likely would have been coated with Al precipitate. Simulated pre-mining Zn and Cu would have been 1300 µg/L and 18 µg/L, lower than the measured concentrations of 3340 and 93 µg/L. Despite these changes, the pre-mining conditions would not have met aquatic-life standards.

Colorado↗

State-dependent resource harvesting with lagged information about system states

Markov decision processes (MDPs), which involve a temporal sequence of actions conditioned on the state of the managed system, are increasingly being applied in natural resource management. This study focuses on the modification of a traditional MDP to account for those cases in which an action must be chosen after a significant time lag in observing system state, but just prior to a new observation. In order to calculate an optimal decision policy under these conditions, possible actions must be conditioned on the previous observed system state and action taken. We show how to solve these problems when the state transition structure is known and when it is uncertain. Our focus is on the latter case, and we show how actions must be conditioned not only on the previous system state and action, but on the probabilities associated with alternative models of system dynamics. To demonstrate this framework, we calculated and simulated optimal, adaptive policies for MDPs with lagged states for the problem of deciding annual harvest regulations for mallards (Anas platyrhynchos) in the United States. In this particular example, changes in harvest policy induced by the use of lagged information about system state were sufficient to maintain expected management performance (e.g. population size, harvest) even in the face of an uncertain system state at the time of a decision.

PLoS ONE↗

Biomarker chemistry and flux quantification methods for natural petroleum seeps and produced oils, offshore southern California

Sustained, natural oil seepage from the seafloor is common off southern California, and is of great interest to resource managers, who are tasked with distinguishing natural from anthropogenic oil sources. The major purpose of this study was to build upon the work previously funded by the Bureau of Ocean Energy Management (BOEM) and the U.S. Geological Survey (USGS) that has refined the oil-fingerprinting process to enable differentiation of the highly similar Monterey Formation oils from Outer Continental Shelf (OCS) production and adjacent natural seeps. In these initial studies, biomarker and stable carbon isotope ratios were used to infer the age, lithology, organic-matter input, and depositional environment of the source rocks for 388 samples of produced crude oil, seep oil, and tarballs mainly from coastal California. The analysis resulted in a predictive model of oil source families that could be applied to samples of unknown origin.

California↗

Kinetic analysis of strontium and potassium sorption onto sands and gravels in a natural channel

A kinetic, first-order mass transfer model was used to describe the sorption of strontium onto sand- and gravel-sized streambed sediments. Rate parameters, empirically determined for strontium, allowed for the prediction of potassium sorption with moderate success. The model parameters varied significantly with particle size. The sorption data were collected during an experimental injection of several elements into a small mountain pool-and-riffle stream. The sorption process onto sand- and gravel-sized sediment was relatively slow compared to changes in the dissolved concentrations.

Water Resources Research↗

A simple daily soil-water balance model for estimating the spatial and temporal distribution of groundwater recharge in temperate humid areas

Quantifying the spatial and temporal distribution of natural groundwater recharge is usually a prerequisite for effective groundwater modeling and management. As flow models become increasingly utilized for management decisions, there is an increased need for simple, practical methods to delineate recharge zones and quantify recharge rates. Existing models for estimating recharge distributions are data intensive, require extensive parameterization, and take a significant investment of time in order to establish. The Wisconsin Geological and Natural History Survey (WGNHS) has developed a simple daily soil-water balance (SWB) model that uses readily available soil, land cover, topographic, and climatic data in conjunction with a geographic information system (GIS) to estimate the temporal and spatial distribution of groundwater recharge at the watershed scale for temperate humid areas. To demonstrate the methodology and the applicability and performance of the model, two case studies are presented: one for the forested Trout Lake watershed of north central Wisconsin, USA and the other for the urban-agricultural Pheasant Branch Creek watershed of south central Wisconsin, USA. Overall, the SWB model performs well and presents modelers and planners with a practical tool for providing recharge estimates for modeling and water resource planning purposes in humid areas. ?? Springer-Verlag 2007.

Hydrogeology Journal↗

Preliminary hydrologic budget of the sand-and-gravel aquifer under unstressed conditions: with a section on water-quality monitoring, Pensacola, Florida

The sand-and-gravel aquifer is the only freshwater aquifer in southern Escambia County, Fla. Problems related to the development of the aquifer include sustained yield, contamination, and saltwater intrusion. A digital model was applied to the sand-and-gravel aquifer in central and southern Escambia County treating the aquifer 's 'main producing zone ' as a discrete, leaky, confined aquifer. Under conditions of no pumping, most values for the final-head matrix agreed with assumed values within 4 feet in the area of principal interest. Discharge per unit land area was 1.04 cubic feet per second per square mile, in close agreement with the base runoff streams maintained by the aquifer. Total natural aquifer discharge within the area of principal interest determined by the model was 159 million gallons per day. The applicability of the present non-unique calibration for predicting the effects of pumping is questionable; a multilayered model may be required. Effluent infiltrating from holding lagoons for spray irrigation at the Scenic Hills Sewage Plant may have affected the quality of local perched ground water in the sand-and-gravel aquifer. Observation wells drilled near areas of heavy pumping around Bayou Chico indicated no saltwater intrusion. (Woodard-USGS)

Florida↗

Disease, drought, and warming: A triple threat to a declining high-elevation amphibian

Managing species in an uncertain future is a reality for natural resource decision makers. Climate change is expected to exacerbate threats such as habitat loss and disease, and cause phenological mismatches, but there is uncertainty in the magnitude of these effects. Amphibians are among the most threatened taxa on earth, and most species in North America are uniquely tied to water availability for breeding, larval development, thermal refugia, and food availability. Changes in water availability and temperature may result in phenological mismatches with one or more of these processes. Thus, quantifying the dependency of amphibians to water on the landscape is critical to understanding how species may respond, as well as understanding the interplay with other threats, such as disease. We developed a dynamic co-occurrence occupancy model to explore the effects of climate change on the breeding occurrence of boreal toads ( Anaxyrus boreas ) and the amphibian chytrid fungus ( Batrachochytrium dendrobatidis , Bd) in the southern Rocky Mountains (SRM). We derived novel covariates to test hypotheses related to multi-generational impacts of climate on the dynamics of both boreal toad breeding and Bd. We report estimates of current (2001–2019) and future (2055–2069) occupancy under a range of plausible climate scenarios. The probability of boreal toad breeding occurrence at a site in the SRM declined > 40% from 2001 to 2019, and further declines are likely under future scenarios, particularly as active season length increases. To help integrate this information into management, we developed a web-based decision support tool to summarize predicted future hydrological and occupancy conditions.

Colorado, New Mexico, Wyoming↗

Leveraging extensive soil, vegetation, fire, and land treatment data to inform restoration across the sagebrush biome

Context Widespread ecological degradation has prompted calls for massive global investments in ecological restoration, yet limited resources necessitate efficient application of restoration efforts. In western North America, altered fire regimes are increasing the scale of restoration needed to preserve the sagebrush ( Artemisia species) biome but prioritizing and implementing effective restoration is complicated by the vast and heterogeneous sagebrush landscape, which includes gradients in climate, disturbance, and species composition. Objectives To develop spatially explicit and context-dependent estimates of treatment efficacy and sagebrush recovery rates. Methods We leveraged a suite of spatio-temporally extensive datasets to evaluate the influence of restoration treatments and environmental conditions on trends in post-disturbance sagebrush cover, with an emphasis on understanding differences between sites recovering naturally and sites receiving restoration treatments. We used estimates from these models to develop spatially explicit projections for sagebrush recovery, conditional on disturbance, restoration practice, and environmental conditions. Results We found seeding Artemisia spp. increased sagebrush cover over time relative to natural recovery, but this relationship depended on spring soil moisture availability and treatment methods. Natural recovery was positively influenced by soil moisture and sagebrush cover and negatively influenced by cumulative burns and annual herbaceous cover, while the influence of perennial herbaceous cover varied with soil moisture. Conclusions Our results provide biome-wide insights and spatially explicit tools that can inform economic cost-effectiveness analyses, restoration prioritization tools, and other scientific endeavors to ensure managers have the tools and information needed to effectively steward the sagebrush biome in a rapidly changing world.

Landscape Ecology↗

Don’t move a mussel: The role of key environmental drivers and management scale in assessing spatial variation in dreissenid spread risk in the Missouri River Basin

The spread of non-native freshwater mussels in North America is a growing threat that has already resulted in substantial ecological and economic damage to infested areas. A primary vector by which invasive mussels spread is watercraft that are transported over land from an infested waterbody to an uninfested waterbody. Management efforts such as watercraft inspection and detection programs that attempt to intercept infected watercraft can help limit this type of spread, but optimizing the effectiveness of these programs under limited resources is complicated. Studies have looked at developing watercraft inspection and decontamination program strategies that focus on policy-specific objectives such as maximizing the number of infested watercraft interceptions. However, there is limited work that has considered the heterogeneous impact of protection efforts across different regions and waterbodies. Knowledge about this heterogeneity can highlight regions that would benefit the most from protection as well as regions that would require less effort to protect, e.g., areas with naturally unsuitable water quality for dreissenids. To this end, we construct a composite relative risk index (CRR) for watersheds within the Missouri River Basin, a region in the United States on the front line of dreissenid spread. The CRR uses a model that mirrors an expected value model but uses relative indexing as a proxy for the model components. The CRR incorporates a wide array of data sets to account for the direct and indirect damages from a potential infestation along with the risk of an infestation occurring. Our results suggest that the relative priority of a specific watershed—measured through CRR—can depend on whether we consider the entire Missouri River Basin or just the watersheds in the same state. This also indicates substantial state-level heterogeneity in the CRR. Another contribution is that the CRR index includes user-specified weights for certain parameters so that a user can adjust the relative importance of various factors to match their specific context. An accompanying web tool allows users to view the CRR results and adjust multiple parameters to see the resulting impacts on the CCR for watersheds in the Missouri River Basin.

Missouri River Basin↗

Undiscovered petroleum resources for the Woodford Shale and Thirteen Finger Limestone-Atoka Shale assessment units, Anadarko Basin

In 2010 the U.S. Geological Survey assessed undiscovered oil and gas resources for the Anadarko Basin Province of Colorado, Kansas, Oklahoma, and Texas. The assessment included three continuous (unconventional) assessment units (AU). Mean undiscovered resources for the (1) Devonian Woodford Shale Gas AU are about 16 trillion cubic feet of gas (TCFG) and 192 million barrels of natural gas liquids (MMBNGL), (2) Woodford Shale Oil AU are 393 million barrels of oil (MMBO), 2 TCFG, and 59 MMBNGL, and (3) Pennsylvanian Thirteen Finger Limestone-Atoka Shale Gas AU are 6.8 TCFG and 82 MMBNGL. The continuous gas AUs are mature for gas generation within the deep basin of Oklahoma and Texas. Gas generation from the Woodford Shale source rock started about 335 Ma, and from the Thirteen Finger Limestone-Atoka Shale AU about 300 Ma. Maturation results are based on vitrinite reflectance data, and on 1D and 4D petroleum system models that calculated vitrinite reflectance (R o ), and Rock-Eval and hydrous pyrolysis transformation (HP) ratios through time for petroleum source rocks. The Woodford Shale Gas AU boundary and sweet spot were defined mainly on (1) isopach thickness from well-log analysis and published sources; (2) estimated ultimate recoverable production from existing, mainly horizontal, wells; and (3) levels of thermal maturation. Measured and modeled Ro ranges from about 1.2% to 5% in the AU, which represents marginally mature to overmature for gas generation. The sweet spot included most of the Woodford that was deposited within eroded channels in the unconformably underlying Hunton Group. The Thirteen Finger Limestone-Atoka Shale Gas AU has no known production in the deep basin. This AU boundary is based primarily on the gas generation window, and on thickness and distribution of organic-rich facies from these mainly thin shale and limestone beds. Estimates of organic richness were based on well-log signatures and published data.

Open-File Report↗

Stochastic analysis of virus transport in aquifers

A large-scale model of virus transport in aquifers is derived using spectral perturbation analysis. The effects of spatial variability in aquifer hydraulic conductivity and virus transport (attachment, detachment, and inactivation) parameters on large-scale virus transport are evaluated. A stochastic mean model of virus transport is developed by linking a simple system of local-scale free-virus transport and attached-virus conservation equations from the current literature with a random-field representation of aquifer and virus transport properties. The resultant mean equations for free and attached viruses are found to differ considerably from the local-scale equations on which they are based and include effects such as a free-virus effective velocity that is a function of aquifer heterogeneity as well as virus transport parameters. Stochastic mean free-virus breakthrough curves are compared with local model output in order to observe the effects of spatial variability on mean one-dimensional virus transport in three-dimensionally heterogeneous porous media. Significant findings from this theoretical analysis include the following: (1) Stochastic model breakthrough occurs earlier than local model breakthrough, and this effect is most pronounced for the least conductive aquifers studied. (2) A high degree of aquifer heterogeneity can lead to virus breakthrough actually preceding that of a conservative tracer. (3) As the mean hydraulic conductivity is increased, the mean model shows less sensitivity to the variance of the natural-logarithm hydraulic conductivity and mean virus diameter. (4) Incorporation of a heterogeneous colloid filtration term results in higher predicted concentrations than a simple first-order adsorption term for a given mean attachment rate. (5) Incorporation of aquifer heterogeneity leads to a greater range of virus diameters for which significant breakthrough occurs. (6) The mean model is more sensitive to the inactivation rate of viruses associated with solid surfaces than to the inactivation rate of viruses in solution.

Water Resources Research↗

Assessing the accuracy of OpenET satellite-based evapotranspiration data to support water resource and land management applications

Remotely sensed evapotranspiration (ET) data offer strong potential to support data-driven approaches for sustainable water management. However, practitioners require robust and rigorous accuracy assessments of such data. The OpenET system, which includes an ensemble of six remote sensing models, was developed to increase access to field-scale (30 m) ET data for the contiguous United States. Here we compare OpenET outputs against data from 152 in situ stations, primarily eddy covariance flux towers, deployed across the contiguous United States. Mean absolute error at cropland sites for the OpenET ensemble value is 15.8 mm per month (17% of mean observed ET), mean bias error is −5.3 mm per month (6%) and r 2 is 0.9. Results for shrublands and forested sites show higher inter-model variability and lower accuracy relative to croplands. High accuracy and multi-model convergence across croplands demonstrate the utility of a model ensemble approach, and enhance confidence among ET data practitioners, including the agricultural water resource management community.

Nature Water↗

Evaluation of anal fin spines, otoliths, and scales for estimating age and back-calculated lengths of yellow perch in southern Green Bay

Southern Green Bay supports important fisheries for yellow perch Perca flavescens and valid estimates of age structure and growth are critical to effective management. Anal fin spines and scales are used by the Wisconsin Department of Natural Resources for age estimation, but these structures may provide lower precision and accuracy than otoliths. The primary objective of our assessment was to determine if age estimates, among-reader precision, and mean back-calculated total lengths (TLs) at age differed among scales, anal fin spines, and otoliths. Ages estimated from anal fin spines were more precise than scale ages, were as precise as otolith-based ages, and generally agreed with consensus ages estimated from sectioned otoliths. Relationships between TL and radii of calcified structures were linear for scales, anal spines, and otoliths along two different transects. Mean back-calculated TLs were generally similar between intercept-corrected direct proportion (ICDP) and linear regression (LR) models, but otolith-based direct proportion models (no intercept correction) generally provided higher back-calculated mean TLs at ages 1 and 2 than ICDP and LR models. Mean back-calculated TLs at age estimated from whole otoliths were higher than estimates for other structures; but differences among anal fin spines, scales, and sectioned otoliths were <10 mm. Our results suggest biologists have little to gain by switching to otoliths when assessing age structure and growth for this fast-growing yellow perch population with relatively few fish ≥age 6, but additional analyses are warranted for slower-growing perch populations in the Great Lakes where older fish are more common.

Wisconsin↗

Including long-term biological index performance in a multi-criteria Decision Support System

A Decision Support System (DSS) was developed for the reservoirs operated by the U.S. Bureau of Reclamation that incorporates biological resources in a palette of decision variables. A scoring technique was developed for the DSS to help to evaluate the long-term effects of proposed reservoir system operations on those variables. The biological component of the DSS was developed to help Bureau of Reclamation reservoir operators evaluate the effects of different scenarios of reservoir operations on a variety of water-related biological resources. In this DSS, Reclamation's Reservoir Operations Modeling System (ROMS) is linked to modules evaluating power production, flood control benefits, irrigation water deliveries, municipal and industrial water supplies, habitat for endemic fish communities, tailwater fisheries, nesting habitat for shorebirds, reservoir recreation, reservoir fisheries, and regeneration of riparian cottonwood forests. Operation scenarios generated in ROMS are scored for each decision variable by comparison to a target range of a decision variable for a reference location and time period. The score for a variable is calculated based on the ratio between the percent of time that target conditions are met under alternative operating conditions and under the reference condition, respectively. A scoring technique was developed that recognizes that under either natural or highly managed conditions the reference target is not met at all times. Higher scores are achieved for environmental decision variables by operations scenarios that approach natural seasonal and annual variability in habitat availability.

Conference Paper↗

Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: NLCD 2001 Imperviousness

This data set represents the mean percent impervious surface from the Imperviousness Layer of the National Land Cover Dataset 2001 (LaMotte and Wieczorek, 2010), compiled for every catchment of NHDPlus for the conterminous United States. The source data set represents imperviousness for the conterminous United States for 2001. The Imperviousness Layer of the National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Data Series↗

Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: NLCD 2001 Land Use and Land Cover

This data set represents the estimated area of land use and land cover from the National Land Cover Dataset 2001 (LaMotte, 2008), compiled for every catchment of NHDPlus for the conterminous United States. The source data set represents land use and land cover for the conterminous United States for 2001. The National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Data Series↗