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At least 19 recordsLinked to original sources
USGS2007

Data integration through region-based nominal filtering

Resource models integrating disparate nominal or class grid-cell data can be implemented by using spatial filters. Most modelling procedures do not adequately handle noise created during the process of merging and integrating multiple grid-cell data sets. Data integration can be best accomplished in an environment where ready access to statistical and database management systems support the reclassification of noise grid-cells. These systems provide access to functionality and information which support the design of the spatial filter and the evaluation of the result of the spatial filter and the resource model.

International Journal of Geographical Information ↗
USGS1991

Monitoring grasshopper and locust habitats in Sahelian Africa using GIS and remote sensing technology

Development programmes in Sahelian Africa are beginning to use geographic information system (GIS) technology. One of the GIS and remote sensing programmes introduced to the region in the late 1980s was the use of seasonal vegetation maps made from satellite data to support grasshopper and locust control. Following serious outbreaks of these pests in 1987, the programme addressed a critical need, by national and international crop protection organizations, to monitor site-specific dynamic vegetation conditions associated with grasshopper and locust breeding. The primary products used in assessing vegetation conditions were vegetation index (greenness) image maps derived from National Oceanic and Atmospheric Administration satellite imagery. Vegetation index data were integrated in a GIS with digital cartographic data of individual Sahelian countries. These near-real-time image maps were used regularly in 10 countries for locating potential grasshopper and locust habitats. The programme to monitor vegetation conditions is currently being institutionalized in the Sahel.

International Journal of Geographical Information ↗
USGS1993

Finite-element mesh generation from mappable features

A vector-based geographical information system (GIS) is used to generate a variably-sized triangular element finite-element mesh from mappable features. Important digitally-mapped features are automatically linked to nodes in the finite-element model, ensuring an efficient, virtually error-free alternative to the tedious process of mesh design and data-input preparation by other methods. The procedure permits the user to work interactively with graphically-displayed hydrologic information about the study area allowing different mesh sizes to be used as needed, based on hydrologic complexity. The mesh-generaiion programs are stand-alone macros within the GIS that set up the basic data defining a finite-element mesh for many different finite-element model programs.

International Journal of Geographical Information ↗
USGS1987

Design of a spatial data structure using the relational normal forms

In previous work, a relational data structure aimed at the exchange of spatial data between systems was developed. As this data structure was relational it was of first normal form, but compliance with the higher normal forms was not investigated. Recently, a new procedural method for composing fully normalized data structures from the basic data fields has been developed by H. C. Smith, as an alternative to the process of non-loss decomposition which is difficult to understand. Smith's method has been applied to data fields required to store points, lines and polygons in a chain-node spatial data model. When geographic domain, coverage layer and map are also considered, the procedure naturally leads to a catalogue model, needed for the exchange of spatial data. Although the method produces a fully normalized data structure, it is not as easy to identify which normal forms are responsible for the ultimate arrangement of the data fields into relations, but the benefits of these criteria for data base development also apply to spatial data structures and related ancillary data.

International Journal of Geographical Information ↗
USGS1994

Simulating and mapping spatial complexity using multi-scale techniques

A central problem in spatial analysis is the mapping of data for complex spatial fields using relatively simple data structures, such as those of a conventional GIS. This complexity can be measured using such indices as multi-scale variance, which reflects spatial autocorrelation, and multi-fractal dimension, which characterizes the values of fields. These indices are computed for three spatial processes: Gaussian noise, a simple mathematical function, and data for a random walk. Fractal analysis is then used to produce a vegetation map of the central region of California based on a satellite image. This analysis suggests that real world data lie on a continuum between the simple and the random, and that a major GIS challenge is the scientific representation and understanding of rapidly changing multi-scale fields.

International Journal of Geographical Information ↗
USGS2013

Accuracy of stream habitat interpolations across spatial scales

Stream habitat data are often collected across spatial scales because relationships among habitat, species occurrence, and management plans are linked at multiple spatial scales. Unfortunately, scale is often a factor limiting insight gained from spatial analysis of stream habitat data. Considerable cost is often expended to collect data at several spatial scales to provide accurate evaluation of spatial relationships in streams. To address utility of single scale set of stream habitat data used at varying scales, we examined the influence that data scaling had on accuracy of natural neighbor predictions of depth, flow, and benthic substrate. To achieve this goal, we measured two streams at gridded resolution of 0.33 × 0.33 meter cell size over a combined area of 934 m2 to create a baseline for natural neighbor interpolated maps at 12 incremental scales ranging from a raster cell size of 0.11 m2 to 16 m2 . Analysis of predictive maps showed a logarithmic linear decay pattern in RMSE values in interpolation accuracy for variables as resolution of data used to interpolate study areas became coarser. Proportional accuracy of interpolated models (r2 ) decreased, but it was maintained up to 78% as interpolation scale moved from 0.11 m2 to 16 m2 . Results indicated that accuracy retention was suitable for assessment and management purposes at various scales different from the data collection scale. Our study is relevant to spatial modeling, fish habitat assessment, and stream habitat management because it highlights the potential of using a single dataset to fulfill analysis needs rather than investing considerable cost to develop several scaled datasets.

Journal of Geographic Information System↗
USGS2004

The U.S. Geological Survey Library

Established in 1879, to build and organize a collection of scientific materials in the earth sciences, the U.S. Geological Survey (USGS) Library is the largest earth sciences collection in the world. The USGS Library System is managed by the Geographic Information Office (GIO), Information Policy and Services Office, and includes four libraries in Reston, Va., Denver, Colo., Menlo Park, Calif., and Flagstaff, Ariz. The library holds over one million books and journals, 700,000 maps, 370,000 microforms, 270,000 pamphlets, and 250,000 photographs. In addition to the four libraries managed by the GIO, the USGS has smaller libraries in other locations with collections closely related to the specialized research of their local USGS scientists. The USGS Library System supports the research of USGS scientists by providing access to worldwide information resources. While continuing to build and maintain the large collections of maps, books, and periodicals, the USGS Library system is evolving from a traditional library to a more "virtual library." USGS employees, wherever they are located, have desktop access to an increasing wealth of electronic resources 24 hours a day, 7 days a week.

Fact Sheet↗
USGS2021

Water quality associations and spatiotemporal distribution of the harmful alga Prymnesium parvum in an impounded urban stream system

The Jim Bertram Lake System consists of several stream impoundments within the City of Lubbock, Texas (USA). Baseflow in the upstream reach is dominated by nitrogen-rich-treated wastewater. While toxic blooms of Prymnesium parvum have occurred in this system for ∼2 decades during fall or winter-spring, little is known about water quality variables that facilitate blooms or the alga’s spatiotemporal distribution. Water quality associations were examined monthly over a 1-year period. Total phosphorus was largely below the detection limit, suggesting that the system is phosphorus limited. Algal abundance was low during the assessment period and associations were determined using multiple logistic regression. Algal incidence was negatively associated with temperature and positively with organic nitrogen and calcium hardness. These findings conform with earlier reports but positive associations with the latter two variables are noteworthy because they have not been widely confirmed. Spatiotemporal distribution was evaluated in fall and winter-spring of three consecutive years. Prymnesium parvum incidence was higher in the upper than in the lower reach, and detections in the lower reach occurred only after a dense bloom developed in the upper reach contemporaneously with stormwater runoff-associated flooding. Thus, the upstream reach is a major source of propagules for downstream sites. Because urban runoff is a source of phosphorus and its nitrogen: phosphorus ratio is lower than prevailing ratios in the upper reach, what triggered the bloom was likely relief from phosphorus limitation. This study provided water quality, geographic and hydrological indices that may inform prevention and control methods for harmful algae in nitrogen-enriched urban systems.

Texas↗
USGS2000

Space use of killdeer at a Great Basin breeding area

Wetland conservation efforts require knowledge of space use by a diversity of waterbirds. However, determining space use of animals requires intensive monitoring of individual organisms. Often, activity patterns during much of the annual cycle are neglected in analyses of home range and habitat use. From 1995-97, we monitored space use in a population of individually marked killdeer ( Charadrius vociferus ) that breed, and reside for a number of additional months each year, in the western Great Basin. We used linear distance measures and home range-area estimates, derived by fixed-kernel methods, to examine patterns of space use of adults prior to, during, and following nesting. Overall, killdeer used a local area of approximately 6 ha. Birds remained closer to nests while tending eggs than either before or after nesting, although extensive movements away from the nest were observed during all time periods. Females tended to move farther from nests than did males. Birds nesting farther from water bodies were generally observed at greater distances from nests than those nesting closer to shorelines during all time periods. Twenty-seven percent of individuals were observed greater than 1 km from nest locations, particularly during postnesting periods. During nesting periods, males were less likely to be observed at longer distances from nests than were females. There were no differences in home range size based upon sex, time period, or distance from water. We suggest that home range size may not always accurately measure differences in space use and that multiple measures, including distance from nests, should be considered. Understanding the sedentary nature of killdeer during much of the annual cycle and their intense use of local areas is important for making management decisions. Coupled with data on other shorebird species, this information also has broader implications for management of wetland systems by indicating large scale spatial and habitat requirements and the connectivity of geographically distinct habitat patches.

California, Idaho, Nevada, Oregon, Washington↗
USGS2013

Cost-effectiveness analysis of sandhill crane habitat management

Invasive species often threaten native wildlife populations and strain the budgets of agencies charged with wildlife management. We demonstrate the potential of cost-effectiveness analysis to improve the efficiency and value of efforts to enhance sandhill crane ( Grus canadensis ) roosting habitat. We focus on the central Platte River in Nebraska (USA), a region of international ecological importance for migrating avian species including sandhill cranes. Cost-effectiveness analysis is a valuation process designed to compare alternative actions based on the cost of achieving a pre-determined objective. We estimated costs for removal of invasive vegetation using geographic information system simulations and calculated benefits as the increase in area of sandhill crane roosting habitat. We generated cost effectiveness values for removing invasive vegetation on 7 land parcels and for the entire central Platte River to compare the cost-effectiveness of management at specific sites and for the central Platte River landscape. Median cost effectiveness values for the 7 land parcels evaluated suggest that costs for creating 1 additional hectare of sandhill crane roosting habitat totaled US $1,595. By contrast, we found that creating an additional hectare of sandhill crane roosting habitat could cost as much as US $12,010 for some areas in the central Platte River, indicating substantial cost savings can be achieved by using a cost effectiveness analysis to target specific land parcels for management. Cost-effectiveness analysis, used in conjunction with geographic information systems, can provide decision-makers with a new tool for identifying the most economically efficient allocation of resources to achieve habitat management goals.

Nebraska↗
USGS2002

A bibliography of terrain modeling (geomorphometry), the quantitative representation of topography: Supplement 4.0

Terrain modeling, the practice of ground-surface quantification, is an amalgam of Earth science, mathematics, engineering, and computer science. The discipline is known variously as geomorphometry (or simply morphometry), terrain analysis, and quantitative geomorphology. It continues to grow through myriad applications to hydrology, geohazards mapping, tectonics, sea-floor and planetary exploration, and other fields. Dating nominally to the co-founders of academic geography, Alexander von Humboldt (1808, 1817) and Carl Ritter (1826, 1828), the field was revolutionized late in the 20th Century by the computer manipulation of spatial arrays of terrain heights, or digital elevation models (DEMs), which can quantify and portray ground-surface form over large areas (Maune, 2001). Morphometric procedures are implemented routinely by commercial geographic information systems (GIS) as well as specialized software (Harvey and Eash, 1996; Köthe and others, 1996; ESRI, 1997; Drzewiecki et al., 1999; Dikau and Saurer, 1999; Djokic and Maidment, 2000; Wilson and Gallant, 2000; Breuer, 2001; Guth, 2001; Eastman, 2002). The new Earth Surface edition of the Journal of Geophysical Research, specializing in surficial processes, is the latest of many publication venues for terrain modeling. This is the fourth update of a bibliography and introduction to terrain modeling (Pike, 1993, 1995, 1996, 1999) designed to collect the diverse, scattered literature on surface measurement as a resource for the research community. The use of DEMs in science and technology continues to accelerate and diversify (Pike, 2000a). New work appears so frequently that a sampling must suffice to represent the vast literature. This report adds 1636 entries to the 4374 in the four earlier publications1. Forty-eight additional entries correct dead Internet links and other errors found in the prior listings. Chronicling the history of terrain modeling, many entries in this report predate the 1999 supplement. Coverage is representative from about 1800 through early–mid 2002. Papers increasingly are published exclusively or in duplicate on the Internet's World Wide Web; the dates given here for Web addresses (URLs) that lack a print publication indicate a Web site's last update or my last access of it. The bibliography is arranged alphabetically and thus is not readily summarized. This introduction cites about 500 entries, a third of them grouped under 24 morphometric topics, as a guide to the listing's contents. Continuing the practice of previous bibliographies in the series to provide more information on a few applications (see summary of past topics in Pike, 2000a), this report elaborates further on topographic data, putative new parameters, tectonic geomorphology/neo-orometry, biogeography, ice-cap morphometry, results from the Mars Global DEM, landslide-hazard mapping, terrain modeling as physics, Hack's law, and broad-scale computer visualization. The literature of some of these subjects is large, and none of the summaries is intended to more than introduce the topic and comment on some of the current contributions of terrain modeling. Closing the essay is a discussion of pre-1900 papers that trace the evolution of ridge-line and watercourse quantification by descriptive geometry, as well as comments on some new books and an on-line bulletin board.

Open-File Report↗
USGS2014

Geospatial considerations for a multiorganizational, landscape-scale program

Geospatial data play an increasingly important role in natural resources management, conservation, and science-based projects. The management and effective use of spatial data becomes significantly more complex when the efforts involve a myriad of landscape-scale projects combined with a multiorganizational collaboration. There is sparse literature to guide users on this daunting subject; therefore, we present a framework of considerations for working with geospatial data that will provide direction to data stewards, scientists, collaborators, and managers for developing geospatial management plans. The concepts we present apply to a variety of geospatial programs or projects, which we describe as a “scalable framework” of processes for integrating geospatial efforts with management, science, and conservation initiatives. Our framework includes five tenets of geospatial data management: (1) the importance of investing in data management and standardization, (2) the scalability of content/efforts addressed in geospatial management plans, (3) the lifecycle of a geospatial effort, (4) a framework for the integration of geographic information systems (GIS) in a landscape-scale conservation or management program, and (5) the major geospatial considerations prior to data acquisition. We conclude with a discussion of future considerations and challenges.

Journal of Map & Geography Libraries↗
USGS2010

Field note--Successful establishment of a phytoremediation system at a petroleum-hydrocarbon contaminated shallow aquifer--Trends, trials, and tribulations

We report the establishment of a mixed hybrid poplar ( Populus spp .) and willow ( Salix spp .) phytoremediation system at a fuel-contaminated site. Several approaches were used to balance competing goals of cost-effectiveness yet successful tree establishment without artificial irrigation or trenching. Bare root and unrooted cuttings were installed using either: (1) 1.2 m deep holes excavated with an 8 cm diameter auger using a direct-push rig and backfilled with the excavated, in situ soil; (2) 1.2 m deep holes created with a 23 cm diameter auger attached to a Bobcat rig and backfilled with clean topsoil from offsite; and (3) shallow holes between 15–30 cm deep that were created with a 1.3 cm diameter rod and no backfill. Tree mortality from initial plantings indicated contaminated zones not quantified in prior site investigations and remedial actions. Aquifer heterogeneity, underground utilities, and prior remediation infrastructure hampered the ability of the site to support a traditional experimental design. Total stem length and mortality were measured for all planted trees and were incorporated into a geographic information system. Planting early in the growing season, augering a larger diameter hole, and backfilling with clean, uncontaminated topsoil was cost effective and allowed for greater tree cutting growth and survival.

International Journal of Phytoremediation↗
USGS2007

Survey of geographical information system and image processing software

The Global Resource Information Database—a part of the United Nations Environment Programme—conducts a bi-annual survey of geographical information system (GIS) and image processing (IP) software. This survey makes information about software products available in developing countries. The 1993 survey showed that the number of installations of GIS, IP, and related software products increased dramatically from 1991 to 1993, mostly in North America and Europe.

International Journal of Remote Sensing↗
USGS2006

Inverse approaches with lithologic information for a regional groundwater system in southwest Kansas

Two practical approaches incorporating lithologic information for groundwater modeling calibration are presented to estimate distributed, cell-based hydraulic conductivity. The first approach is to estimate optimal hydraulic conductivities for geological materials by incorporating thickness distribution of materials into inverse modeling. In the second approach, residuals for the groundwater model solution are minimized according to a globalized Newton method with the aid of a Geographic Information System (GIS) to calculate a cell-wise distribution of hydraulic conductivity. Both approaches honor geologic data and were effective in characterizing the heterogeneity of a regional groundwater modeling system in southwest Kansas. ?? 2005 Elsevier Ltd All rights reserved.

Journal of Hydrology↗
USGS2007

United States‐Mexican border watershed assessment: Modeling nonpoint source pollution in Ambos Nogales

Ecological considerations need to be interwoven with economic policy and planning along the United States‐Mexican border. Non‐point source pollution can have significant implications for the availability of potable water and the continued health of borderland ecosystems in arid lands. However, environmental assessments in this region present a host of unique issues and problems. A common obstacle to the solution of these problems is the integration of data with different resolutions, naming conventions, and quality to create a consistent database across the binational study area. This report presents a simple modeling approach to predict nonpoint source pollution that can be used for border watersheds. The modeling approach links a hillslopescale erosion‐prediction model and a spatially derived sediment‐delivery model within a geographic information system to estimate erosion, sediment yield, and sediment deposition across the Ambos Nogales watershed in Sonora, Mexico, and Arizona. This paper discusses the procedures used for creating a watershed database to apply the models and presents an example of the modeling approach applied to a conservation‐planning problem.

Arizona, Sonoma↗
USGS2003

Development of hardwood seed zones for Tennessee using a geographic information system

For species that have no or limited information on genetic variation and adaptability to nonnative sites, there is a need for seed collection guidelines based on biological, climatological, and/or geographical criteria. Twenty-eight hardwood species are currently grown for reforestation purposes at the East Tennessee State Nursery. The majority of these species have had no genetic testing to define guidelines for seed collection location and can be distributed to sites that have a very different environment than that of seed origin(s). Poor survival and/or growth may result if seedlings are not adapted to environmental conditions at the planting location. To address this problem, 30 yr of Tennessee county precipitation and minimum temperature data were analyzed and grouped using a centroid hierarchical cluster analysis. The weather data and elevational data were entered into a Geographic Information System (GIS) and separately layered over Bailey's Ecoregions to develop a seed zone system for Tennessee. The seed zones can be used as a practical guideline for collecting seeds to ensure that the resulting seedlings will be adapted to planting environments.

Tennessee↗
USGS2008

Dispersal of Culex quinquefasciatus (Diptera: Culicidae) in a Hawaiian rain forest

Introduced mosquito-borne pathogens avian malaria (Plasmodium relictum Grassi and Feletti) and avian pox virus (Avipoxvirus) have been implicated in the past extinctions and declines of Hawaiian avifauna and remain significant obstacles to the recovery and restoration of endemic Hawaiian birds. Effective management of avian disease will require extensive mosquito control efforts that are guided by the local ecology of the vector Culex quinquefasciatus Say (Diptera: Culicidae). During October and November 1997 and September through November 1998 five mark-release-recapture experiments with laboratory-reared Cx. quinquefasciatus were conducted in a native rain forest on Hawaii Island. Of the overall 66,047 fluorescent dye-marked and released females, 1,192 (1.8%) were recaptured in 43-52 CO2-baited traps operated for 10-12-d trapping periods. Recaptured mosquitoes were trapped in all directions and at distances up to 3 km from the release site. The cumulative mean distance traveled (MDTs) over the trapping period ranged from a high of 1.89 km after 11 d (September 1998) to a low of 0.81 km after 11 d (November 1998). Released mosquitoes moved predominately in a downwind direction and they seemed to use forestry roads as dispersal corridors. Applying an estimated MDT of 1.6 km to a geographical information system-generated map of the Hakalau Forest National Wildlife Refuge clearly demonstrated that the effective refuge area could be reduced 60% by mosquitoes infiltrating into managed refuge lands. These findings should have significant implications for the design of future refuges and development of effective mosquito-borne avian disease control strategies.

Journal of Medical Entomology↗