The Use of Geographical Information Systems to Enhance Environmental Decision Making at the Naval Air Weapons Station Point Mugu, California.

Abstract

The establishment of a formal military base at Point Mugu, California, was authorized by Congress in 1946 and signed by President Truman on May 24, 1946. Today, the Point Mugu Naval Air Weapons Station serves as an important Department of Defense (DOD) asset as a Sea Test Range. In addition to the primary mission of the base, Pt. Mugu has developed an active environmental program to preserve and protect important natural and cultural resources. To meet these important missions, Point Mugu has developed a Geographical Information Systems (GIS) to facilitate land use and environmental planning functions. As a result, ArcInfo was selected as one of the preeminent GIS tools for presenting complex environmental data and issues at the Point Mugu facility. The use of GIS is also important to the Installation Restoration (IR) Program administered by the Department of the Navy. The IR program has been authorized by the DOD to facilitate in the environmental evaluation, remediation, and potential restoration of hazardous-waste sites on DOD facilities. GIS and concomitant database development and design activities are critically important in the decision-management process. Consequently, a large body of IR environmental data are being incorporated into a holistic GIS that combines IR data with other natural and cultural thematic datasets. The overall goals of the GIS effort are (1) to reduce GIS development costs, (2) to accelerate the environmental decision-management process, and (3) to facilitate planning efforts between various Point Mugu divisions, Federal and State agencies, and Navy contractors.

Introduction

The Naval Air Weapons Station Point Mugu (NAWS) is located in Ventura County, California . Its mission is to support the Naval Air Warfare Center Weapons Division (NAWCWPNS). The mission of the NAWCWPNS is to be a full-spectrum Research and Development and Test and Evaluation (RDT&E) engineering center of excellence for weapon systems associated with air warfare, missiles, and missile subsystems; maintain and operate an air, land, and sea range complex; conduct aircraft weapons integration; and airborne electronic warfare systems. Fundamental to this mission is the requirement to conduct testing at the component, sub-system, and system level. The Sea Test Range provides the environment required to successfully execute Naval Air Warfare Center Weapons testing.

Located in the Pacific Ocean approximately 50 miles northwest of Los Angeles, the Sea Test Range represents DOD's largest, most heavily instrumented sea/air range. Extending 180 x 200 miles, it encompasses 36,000 square miles of controlled airspace and 125,000 square miles of instrumented airspace. Sea Test Range highly instrumented sites include several off-shore islands: San Nicolas Island, Santa Cruz Island, Santa Rosa Island, and various sites (e.g., Laguna Peak) along the California coast.

NAWS Point Mugu is situated on a coastal plain which contains 2,762 acres of intertidal flats, salt marsh, and the Mugu Lagoon. The Mugu Lagoon is home to diverse flora and fauna that may be impacted by activities at the facility. The Mugu Lagoon is one of the largest estuarine systems with a natural ocean entrance in Southern California. This ecosystem, although not pristine, is in relative good condition with tidal creeks, ponds, and a very active tidal regime. Historically, Mugu Lagoon was an important Chumash Indian settlement area during ethnohistoric times, but this was no longer the case when Franciscans moved most of the local population to Mission San Buenaventura. The area remained relatively depopulated during most of the nineteenth century, when cattle and sheep ranching were the primary concerns in southern California. However, ranching had no use for the marshes of Mugu Lagoon, so only the areas along the margins were exploited by the early ranchers. Ranching was supplanted in the early twentieth century by farming of lima beans and sugar beet cultivation. Direct use of the Mugu Lagoon salt marsh occurred in early the 1900s with the establishment of private hunting preserves to exploit the area's extensive waterfowl populations.

By the 1930s, more use was made of Mugu Lagoon as the Mugu Fish Camp became popular near the mouth of the lagoon. With the advent of the Pacific Coast Highway, the movie industry took advantage, and Mugu Lagoon became the set for two film productions--the best known of which was the 1938 film "The Real Glory" starring Gary Cooper and directed by Henry Hathaway (Swanson, 1994).

After the Japanese attack on Pearl Harbor in December 1941, the military presence at Pt. Mugu increased greatly. The Point Mugu Naval Complex was developed 1943-1945. In 1946, a runway was built to handle squadrons of pilotless aircraft, and the facility was designated the Naval Air Missile Test Center. In 1958, it became part of the Pacific Missile Range; in 1983 it was designated as the Pacific Missile Test Center (PMTC). In the early 1990s, it was incorporated into the NAWC Weapons Division and the Naval Air Station Point Mugu was designated as the NAWS and the PMTC was designated as the NAWCWPNS.

GIS Development

Over the past decade, a large amount of environmental, facilities, and associated landscape-level information had been collected at Point Mugu. Because of the complexity of the DOD mission and the large amount of spatially referenced data, a computer-based Geographical Information System (GIS), such as ArcInfo, which would to track, reference, document, and illustrate complex environmental issues in the context of a dynamically used landscape. Current state-of-the-art trends in natural resource management, coupled with recent advances in computer technology, require and permit the use of computer-based systems to model and quantify dynamic resource changes stemming from either natural ecosystem perturbations or human activities. Complex ecosystems and extensive data collection efforts to monitor environmental contaminants cannot be understood or cost effectively managed without an effective information management and analysis system.

The initial goals of the NAWS Point Mugu GIS project were to: (1) integrate existing information (in variable paper and report formats) from past ecological field studies and hazardous waste investigations to digital, spatially based information sets, such as CAD/CAM drawings; (2) develop a Digital Elevation Model (DEM) to help delineate and characterize wildlife habitats such as tidally influenced habitats (coastal embayment, tidal marsh, intertidal sand, and mudflats) and nontidal habitats (non-native grassland, coastal dunes, or fresh- to brackish-water marshes); (3) adapt current environmental based field studies and monitoring protocols, to the degree possible, for direct integration into a GIS; (4) develop GIS landscape models to better protect species, natural resources, ground and surface water; (5) accelerate the land-use decision making and permitting processes; and (6) avoid duplication of effort and associated database-development costs by promoting cooperative data-sharing mechanisms that could be used by various NAWS divisions, cooperating federal and state agencies, and contractors. The utilization of an ArcInfo GIS to institutionalize and integrate a wide variety of resource information from diverse vector, raster, and database sources will permit faster tabulation and analysis of research data to model ecosystem and landscape-level changes at Point Mugu.

It is hoped that the GIS will eventually become a primary management tool to collect, evaluate, and illustrate a wide variety of day-to-day, mission-based environmentally sensitive issues and concerns. To illustrate some of the significant benefits and complex issues associated with the initial development phases of the NAWS Point Mugu GIS, we present a few environmental program examples that require the use of basic thematic datasets such as administrative boundaries and roads. It should be stated that concurrent GIS activities by NAWS Point Mugu GIS cooperators and partners, while beneficial, add a management complexity to the program that is often overlooked. In this paper, we present a selection of GIS-based activities to illustrate the broad utility and power of GIS in two distinct, but environmentally related, programs that are required to adhere to regulatory constraints, policies, or guidelines established by federal and state regulatory agencies.

It should be emphasized that, while GIS cooperators have contractually different missions, there is a great need to share basic GIS thematic data. For example, DEM and related contour data are important to determine potential habitat, wetlands versus uplands, and develop contaminant flow models. To produce a good DEM surface model, data and expertise from three cooperators were used: (1) survey-based contour data from AutoCAD tiles were provided by the NAWS Pt. Mugu Public Works Division, (2) Mugu Lagoon bathymetric data and associated field notes were supplied by PRC, Environmental Management Inc., and (3) low- altitude airborne photography and an assortment of thematic data created from numerous historical sources were generated by the Advanced Resources Technology (ART) program and the National Biological Service's Cooperative Park Studies Unit (NBS), both of which are located at The University of Arizona (U/A).

Contours and Digital Elevation Models

The elevation contours for the base were derived from GPS ground surveys, photogrammetric techniques, and AutoCAD drawings from the 1993 Utility Technical Study. Originally, the contour lines were separated into index or intermediate contours, regular or depression contours. The elevation of each line was also recorded. Since the AutoCAD drawings were developed for graphic display and engineering purposes rather than for GIS spatial modeling, considerable editing was required before they could be used (ArcView of AutoCAD contours).

Several types of inconsistencies were encountered when converting the AutoCAD contours to usable ArcInfo form. The first problem was the numerous discontinuous arcs encountered in each AutoCAD file. When the original study was completed for graphic display, all elevation contour lines were interrupted at varying intervals, and the value of the elevation line was inserted as an annotation item. As such, a single elevation contour might be made up of dozens of disconnected lines separated by short label spaces. All of these spaces had to be closed to create continuous elevation contour lines. In addition, many contour lines stopped abruptly in space. Some of these lines were found to be continued on a different AutoCAD layer (curbs, bridges, sidewalks, etc.), and these lines were extracted from the appropriate layer and added into the contour coverage to complete the line. In other places, lines stopped at the edges of buildings or other structures. Wherever possible, these contour lines were continued around the low side of the building or structure, following the outline as closely as possible. The low side of the structure was selected since these contours will be used primarily for surface water flow modeling. As such, it would be important to know the lowest elevation which a building or structure might occupy, as that area would flood first.

Another problem encountered with the AutoCAD contour lines was errors made while assigning elevation values to the lines. Most contour lines were attributed with an elevation value which included up to four decimal places. The first step in correcting attributional errors was to round all values to whole numbers. After the line-closure errors were corrected, all contiguous arcs with the same elevation value were concatenated into single arcs. Following this step, many connecting-line segments were found with disparate elevation values. These all had to be corrected by hand. Errors ranged from lines with no values (incorrectly labeled zero) to lines with inordinately high values. In cases where the correct value was not obvious from the connecting and/or surrounding line values, spot point elevations were used to determine the correct elevation value.

After these corrections were completed on all 179 tiles of contours, they were appended into four-tile blocks. These blocks were then edgematched, and additional spatial corrections made where necessary to ensure continuity of contour lines from one tile to the next. All elevations were again checked, and connecting lines with the same elevation were concatenated where possible (due to size limitations). The four-tile blocks were then appended into four larger blocks, with the same editing process. Finally, the four large blocks were appended into one final coverage, which includes all 179 of the original AutoCAD tiles. This coverage includes the entire base plus some contours to the northeast of the Pacific Coast Highway leading up to Laguna Peak. Two versions of this contour coverage were created. One version follows contour lines across bridges and roadways, where they cross hydrologic features like drainage ditches, lagoons, or stream channels, creating an apparent barrier to water flow. The other version follows contour lines along the hydrologic features, and cuts through surface features such as roads and the runway. This coverage will be used for hydrologic modeling to allow water to flow across the surface unimpeded by features which the water actually flows under.

Both versions of the final topography for the main base will be used to create continuous surface models in ArcInfo. Additional contour lines outside the base boundary are being captured from USGS 7.5-minute quads; these contours will be used to square out the base area, which is necessary for raster-file creation. Once all contours are available, standard ArcInfo algorithms will be used to convert the contour-line coverages to a DEM. Hydrological and bathymetric coverages as well as survey control points will be used to ensure the proper placement of coastal and intertidal channels and other landscape features of importance. The creation of an accurate DEM is a critical first step in delineating important estuarine habitats. The second step, taken January 1-2, 1995, was to obtain high resolution, low altitude, airborne color imagery to help define the spatial extent of maximum and low tides, main lagoon channels, and the coastal "shore" line. Because of the complexity of the tidal channels, we are still in the process of extracting shape information from the imagery.

The DEM and recently acquired imagery in conjunction with soils, vegetation, and other thematic coverages help characterize and delineate critical wildlife habitats. This is especially true for tidally influenced habitats such as open water, intertidal sand and mudflats, tidal marshes, and salt panne, which comprise approximately 50% of the NAWS Point Mugu area. For example, with adequate surface information, a GIS analysis could easily determine potential hypersaline salt-panne habitats (created by a disturbance event) that are found along the upper edges of the tidally influenced areas and are inundated by only maximum high tides and occasional storm events. The DEM and contour-related data were also required by PRC Inc. for conducting spatial contaminant analyses, isopleth contaminant mapping, and for numerous surface-water modeling activities.

Habitat Delineation and Species Management

Each particular habitat type has specific structural components that unite the flora and fauna into an ecologically functioning unit. For example, marsh vegetation provides food, shelter, and reproductive areas for a variety of birds and small mammals. Likewise, tidally influenced sand and mudflats support dense communities of invertebrates that are important migratory and overwintering habitat, as well as, foraging habitat for a vast array of shorebirds. wadders, and waterfowl. In general, GIS coverages must be developed which represent various resident and migratory species' habitats for breeding, foraging, and species-specific sensitivity to habitat alteration or disturbance. Habitat, wildlife prediction, and wildlife utilization GIS models must be designed to accommodate species-specific spatial, temporal, and functional requirements as well as other landuse, regulatory, and mission-related factors.

For example, California brown pelicans may occasionally feed in the deeper waters of the Mugu Lagoon, roost on the sand and mudflats, or forage in open-water habitats, where they dive in search of pelagic fish species such as the Northern Anchovy (Engraulis mordax), Pacific Mackerel (Scomber japonicus), Topsmelt (Atherinops affinis), or the Pacific Sardine (Sardinops sagax). Western Snowy Plovers (Charadrius alexandrinus nivosus) are year-round residents that forage for sand flees and kelp flies along the wrack line, salt panne's, or exposed mudflats in the winter. Peregrine Falcons (Falco peregrinus anatum) are found seasonally in all habitat types that provide foraging habitat for its prey species (numerous shorebirds and waterfowl). Willets (Catoptrophorus semipalmatus), that probe their bills deeply into mudflats for prey, are typically spring and fall migratory visitors as well as overwinter residents to the Mugu Lagoon. All of the above birds occupy numerous ecological "niches" at varying spatial scales for a variety of reasons. Usually, the situation is even more complex because many functions, such as reproductive activities or migration, are dictated by time or process-dependent factors. Sometimes habitats may be directly affected for anthropogenic reasons. Furthermore, human activities such as vehicular trampling of sand dunes, when significant, must also be factored into GIS species-based models. Habitat alteration by "off-the-road" vehicles (or perhaps other activities) was believed to be one of the causes of the decline of the Globose Dune Beetle (Coelus globosus). This beetle is often found burrowed just beneath the surface of sand under native dune or sand hummock vegetation (Onuf, 1987). However, no "off-the-road or vehicular trampling of sand dune habitat ever occurred at NAWS Point Mugu nor is it allowed. Many of Onuf's (1987) reported findings are in error because his limited study focussed only on a small portion of the Mugu Lagoon (Keeney, 1996 personal communication). The spatial scale of the analysis has important ecological and management consequences. The need for standardized inventory and monitoring programs, established well documented field protocols, adequate GPS positioning and sampling, and complete coverage metadata are critical underlying factors that must be considered in the GIS database design and development process.

Special management emphasis must also be given to rare, threatened, or endangered species that have been given specific legal protection under various Federal and State acts such as the Endangered Species Act of 1973, the Marine Mammal Protection Act of 1972, the National Environmental Policy Act of 1969, the Coastal Zone Management Act of 1972, the Migratory Bird Treaty Act of 1918, and the California Endangered Species Act (Table 1). For example, federally and state-listed Salt Marsh Bird's-Beak (Cordylanthus maritimus maritimus) occur in numerous large colonies on the southwest portion of Mugu Lagoon, typically at the extreme upper limit of the tidal salt-marsh plant community.

TABLE 1: Listed or Protected Species at NAWS Point Mugu

The Salt Marsh Bird's-Beak is an unusual element in the salt marsh-ecosystem because it is a hemiparasitic annual that commonly occurs with associated co-dominant species such as pickelweed (Salicornia spp.) and salt grass (Distichlis spicata). According to Vanderweir (1984), hemiparasitism "permits Salt Marsh Bird's-beak to flourish in the hot, dry conditions of summer when most other annuals have completed their life cycles." Some of these colonies are unusual, in that they appear to be thriving in areas that are inundated by freshwater seeps originating from nearby, artificially maintained duckponds. In addition, plant size and productivity at Pt. Mugu may be constrained by pest and fungal diseases and beetle and caterpillar predation (Murphy, Newman, and Dow, 1981). Each year since 1980, estimates of total colony cover, density, vigor, growth, and other attributes have been collected by numerous researchers using various protocols. More recently, we have been using Global Positioning Systems (GPS), a laptop computer, and Geolink field-mapping software to delineate plant colonies. Last November, we mapped hundreds of colonies representing three separate years. Colony cover (polygon shape) was determined by walking around several thousand color-coded survey flags placed in position earlier by field crews. By using GPS/GEOLINK mapping techniques and background coverages, we were able to map three years of polygon data in three days. In addition, GPS post- processing allowed us to differentially correct the position data to sub-meter accuracies. When reprojected using an ArcInfo project "AML" routine, the colony data overlaid existing GIS coverages perfectly. In prior years, colony positions were estimated visually and subsequently hand-drawn on a variety of photocopied or photoreduced base maps. The net result, using GPS and Geolink field-mapping techniques, was increased productivity with fewer processing and interpretative steps required to produce a final map. The ability to visualize background coverages and imagery in the field while collecting descriptive attribute data necessary for the development of species-specific, GIS-based ecological models is an enormous advantage in discovering new spatial relationships and detecting map errors. With PC-ArcInfo and ArcView for Windows installed in the computer, GIS capabilities are available in the field.

Currently, we are working toward more elaborate, ecologically sound, GIS-based species models and composite "sensitivity" surfaces to assist management in the environmental decision-making process. To do this effectively, species-specific GIS coverages and related ecological information must be tightly integrated with rule-based models, regulatory constraints, and management priorities in an efficient, user-friendly interface that supports interactive queries.

GIS and Hazardous Waste Management

The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA) established a series of programs for the cleanup of hazardous-waste disposal and spill sites nationwide. Hazardous waste has been generated at many Navy bases through such activities as shipyard or airfield maintenance operations, fuel management, munitions handling, and fire training. Some common chemicals of potential concern include waste oils, jet and automobile fuels, solvents and cleaners, paints, pesticides, battery acid, and poly-chlorinated biphenyls (PCBs). In accordance with CERCLA and SARA, the Navy established the Installation Restoration (IR) Program to identify, assess, and remediate contamination at past hazardous-waste spill and disposal sites from Navy activities.

Several sites at NAWS Point Mugu were identified for remedial investigation (RI) under the IR program, and PRC Environmental Management, Inc. (PRC), was contracted to conduct the RI. RI activities at these sites included evaluating historical data; designing and installing groundwater monitoring wells; characterizing sites using chemical analyses from groundwater, soil, sediment, and surface-water samples; measuring and tracking surface water and ground water levels; performing land and bathymetric surveys; and conducting an ecological assessment at the facility. The volume and complexity of the data, and the variety of data sources and formats, necessitated development of a comprehensive data-management program. ArcInfo, Oracle, ArcView, and ArcCAD provide important capabilities needed for data management, data integration, data interpretation, graphic visualization, predictive modeling, and community relations at NAWS Point Mugu. PRC developed a data-management system to store, manipulate, and present the large volume of data collected in the RI program and to accommodate future data that contractors may collect at NAWS Point Mugu. Database management using ArcInfo GIS software in conjunction with the Oracle relational database-management system (RDBMS) facilitates integration, analysis, and display of these diverse types of data on a single platform.

The GIS has been used for attribute display, spatial analysis, contour or isopleth mapping, surface modeling, statistical interfacing, and pre-processing and post-processing for surface- water modeling. In addition, ArcView is being used to develop query stations to provide both the Navy and PRC technical staff with direct access to the data in a graphic format. At NAWS Point Mugu, there are more than 80 monitoring wells and 400 soil, sediment, and surface-water sampling locations resulting from the IR program. Each round of soil, sediment, or groundwater sampling may yield chemical data for as many as 160 specific compounds, as well as extensive supporting chemistry used to meet the quality assurance/ quality-control objectives of the program. Use of a powerful RDBMS such as Oracle allows the storage and maintenance of complex data in a highly normalized form. The implementation of stored constraints and triggers in Oracle facilitates data integrity checking during data upload. Hash clustering is used to enhance data-retrieval performance. Furthermore, ArcInfo's database integrator allows integration, interpretation, and analysis of these data in a spatial context.

The database-management system was also designed for compatibility with the ArcInfo GIS database developed by The University of Arizona (UA) and the National Biological Service (NBS) for the Natural Resources Department at NAWS Point Mugu. Spatial data created by the UA/NBS team, including base boundaries, roads, topographic contour lines, and ecological data, were incorporated into PRC's ArcInfo system. This cooperative effort between the Navy, Federal agencies, and Navy contractors ensures the use of identical datums and projections while avoiding the duplication of effort, and expense, for the development of a comprehensive database for NAWS Point Mugu.

The NAWS Point Mugu RDBMS and ArcInfo spatial-analysis tools are used for a variety of environmental restoration activities. For instance, the GIS is commonly used to determine and display the nature and extent of contaminants of concern in the groundwater, surface water, soil, and sediment. RDBMS queries can be constructed quickly to determine the frequency of particular chemicals, and the spatial distributions of constituents of concern can be displayed. NAWS Point Mugu includes approximately 2,762 acres of lagoon and tidal flats which are important ecosystems subject to disturbance by military activity. The Navy is trying to preserve and manage this ecosystem while trying to maintain the Navy's missions; such as weapons-system testing and naval air operations. A hydrodynamic model was developed for the NAWS Point Mugu Lagoon to evaluate flow within the lagoon system for engineering control purposes and to assess potential contaminant fate and transport. Data generated from the model, such as flow direction and velocity at various tidal cycles, can be exported into MOSS format and then can be imported into ArcInfo. Using sample chemistry from the IR database, the spatial distribution of contaminants can be determined and integrated with the hydrodynamic model to evaluate potential transport of contaminants in the lagoon system. Because seasonal fluctuations could significantly alter the results, the comparison may be conducted periodically to determine seasonal trends or patterns.

Without the spatial analysis and visualization power of ArcInfo, this project would have required extensive manual map overlay and computer-aided drafting support. ArcInfo facilitated data analysis will make repeated processing simple for each subsequent measurement event.

Future Directions

The database management system developed for NAWS Point Mugu is highly effective for supporting environmental management activities and facilitates data integration with other agencies. However, we are taking additional measures to increase utilization and efficiency in data compilation and analysis. Data generated from field investigations frequently require manual entry or reformatting of pertinent data collected at the time of sampling. Due to the complexity of the field measurements and sample tracking, essential data such as unique sample identifiers, requested analyses, and survey benchmarks may occasionally be omitted from the package submitted to the database-management team. This is compounded by concurrent sampling by multiple field teams and separate contractors. PRC is currently developing pen-based computer digital field forms that prompt the field technician for key pieces of information and then directly transpose the field data into digital format suitable for upload to the main database tables. The forms will be filled out during the day's field activities by the field team, and data will be electronically transferred by modem to the database coordinator on a predetermined schedule. If data are missing or incorrectly entered, the database coordinator can notify the field team immediately, and request the missing information. Without this technology, the database specialists periodically have to retrace events or contact field personnel collecting the data, often months after the sampling event is over, to track down and enter all pertinent information into the database and GIS. The pen-based computers are designed to function under field conditions. This technology should make data collection easier for field personnel, and increase efficiency and data completeness for database-management tasks. Laptop computers and GPS technologies are also being incorporated into field systems to collect and review database attributes. To facilitate data sharing and communications between GIS cooperators, Internet e-mail services and FTP sites have been established, as well as a distributed computing environment. Consequently, it is now possible for project participants to use ArcView and/or ArcInfo to view or manipulate remote coverages that are posted on the network Unix-based file servers.

Conclusions

The most important benefit of this project has been the consolidation, coordination, and integration of spatially based information into a computer system that permits interactive management queries and ecological modeling on a landscape level. With GIS and related technologies, vast arrays of seemingly non-related data can be combined in significant ways to address numerous institutional issues quickly. The adoption of standard inventory and monitoring protocols, GPS-Geolink field-mapping techniques, standardized electronic field forms, and network-compatible GIS software such as ArcInfo, ArcView for Windows, and a robust RDBMS such as Oracle accelerates the decision-making process.

Acknowledgments

We would like to express our appreciation to Lynne Stauss (Naval Field Engineering Services Center, Port Hueneme, CA) and Nadine Spertus (Naval Facilities Engineering Command, Southwest Division, San Diego, CA). This project was also made possible by support and funding received from NAWS Point Mugu and the DOD Legacy Resources Management Program, Naval Facilities Engineering Command Western Division (Mr. Richard Rugen). We also express our gratitude to: Motorola of Scottsdale, Arizona, who generously donated the Global Positioning System receivers used on this project; and to GeoResearch Inc. of Billings, Montana, for the donation of the GeoLink Automated Mapping and GPS related software. With state-of-the-art tools and software this project was done much more efficiently and cost effectively.

References Cited

Murphy, T.G., J.C. Newman, and R.J. Dow. 1981. Ecology and Natural History of Salt Marsh Bird's Beak (Cordylanthus maritimus spp. maritimus) in Mugu Lagoon. In Biennial Mugu Lagoon/San Nicolas Island Ecological Research Symposium, ed. R.J. Dow, 187-190. Pacific Missile Test Center, Naval Air Station, Point Mugu, California.

Onuf, C.P. 1987. The Ecology of Mugu Lagoon, California: An Estuarine Profile. U.S. Fish and Wildlife Service, Biological Report 85-7.15. 122 pp.

Swanson, M.T. 1994. From Spanish Land Grants to World War II: An Overview of Historic Resources at the Naval Air Weapons Station, Point Mugu, California, Statistical Research Inc. Technical Report #50, 107 pp.

Vanderweir, J. 1984, Annotated Checklist of Vascular Plants, Pacific Missile Test Center, Point Mugu, California. Unpublished report.

About the authors

Michael R. Kunzmann is an ecologist for the U.S. National Biological Service Cooperative Park Studies Unit (NBS-CPSU) and is a participant in the Advanced Resources Technology Program at the University of Arizona. Correspondence may be sent to: NBS-CPSU, 125 Biological Sciences East, The University of Arizona, Tucson, AZ. 85721, phone (520) 621-7282, Internet email: MRSK@npscpsu.srnr.arizona.edu

Thomas W. Keeney is an ecologist for the NAWS Point Mugu. Correspondence may be sent to: Environmental Division, Point Mugu Naval Air Weapons Station, Point Mugu, CA. 93042-5000, phone (805) 989-3808, email: Keeneyt@mugu.navy.mil

Katy Norris is a GIS Program Manager for PRC Environmental Management Inc.. Correspondence may be sent to: PRC Environmental Management Inc., 600 University Street - Suite 800, Seattle, Washington 98101, phone (206) 624-2692, Internet email: knorris200@aol.com

Anne Leibold, GIS Specialist (Denver) for PRC, Environmental Management Inc. Correspondence may be sent to: PRC, Environmental Management Inc. 1099 18th Street, Suite 1960, Denver, Colorado 80202, phone (303) 295-1101, Internet email: Leibola@prcemi.com

Barbara J. Ball is GIS Specialist, in the Advanced Resources Technology Program in the School of Renewable Natural Resources (SRNR). Correspondence may be sent to: ART Program (SRNR), 203 Biological Sciences East, The University of Arizona, Tucson, AZ, 85721., or by Internet email: Barb@nexus.srnr.arizona.edu