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At least 559 records · Page 31Linked to original sources

Fire management of California shrubland landscapes

Fire management of California shrublands has been heavily influenced by policies designed for coniferous forests, however, fire suppression has not effectively excluded fire from chaparral and coastal sage scrub landscapes and catastrophic wildfires are not the result of unnatural fuel accumulation. There is no evidence that prescribed burning in these shrublands provides any resource benefit and in some areas may negatively impact shrublands by increasing fire frequency. Therefore, fire hazard reduction is the primary justification for prescription burning, but it is doubtful that rotational burning to create landscape age mosaics is a cost effective method of controlling catastrophic wildfires. There are problems with prescription burning in this crown-fire ecosystem that are not shared by forests with a natural surface-fire regime. Prescription weather conditions preclude burning at rotation intervals sufficient to effect the control of fires ignited under severe weather conditions. Fire management should focus on strategic placement of prescription burns to both insure the most efficient fire hazard reduction and to minimize the amount of landscape exposed to unnaturally high fire frequency. A major contributor to increased fire suppression costs and increased loss of property and lives is the continued urban sprawl into wildlands naturally subjected to high intensity crown fires. Differences in shrubland fire history suggest there may be a need for different fire management tactics between central coastal and southern California. Much less is known about shrubland fire history in the Sierra Nevada foothills and interior North Coast Ranges, and thus it would be prudent to not transfer these ideas too broadly across the range of chaparral until we have a clearer understanding of the extent of regional variation in shrubland fire regimes.

Environmental Management↗

Population momentum across vertebrate life histories

Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally has a larger effect on long-term population size for organisms with long generation times than for organisms with short generation times. However, patterns between population momentum and generation time varied across taxonomic groups and according to the life history parameter that was changed. Our findings indicate that momentum may be an especially important aspect of population dynamics for long-lived vertebrates, and deserves greater attention in life history studies. Further, we discuss the importance of population momentum in natural resource management, pest control, and conservation arenas. ?? 2006 Elsevier B.V. All rights reserved.

Ecological Modelling↗

Maine and Landsat

Maine is a place of rocky coastlines, of rich maritime history symbolized by lighthouses dotting the ocean bluffs, and of wondrous nature areas like the granite and spruce islands of Acadia National Park. But Maine is a place of changes, too. Climate variability has brought the state heavier and more frequent rainstorms. Summers are hotter and drier. With sea levels rising, severe storms increasingly cause floods that damage property and infrastructure. In the coming decades, Landsat satellite systems can be valuable tools in monitoring those changes and their effects on the land and in the water.

Maine↗

Massachusetts and Landsat

Massachusetts is the seventh smallest U.S. State in land area, but its size is surpassed by its contributions to U.S. history and the economy, its academic and medical expertise, and its natural features. The Atlantic Ocean to the east gives the “Bay State” more than 1,500 miles of coastline that were important in past fishing and maritime trade industries and in the tourism industry of today for destinations such as Boston, Cape Cod, Nantucket, and Martha’s Vineyard. Forests cover roughly 60 percent of the State, which owns 315,000 acres of forests in parklands, reserves, and woodlands. Massachusetts celebrates many strengths, but its strengths can be vulnerable to environmental change. A robust population of 7 million translates to a density of more than 800 people per square mile; in Boston, the density rises to more than 18,000 people per square mile. Urban temperature hotspots can increase health risks to residents. Although the whims of wind and water have long reshaped coastlines, sea-level rise and severe storms can amplify coastal effects. In forests, changes in precipitation can provide more favorable conditions for invasive species. Here are several ways Landsat has benefited the residents of Massachusetts.

Massachusetts↗

The decline of North American freshwater fishes

North America has a broad array of freshwater ecosystems because of the continent's complex geography and geological history. Within a multitude of habitats—that include streams, large rivers, natural lakes, springs, and wetlands—rich assemblages of fishes reside, representing diverse taxonomic groups with unique ecological requirements. They face an unprecedented conservation crisis. 1 In the last few decades, the proportion of inland fishes of North America, which are considered imperiled or extinct, increased from 20 to 40%. 2 Although extinctions have occurred, many species and populations are declining in range size and abundance. The fish biota of the continent as a whole remains diverse; however, we can take action to stem any further declines.

ActionBioscience↗

Synthesis of thirty years of surface water quality and aquatic biota data in Shenandoah National Park: Collaboration between the US Geological Survey and the National Park Service

The eastern United States has been the recipient of acidic atmospheric deposition (hereinafter, “acid rain”) for many decades. Deleterious effects of acid rain on natural resources have been well documented for surface water (e.g., Likens et al. 1996; Stoddard et al. 2001), soils (Bailey et al. 2005), forest health (Long et al. 2009), and habitat suitability for stream biota (Baker et al. 1993). Shenandoah National Park (SNP) is located in northern and central Virginia and consists of a long, narrow strip of land straddling the Blue Ridge Mountains (Figure 1). The park’s elevated topography and location downwind of the Ohio River valley, where many acidic emissions to the atmosphere are generated (NSTC 2005), have made it a target for acid rain. Characterizing the link between air quality and water quality as related to acid rain, contaminants, soil conditions, and forest health is a high priority for research and monitoring in SNP. The US Geological Survey (USGS) and SNP have had a long history of collaboration on documenting acid rain effects on the park’s natural resources, starting in 1985 and continuing to the present (Lynch and Dise 1985; Rice et al. 2001, 2004, 2005, 2007; Deviney et al. 2006, 2012; Jastram et al. 2013).

Virginia↗

Temporal variation in capture efficiency underrepresents spring out-migrating Bull Trout in a trap-and-haul program

Trap-and-haul programs can maintain connection among habitats for migratory salmonids in fragmented systems. To conserve diversity within and among life history strategies, downstream trap and transport of juvenile salmonids could ideally mimic the natural, underlying out-migration dynamics of the population. A two-way trap-and-haul program is implemented in the lower Clark Fork River, Montana, to conserve adfluvial Bull Trout Salvelinus confluentus. We used PIT technology to assess whether downstream trapping efforts are effectively capturing variation in the out-migration dynamics of juvenile Bull Trout in Graves Creek, a key spawning and rearing tributary in the system. We tagged 821 juvenile Bull Trout in Graves Creek and used these tagged Bull Trout in conjunction with stationary PIT antennas to monitor out-migration and evaluate efficiency of the downstream trapping program. Capture efficiency in Graves Creek varied substantially from autumn to spring, with 89–96% of autumn out-migrating Bull Trout captured and 5–10% of spring out-migrating Bull Trout captured. Overall, we found that Bull Trout transported during the autumn out-migration periods generally reflect the natural out-migration dynamics of the population; however, Bull Trout that out-migrate in the spring are currently underrepresented in the downstream transport program. By understanding the underlying out-migration dynamics of the Bull Trout population in Graves Creek, management of the downstream trapping efforts can focus on minimizing potential selection for or against out-migrants based on timing and age at out-migration. Minimizing selection will conserve variation within the adfluvial life history strategy and therefore maximize resilience of the adfluvial Bull Trout populations.

Idaho, Montana↗

Annealing history limits for inhomogeneous, native gold grains as determined from Au-Ag diffusion rates

Quantitative study of intrinsic inhomogeneities in native gold grains from three deposits in the western United States has revealed concentration profiles that represent the integrated sum of natural diffusion plus original chemical heterogeneity. By assuming that measured natural concentration gradients result solely from diffusion, upper limits may be placed on the temperature-time annealing history of the gold nuggets. This assumption focuses on the end member case in which an initial step-discontinuity is assumed between measured extremes of concentration.Concentration changes of up to 30 weight percent Ag indicate probable deposition temperatures of less than 300 degrees C for electrum from Copper Basin, Arizona, and Alder Gulch, Montana. The gold in the Homestake, South Dakota, deposit probably was formed at temperatures well under 400 degrees C.In support of this study, new data for interdiffusion in the Au-Ag system were obtained from a series of annealing experiments followed by electron microprobe analysis. The interdiffusion coefficient, D, in the range 10 (super -10) to 10 (super -17) cm 2 sec (super -1) was determined from measured profiles across synthetic alloy pairs held at eight fixed temperatures from 297 degrees to 799 degrees C, for periods ranging from 32 hours to 730 days.

Arizona, Montana, South Dakota↗

Death Valley regional ground-water flow system, Nevada and California -- hydrogeologic framework and transient ground-water flow model

A numerical three-dimensional (3D) transient ground-water flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Energy programs at the Nevada Test Site and at Yucca Mountain, Nevada. Decades of study of aspects of the ground-water flow system and previous less extensive ground-water flow models were incorporated and reevaluated together with new data to provide greater detail for the complex, digital model. A 3D digital hydrogeologic framework model (HFM) was developed from digital elevation models, geologic maps, borehole information, geologic and hydrogeologic cross sections, and other 3D models to represent the geometry of the hydrogeologic units (HGUs). Structural features, such as faults and fractures, that affect ground-water flow also were added. The HFM represents Precambrian and Paleozoic crystalline and sedimentary rocks, Mesozoic sedimentary rocks, Mesozoic to Cenozoic intrusive rocks, Cenozoic volcanic tuffs and lavas, and late Cenozoic sedimentary deposits of the Death Valley Regional Ground-Water Flow System (DVRFS) region in 27 HGUs. Information from a series of investigations was compiled to conceptualize and quantify hydrologic components of the ground-water flow system within the DVRFS model domain and to provide hydraulic-property and head-observation data used in the calibration of the transient-flow model. These studies reevaluated natural ground-water discharge occurring through evapotranspiration and spring flow; the history of ground-water pumping from 1913 through 1998; ground-water recharge simulated as net infiltration; model boundary inflows and outflows based on regional hydraulic gradients and water budgets of surrounding areas; hydraulic conductivity and its relation to depth; and water levels appropriate for regional simulation of prepumped and pumped conditions within the DVRFS model domain. Simulation results appropriate for the regional extent and scale of the model were provided by acquiring additional data, by reevaluating existing data using current technology and concepts, and by refining earlier interpretations to reflect the current understanding of the regional ground-water flow system. Ground-water flow in the Death Valley region is composed of several interconnected, complex ground-water flow systems. Ground-water flow occurs in three subregions in relatively shallow and localized flow paths that are superimposed on deeper, regional flow paths. Regional ground-water flow is predominantly through a thick Paleozoic carbonate rock sequence affected by complex geologic structures from regional faulting and fracturing that can enhance or impede flow. Spring flow and evapotranspiration (ET) are the dominant natural ground-water discharge processes. Ground water also is withdrawn for agricultural, commercial, and domestic uses. Ground-water flow in the DVRFS was simulated using MODFLOW-2000, a 3D finite-difference modular ground-water flow modeling code that incorporates a nonlinear least-squares regression technique to estimate aquifer parameters. The DVRFS model has 16 layers of defined thickness, a finite-difference grid consisting of 194 rows and 160 columns, and uniform cells 1,500 m on each side. Prepumping conditions (before 1913) were used as the initial conditions for the transient-state calibration. The model uses annual stress periods with discrete recharge and discharge components. Recharge occurs mostly from infiltration of precipitation and runoff on high mountain ranges and from a small amount of underflow from adjacent basins. Discharge occurs primarily through ET and spring discharge (both simulated as drains) and water withdrawal by pumping and, to a lesser amount, by underflow to adjacent basins, also simulated by drains. All parameter values estimated by the regression are reasonable and within the range of expected values. The simulated hydraulic heads of the final calibrated transient model gener

Scientific Investigations Report↗

Petrology and geochronology of crustal xenoliths from the Bering Strait region: Linking deep and shallow processes in extending continental crust

Petrologic, geochemical, and metamorphic data on gneissic xenoliths derived from the middle and lower crust in the Neogene Bering Sea basalt province, coupled with U-Pb geochronology of their zircons using sensitive high-resolution ion microprobe-reverse geometry (SHRIMP-RG), yield a detailed comparison between the P-T-t and magmatic history of the lower crust and magmatic, metamorphic, and deformational history of the upper crust. Our results provide unique insights into the nature of lithospheric processes that accompany the extension of continental crust. The gneissic, mostly maficxenoliths (constituting less than two percent of the total xenolith population) from lavas in the Enmelen, RU, St. Lawrence, Nunivak, and Seward Peninsula fields most likely originated through magmatic fractionation processes with continued residence at granulite-facies conditions. Zircon single-grain ages (n ??? 125) are interpreted as both magmatic and metamorphic and are entirely Cretaceous to Paleocene in age (ca. 138-60 Ma). Their age distributions correspond to the main ages of magmatism in two belts of supracrustal volcanic and plutonic rocks in the Bering Sea region. Oscillatory-zoned igneous zircons, Late Cretaceous to Paleocene metamorphic zircons and overgrowths, and lack of any older inheritance in zircons from the xenoliths provide strong evidence for juvenile addition of material to the crust at this time. Surface exposures of Precambrian and Paleozoic rocks locally reached upper amphibolite-facies (sillimanite grade) to granulite-facies conditions within a series of extension-related metamorphic culminations or gneiss domes, which developed within the Cretaceous magmatic belt. Metamorphic gradients and inferred geotherms (??30-50 ??C/km) from both the gneiss domes and xenoliths aretoo high to be explained by crustal thickening alone. Magmatic heat input from the mantle is necessary to explain both the petrology of the magmas and elevated metamorphic temperatures. Deep-crustal seismic-reflection and refraction data reveal a 30-35-km-thick crust, a sharp Moho and refl ective lower and middle crust. Velocities do not support a largely mafic (underplated) lower crust, but together with xenolith data suggest that Late Cretaceous to early Paleocene maficintrusions are likely increasingly important with depth in the crust and that the elevated temperatures during granulite-facies metamorphism led to large-scale flow of crustal rocks to produce gneiss domes and the observed subhorizontal refl ectivity of the crust. This unique combined data set for the Bering Shelf region provides compelling evidence for the complete reconstitution/re-equilibration of continental crust from the bottom up during mantle-driven magmatic events associated with crustal extension. Thus, despite Precambrian and Paleozoic rocks at the surface and Alaska's accretionary tectonic history, it is likely that a significant portion of the Bering Sea region lower crust is much younger and related to post-accretionary tectonic and magmatic events. ?? 2009 The Geological Society of America.

Special Paper of the Geological Society of America↗

The periodic structure of the natural record, and nonlinear dynamics

Concepts of cyclicity in geology have involved many famous protagonists in the history of Earth sciences. Early in this century, sophisticated theories of terrestrial rhythms had been formulated by such pioneers as T. C. Chamberlin [1909], R. T. , Chamberlin [1914], Barrell [1917], Stille [1924], Joly [1925, 1930], Holmes [1926], Lull [1929], Schuchert [1932], Grabau [1940], and Umbgrove [1939 a,b, 1947] (see the review by Williams [1981]). The physical chemist S. Arrhenius [1908] had also formulated a general hypothesis for cosmological origins of terrestrial phenomena. Khain [1964] later proposed resonances between terrestrial and cosmological rhythms, and McCrea [1975] and Williams [1975] summarized evidence of galactic correlations with glaciation.

Eos, Transactions, American Geophysical Union↗

Monitoring amphibians in Great Smoky Mountains National Park

Amphibian species have inexplicably declined or disappeared in many regions of the world, and in some instances, serious malformations have been observed. In the United States, amphibian declines frequently have occurred even in protected areas. Causes for the declines and malformations probably are varied and may not even be related. The seemingly sudden declines in widely separated areas, however, suggests a need to monitor amphibian populations as well as identify the causes when declines or malformations are discovered. In 2000, the President of the United States and Congress directed Department of the Interior (DOI) agencies to develop a plan to monitor the trends in amphibian populations on DOI lands and to conduct causes of declines. The DOI has stewardship responsibilities over vast land holdings in the United States, much of it occupied by, or potential habitat for, amphibians. The U.S. Geological Survey (USGS) was given lead responsibility for planning and organizing this program, named the Amphibian Research and Monitoring Initiative (ARMI). Authorization carried the mandate to set up a national amphibian monitoring program on Federal lands, to develop the sampling techniques and biometrical analyses necessary to determine status and trends, and to identify possible causes of amphibian declines and malformations. The biological importance of Great Smoky Mountains National Park has been recognized by its designation as an International Biosphere Reserve. As such, it is clearly the leading region of significance for amphibian research. Although no other region shares the wealth of amphibians as found in the Great Smokies (31 species of salamanders, and 13 of frogs), the entire southern and mid-section of the Appalachian Mountain chain is characterized by a high diversity of amphibians, and inventories and monitoring protocols developed in the Smokies likely will be applicable to other Appalachian National Park Service properties. From 1998 to 2001, USGS biologists carried out a pilot inventory and monitoring research project in Great Smoky Mountains National Park. A variety of inventory, sampling, and monitoring techniques were employed and tested. These included wide-scale visual encounter surveys of amphibians at terrestrial and aquatic sites, intensive monitoring of selected plots, randomly placed small-grid plot sampling, litterbag sampling in streams, monitoring nesting females of selected species, call surveys, and monitoring specialized habitats, such as caves. Coupled with information derived from amphibian surveys on Federal lands using various other techniques (automated frog call data loggers, PVC pipes, drift fences, terrestrial and aquatic traps), an amphibian monitoring program was designed to best meet the needs of biologists and natural resource managers after taking into consideration the logistics, terrain, and life histories of the species found within Great Smoky Mountains National Park. This report provides an overview of the Park’s amphibians, the factors affecting their distribution, a review of important areas of biodiversity, and a summary of amphibian life history in the Southern Appalachians. In addition, survey techniques are described as well as examples of how the techniques are set up, a critique of what the results tell the observer, and a discussion of the limitations of the techniques and the data. The report reviews considerations for site selection, outlines steps for biosecurity and for processing diseased or dying animals, and provides resource managers with a decision tree on how to monitor the Park’s amphibians based on different levels of available resources. It concludes with an extensive list of references for inventorying and monitoring amphibians. USGS and Great Smoky Mountains National Park biologists need to establish cooperative efforts and training to ensure that congressionally mandated amphibian surveys are performed in a statistically rigorous and biologically meaningful manner, and that amphibian populations on Federal lands are monitored to ensure their long-term survival. The research detailed in this report will aid these cooperative efforts.

North Carolina, Tennessee↗

Climatology, hydrology, and simulation of an emergency outlet, Devils Lake basin, North Dakota

Devils Lake is a natural lake in northeastern North Dakota that is the terminus of a nearly 4,000-square-mile subbasin in the Red River of the North Basin. The lake has not reached its natural spill elevation to the Sheyenne River (a tributary of the Red River of the North) in recorded history. However, geologic evidence indicates a spill occurred sometime within the last 1,800 years. From 1993 to 1999, Devils Lake rose 24.5 feet and, at the present (August 2000), is about 13 feet below the natural spill elevation. The recent lake-level rise has caused flood damages exceeding $300 million and triggered development of future flood-control options to prevent further infrastructure damage and reduce the risk of a potentially catastrophic uncontrolled spill. Construction of an emergency outlet from the west end of Devils Lake to the Sheyenne River is one flood-control option being considered. This report describes the climatologic and hydrologic causes of the recent lake level rise, provides information on the potential for continued lake-level rises during the next 15 years, and describes the potential effectiveness of an emergency outlet in reducing future lake levels and in reducing the risk of an uncontrolled spill. The potential effects of an outlet on downstream water quantity and quality in the upper Sheyenne River also are described.

South Dakota↗

Remote sensing sensors and applications in environmental resources mapping and modeling

The history of remote sensing and development of different sensors for environmental and natural resources mapping and data acquisition is reviewed and reported. Application examples in urban studies, hydrological modeling such as land-cover and floodplain mapping, fractional vegetation cover and impervious surface area mapping, surface energy flux and micro-topography correlation studies is discussed. The review also discusses the use of remotely sensed-based rainfall and potential evapotranspiration for estimating crop water requirement satisfaction index and hence provides early warning information for growers. The review is not an exhaustive application of the remote sensing techniques rather a summary of some important applications in environmental studies and modeling.

Sensors↗

Natural and anthropogenic landscape factors shape functional connectivity of an ecological specialist in urban Southern California

Identifying how natural (i.e., unaltered by human activity) and anthropogenic landscape variables influence contemporary functional connectivity in terrestrial organisms can elucidate the genetic consequences of environmental change. We examine population genetic structure and functional connectivity among populations of a declining species, the Blainville's horned lizard ( Phrynosoma blainvillii ), in the urbanized landscape of the Greater Los Angeles Area in Southern California, USA. Using single nucleotide polymorphism data, we assessed genetic structure among populations occurring at the interface of two abutting evolutionary lineages, and at a fine scale among habitat fragments within the heavily urbanized area. Based on the ecology of P. blainvillii , we predicted which environmental variables influence population structure and gene flow and used gravity models to distinguish among hypotheses to best explain population connectivity. Our results show evidence of admixture between two evolutionary lineages and strong population genetic structure across small habitat fragments. We also show that topography, microclimate, and soil and vegetation types are important predictors of functional connectivity, and that anthropogenic disturbance, including recent fire history and urban development, are key factors impacting contemporary population dynamics. Examining how natural and anthropogenic sources of landscape variation affect contemporary population genetics is critical to understanding how to best manage sensitive species in a rapidly changing landscape.

California↗

Inference of population structure and demographic history in Taxodium distichum , a coniferous tree in North America, based on amplicon sequence analysis

PREMISE OF THE STUDY: Studies of natural genetic variation can elucidate the genetic basis of phenotypic variation and the past population structure of species. Our study species, Taxodium distichum , is a unique conifer that inhabits the flood plains and swamps of North America. Morphological and ecological differences in two varieties, T. distichum var. distichum (bald cypress) and T. distichum var. imbricarium (pond cypress), are well known, but little is known about the level of genetic differentiation between the varieties and the demographic history of local populations. METHODS: We analyzed nucleotide polymorphisms at 47 nuclear loci from 96 individuals collected from the Mississippi River Alluvial Valley (MRAV), and Gulf Coastal populations in Texas, Louisiana, and Florida using high-throughput DNA sequencing. Standard population genetic statistics were calculated, and demographic parameters were estimated using a composite-likelihood approach. KEY RESULTS: Taxodium distichum in North America can be divided into at least three genetic groups, bald cypress in the MRAV and Texas, bald cypress in Florida, and pond cypress in Florida. The levels of genetic differentiation among the groups were low but significant. Several loci showed the signatures of positive selection, which might be responsible for local adaptation or varietal differentiation. CONCLUSIONS: Bald cypress was genetically differentiated into two geographical groups, and the boundary was located between the MRAV and Florida. This differentiation could be explained by population expansion from east to west. Despite the overlap of the two varieties’ ranges, they were genetically differentiated in Florida. The estimated demographic parameters suggested that pond cypress split from bald cypress during the late Miocene.

American Journal of Botany↗

Average kinship within bighorn sheep populations is associated with connectivity, augmentation, and bottlenecks

Understanding the influence of population attributes on genetic diversity is important to advancement of biological conservation. Because bighorn sheep ( Ovis canadensis ) populations vary in size and management history, the species provides a unique opportunity to observe the response of average pairwise kinship, inversely related to genetic diversity, to a spectrum of natural and management influences. We estimated average pairwise kinship of bighorn sheep herds and compared estimates with population origin (native/indigenous/extant or reintroduced), historical minimum count, connectivity, and augmentation history, to determine which predictors were the most important. We evaluated 488 bighorn sheep from 19 wild populations with past minimum counts of 16–562 animals, including native and reintroduced populations that received 0–165 animals in augmentations. Using the Illumina High Density Ovine array, we generated a dataset of 7728 single nucleotide polymorphisms and calculated average pairwise kinship for each population. Multiple linear regression analysis determined that connectivity between populations via dispersal, greater number of animals received in augmentations, and greater minimum count were correlated with lower average pairwise kinship at the population level, and whether the population was extant or reintroduced was less important. Thus, our results indicated that genetic isolation of populations can result in increased levels of inbreeding. By determining that natural and human-assisted gene flow were likely the most important influences of average pairwise kinship at the population level, this study can serve as a benchmark for future management of bighorn sheep populations and aid in identifying populations of genetic concern to define priorities for conservation of wild populations.

Montana, Wyoming↗

Atlas of natural hazards in the Hawaiian coastal zone

The purpose of this report is to communicate to citizens and regulatory authorities the history and relative intensity of coastal hazards in Hawaii. This information is the key to the wise use and management of coastal resources. The information contained in this document,we hope,will improve the ability of Hawaiian citizens and visitors to safely enjoy the coast and provide a strong data set for planners and managers to guide the future of coastal resources. This work is largely based on previous investigations by scientific and engineering researchers and county, state, and federal offices and agencies. The unique aspect of this report is that, to the extent possible, it assimilates prior efforts in documenting Hawaiian coastal hazards and combines existing knowledge into a single comprehensive coastal hazard data set. This is by no means the final word on coastal hazards in Hawaii. Every hazardous phenomenon described here, and others such as slope failure and rocky shoreline collapse, need to be more carefully quantified, forecast, and mitigated. Our ultimate goal, of course, is to make the Hawaiian coast a safer place by educating the people of the state, and their leaders, about the hazardous nature of the environment. In so doing, we will also be taking steps toward improved preservation of coastal environments, because the best way to avoid coastal hazards is to avoid inappropriate development in the coastal zone. We have chosen maps as the medium for both recording and communicating the hazard history and its intensity along the Hawaiian coast.Two types of maps are used: 1) smallscale maps showing a general history of hazards on each island and summarizing coastal hazards in a readily understandable format for general use, and 2) a large-scale series of technical maps (1:50,000) depicting coastal sections approximately 5 to 7 miles in length with color bands along the coast ranking the relative intensity of each hazard at the adjacent shoreline.

Hawaii↗