Satellite remote sensing is an effective tool for mapping snow covered area. However, complex terrain and heterogeneous land cover, due to vegetation and patchy snow cover, present challenges to snow cover mapping. This research compares two techniques for mapping snow covered area: binary and enhanced fractional snow cover mapping techniques....
Although the Pacific Northwest has the least proportion of non-native plant species in relation to other regions of North America, exotic species continue to spread into mountainous areas, including the Cascade Range. In a forested landscape, road networks can act as corridors for exotic plant dispersal and establishment, helping species...
The U.S. Forest Service on the Willamette National Forest currently employs the “Disturbed Water Erosion Prediction Project” (WEPP) model to determine potential suspended sediment delivery from timber harvests or other treatment scenarios given user-defined hillslope parameters. At the time of this study there was no known calibration or testing of...
The 2004 Indian Ocean tsunami raised concern among marine park managers and
hazard mitigation professionals about the significant impact of major coastal hazards
on marine park natural resources and ecosystems. The main reason for this concern is
the strong linkage of marine parks and their rich assortment of ecosystem services...
With 97% of the world’s freshwater resources stored underground, the connection between groundwater resources to the metrics of space, scale and time common to the geographic study of natural resources has not been extensively investigated by geographers. While nearly 240 transboundary aquifers are mapped across the world, a potential “tragedy”...
This dissertation uses a new methodological approach for an in-depth analysis of three cartographic works. Studies within the discipline of the history of cartography have followed various methodologies throughout the past century. This dissertation argues that in order to come to a more complete understanding of how maps were produced...
Floods are the most frequent and damaging of all types of natural disasters and annually affect the lives of millions all over the globe. However, researchers seem to have overlooked the fact that floods do not recognize national boundaries. Therefore, the phenomena of shared, or transboundary floods occurring in international...
Once considered the largest wetland in Central Asia, the Mesopotamian Marshlands of Southeastern Iraq have nearly disappeared. Various hydrological projects by the Iraqi government and dam construction in the region have nearly destroyed these once rich freshwater wetlands by over 90%. With the launching of Operation Iraqi Freedom recent attempts...
Invasion by exotic species can pose a major challenge for developing native
plant communities in wetland restoration projects. Often native plant communities
do not develop as anticipated in restored wetlands due to colonization by exotic
species that dominate the native plant community. Despite the time and expense to
restore wetlands,...
The objective of this study was to examine vegetation and vegetation change in Eritrea over a period from the mid 1980s to 2002 using satellite remote sensing, and relate observed changes to the recent history of drought and war in the region. Specific objectives were (1) to examine vegetation change...
Vegetation change is an important factor affecting the global carbon cycle, land-atmosphere interaction, and terrestrial ecology. The study of vegetation change on a global scale can be used to evaluate the impact of global climate change on terrestrial ecosystems. Satellite remote sensing can monitor vegetation change at the global scale,...
In 2001, an extreme drought tightened water supply in the Upper Klamath Basin (basin) while earlier increases in Endangered Species Act (ESA) water requirements for basin fish species that same year elevated demands. The Bureau of Reclamation (Reclamation), which manages irrigation water in parts of the basin located near the...
Geographical data and information are virtually unlimited in their quantity and are oftentimes scattered throughout a multitude of locations and stored in various formats on a wide variety of platforms. The Oregon Coast Geospatial Clearinghouse (OCGC) is a web-based central repository for metadata (data about data) corresponding to collected data...
Since their discovery in 1977, hydrothermal vent communities have offered scientists
a unique glimpse into a world that is supported primarily by chemically derived
energy rather than direct energy from the sun. Furthermore, studies of hydrothermal
vent ecosystems have introduced scientists to amazing animals that have successfully
adapted to living...
Spatialization is an innovative way to expand searching capabilities for a
marine/coastal reference database by using a metaphorical map framework to establish
a sense of place for non-spatial information. Spatializing the Catalogue of Oregon
Marine and Coastal Information (COMCI), a coastal reference database, enables the
marine and coastal resource community...
Ecoregions are regions of relative homogeneity with respect to specific
ecosystem variables (Bailey 1976; Omernik 1995). There has been an increasing
awareness that effective management of environmental resources must be undertaken
with an ecosystem perspective (Omernik, 1995). Ecoregions serve as a spatial
framework for assessing, managing, and monitoring ecosystems that...
An Internet Map Server (IMS) web site was constructed with the goal of
helping middle- through high-school students learn about ocean processes. This IMS was
developed in conjunction with the activities of the Science & Math Investigative
Learning Experience (SMILE) program, and for eventual use with the Oregon Coastal
Atlas,...
Web geographic information systems (GISs) and the Internet are now providing the connectivity necessary to support large-scale data access by a wide variety of users, including not just scientific researchers, but also policy-makers and marine resource managers. However, connectivity alone cannot ensure that those who need natural resource information will...
Mount Shasta, the southernmost stratovolcano in the Cascade Range (41.4°N) has
frequently produced lahars of various magnitudes during the last 10,000 yr. These include
large flows of eruptive origin, reaching more than 40km from the summit, and studies have
shown that at least 70 debris flows of noneruptive origin have...
Oregon is the number one producer of cool-season grass seed in the United
States. The center of the grass seed industry of Oregon is located in the Willamette
Valley, where about 470,000 acres of seed are grown. Innovative grass seed growers
of the area are beginning to implement precision agriculture...
Coral reefs around the world face numerous threats, both natural and
anthropogenic, including pollution, natural disasters, invasive species, habitat destruction,
and destructive methods of fishing. Given enough time, coral can recover from natural
disasters, but anthropogenic threats decrease corals’ ability to recover from things such as
hurricanes. It is difficult...
Overfishing of our national marine resources has degraded some of the most productive fishing regions in the Northwest Atlantic Ocean, most notably the Gulf of Maine and Georges Bank. These regions may have shifted from productive trophic regimes to a less than optimal state therefore reducing fishers’ catches and associated...
In response to anthropogenic pressures that have degraded habitat and put marine resources at risk (Leslie et al., 2003; Mumby et al., 2001; Puniwai et al., 2003), there has been a growing interest in the use of marine protected areas (MPAs) as a management tool to help slow, prevent or...
Geographic information systems (GISs) offer a useful tool for educators to teach students about local and global communities in various subjects. GISs are increasingly being used in K-12 education, but that growth is hindered due to many teachers’ limited access to time or resources necessary to adequately learn a GIS...
The purpose of this work is to broaden the theoretical foundations of interpolation of spatial data, by showing how ideas and methods from information theory and signal processing are applicable to the the work of geographers. Attention is drawn to the distinction between what we study and how we represent...
This study examined two neighborhoods in San Francisco with similar earthquake-induced ground failure history -- the Marina District and the South of Market Area (SoMa) -- in the aftermath of the 1989 Loma Prieta earthquake. The earthquake struck shortly after 5 pm on October 17th, 1989 and registered 6.9 in...
Although the timber industry was the major economic force in the lives of several generations of Oregon families, very little archaeological investigation has been done on the dozens of abandoned logging camps that are scattered throughout the forests of the Pacific Northwest. This project focuses on Camp 1, a 1920s...
This research provides details of water resource conflict and cooperation in Oregon between 1990 and 2004 by using an event database methodology. Events were concentrated in four of 18 basins. No basin accounted for more that 25% of the total water rights events, the most evenly distributed issue type. Overall...
Since 1935, France has introduced a set of strict national wine rules and regulations, the Appellation d’Origine Contrôlée (AOC). The AOC limits fraud and oversees quality control by basing the rules on terroir. High quality from terroir comes has both physical and cultural factors. Before 1935, France produced a variety...
Increasing population and land use decisions have had a negative effect on the aquatic ecosystems in the Willamette River Basin. One result is elevated temperatures in many of the Basin’s streams, which adversely affect the fish that live in these streams. There are several regulatory mechanisms in place to improve...
From a landscape ecology perspective, meadows are often seen as landscapes in
transition. Succession and change in meadows may be investigated by considering the
physical and anthropogenic factors that influence the landscape through time. What is
often unknown is how changes occur and how physical and anthropogenic factors
contribute to...
This study examined patterns and controls on 35-years of forest succession following logging in the 236 ha South Umpqua Experimental Forest within the Umpqua National Forest in southwestern Oregon. Prior to logging, the overstory in all three watersheds (~50% cover) was composed of Douglas-fir (30-40% cover), grand fir (2 to...
The rugged Cascade Range of central Oregon has been long regarded as an enigmatic, archaeological puzzle in the study of the Pacific Northwest's ancient past. While ethnographic and archaeological research in the adjacent northern Great Basin, Columbia Plateau and Willamette Valley have revealed a rich and ancient tapestry of Native...
Urban sprawl and the establishment of greenbelts to separate growing cities and towns has become a popular topic of conversation among land use professionals. Economists focus on urban growth in terms of land rents and have sought market solutions such as transfers and purchases of development rights to slow this...
Fire history and fire regime were interpreted from tree ring analysis of 4320 stumps at 178 sites in a 25 by 55 km area in the central Oregon Coast Range. A total of 27 fire episodes were identified in a 516 year period, with sizes estimated at 18 to 544...
The EPA’s Western Ecology Division (WED) had been accumulating geographic information system (GIS) data files for up to 20 years. There was no index or catalog for these files; locating data became more difficult over time. More that 4 Tb of data existed on numerous disk volumes in hundreds of...
Gathering empirical data on the factors and processes affecting bedload transport
in the field is difficult. This project conducted during the winter of 1996 field tested a new passive method of positively tracking individual particle movement. The project was conducted in Oak Creek, a gravel bedded stream, located in Corvallis,...
Geospatial technology is a rapidly growing and changing field. The term geospatial technology (GST) refers to geographical information systems (GIS), global positioning systems (GPS), and remote sensing (RS), all emerging technologies that assist the user in the collection, analysis, and interpretation of spatial data. The speed at which new fields...
Archaeological research in the lower Rogue River Basin between Galice Creek on the middle Rogue River and Gold Beach at the mouth of the Rogue has been minimal. Tlegetlinten (35CU59), a site located at the confluence of the Rogue and Illinois rivers is one of only three sites that have...
The Arc Marine data model is a generalized template to guide the implementation of geographic information systems (GIS) projects in the marine environment. Arc Marine developed out of a collaborative process involving research and industry shareholders in coastal and marine research. This template models and attempts to standardize common marine...
This study delineates and characterizes the distribution of montane meadows in the Willamette National Forest, identifies encroachment patterns in relation to topographic features and proximity to trees in the Chucksney-Grasshopper meadow complex, and examines tree species and age distributions in relation to distance from forest edges or isolated tree clusters...
Abstract Watershed-scale fate/transport modeling of contaminants is a tool that scientists and land managers can use to assess pesticide contamination to stream systems. The Catchment Modeling Framework (CMF) is a catchment-scale fate/transport modeling tool. It was developed to help scientists and land managers assess the effects of possible land-use decisions...
This study quantified the magnitude and timing of summer streamflow deficits in paired-watershed experiments in the Cascade Range of Oregon where mature and old-growth conifer forests were subjected to clearcutting, patch cutting, and overstory thinning treatments in the 1960s and 1970s. Hydrologic effects of clearcutting, small-patch cutting, and overstory thinning...
The geologic processes at work in American Samoa have long been a point of scientific debate. Of its numerous volcanic formations, few breach sea level, leaving an enormous proportion of their mass unavailable to traditional observation. This study aims to describe the deep sea geomorphology of American Samoa through compilation,...
The development of new technologies in science is a balance between existence and use. There are three versions of this duality – something is built and users come, something is built and users don’t come, and, finally, potential users show up but the ballpark has not yet been built. In...
An integrative method for monitoring glacier geometry change and mass balance is presented and applied to the Pacific Northwest, USA. Acting as a baseline for interpretation of future changes in glacier size and shape, we first derive a new inventory of regional glacier cover using remotely sensed data. To investigate...
According to USDA research, Oregon in 2002 had the highest rate of hunger and one of the highest rates of food insecurity in the United States. Although the margin of error involved with these statistics indicates that the state may not actually be at the top of the list, a...
Agriculture in the Willamette Valley, Oregon, has undergone continual change since the annual migrations of American pioneer farmers began to arrive in the early 1840's. The comparisons of data from each of the agricultural censuses of Oregon counties taken since 1850 confirms that change has been continual. The data revealed...
This dissertation primarily uses observations made during the 2005 Kashmir earthquake relief effort and available disaster literature to address problems that impede effective and efficient disaster preparedness and response. Three manuscripts form the body of the dissertation. The manuscripts are thematically linked through the Emergency Management Cycle. Each manuscript examines...
The lower Columbia River (LCR) riparian zone is rich in habitat diversity. However, the natural beauty and species diversity along the river have increasingly become affected by human activity. This study quantifies the areal extent and degree of wetlands change and associated causes along the LCR over the past 44...
An investigation of the 28-year climatic record of the Pacific Northwest in Oregon and Washington reveals the natural seasons, subseasons, and singularities evident in
the record. So much emphasis is placed on the topography and temperature of each station site that the term topothermal is introduced and defended. Statistical analyses...
Conflict and competition between outdoor recreational activities is increasing in intensity. Thus, management agencies and persons responsible for regulation of outdoor recreation areas have become increasingly concerned and are seeking appropriate means for amelioration of the intensifying problem.
This research was designed to seek better understanding of conflicts and incompatabilities...
A long standing problem has been the question of what maps to select for acquisition in a college map library. This thesis addresses
the problem and provides a carto-bibliography of basic maps for a map library. Following a brief review of pertinent literature, criteria for evaluation and selection of maps...
This research seeks to understand the influences of perception on land use around
the Mount Hood area of Oregon and evaluate how it has evolved over the past 4,000
years. The study addresses three specific questions:
1) How has the study area evolved over time into the modern landscape?
2)...
The analysis of material and energy exchange between the marine and terrestrial components of island ecosystems enables research into the impact of human population and land use on the health of coral reef habitat. Satellite and acoustic remote sensing technologies enable the collection of data to produce high resolution bathymetry...
In 1976, cultural resource technicians for the Rogue River National Forest located a prehistoric archaeological site, 35JA85, while performing a survey for the proposed J. Herbert Stone Nursery. The site, situated next to Jackson Creek in the Bear Creek Valley southwestern Oregon, is approximately three miles northwest of Medford, and...
Detailed phytosociological and physical data were gathered from six grass-fern balds in the Oregon Coast Range, Monmouth Peak, Grass Mountain, Prairie Peak, Roman Nose Mountain, Tyee Mountain, and Saddle Mountain. Panchromatic and color infrared air photography guided sampling within individual balds. The resultant floristic data was manipulated by a Braun-Blanquet...
Salmon management philosophies of the five salmon jurisdictions of the North Pacific (Japan, Russia, Canada, Alaska and the American Northwest) are examined in a historical and geographic context. The first objective is to provide a synthesis of salmon management experience across the North Pacific, to serve as a context for...
Knowledge of the timber production potential of a wildland area plays an important role in its wise management. For the past several years, resource managers of the United States Forest Service (USFS) at the Plumas National Forest have been concerned with the establishment of a procedure to evaluate timber production...
Few landscapes are immune to invasion by exotic plant species. The forested landscape in the western Cascade Range of Oregon appears to have some barriers to invasion, but the extensive road network provides a corridor and habitat for a suite of exotic species to enter and become established. This study...
The goal of this dissertation is to develop a chronology of the retreat of the southern margin of the Scandinavian Ice Sheet (SIS) during the late Pleistocene using surface exposure dating with cosmogenic 10Be. A sequence of seven prominent moraines in northeastern Europe (the Leszno Moraine, the Pomeranian Moraine, the...
This study illustrates geoarchaeological and paleoenvironmental approaches to the
investigation of an active margin coastal setting and provides examples of how information gleaned through examination of the stratigraphic record can reveal depositional signatures that provide insights into the geomorphic and tectonic forces active within coastal river basins. Three case studies...
The 18 May 1980 eruption of Mount St. Helens, emplaced between 3-3.5 billion cubic yards (bcy) of poorly sorted material ranging from silt to boulders, extending from river mile (RM) 25 to RM 38 in the upper North Fork Toutle River drainage. Sediment yields from the debris avalanche were calculated...
The diffusion of livestock guarding dogs into American agriculture provides an example of a developed nation adopting a peasant husbandry practice. Guarding dogs, associated with transhumant husbandry, have been used to protect sheep and other livestock from predators in Eurasia for 2000 years. However, they were virtually unknown by Anglo-American...
The study examines the effect of forest clearance on fire occurrences in major islands of Indonesia, namely: Borneo, Sumatra, Sulawesi and Irian Jaya. The working hypothesis of the study is that forest clearing is a necessary predecessor for extensive fires to occur. The study is designed to test the idea...
The Central Western Cascades and southeast Zaire were selected to test the distance decay and deforestation models on forest environments. Distance gradients included away from cities, and away from highways/roads. Two forest definitions were used in each study site. The "extended-forest" definition included areas with at least 30 percent canopy...
A per-segment classification system was developed to map aspen (Populus tremuloides) stands on Winter Ridge in central Oregon from remote sensing imagery. A 1-meter color infrared (CIR) image was segmented based on its hue and saturation values to generate aspen "candidates", which were then classified to show aspen coverage according...
The Willamette River and its floodplain in northwest Oregon have changed dramatically since European settlement. At one time, the river was a vast complex system of braided channels with a broad floodplain forest; it has now been simplified by channelization and dams, and the forest has been removed to support...
Nehalem Bay is located on the northern coast of Oregon in Tillamook County and contains approximately 243 ha of salt marsh. The Nehalem marshes occur as islands and land-tied units. West Island is the largest marsh island with an area of 82.9 ha and a maximum elevation of 3.079 m...
The main theme of this research is the application of geographic techniques in a study involving environmental monitoring and analysis of the associations between landscape and in-stream characteristics in the Pacific Northwest. The geographic techniques used in this study include (1) geographic information systems (GIS) coupled with statistical analysis and...
Stream management and design recommendations related to the Salmon Habitat Recovery Program in the Pacific Northwest require area specific information concerning appropriate methods of stream classification, bankfull discharge recurrence intervals, and hydraulic geometry relationships. New region specific information, based on field measurements, is presented here. The Rosgen Classification of Natural...
Oregon's beaches were designated public recreation areas by the 1967 Beach Law. These beaches and adjacent shorelands experience erosion and other hazards due to winter storm waves, weathering, and geologic instability. Sea cliff recession threatens older development and inadequate construction setbacks create hazards for new buildings. The typical hazard response...
Transcending human-defined political and administrative boundaries, the world's transboundary freshwater resources pose particularly challenging management problems. Water resource users at all scales frequently find themselves in direct competition for this economic and life-sustaining resource, in turn creating tensions, and indeed conflict, over water supply, allocation and quality. At the international...
Common resources are those for which rights to use, access and management have not been assigned. Common resources are frequently subject to over-exploitation, a phenomenon frequently referred to as the "tragedy of the commons," and solutions to commons problems are often sought through the establishment of rights regimes. An examination...
Throughout the 20th century, windthrow has affected forests in the Bull Run watershed, a 26,500 ha basin that is the principal water source for the city of Portland, Oregon. Windthrow from storms in 1973 and 1983 was mapped into a geographic information system (GIS) and compared to a 1931 windthrow...
This study traces the evolution of federal legislation to control water pollution in the period between 1935 and 1965. In this legislative history, the function of interest groups, the actions of congressmen and congressional committees, and the role of the President and the Executive Branch are reviewed. The water pollution...
A new era for partnerships between the US land grant university community and the US Agency for International Development began when Title XII legislation was enacted by the US Congress in 1975. Collaborative Research Support Programs emerged as an institutional innovation for the Agency and participating universities. This study uses...
This dissertation had three main objectives: 1) investigate the role of macro and micro geomorphology in determining lizard distributions in the Southern California Mojave Desert; 2) develop a spatially explicit lizard habitat model based upon geomorphology; and, 3) determine the interactive effects of geomorphology, roads, and land use in defining...
The navigability of the Columbia river permits Portland, located more than 100 miles inland from the Pacific Ocean, to function as the major port of the state of Oregon. It could be expected that the waterfront spanning the greatest share of the distance between Portland and the ocean should reflect...
Since the eruption of Mount St. Helens on May 18,1980, the rural communities within its shadow have experienced tremendous change. Tourism has become a highly visible and somewhat controversial component of change in the region, and its importance to local economies has increased. As a result of increased tourism development...
This study compared effects of human and natural wildfire disturbance on age class distribution and associated ecosystem properties of forests in a 15,670 km2 area of the western Cascades of Oregon. The study site is characterized by three forest use types: low elevation, intensively harvested private industrial lands; mid elevation...
The equilibrium response of Canadian vegetation to climate and climatic change was modeled at three organizational levels of the vegetation mosaic. The climatic parameters used as model drivers (i.e., snowpack, degree-days, minimum temperature, soil moisture deficit, and actual evapotranspiration) are components of climate that physiologically constrain the distribution of dominant...
Chameleon is a physics-based landscape modeling software system designed for modeling and simulations applications. Hyperspectral laboratory, field, and imaging spectrometer measurements are collected as empirical foundation data. Linear spectral unmixing is performed to decompose each image pixel into spectral endmembers. Mathematical manipulation of these fractional abundances and introduction of new...
This dissertation is concerned with the diminution of Oregon's Umatilla Indian Reservation over a 120 year period (1855-1975). Its objective is to show that the transfer of land from Indian to non-Indian ownership was most attributable to four casual factors:
(1) historical happenstance, including the passage of the Oregon Trail...
The effect of scale is an important concern in mapping of biodiversity. Scale issues include the grid cell size used for analysis and the effect of the extent and internal boundaries. Because biodiversity analysis involves combinatorial processes, determining the proper scale is data dependent and cannot be predicted from the...
This study characterizes the production of hypogeous sporocarps (broadly referred to as truffles) by ectomycorrhizal fungi within Douglas-fir dominated forests that are considered typical of those found on the west slopes of the central Cascade mountains in Oregon. Three aspects of sporocarp production are addressed: 1) the distribution of total...
An innovative regional planning institution, the Northwest Power Planning Council, was created to plan for two conflicting water-related resources, fish and wildlife and electrical power. The Council is responsible for regional planning but implementation of those plans is largely the responsibility of four federal agencies and four state governments. As...
The relationships between spectral reflectance in the Landsat Thematic Mapper (TM) bands and grass canopy variables were evaluated using in situ remote sensing techniques. Reflectance data were collected from experimental plots of annual ryegrass (Lolium multiflorum) and tall fescue (Festuca arundinacea) using a Barnes Modular Multiband Radiometer (MMR). The canopy...
In the American West keeping water instream to protect fish and wildlife, recreation, and water quality is in direct conflict with traditional water laws. While most western states have established instream flow protection programs, protection has been hindered by the basic tenet of the prior appropriation doctrine, first in time,...
Coastal wetlands provide basic linkages between productive estuarine and freshwater ecosystems. Throughout the Mexican coast, rates of wetland loss and change are unknown. This project developed wetland inventories for 1973 and 1991, including ecological functions and values, and human activities in and around the wetlands. Data was integrated by use...
This work examined the transformation of the concept of biodiversity into natural resource policies of the U.S. Agency for International Development and the World Bank through 1988. The study identified several groups as playing key roles in the transformation process. These were nongovernmental environmental organizations, the scientific community, and the...
A million acre tract of land within the "Big Bend" of the
Columbia River in south-central Washington became the locale for an
important public area planning experiment and geotechnic enterprise
in the late 1930's and early 1940's. The Columbia Basin Project
(CBP) of the Bureau of Reclamation was conceived to...
Water right marketing and transfers represent a resource reallocation
strategy that has received considerable attention in the American West owing to
nearly full appropriation of water in the region. Several western states permit
transfers between different uses and places of use thus allowing water to move to
higher-value economic activities....
This research focuses on the relationship between the emerging role of land trusts and
rapid growth and change in the West. Teton County, Idaho, Teton County, Wyoming, and
Sublette County, Wyoming, and each of their associated land trusts, are used as case studies. Each county has experienced varying levels of...
The Willamette River Basin, Oregon, viewed in terms of a cultural-ecological system, has been subject to three phases of cultural development: hunting and gathering, agrarian, and industrial-urban. Each population base has employed a technology to exploit the environment to the extent that its patterns of culture would allow. This technology...
The cultural influence of volcanic eruptions has been emphasized in the archaeological literature. However, the larger effects that Mount St. Helens volcanic eruptions had upon prehistoric populations in the Pacific
Northwest is not understood. This thesis asks questions of the archaeological and paleoenvironmental record of the Pacific Northwest to assess...
The Willamette River Greenway Program was created by an act of the Oregon Legislature in 1968 and modified by a second act in 1973.
The purpose of the program was to protect the natural environment of the river from approximately the foot of the Cascade Range near Eugene, north to...
Rapid, shallow soil mass movements (landslides) are examined for a 6,000 ha managed forest area in the Oregon Western Cascades. Analysis of landslide occurrence considers the physical characteristics and frequency, the influence of clearcutting and road construction, and some resource impacts. Nonparametric statistical methods
are employed to test the significance...