Throughout many of the world’s mountain ranges snowpack accumulates during the winter and into the spring, providing a natural reservoir for water. As this reservoir melts, it fills streams and recharges groundwater for over 1 billion people globally. Despite its importance to water resources, our understanding of the storage capacity...
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...
Forested, mountain landscapes in the Pacific Northwest (PNW) are changing at an unprecedented rate, largely due to shifts in the regional climate regime. Documented climatic trends across the PNW include increasing wildfire frequency and intensity and an increasingly ephemeral snowpack, especially at moderate elevations. One relationship that has yet to...
California's water resources vary throughout the state owing to the regions varying topography, diverse climate, and the distribution of precipitation. Most of the state's precipitation falls over the northern coastal range and the western slopes of the Sierra Nevada Mountains. Winter snowpack that accumulates within these mountain basins serves as...
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Anne W. Nolin
California’s water resources vary throughout the state owing to the regions
The western United States is experiencing significant changes in wildfire and snow regimes as a result of warming temperatures. An amplification of wildfire activity and reduction in snow water equivalent, snow covered area, and earlier spring snowmelt are documented trends that are projected to continue into the future. With an...
Glaciers are effective reservoirs because they moderate variations in runoff and
supply reliable flow during drought periods. Thus, there needs to be a clear
understanding of the influence of glacier runoff at both the basin and catchment scale.
The objectives of this study were to quantify the late summer contributions...
As global temperatures continue to rise there has been an increase in forest fire frequency and severity. With larger areas of forest being burned it is increasingly important to understand how forest fires effect snow processes. Previous research shows that burned areas will accumulate more snow and that this snow...
Declines in glacier area and volume are widespread. These changes will have important hydrologic consequences since glaciers store tremendous amounts of fresh water and buffer seasonally low flows in many densely populated regions. In this thesis I focus on a region that is hydrologically vulnerable to glacier change, namely the...
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Anne W. Nolin
Declines in glacier area and volume are widespread. These changes will have
Shifting climate patterns in the Columbia River basin are affecting snow pack, and, as a result, stream flow throughout the region. In the Oregon Cascades, ever growing populations, and their associated activities, place increasing stress on an already over allocated hydrologic system. Political pressures, including the possibility of renegotiation or...
Rising global temperatures are having lasting effects on mountain snow environments in the form of diminishing snowpacks, shorter accumulation seasons, and shifts in meltwater timing. Seasonal snowpack is a vital source of water for natural and human systems. In the forested mountain landscapes of the Pacific Northwest seasonal snowmelt feeds...
Arctic-boreal regions are exhibiting the symptoms of profound ecological shifts as they experience pronounced warming. Wildlife in high-latitudes are one such harbinger of change, and their populations are undergoing range-shifts, declines, and extinctions in response to their rapidly altering habitats. As the circumpolar and boreal north is snow-covered for up...
Forest canopy cover presents a major challenge for remote sensing of fractional snow-covered area (ƒSCA). Snow cover is systematically underestimated where satellites sensors cannot penetrate the forest canopy. Current canopy adjustments scale observable ƒSCA with the vegetation fraction, assuming that snow cover distributions are similar between sub-canopy and open locations....
Snow water equivalent (SWE) is a critical measurement in hydrology and water resources management. Microwave remote sensing can estimate snow water equivalent (SWE). However, the algorithms used to estimate SWE require snow grain size information. Thus, determining snow grain size is pertinent to estimate SWE. Currently, there are several models...
As a result of a warming climate, subsequent declining snowpack, and a century of fire suppression, forest fires are increasing across the western United States. However, we still do not fully understand how forest fire effects snowpack energy balance, nor the volume and availability of snow melt and associated water...
In the mountains of the Western US, shifts in the timing and magnitude of snow water equivalent (SWE) over the past century are well documented and attributed to climate warming, but the magnitude of sensitivity depends on elevation. We modeled the spatial distribution of SWE and its sensitivity to climate...
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....
Mountain glaciers are receding worldwide with numerous consequences including changing hydrology and geomorphology. This study focuses on changes in glacier area on Mt. Hood, Oregon and Mt. Rainier, Washington where damaging debris flows have occurred in glaciated basins. Landsat imagery is used to map debris-free ice on a decadal time...
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,...
Cold-season storms are responsible for generating most of the snow that accumulates in mountainous watersheds across the western United States, but with overwhelming evidence of warming temperature trends, this seasonal snowpack is at risk for melt, The vast majority of snow trend studies utilize undifferentiated air temperature records – these...
In November of 2006 an intense rainstorm of tropical origin, known colloquially as the "Pineapple Express," inundated the Pacific Northwest region of the United States, initiating numerous periglacial debris flows on several of the
stratovolcanoes in the Cascade Range of Oregon and Washington. These debris flows rapidly aggrade channels, deposit...
The net mass balance fluctuations of Arctic and Sub-Arctic glaciers, north of 47.5°
North latitude, are described over a 45-year period from 1957 to 2002 using two
parameters derived from a gridded climatology reanalysis. Variability among 185
measured glaciers was represented according to two main components. The first
component represents...
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Anne W. Nolin
The net mass balance fluctuations of Arctic and Sub-Arctic glaciers, north of
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...
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Anne W. Nolin
An integrative method for monitoring glacier geometry change and mass balance
This study examines climatological influences, particularly that of snowpack, on tree growth and stable carbon isotope discrimination (Δ¹³C) from ~1980 to 2013 at two sites located in the upper reaches of the McKenzie River watershed of the Oregon Cascade Mountains. We tested the use of Δ¹³C values from latewood, corroborated...
Numerous studies have demonstrated that vegetation canopies affect snow
accumulation and ablation processes. In addition, estimates of remotely sensed snow
covered area can be biased by the presence of an overlying vegetation canopy.
Consequently, any attempts to measure, model, or map the distribution of snow in a
region with heterogeneous...
Remote sensing offers local, regional and global observations of seasonal snow, providing key information on snowpack processes. This brief review highlights advancements in instrumentation and analysis techniques that have been developed over the past decade. Areas of advancement include improved algorithms for mapping snow-cover extent, snow albedo, snow grain size,...
With improvements in both instrumentation and algorithms, methods for mapping terrestrial snow cover using optical remote sensing data have progressed significantly over the past decade. Multispectral data can now be used to determine not only the presence or absence of snow but the fraction of snow cover in a pixel....
From both social and environmental perspectives, water is the main connection between highland and lowland processes in mountain watersheds: Water flows downhill while human impacts flow uphill. For example, in the Oregon Cascades mountain range, geology, vegetation, and climate influence the hydrologic connections within watersheds. Geology determines which watersheds are...
The topics in this dissertation center on the snow processes that dominate mountain environments in the Western U.S. and Alaska, particularly in locations lacking long-term observational datasets or locales that are difficult to access in-person. Some are currently glacierized or have been glaciated in the recent past. Each of the...
Debris flow initiation is controlled by a complex interaction of geology, geomorphology, climate, and weather. In the Cascade Range of Pacific Northwest and mountainous areas globally, patterns of temperature and precipitation are being altered by climate change, which may in turn impact debris flow initiation. Temperature has increased and patterns...
As a result of warming temperatures and subsequently declining snowpacks, forest fires are increasing in frequency, intensity and extent across the western USA. In turn, forest fire disturbance affects patterns of snow accumulation and ablation by reducing canopy interception and modifying the snowpack energy balance. Following a 2011, high severity...
As a result of warming temperatures and subsequently declining snowpacks, forest fires are increasing in frequency, intensity and extent across the western USA. In turn, forest fire disturbance affects patterns of snow accumulation and ablation by reducing canopy interception and modifying the snowpack energy balance. Following a 2011, high severity...
As a result of warming temperatures and subsequently declining snowpacks, forest fires are increasing in frequency, intensity and extent across the western USA. In turn, forest fire disturbance affects patterns of snow accumulation and ablation by reducing canopy interception and modifying the snowpack energy balance. Following a 2011, high severity...
As a result of warming temperatures and subsequently declining snowpacks, forest fires are increasing in frequency, intensity and extent across the western USA. In turn, forest fire disturbance affects patterns of snow accumulation and ablation by reducing canopy interception and modifying the snowpack energy balance. Following a 2011, high severity...
As a result of warming temperatures and subsequently declining snowpacks, forest fires are increasing in frequency, intensity and extent across the western USA. In turn, forest fire disturbance affects patterns of snow accumulation and ablation by reducing canopy interception and modifying the snowpack energy balance. Following a 2011, high severity...
This study utilized long-term daily precipitation and snow-water equivalent (SWE) data derived from the Natural Resources Conservation Service’s Snow Telemetry Network (SNOTEL). All existing SNOTEL sites in the Olympic, Coast and Cascade ranges in Washington (n = 66) and Oregon (n = 52) and in the California Sierra Nevada (n...
Snowpack impacts and trends in precipitation regimes are investigated for the mountainous western United States from water years 1984–2016. The vast majority of snow trend studies utilize undifferentiated air temperature records, which do not segregate between days with and without precipitation and effectually dilute temperature trends relevant for snowpack monitoring....
Despite advances in the understanding of rain-on-snow storms and their resulting peak flows, little is understood about the response of snowmelt to precipitation and the relative timing of the two at multiple temporal scales within such events. To address this issue, climate, snowmelt, and streamflow data were analyzed for 26...
One fundamental concern in conservation biology is species abundance. For many taxa, however, these data are costly to obtain via direct observation and thus limited in geographic or temporal scope. Very high-resolution satellite imagery provides a means to address these limitations and provide remotely-sensed counts of large, colonial species. We...
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...
Many studies have looked at human settlements around individual volcanoes for
volcanic risk analyses, but few have done a comparative study to identify possible global
patterns. With the use of Landsat ETM+ data, this study identifies and compares urban
proximity to the Decade Volcanoes to identify volcanic settlement patterns. These...
The western slope of the Oregon Cascades receives up to 3500 mm of precipitation annually, with a majority falling between the months of November-March. In this maritime climate, the partitioning of precipitation between rain and snow is highly sensitive to temperature. Climate models generally agree that winter temperatures in the...
The interannual and intraseasonal variability of the North American monsoon is of great interest because a large proportion of the annual precipitation for Arizona and New Mexico arrives during the summer monsoon. Forty-one years of daily monsoon season precipitation data for Arizona and New Mexico were studied using wavelet analysis....
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...
The Forest Elevation Snow Transect (ForEST) project is a paired site elevational snow study. It is designed to measure how snow accumulates and ablates under different forest structures across an elevation range. The ForEST project has been ongoing since the winter of 2011-2012 within the McKenzie River Basin of the...