No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

The goals of this thesis are to assess the use of remote sensmg and Geographic Information Systems (GIS) to map and classify coastal wetland habitat along the entire coast of eastern Georgian Bay, Lake Huron. Little mapping has been completed in this region where there is potentially the largest concentration of coastal wetlands in the Great Lakes. In chapter 1, we developed a method that uses high-resolution IKONOS imagery (1-m resolution) with an object-based approach to classify wet meadow vegetation in these coastal wetlands, and assessed the transferability of classification rulesets developed independently for 3 different satellite scenes. We showed that 4 different classes (meadow/shrub, emergent, senescent vegetation, and rock) can be mapped with an overall accuracy of 76%. When classification rulesets developed for individual scenes were transferred to other scenes without gathering additional field information for those scenes, we found a difference in accuracy of about 5%. This difference in accuracy is acceptable considering the trade-off in costs associated with field surveys. We recommend that managers use IKONOS in fine-scale habitat mapping and that rulesets only be developed for geographically distinct areas. In Chapter 2, we conducted a study to test the feasibility of using this mapping approach to complete the field surveys required in Ontario Wetland Evaluation System (OWES). In addition, we determined empirically how inclusion of vegetated deep-water habitat below 2 m can affect relevant OWES component scores, because the current system does not consider any vegetated habitat below 2 m, even though this portion of coastal wetlands is known to provide critical habitat for many Great Lakes fishes. We sampled 16 wetlands that varied in size and inundation characteristics and grouped them into 4 categories: small aquatic, small terrestrial, large aquatic, and large terrestrial. When the vegetated deep-water habitat was included, total wetland area and the overall score for all assessed criteria assessed increased significantly; however, this increase was not sufficiently large to make any practical difference in the overall score using existing the point-scale. This is largely because submerged aquatic habitat is not adequately represented in current evaluation protocols and is severely undervalued. In chapter 3 we developed a method to quantify and monitor change in coastal marsh habitat in southeastern Georgian Bay using multi-temporal IKONOS imagery. We detected a significant increase in the proportion of terrestrial habitat (high marsh) at the expense of the aquatic habitat (low marsh) over six years from 2002 to 2008. There did not appear to be any effect of human activities (indicated by the number of buildings within 500 m of wetlands) on habitat changes. We conclude that water levels may currently exert greater pressure on these systems than does cottage density in the region. We recommend that the approaches developed in this study be applied as quickly as possible to comprehensively map existing wetland habitat in eastern Georgian Bay to monitor responses to further water-level and human-induced disturbance. / Thesis / Master of Science (MSc)

High-latitude ecosystems have experienced substantial warming over the past 40 years, which is expected to continue into the foreseeable future. Consequently, an increase in vegetation growth has occurred throughout the circumpolar North as documented through remote sensing and plot-level studies. A major component of this change is shrub expansion (shrubbing) in arctic and subarctic ecotones. However, these changes are highly variable depending on plant species, topographic position, hydrology, soils and other ecosystem properties. Changes in shrub and other vegetation properties are critical to document due to their first-order control on water, energy and carbon balances. This study uses a combination of multi-temporal LiDAR (Light Detection and Ranging) and field surveys to measure temporal changes in shrub vegetation cover over the Wolf Creek Research Basin (WCRB), a 180 km2 long-term watershed research facility located ~15 km south of Whitehorse, Yukon Territory. This work focuses on the smaller Granger Basin, a 7.6 km2 subarctic headwater catchment that straddles WCRB’s subalpine and alpine tundra ecozones with a wide range of elevation, landscape topography, and vegetation. Airborne LiDAR surveys of WCRB were conducted in August 2007 and 2018, providing an ideal opportunity to explore vegetation changes between survey years. Vegetation surveys were conducted throughout Granger Basin in summer 2019 to evaluate shrub properties for comparisons to the LiDAR. Machine learning classification algorithms were used to predict shrub presence/absence in 2018 based on rasterized LiDAR metrics with up to 97% overall independent accuracy compared to field validation points, with the best-performing model applied to the 2007 LiDAR to create binary shrub cover layers to compare between survey years. Results show a 63.3% total increase in detectable shrub cover > 0.45 m in height throughout Granger Basin between 2007 and 2018, with an average yearly expansion of 5.8%. These changes in detectable shrub cover were compared across terrain derivatives created using the LiDAR to quantify the influence of topography on shrub expansion. The terrain comparison results show that shrubs in the study area are located in and are preferentially expanding into lower and flatter areas near stream networks, at lower slope positions and with a higher potential for topographic wetness. The greatest differences in terrain derivative value distributions across the shrub and non-shrub change categories were found in terms of stream distance, elevation, and relative slope position. This expansion of shrubs into higher-resource areas is consistent with previous studies and is supported by established physical processes. As vegetation responses to warming have far-reaching influences on surface energy exchange, nutrient cycling, and the overall water balance, this increase in detectable shrub cover has a wide range of impacts on the future of northern watersheds. Overall, the findings from this research reinforce the documented increase in pan-Arctic shrub vegetation in recent years, quantify the variation in shrub expansion over terrain derivatives at the landscape scale, and demonstrate the feasibility of using LiDAR to compare changes in shrub properties over time. / Thesis / Master of Science (MSc)

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Bibliography : leaves 44-51. / M.S.

NASA's Clouds and the Earth's Radiant Energy System (CERES) program is a key component of the Earth Observing System (EOS). The CERES Proto-Flight Model (PFM) instrument is to be launched on NASA's Tropical Rainfall Measuring Mission (TRMM) spacecraft in November, 1997. Each CERES instrument will contain three scanning thermistor bolometer radiometers to monitor the longwave, 5.0 to >100 microns, and shortwave, 0.3 to 5.0 microns, components of the Earth's radiative energy budget. High-level, first-principle dynamic electrothermal models of the CERES radiometric channels have been completed under NASA sponsorship. These first-principle models consist of optical, thermal and electrical modules. Optical characterization of the channels is ensured by Monte-Carlo-based ray-traces. Accurate thermal and electrical characterization is assured by transient finite-difference formulations. This body of research presents the evolution of these models by outlining their development and validation. Validation of the models is accomplished by simulating the ground calibration process of the actual instruments and verifying that the models accurately predict instrument performance. The result of this agreement is a high confidence in the model to predict other aspects of instrument performance. / Ph. D.