<p> Soil moisture sensor use in crop production systems has the potential to give inference on plant water status for the purpose of irrigation scheduling and site-drought characterization. These processed measurements could serve as the framework on which to compile trial results across locations, thereby more accurately defining varietal yield response to drought. Still, the ability to characterize drought within a given field or initiate irrigations from these data hinge upon the ability of the instrument to characterize soil moisture at the sampled point and extrapolate that information across the landscape and time. Therefore, the objectives of this research were to: (1) test the response of the Watermark 200SS (Irrometer Company, Inc., Riverside, CA) and Decagon 10HS (Decagon Devices, Inc., Pullman, WA) to changes in water content of three dissimilar soils representing common soils in row-crop production under variable environmental conditions; (2) develop a soil moisture-based index to quantify drought stress in dryland cotton cultivar trials; and (3) determine if a limited number of soil moisture sensors deployed into a dryland cultivar trial could accurately characterize the VWC at a given point within the field and if this measurement could be extrapolated out to the field scale from the very small sphere of influence characterizing the utilized soil moisture sensors. During the 2012 and 2013 growing seasons soil moisture sensors were deployed into over 14 cotton cultivar trials across the U.S. Cotton Belt and into a water-input controlled container study. Tested sensors' inability to accurately predict container VWC emphasized the relatively small quantity of soil on which these sensors rely and the variability in soil moisture within a very limited volume. Results from the drought-index studies suggested both the Accumulated Soil Moisture Stress Index (ASMSI) and the relative reduction in evapotranspiration (1-(ET_{c adj}/ET_c)) appear to have potential in characterizing the amount of stress experienced within dryland cultivar trials. Analysis of spatial and temporal stability suggested trends between sensors were consistent, but absolute node readings varied. Optimism concerning the potential of these measurements/approaches for increasing water use efficiency is coupled with a call for more arbitrary, universal methods of measurement analysis.</p>

Data retrieved from airborne laser scanning represents a new source of forest data. Today, the technology has matured so that it can function in an operational environment. The aim of this study was to compile areas of application of laserdata in forestry. Moreover to analyze costs and accessibility of laserdata. The goal was to provide private forest owners information to support assessments of possible benefits of laserdata. Data produced by Skogsstyrelsen and SLU seems to be useful for private forest owners. These data i.e. includes maps of digital terrain models, tree heights, stand volumes, tree diameters, basal areas and biomass. Today, the costs for airborne laser scanning are high for the private forest owners. Perhaps co- ordinations between forest owner organizations and other timber buying companies could solve this problem.

<p> Many methods have been employed to study coastline change. These methods range from historical map analysis to GPS surveys to modern airborne LiDAR and satellite imagery. These previously used methods can be time consuming, labor intensive, and expensive and have varying degrees of accuracy and temporal coverage. Additionally, it is often difficult to apply such techniques in direct response to an isolated event within an appropriate temporal framework. Here we utilize a new ground based Canopy Biomass LiDAR (CBL) system built at The University of Massachusetts Boston (in collaboration with the Rochester Institute of Technology) in order to identify and analyze coastal change on Lovells Island, Boston Harbor. Surveys of a bluff developing in an eroding drumlin and beach cusps on a high-energy cobble beach on Lovells Island were conducted in June, September and December of 2013. At each site for each survey, the CBL was set up and multiple scans of each feature were taken on a predetermined transect that was established parallel to the high-water mark at distances relative to the scale of the bluff and cusps. The scans from each feature were compiled, integrated and visualized using Meshlab. Results from our surveys indicate that the highly portable and easy to deploy CBL system produces images of exceptional clarity, with the capacity to resolve small-scale changes to coastal features and systems. The CBL, while still under development (and coastal surveying protocols with it are just being established), appears to be an ideal tool for analyzing coastal geological features and is anticipated to prove to be a useful tool for the observation and analysis of coastal change. Furthermore, there is significant potential for utilizing the low cost ultra-portable CBL in frequent deployments to develop small-scale erosion rate and sediment budget analyses.</p>

The National Aeronautics and Space Agency NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) platform carried by Terra and Aqua satellites, is providing systematic measurements summarized in high quality, consistent and well-calibrated satellite images and datasets ranging from reflectance in the visible and near infrared bands to estimates of leaf area index, vegetation indices and biome productivity. The objective of this research was to relate the spectral responses and derived MODIS products of ecosystems, to biogeochemical processes and trends in their physiological variables. When different sources of data were compared, discrepancies between the MODIS variables and the corresponding ground measurements were evident. Uncertainties in the input variables of MODIS products algorithms, effects of cloud cover at the studied pixel, estimation algorithm, and local variation in land cover type are considered as the cause. A simple "continuous field" model based on a physiologically-driven spectral index using two ocean-color bands of MODIS satellite sensor showed great potential to track seasonally changing photosynthetic light use efficiency and stress-induced reduction in net primary productivity of terrestrial vegetation. The model explained 88% of the variability in Flux tower-based daily Net Primary Productivity. Also a high correlation between midday gross CO2 exchange with both daily and 8-day mean gross CO2 exchange, consistent across all the studied vegetation types, was found. Although it may not be possible to estimate 8-day mean Light Use Efficiency reliably from satellite data, Light Use Efficiency models may still be useful for estimation of midday values of gross CO2 exchange which could then be related to longer term means of CO2 exchange. In addition, the MODIS enhanced vegetation index shows a high potential for estimation of ecosystem gross primary production, using respiration values from MODIS surface temperature, providing truly per-pixel estimates. / Department of Natural Resources and Environmental Management

The Maputaland Coastal Plain is situated in north-eastern KwaZulu-Natal Province, South Africa. The Maputaland Coastal Plain and underlying aquifer are two separate but inter-linked entities. This area with high permeable cover sands, low relief and regional geology that slopes towards the Indian Ocean, hosts a variety of important wetlands in South Africa (e.g. 66% of the recorded peatlands). The wetlands overlie and in some cases also connect to the underlying regional water-table. The apparent distribution of wetlands varies in response to periods of water surplus or drought, and over the long-term has been reduced by resource (e.g. agriculture, forestry) and infrastructure (e.g. urbanisation) development. Accurate wetland mapping and delineation in this environment is problematic due to the ephemeral nature of wetlands and extensive land-use change. Furthermore the deep aeolian derived sandy soils often lacks soil wetness indicators in the soil profile. It is postulated that the aquifer is the source of water to rivers, springs, lakes and wetlands (and vice versa). However, the role of groundwater in the sustainability of hydro-ecological systems is unclear. Consequently this research attempted to determine spatial and temporal changes in the distribution of these wetlands, their susceptibility to human development, understand the landscape processes and characterise and classify the different wetland types. An underlying assumption of the hydrogeomorphic wetland classification concept in South Africa is that wetlands belonging to the same hydrogeomorphic unit share common features in terms of environmental drivers and processes. Given the above, the objectives of this thesis relating to the north-eastern corner of the Maputaland Coastal Plain are to: 1) Map the distribution of wetlands and their relation to other land-use; 2) Characterise the landscape processes shaping the dynamics of wetland type and their distribution; 3) Classify wetlands by applying hydrogeomorphic wetland classification system. This study used Landsat TM and ETM imagery acquired for 1992 and 2008 (dry) and Landsat ETM for 2000 (wet) along with ancillary data. Wetland type characteristics were described using terrain unit position in the landscape, SRTM DEM, land surveyor elevation measurements along with long-term rainfall records, in situ water-table levels with soil analysis and geology and vegetation descriptions. A conceptual model was used to account for the available data, and output from a hydrology model was used to support the interpretation of wetland distribution and function. Wetlands in the study area include permanent wetlands (swamp forests and reed/sedge wetlands), but the majority of sedge/moist grassland wetlands are temporary systems. The wetland distribution reflects the rainfall distribution and groundwater discharge in lower lying areas. The weathering of the Kosi Bay Formation is a key factor in wetland formation. Because of an increase in clay content with depth, the pore-space and hydraulic conductivity are reduced which causes water to impede on this layer. The nature of the aquifer and regional geology that slope towards the east along with extreme rainfall events in wet and dry periods are contributing drivers of wetland and open water distribution. In 2008 (a dry year) the smaller wetland extent (7%) could primarily identify “permanent” groundwater-fed wetland systems, whereas for the wet year (2000) with larger wetland extent (18%) both “temporary” and “permanent” wetlands were indicated. Comparison between both dry years (1992 and 2008) indicates an 11% decrease in wetland (sedge/moist grassland) and a 7% increase in grassland distribution over time. Some areas that appear to be grassland in the dry years were actually temporary wetland, based on the larger wetland extent (16%) in 2000. The 2008 Landsat TM dataset classification for the entire Maputaland Coastal Plain gave an overall 80% mapping accuracy. Landscape settings identified on this coastal aquifer dominated by dune formations consist of 3 types: plain (upland and lowland), slope and valley floor. Although the wetland character is related to regional and local hydrogeology as well as climate affecting the temporal and spatial variability of the wetlands this research confirms that the patterns and wetland form and function are predominantly shaped by the hydrogeomorphic setting and not the rainfall distribution. The following wetland types were identified: permanent wetlands such as peat swamp forests, peat reed and sedge fens; temporary wetland systems such as perched depressions, and sedge/moist grasslands. The Hydrogeomorphic wetland classification system was applied using a semi-automated method that was 81% accurate. The following hydrogeomorphic units could be identified: one floodplain, i.e., Siyadla River Floodplain, channelled valley-bottoms, unchannelled valley-bottoms, depressions on modal slope values <1%, seepage wetlands on modal slope values 1-2%. However, evaluation of the hydrogeomorphic classification application results suggests that the “flat” hydrogeomorphic class be revised. It did not fit meaningfully on the upland plain area. This research finding concludes wetland function does depend on landscape setting and wetland function is not truly captured by the hydrogeomorphic type classification. Not all depression on the coastal plain function the same way and three types of depressions occurs and function differently, i.e., perched depression with no link to the regional water-table vs. depressions that are linked with the regional water-table on plain, slope and valley floor landscape settings. Overall, this research study made a useful contribution in characterising and classifying wetland type and distribution for a high priority wetland conservation area in South Africa. Applying similar methods to the broader Maputaland Coastal Plain will particularly benefit from the research findings. The importance of using imagery acquired in wet and dry periods as well as summer and winter for a more comprehensive wetland inventory of the study area, is stressed. To manage the effects of climate variability and development pressure, informed land-use planning and rehabilitation strategies are required based on landscape analysis and interpretation.

<p> Pompeii suffered a famous volcanic disaster in 79 AD. This led to a tremendous loss of life. This thesis examines that loss of life and the geography of death left behind by the eruption. Where did the citizens of Pompeii die, and how could they have avoided their fate? These are issues that are examined through geographic methodologies and the use of GIS. The results indicate a people that could have been spared with proper hazards management, and one that shows through mapping the large loss of life that accompanied one of history's most famous volcanic eruptions.</p>

<p> Mountain Lake is one of only two natural lakes in the state of Virginia. The lake's origin has been attributed to either a natural solution-collapse basin, or to a landslide damming the valley of northwesterly flowing Pond Drain, or to a NW-SE trending fracture lineation. The lake is located within the breached northwest limb of a gently plunging anticline, a part of the larger Valley and Ridge physiographic province. In recent years, the lake drained almost completely, exposing the lake bottom and revealing the presence of four sinkhole-like depressions, containing piping holes at their sides and bottoms, at the northeastern and northwestern margins of the lake. This study focuses on the most likely origin of large sandstone blocks present at the northern end of the lake in an area locally referred to as "Rock City", including mapping of the block locations and analyzing the mode and extent of displacement that they have undergone. An additional objective is to investigate the piping potential of the lake-bottom sediment and its role in seepage out of the lake basin causing lake-level fluctuations. </p><p> Mapping of Rock City was conducted by taking GPS readings at the corners of the rock blocks and using ArcMap Software. Investigations of the displacement mode of the rock blocks was done by comparing the measured orientations of principal discontinuity sets, forming the rock-block boundaries, with discontinuity orientations of undisturbed outcrops within the headscarp, using stereonet analysis. Grain size analysis, Atterberg limits, and a compaction-mold permeameter test were used to evaluate lake sediment's susceptibility to piping. </p><p> Field observations and discontinuity data analysis indicate that Rock City is a landslide that dammed the valley of Pond Drain, consequently forming the lake. The primary mode of slope movement involves lateral spreading that is associated with extension occurring along discontinuities. The Tuscarora Sandstone rock blocks comprising Rock City were detached from the scarp face along a northwest-southeast trending joint set and were displaced laterally towards the west. A seismic event appears to be the most likely triggering mechanism for slope movement. </p><p> Laboratory testing reveals that lake-bottom sediment is susceptible to piping, which is the primary mechanism responsible for the formation of the lake-bed depressions and lake-levels fluctuations. Grain size analysis reveals that lake-bottom sediment consists predominantly of fine sand and silt, both of which are highly susceptible to piping. Results of the compaction-mold permeameter test show that the hydraulic gradient at which lake-bottom sediment starts to pipe, the critical hydraulic gradient, ranges between 1 and 10, depending on the density, grain size distribution and cohesive properties of the sediment.</p>

This thesis presents results from spatial-temporal and volumetric change analysis of blowouts on the Cape Cod National Seashore (CCNS) landscape in Massachusetts, USA. The purpose of this study is to use methods of analysing areal and volumetric changes in coastal dunes, specifically blowouts, and to detect patterns of change in order to contribute to the knowledge and literature on blowout evolution. In Chapter 2.0, the quantitative analysis of blowout change patterns in CCNS was examined at a landscape scale using Spatial-Temporal Analysis of Moving Polygons (STAMP). STAMP runs as an ArcGIS plugin and uses neighbouring year polygon layers of our digitized blowouts from sequential air photo and LiDAR data (1985, 1994, 2000, 2005, 2009, 2011, and 2012 for 30 erosional features, and 1998, 2000, 2007, and 2010 for 10 depositional features). The results from STAMP and the additional computations provided the following information on the evolution of blowouts: (1) both geometric and movement events occur on CCNS; (2) generation of blowouts in CCNS is greatest in 1985 and is potentially related to vegetation planting campaigns by the Park; (3) features are expanding towards dominant winds from the North West and the South West; (5) the erosional and depositional features are becoming more circular as they develop, (6) the evolution of CCNS blowouts follows a similar pattern to Gares and Nordstrom’s (1995) model with two additional stages: merging or dividing, and re-activation. In Chapter 3.0, the quantitative analysis of volumetric and areal change of 10 blowouts in CCNS at a landscape scale is examined using airborne LiDAR and air photos. The DEMs of neighbouring years (1998, 2000, 2007, and 2010) were differenced using Geomorphic Change Detection (GCD) software. Areal change was detected by differencing the area of polygons that were manually digitized in ArcGIS. The changes in wind data and vegetation cover were also examined. The results from the GCD and areal change analysis provide the following information on blowout evolution: (1) blowouts generate/initiate; (2) multiple blowouts can merge into an often larger blowout; (3) and blowouts can experience volumetric change with minimal aerial change and vice versa. From the analyzes of hourly Provincetown wind data (1998-2010), it was evident that blowouts developed within all three time intervals. The percentages of comparable winds (above 9.6 m s-1) were highest in 1998, 1999, 2007 and 2010. It is speculated that tropical storms and nor'easters are important drivers in the development of CCNS blowouts. In addition, supervised classifications were run on sequential air photos (1985 to 2009) to analyze vegetation cover. The results indicated an increase in vegetation cover and decrease of active sands over time. Two potential explanations that link increased vegetation to blowout development are: (1) sparse vegetation creates a more conducive environment for the initiation of blowouts by providing stability for the lateral walls, and (2) high wind events (e.g. hurricanes and nor'easters) could cause vegetation removal, allowing for areas of exposed sand for blowout initiation and development. / Graduate / 0799 / 0368 / kimia.abhar@gmail.com

This dissertation presents new research into the study of simulation and measurement techniques for microwave remote sensing of sea ice. We have embarked on a major study of the microwave propagation and scattering properties of sea ice in an attempt to link the physics of the sea ice medium to experimentally obtained concomitant scatterometer measurements. During our fieldwork, we studied the polarimetric backscattering response of sea ice, focusing on newly-formed sea ice under a large assortment of surface coverage. Polarimetric backscattering results and physical data for 40 stations during the fall freeze-up of 2003, 2006, and 2007 are presented. Analysis of the co-polarization correlation coefficient showed its sensitivity to sea ice thickness and surface coverage and resulted in a statistically significant separation of ice thickness into two regimes: ice less than 6 cm thick and ice greater than 8 cm thick. A case study quantified the backscatter of snow-infiltrated frost fl owers on new sea ice, showing that the presence of the frost flowers enhanced the backscatter by more than 6 dB. In our simulation work, an efficient method for simulating scattering from objects in multi-layered media was incorporated into a scattered-field formulation of the FVTD method. A total-field 1D-FDTD solution to the plane-wave propagation through multi-layered meda was used as a source. The method was validated for a TE-polarized incident-field through comparisons with other numerical techniques involving examples of scattering from canonically-shaped objects. Methods for homogenization of inhomogeneous media were developed and validated using well-known dielectric mixture models. A Monte Carlo Method for simulating scattering from statistically rough surfaces was developed and was validated through favorable comparison with the SPM method for rough surface scattering. Finally, we presented a new Monte Carlo Method for simulating sea ice remote sensing that utilized the framework of the FVTD method for scattering simulations. The modeling process was driven by actual physical measurements of sea ice, wherein dielectric and physics-based modeling techniques were employed. The method was demonstrated through a series of case studies where the scattering from newly-formed sea ice was simulated using a TE-polarized incident- eld. Good agreement between experimental scatterometer measurements and simulated results was obtained for co-polarized returns, whereas cross-polarized results indicated that more depolarizing features must be taken into account.

The Brazilian Pantanal, a continuous tropical wetland located in the center of South America, has been recognized as one of the largest and most important wetland ecosystems globally. The Pantanal exhibits a high biodiversity of flora and fauna species, and many threatened habitats. The spatial distribution of these habitats influence the distribution, abundance and interactions of animal species, and the change or destruction of habitat may cause alteration of key biological processes. The Pantanal may be divided into several distinct subregions based on geology and hydrology: flooding in these subregions is distinctly seasonal, but the timing, amplitude and duration of inundation vary considerably as a result of both the delayed release of floodwaters and regional rainfall patterns. Given the ecological importance of the Pantanal wetland ecosystem, the primary goal of this research was to utilize a dual season set of L-band (ALOS/PALSAR) and C-band (RADARSAT-2 and ENVISAT/ASAR) imagery, a comprehensive set of ground reference data, and a hierarchical object-oriented approach. This primary goal was achieved through two main research tasks. The first task was to define the diverse habitats of the Lower Nhecolândia subregion of the Pantanal at both a fine spatial resolution (12.5 m), and a relatively medium spatial resolution (50 m), thus evaluating the accuracy of the differing spatial resolutions for land cover classification of the highly spatially heterogeneous subregion. The second task was to define on a regional scale, using the 50 m spatial resolution imagery, the wetland habitats of each of the hydrological subregions of the Pantanal, thereby producing a final product covering the entire Pantanal ecosystem. The final classification maps of the Lower Nhecolândia subregion resulted in overall accuracies of 83% and 72% for the 12.5 m and 50 m spatial resolutions, respectively, and defined seven land cover classes. In general, the highest degree of confusion for both fine and medium resolution classifications related to issues of 1) scale of habitats, for instance, capões, cordilheiras, and lakes, in relation to spatial resolution of the imagery, and 2) issues relating to variable flooding patterns in the subregion, and 3) arbitrary class membership rules. The 50 m spatial resolution classification of the entire Pantanal wetland resulted in an overall accuracy of 80%, and defined ten land cover classes. Given the analysis of the comparison of fine and relatively medium spatial resolution classifications of the Lower Nhecolândia subregion, I conclude that significant improvements in accuracy can be achieved with the finer spatial resolution dataset, particularly in subregions with high spatial heterogeneity in land cover. The produced habitat spatial distribution maps will provide vital information for determining refuge zones for terrestrial species, connectivity of aquatic habitats during the dry season, and crucial baseline data to aid in monitoring changes in the region, as well as to help define conservation strategies for habitat in this critically important wetland. / Graduate / 0366 / tevans@uvic.ca