<p>The present study focuses on delineation of the southern edge of the middle Devonian Prairie Evaporite (PE) in south-central Saskatchewan. The purpose of this work was to improve the accuracy and resolution of subsurface mapping by including additional information from well logs and seismic data not included in the previous studies.</p><p>Approximately 330 km of 2-D seismic data were integrated with horizon picks from 1334 well logs to improve the delineation of the southern margin of the PE. Thirteen seismic lines were re-processed with an emphasis on high-frequency imaging. The resulting seismic sections show marked improvement in the accuracy and resolution of mapping of the PE salt edges, with the estimated depth resolution improved to ~15 m. Seismic data indicate that salt dissolution structures were created by multistage processes. Salt collapses were identified within the body of the Prairie Evaporite and off-salt.</p><p>Well log data were combined with seismic results and gridded to create an updated map of the Prairie Evaporite. Different gridding methods provided different interpolations of the data set, particularly where the salt layer is thin near its margin. Incorporation of seismic interpretations resulted in 2-9 km changes in the positions of the salt edges derived earlier from well log and limited seismic interpretations. Therefore, integration of the seismic and well log data should increase the accuracy of the positions of the salt edge.</p><p>In order to evaluate the effects of the basin fill on regional gravity signatures and to determine whether the effect of the salt edge could be observed in gravity data, two gravity profiles crossing the salt collapse margin and the Trans-Hudson Orogen and the Wyoming Structural Province were analysed. Regional-scale gravity modeling showed that the transition from the Trans-Hudson Orogen to Wyoming Province was marked by deep-seated structures within the basemen. Detailed gravity modeling of a shorter profile well-constrained by seismic data showed that the salt collapses contribute ~0.4 mgal to the total anomaly of about 4 mgal. Although a direct observation of salt edge by gravity appears hardly feasible, performing high-resolution gravity survey with station interval ~100 m might still be useful to constrain the overburden and thereby help detect salt collapses.

<p>The present study focuses on delineation of the southern edge of the middle Devonian Prairie Evaporite (PE) in south-central Saskatchewan. The purpose of this work was to improve the accuracy and resolution of subsurface mapping by including additional information from well logs and seismic data not included in the previous studies.</p><p>Approximately 330 km of 2-D seismic data were integrated with horizon picks from 1334 well logs to improve the delineation of the southern margin of the PE. Thirteen seismic lines were re-processed with an emphasis on high-frequency imaging. The resulting seismic sections show marked improvement in the accuracy and resolution of mapping of the PE salt edges, with the estimated depth resolution improved to ~15 m. Seismic data indicate that salt dissolution structures were created by multistage processes. Salt collapses were identified within the body of the Prairie Evaporite and off-salt.</p><p>Well log data were combined with seismic results and gridded to create an updated map of the Prairie Evaporite. Different gridding methods provided different interpolations of the data set, particularly where the salt layer is thin near its margin. Incorporation of seismic interpretations resulted in 2-9 km changes in the positions of the salt edges derived earlier from well log and limited seismic interpretations. Therefore, integration of the seismic and well log data should increase the accuracy of the positions of the salt edge.</p><p>In order to evaluate the effects of the basin fill on regional gravity signatures and to determine whether the effect of the salt edge could be observed in gravity data, two gravity profiles crossing the salt collapse margin and the Trans-Hudson Orogen and the Wyoming Structural Province were analysed. Regional-scale gravity modeling showed that the transition from the Trans-Hudson Orogen to Wyoming Province was marked by deep-seated structures within the basemen. Detailed gravity modeling of a shorter profile well-constrained by seismic data showed that the salt collapses contribute ~0.4 mgal to the total anomaly of about 4 mgal. Although a direct observation of salt edge by gravity appears hardly feasible, performing high-resolution gravity survey with station interval ~100 m might still be useful to constrain the overburden and thereby help detect salt collapses.

No description available.

Four small watersheds, Kamwamphula, Luelo, Kanyanga and Mphiri, near Emusa (Lundazi District) in Eastern Province, Zambia, were studied to document transitions in land use over time and to project the impacts of land use and topography on runoff, erosion and sediment delivery. Landuse was delineated from 2007 IKONOS image (one meter pixel), and Landsat imagery was used to depict the historic changes in landuse between the period of 1989 and 2007. The GWLF model was used to predict the impact of the landuses on the hydrology of the area. There had been an increase in clearing of forest area mainly due to the expansion of cropland area. The highest rate of clearing was predicted for the Kamwamphula watershed where the forest cover decreased from 95% to 71% over the 18 year period. The GWLF model was used to predict the impact of the landuse on the hydrology and sediment delivery. In comparison with the limited field data available from the four watersheds, the GWLF model gave poor prediction of streamflow, probably because the hydrology of the area is poorly understood and dambo function in the landscape is not well represented in the model. Highest runoff, erosion and sediment yields came from Luelo watershed which has steeper slopes and, less vegetative cover and poor permeability of soils. The GWLF gave poor prediction of streamflow, probably, because the hydrology of the area is poorly understood. / Master of Science

PhD, Faculty of Engineering and the Built Environment, University of the Witwatersrand, 2010 / Informal settlements are a growing world-wide phenomenon. Up-to-date spatial information mapping settlements is essential for a variety of end-user applications from planning settlement upgrading to monitoring expansion and infill. One method of gathering this information is through the analysis of nadir-view aerial imagery and the automated or semi-automated extraction of individual shacks. The problem of shack detection and delineation in, particularly South African, informal settlements is a unique and difficult one. This is primarily due to the inhomogeneous appearance of shack roofs, which are constructed from a variety of disparate materials, and the density of shacks. Previous research has focused mostly on the use of height data in conjunction with optical images to perform automated or semi-automated shack extraction. In this thesis, a novel approach to automating shack extraction is presented and prototyped, in which the appearance of shack roofs is homogenised, facilitating their detection. The main features of this strategy are: construction of an anisotropic scale-space from a single source image and detection of hypotheses at multiple scales; simplification of hypotheses' boundaries through discrete curve evolution and regularisation of boundaries in accordance with an assumed shack model - a 4-6 sided, compact, rectilinear shape; selection of hypotheses competing across scales using fuzzy rules; grouping of hypotheses based on their support for one another, and localisation and re-regularisation of boundaries through the incorporation of image edges. The prototype's performance is evaluated in terms of standard metrics and is analysed for four different images, having three different sets of imaging conditions, and containing well over a hundred shacks. Detection rates in terms of building counts vary from 83% to 100% and, in terms of roof area coverage, from 55% to 84%. These results, each derived from a single source image, compare favourably with those of existing shack detection systems, especially automated ones which make use of richer source data. Integrating this scale-space approach with height data offers the promise of even better results.

During the last century wetlands have considerably decreased. The principal cause is urbanization, especially in large urban regions such as the Houston area. In order to protect the remaining wetlands, they have to be monitored carefully. However monitoring wetland is a difficult and time-demanding task because it has to be done repetitively on large areas to be effective. This study was conducted to determine if Geographical Information System (GIS) and remote sensing technologies would allow accurate monitoring of wetland as a less time-consuming method. With this idea, a suitability model was developed to delineate wetlands in the Houston area. This model combined GIS and remote sensing technologies. The data used for this study were as high spatial resolution as possible and were generally easy to obtain. This suitability model consisted of four submodels: hydrology, soil, vegetation and multi- attribute. Each submodel generated a Wetland Suitability Index (WSI). Those WSI were summed to obtain a general WSI. The suitability model was calibrated using half of the study area. During calibration, the general model was evaluated as well as each individual index. Generally, the model showed a lack of sensitivity to changes. However, the model was slightly modified to improve the delineation of upland wet- lands by increasing the weight of the soil submodel. This model was validated using the second half of the study area. The validation results improved a bit compared to the calibration results; however they remained weak. It was demonstrated that the model does not favor riverine wetlands over upland wetlands, nor large size wetlands. The model ground truth data were evaluated and were suffciently proven to be up to date. Those results indicated that the weakness of the model must come from inac- curacy in the input data. Therefore, the study showed that while existing computing capacity supports remote delineation, spatial accuracy is still insuffcient to perform correct wetland delineation using remote sensing and GIS technologies.

<p> The central theme of this paper is territoriality. Essentially, I am concerned with the part that territoriality plays in determining spatial behaviour. Part One introduces the subject and demonstrates the need for geographers to examine territoriality more thoroughly. The newly developed field of behavioural geography is assessed, the importance of scale being a fundamental consideration. Part Two deals with definition of territoriality in animal and human populations. The problems encountered in definition and delineation of human territories are discussed. Part Three poses two important questions. 1. What function does territoriality serve? 2. Is territory innate or a cultural acquisition? Although the answers to these questions are subject to further research, the importance of these considerations is demonstrated. Part Four considers dominance and leadership. The spatial implications of these concepts are developed. Part Five centres about territorial encroachment and the subsequent reaction. Essentially territorial encroachment (or intrusion) is conceived as a violation of regular spacing patterns. Possible reactions to encroachment are considered. Part Six deals with typology. Two levels of study are distinguished those being Micro territories (personal space) and macro territories (larger units of territory). These two concepts are differentiated by scale. Studies conducted at each of these levels are discussed. Part Seven puts forth a hypothetical construct which integrates the work of several researchers. The "interaction distance" equation is a model which, hopefully, assists the researcher in understanding and possibly predicting the space maintained between interactants. Briefly, the model consists of the subject, the object and the situation. These components determine the interaction distance. Although quantification of the components is not included in this paper, problems in calibration are considered. The utility of the model is also discussed. Part Eight applies a methodological construct, of field theory, to spatial behaviour. The essential concepts of field theory, (the life space, boundary zones, and space of free movement), are discussed in a conceptual and physical sense. Finally, the life space concept is conceived as a territorial range or orbit in which the spatial behaviour of the individual is conducted. In fact, the field theory might greatly assist geographers in understanding and predicting spatial behaviour.</p> / Thesis / Bachelor of Arts (BA)

The timing of Mississippian-period occupations in the North Central Hills physiographic region of Mississippi has been debated. Some researchers believe they occurred in conjunction with Late Woodland period occupations during the Early Mississippian period, while others assert they were later, in either the Late Mississippian or early Protohistoric periods. A program of systematic shovel testing, excavation and frequency seriation was used to delineate Mississippian-period occupations and test the cultural lineage between them and Late Woodland period occupations at nine sites on the Ackerman Unit of the Tombigbee National Forest.

In recent years, the impressive progress performed in imaging, computational and technological fields have made possible the emergence of image-guided radiation therapy (IGRT) and adaptive radiation therapy (ART). The accuracy in radiation dose delivery reached by IMRT offers the possibility to increase locoregional dose-intensity, potentially overcoming the poor tumor control achieved by standard approaches. However, before implementing such a technique in clinical routine, a particular attention has to be paid at the target volumes definition and delineation procedures to avoid inadequate dosage to TVs/OARs. In head and neck squamous cell carcinoma (HNSCC), the GTV is typically defined on CT acquired prior to treatment. However, providing functional information about the tumor, FDG-PET might advantageously complete the classical CT-Scan to better define the TVs. Similarly, re-imaging the tumor with optimal imaging modality might account for the constantly changing anatomy and tumor shape occurring during the course of fractionated radiotherapy. Integrating this information into the treatment planning might ultimately lead to a much tighter dose distribution. From a methodological point of view, the delineation of TVs on anatomical or functional images is not a trivial task. Firstly, the poor soft tissue contrast provided by CT comes out of large interobserver variability in GTV delineation. In this regard, we showed that the use of consistent delineation guidelines significantly improved consistency between observers, either with CT and with MRI. Secondly, the intrinsic characteristics of PET images, including the blur effect and the high level of noise, make the detection of the tumor edges arduous. In this context, we developed specific image restoration tools, i.e. edge-preserving filters for denoising, and deconvolution algorithms for deblurring. This procedure restores the image quality, allowing the use of gradient-based segmentation techniques. This method was validated on phantom and patient images, and proved to be more accurate and reliable than threshold-based methods. Using these segmentation methods, we proved that GTVs significantly shrunk during radiotherapy in patients with HNSCC, whatever the imaging modality used (MRI, CT, FDG-PET). No clinically significant difference was found between CT and MRI, while FDG-PET provided significantly smaller volumes than those based on anatomical imaging. Refining the target volume delineation by means of functional and sequential imaging ultimately led to more optimal dose distribution to TVs with subsequent soft tissue sparing. In conclusion, we demonstrated that a multi-modality-based adaptive planning is feasible in HN tumors and potentially opens new avenues for dose escalation strategies. As a high level of accuracy is required by such approach, the delineation of TVs however requires a special care.

Multispectral aerial videography was used to reproduce the jurisdictional delineation of wetland area of approximately 50 hectares in Davis County, Utah Imagery from the system consisted of three-band composite with wavelengths covering 550 nm (±10 nm), 650 nm (±10 nm), and 850 nm (±10 nm). The site was overflown at three different flight dates during the 1992 growing season (June 2, July 22, October 1). Imagery resolution varied from 0.56 m to 0.81 m. Mosaiced images were analyzed with a Supervised clustering/maximum likelihood classifier, ISODATA clustering/Euclidan classifier, statistical clustering/maximum likelihood classifier, and fuzzy c-means clustering. Overall accuracies for wetland/upland designations as compared to ground truth data varied from 60% to 75%. The ISODATA method was the poorest performer for all dates and both of two accuracy testing techniques. Supervised clustering and statistical clustering were comparable with a slight edge in accuracy to the supervised clustering. The best all-round performer was the fuzzy c-means algorithm in terms of time spent and accuracy.