To what extent can GIS be used to address the needs of 2D, 3D and 4D environmental conceptual modelling at UK nuclear sites?
Creation of site conceptual models of the subsurface forms the basis of safety case development at UK nuclear sites. The process is time consuming and complex, and lacks transparency at the audit and regulation stage. Conceptual models can rarely be visualised in 2D or 3D, and the interrogation of their components is almost impossible, with typically only raw environmental data stored electronically. The time consuming process and lack of a visual slant, is partly due to a lack of systematic planning at the start of the process.
This dissertation examines the conceptual modelling process in the context of safety case development at nuclear sites, and describes the design of both a systematic process and creation of associated database schemas in an object-relational database using free-to-download software. The whole process is implemented in a GIS (Geographical Information Systems) environment, and tested and validated to assess the extent to which GIS can be used to address the needs of 2D, 3D and 4D (i.e. forward in time) conceptual modelling at UK nuclear sites.
The successful implementation and validation of the process and GIS database schemas described above uses a case study employing real data from the Sellafield nuclear site, and shows that almost the whole process of conceptual model development can be completed within a GIS environment.
Delineation of Landcover Boundaries in Areas Utilized or Avoided by Female Caribou during Calving and Post-Calving Using Publicly Available Spatial Datasets
The availability and utility of spatial datasets, at no cost to the end user, directly impacts the ability of government and non-governmental wildlife management agencies to delineate landcover utilization or avoidance for targeted wildlife species. The availability and utility of four datasets;
- Canada Land Inventory for Ungulates
- Earth Observation for Sustainable Development of Forests
- Provincial Forest Inventory for the Island of Newfoundland
- Landsat 7 ETM+
were evaluated for their usefulness in delineating landcover boundaries in areas utilized by caribou during calving and post-calving. To perform this evaluation a representative sample of landcover features, in both utilized and avoided areas, were selected through the use of space-time scan statistics and maximum step length calculations, then landcover boundaries were recorded using spiral transects based on the Fibonacci sequence. The location of all land cover boundaries intersected during the completion of ground based transects were recorded and provided a baseline dataset for comparison to those depicted using the selected datasets. Object-oriented segmentation had to be completed for the Landsat ETM+ dataset before a comparison could be conducted. Root mean square error (RMSE) values were calculated for all datasets and compared with the ground based results. In addition, RMSE values were also calculated for a set of randomly generated boundary locations for each completed transect. For all datasets errors of omission were taken into account on an independent basis. Upon completion of the evaluation it was determined that all datasets, except the Earth Observation for Sustainable Development of Forests, where both the RMSE for random and actual boundary points (22.89, 14.93, error 25) was below the associated positional error of the dataset, would be useful for the delineation of landcover boundaries. The Canada Land Inventory (86.60, 30.43, error 35) was deemed useful only for its ability to provide information on historical location and permanence of boundaries at the landscape scale. To provide landcover delineation for the island of Newfoundland a combination of both the forest inventory (64.71, 39.47, error 35m) and landsat datasets (37.02, 27.92, error 30m) must be utilized along with a variety of ancillary data sources.
Remote Sensing of Polar Environments
Despite many years of research, climate change is still little understood. Scientists therefore continue to seek ways in which the impacts of climate change can be monitored and evaluated. Polar environments have shown the most notable indicators of warming in recent decades with sea ice extent and concentration being of particular interest (Drobot et al., 2007). However, the remote locations of polar environments has made ground observations of sea ice both costly and impractical. Scientists have therefore found remote sensing to be an effective way to monitor sea ice concentration and extent. This study aims to identify remote sensing and geographical information systems (GIS) methods and techniques suitable for monitoring the impacts of climate change in polar environments. Particular attention was paid to the Antarctic region where it has been found that there has been a slight increase in sea ice extent in recent decades (Oszoy-Cicek et al., 2009). This is contrary to what would be expected given the global trend of increased carbon dioxide concentration levels and temperatures. The UK Meterological Office Global Ice and Sea Surface Temperature (GISST2.2) dataset for the years 1965 to 1994 was used for area and time series (TSA) analyses of Antarctic sea ice. Areas of sea ice vulnerable to change were also identified at a global level. The analyses indicated a decrease in the Antarctic maximum (September) sea ice extent, but no such correlation could be found in the minimum (March) sea ice extent. It was concluded that the high degree of variance in the March dataset may have accounted for the overall increase in sea ice extent observed in Antarctica. Remote sensing techniques were successfully identified and GIS methods were tested for their suitability for the monitoring of polar environments.
IFSAR, LiDAR and Photogrammetry for new build overhead power transmission line routing
The UK’s OverHead Line power transmission network is the source of the country’s homes and business electricity. Over the years electricity demand has increased substantially and in order to meet this ever increasing demand for electricity, the power transmission network is undergoing massive refurbishment and new developments. This research focuses on new build OverHead Line routes and the potential application of remotely sensed data for feasibility studies. Four ‘off the shelf’ elevation datasets are investigated for the OHL industry to utilise within its new build feasibility studies; IFSAR, fixed wing LiDAR, helicopter LiDAR and Photogrammetry. The datasets are compared against a series of visual observations and a statistical RMSE investigations. This provides results that are focused specifically on the OHL industry and its requirements from elevation datasets. The results take into account; profile accuracy, UK coverage available and data purchase costs. The results from the research showed that Photogrammetry derived Digital Elevation Models provide low profile RMSE values and accurate visual results. Subsequently Photogrammetry was classified as the most suitable data source tested for OHL feasibility studies. The research also makes further recommendations on data types and specifications for datasets that are best suitable for OHL feasibility studies.
Spatial data Integration/analysis UsingFuzzy Model Application in: Copper Mineralization Prospecting
Using geological, geochemical and alteration data and integrating these data layers together is usual method for porphyry copper deposits prospecting. An area is selected in south-east of Iran part of Urumieh-Dokhtar magmatic assemblage to examine fuzzy spatial analysis of these datasets.
ASTER image processed to prepare the alteration haloes, from 1:100k geological map digitized to prepare rock units and faults map. Weight factor assigned to buffered alteration and fault maps and distribution map of Cu, Mo, and other pathfinder elements in accordance to geological experience and knowledge. Prepared datasets integrated together with fuzzy operation in series of steps. Alteration and geochemical datasets integrated separately using OR operation, Faults Rock unit and intermediate model of alterations integrated using SUM operation and finally 0.9 Gamma applied to prepare the favorability map of the area.
Final favorability map shows that fuzzy method performs a reliable result which is more similar to real world than other integration models.
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