In recent years, the Mekong delta has been strongly developed both for agriculture and aquaculture. However, there is scope for a negative impact of agriculture on aquaculture in term of production and quality of seafood products. Specifically, the large amount of pesticides imported and used in the Mekong delta not only help agriculture purposes but can also easily enter aquatic systems and affect aquaculture. Pesticides can be transported in the environment by chemo-dynamic procedures and hydrological processes. As a result, pesticides used in agriculture become dispersed and their residues in sediment, water and biota have been detected in the Mekong delta. This study investigated the overall pesticide process including pesticide use, modelling pesticide accumulation and evaluating the potential impact on aquaculture sites for some target aquatic species. The risk of pesticides use in the Mekong delta was addressed in three stages: (1) investigating current pesticide use status in the Mekong delta; (2) modelling pesticide loss and accumulation; (3) classifying pesticide risk areas for aquaculture of target cultured species. A survey of 334 farms covering a total area of ~20,000km2 in the Mekong delta took place between 2008 and 2009. Information on pesticide types and quantities was recorded using questionnaires, and it was found that 96 pesticides in 23 groups were popularly used for agricultural purposes. Dicarboximide, Carbamate and Conazole had the highest use at ~3000, ~2000 and ~2000 g/ha/year respectively. The survey revealed an increase in pesticide use per hectare since previous surveys in the Mekong delta in 1994, 2000, and 2004. However, the highly persistent compounds (WHO classification classes II, III and IV) appeared to have reduced in use. Insecticides previously represented >50% of the total pesticides used, however, the resent survey has shown their use has decreased to ~38%.There was a parallel increase in use of fungicides from previous levels of <30% of total pesticides to more recently ~41%. The combination of pesticide information and geo-location data enabled display and analysis of this data spatially using a Geographic Information System (GIS). A pesticide loss and accumulation model was established through combination of several sub-models including sediment loss and accumulation, direct loss, and water runoff, all of which were implemented and integrated within the GIS environment. MUSLE (Modified Universal Soil Loss Equation) was used to estimate sediment loss and accumulation in the Mekong delta and the Curve Number method (CN Method) was applied to predict water runoff and discharges and flow accumulation. Modelling commenced from the first pesticide application in April, based on 4 day time-steps. All mathematical calculations run within each time step automatically reiterated in the following time step with the new input datasets. The results from fuzzy classification of the pesticide model outcomes were considered in terms of the 96hr lethal concentration (LC50) in order to classify the risk and non-risk areas for catfish and tiger shrimp culture. The sediment loss and accumulation model shows that the highest loss of sediment was in the rainy season, especially in May to October. Vegetables and short term crop areas were found be most strongly eroded. The MUSLE model showed that the highest sediment accumulation was in the hilly areas (~1066.42 tonne/ha/year); lower in riverside areas (~230.39 tonne/ha/year) and lowest in flooded paddy areas (~150.15tonne/ha/year). Abamectin was used as an example throughout this study to estimate pesticide loss and its effects on aquaculture. The results showed that pesticide loss by runoff and sediment loss is less than the loss by half-life degradation (for Abamectin specifically). Accumulation of Abamectin occurred at highest rate in May and October and decreased with time. The spatial models showed that pesticide residues concentrated in the river and riverside areas. In order to evaluate the acute toxicity impacts, three levels of water depth in ponds were modelled as culture depths for catfish and tiger shrimp. The results show that the highest risk areas for catfish occurred in May and October with ~333,000 and ~420,000 ha at a pond depth of 0.5 m; ~136,000 and ~183,000 ha at a pond depth of 1.0 m; and ~10,840 and ~19,000 ha at a pond depth of 1.5 m. Risk areas for catfish mainly concentrated at the riverside and in part of the coastal areas. For tiger shrimp, the risk periods during the year were similar to those found for catfish. The highest risk areas for shrimp were ~648,000 and ~771,000 ha at 0.5 m pond depth; ~346,000 and ~446,700 ha at 1.0 m pond depth; and ~185,000 and ~250,000 ha at 1.5 m pond depth. Overall, deeper ponds reduced the risk. This study has developed a method to evaluate the negative impact of input pesticides to the environment from agricultural use related to fluctuation of aquaculture risk areas. The research indicates the potential relationship between pesticide input and the risk areas for aquaculture. The model has several significant uses: 1) it can provide information to policy makers for a more harmonized development of both aquaculture and agriculture in the Mekong delta in the future, 2) it provides data for aquaculture investment analysis to decrease the hazards caused by pesticide impacts, and 3) it provides a model capable of application to wide field scenarios and suitable for any pesticide type.

Globally fish production has continued to increase during recent years at a rate exceeding that of human population growth. However the contribution from capture fisheries has remained largely static since the late 1980s with the increase in production being accounted for by dramatic growth in the aquaculture sector. As of 2012 aquaculture accounted for approximately 42% of total fisheries production and 78% of inland fish production. In view of these figures it is unsurprising that for a number of regions aquaculture represents an important source of both food security and income. The use of Geographical Information Systems (GIS) and spatial data have seen substantial developments in recent years with the help of increasingly affordable computing capacity. From an aquaculture perspective the use of GIS has shown significant potential as a means of combining varied data sources, including those acquired via remote sensing, into models to provide decision support in relation to site selection. A common theme amongst site suitability assessments is the incorporation of climate variables relating to temperature and water availability. These factors in turn can have a significant influence on aquaculture in terms of water availability and quality, and temperature modulated growth performance. There is now a strong consensus that during the 20th century, and especially during recent decades, the earth has experienced a significant warming trend. There is also strong agreement that this warming trend is at least partially a consequence of anthropogenic greenhouse gas emissions and that some degree of further warming is inevitable. While global warming is typically discussed in terms of degrees centigrade of average global temperature increase the full effects in terms of climate changes will be varied both in terms of location and season. The current project focuses on site suitability for aquaculture in relation to changing climate conditions. Significant use is made of GIS and a range of spatial data including remotely sensed data and output from a series of climate models. The project consists of a number of key components: 1. Vulnerability of aquaculture related livelihoods to climate change was assessed at the global scale based on the concept of vulnerability to climate related impacts as a function of sensitivity to climate change, exposure to climate change, and adaptive capacity. Use was made of national level statistics along with gridded climate and population data. Climate change scenarios were supplied using the MAGICC/SCENGEN climate modelling tools. Analysis was conducted for aquaculture in freshwater, brackish, and marine environments with outputs represented as a series of raster images. A number of Asian countries (Vietnam, Bangladesh, Laos, and China) were indicated as most vulnerable to impacts on freshwater production. Vietnam, Thailand, Egypt and Ecuador stood out in terms of brackish water production. Norway and Chile were considered most vulnerable to impacts on Marine production while a number of Asian countries (China, Vietnam, and the Philippines) also ranked highly. 2. Site suitability for pond-based aquaculture was modelled at the global scale using a 10 arcsecond grid. Data from an ensemble of 13 climate models was used to model pond temperature and water availability for rain fed ponds under late 20th century conditions and for a 2°C global warming scenario. Two methods are demonstrated for combining data with a focus on the culture of warm water species. Results suggest both positive and negative impacts in relation to the 2°C warming scenario depending on location and season. Some areas are projected to see negative effects from maximum temperatures during the warmest parts of the year while for many regions there are likely to be potential increases in growth performance during colder months with possible expansion into previously unsuitable areas. 3. Methods for detecting surface water using remotely sensed data were investigated for Bangladesh. Use was made of data from the Moderate-resolution Imaging Spectroradiometer (MODIS) and Landsat ETM+ instruments with accuracy assessed against ground truth data collected in the field. A time series was constructed using all available MODIS data (approximately 13 years with an 8 day temporal resolution) to show areas of: surface water, land, and mixed land and water. The time series was then analysed to produce a layer showing the percentage of the total time series where surface water is indicated thus providing a spatial representation of flood prevalence. 4. A land cover data set was produced using 9 Landsat ETM+ scenes to cover the majority of Bangladesh. 10 different classification routines were evaluated including a decision tree approach unique to the current study. Classification results were assessed against two sets of ground control points produced: one based on field collected ground truth data and the other using a stratified random sampling procedure in association with visual analysis of high resolution true colour satellite images and ETM+ composites. The most accurate classifications were provided by the decision tree method developed for the current study and a Multi-Layer Perceptron (MLP) neural network based classifier. 5. Site suitability for pond-based aquaculture within Bangladesh was assessed using a GIS in combination with the ETM+ based land cover data, the MODIS based surface water time series, and components of the global site suitability assessment including modelled pond temperature data. Assessments were made based on late 20th century conditions and a 2°C global warming scenario. The MODIS surface water time series was also used to show the effects of storm surge flooding in relation to cyclone Aila that struck Bangladesh on 25th May 2009. The south and east of the country were considered most suitable for aquaculture due to more favourable cold season temperatures and higher water balance values. The north west of the country was considered least favourable due to higher maximum modelled pond temperatures and lower water balance values. The effect of the 2°C warming scenario was to enhance these trends. To date the potential spatial implications of changing climate for aquaculture has been significantly under researched. In this respect the current study provides a highly useful indication of where aquaculture related livelihoods may be vulnerable. In addition valuable and unique insights are provided into the distribution of areas of both potential increased, as well as decreased, suitability for existing aquaculture and further aquaculture development.

by Shu Keung Choi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 145-150). / ABSTRACT --- p.i / ACKNOWLEDGMENTS --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF FIGURES --- p.ix / LIST OF PLATES --- p.xi / LIST OF TABLES --- p.xii / Chapter CHAPTER 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Concerns on Current Air Quality Modeling Process --- p.2 / Chapter 1.2 --- Objective --- p.2 / Chapter 1.3 --- Rationale --- p.4 / Chapter 1.4 --- System Overview --- p.4 / Chapter 1.5 --- Questions --- p.6 / Chapter 1.6 --- Thesis Organization --- p.6 / Chapter CHAPTER 2. --- LITERATURE REVIEW --- p.8 / Chapter 2.1 --- Introduction --- p.8 / Chapter 2.2 --- Geographic Information System --- p.8 / Chapter 2.2.1 --- Data Assimilation --- p.9 / Chapter 2.2.1.1 --- Data Representation --- p.9 / Chapter 2.2.1.2 --- Data Format --- p.10 / Chapter 2.2.1.3 --- Data Alignment --- p.11 / Chapter 2.2.2 --- Modeling Support --- p.11 / Chapter 2.3 --- Environmental Modeling --- p.12 / Chapter 2.4 --- Integration of GIS and Environmental Modeling --- p.15 / Chapter 2.4.1 --- The Need for Integration --- p.15 / Chapter 2.4.2 --- Forms of Integration --- p.17 / Chapter 2.5 --- Air Quality Modeling --- p.20 / Chapter 2.5.1 --- Classes of Models --- p.21 / Chapter 2.5.1.1 --- Classification by Spatial Scale --- p.21 / Chapter 2.5.1.2 --- Classification by Modeling Approach --- p.22 / Chapter 2.6 --- Gaussian Plume Models --- p.24 / Chapter 2.6.1 --- Formulation --- p.24 / Chapter 2.6.2 --- Determination of σy and σz --- p.25 / Chapter 2.6.3 --- The Stability Classification --- p.26 / Chapter 2.6.4 --- Estimation of σy and σz --- p.27 / Chapter 2.6.5 --- Assumptions in the Gaussian Model --- p.30 / Chapter 2.7 --- Air Quality Model Evaluation --- p.31 / Chapter 2.7.1 --- Model Uncertainties --- p.31 / Chapter 2.7.1.1 --- Inherent Uncertainty --- p.31 / Chapter 2.7.1.2 --- Reducible Uncertainty Errors --- p.33 / Chapter 2.7.1.2.1 --- Meteorological Data Errors --- p.33 / Chapter 2.7.1.2.2 --- Emission Data Errors --- p.34 / Chapter 2.7.1.2.3 --- Model Errors --- p.34 / Chapter 2.7.2 --- Operational Performance Evaluation --- p.36 / Chapter 2.7.2.1 --- Woods Hole Performance Measures --- p.36 / Chapter 2.7.2.2 --- Fractional Bias and Fractional Scatter --- p.38 / Chapter 2.7.2.3 --- Measuring the Normalized Ratios --- p.39 / Chapter 2.7.2.4 --- Combination of Statistical Measures --- p.40 / Chapter 2.8 --- Visualization --- p.43 / Chapter 2.8.1 --- Visualization Software Framework --- p.43 / Chapter 2.8.2 --- GIS and Visualization --- p.46 / Chapter 2.9 --- Conclusion --- p.47 / Chapter CHAPTER 3. --- SYSTEM DESIGN --- p.48 / Chapter 3.1 --- System Overview --- p.48 / Chapter 3.2 --- Supported Models --- p.50 / Chapter 3.3 --- System Software Platforms --- p.51 / Chapter 3.3.1 --- ARC/INFO --- p.52 / Chapter 3.3.1.1 --- Overview --- p.52 / Chapter 3.3.1.2 --- The Role in the System --- p.53 / Chapter 3.3.2 --- Advanced Visualization System (AVS) --- p.54 / Chapter 3.3.2.1 --- Overview --- p.54 / Chapter 3.3.2.2 --- The Role in the System --- p.54 / Chapter 3.4 --- System Requirements and Specification --- p.56 / Chapter 3.4.1 --- Notation --- p.56 / Chapter 3.4.2 --- Data Preprocessing --- p.57 / Chapter 3.4.3 --- Data Postprocessing --- p.63 / Chapter 3.4.4 --- Model Performance Evaluation --- p.68 / Chapter 3.4.5 --- Visualization --- p.74 / Chapter 3.4.5.1 --- Reading ARC/INFO Data --- p.74 / Chapter 3.4.5.2 --- Applying Visualization Techniques --- p.77 / Chapter 3.4.5.2.1 --- Surface Mesh --- p.77 / Chapter 3.4.5.2.2 --- Multi-window Approach --- p.79 / Chapter 3.5 --- Data File Format --- p.85 / Chapter CHAPTER 4. --- A TEST CASE --- p.92 / Chapter 4.1 --- Introduction --- p.92 / Chapter 4.2 --- Test Case Components --- p.92 / Chapter 4.2.1 --- Study Area --- p.92 / Chapter 4.2.2 --- Source Data --- p.93 / Chapter 4.2.3 --- Air Quality Model - MPTER --- p.93 / Chapter 4.2.4 --- Meteorological Data Preprocessor - RAMMET --- p.95 / Chapter 4.3 --- Executing the Test Case --- p.95 / Chapter 4.3.1 --- Main Menu --- p.95 / Chapter 4.3.2 --- Viewing the study area --- p.96 / Chapter 4.3.3 --- Data Preprocessing --- p.96 / Chapter 4.3.3.1 --- Define Data Mapper --- p.98 / Chapter 4.3.3.2 --- Execute Data Preprocessor --- p.101 / Chapter 4.3.3.3 --- Meteorological Data Preprocessing --- p.102 / Chapter 4.3.3.4 --- Model Input File Editing --- p.103 / Chapter 4.3.3.5 --- Discussions --- p.105 / Chapter 4.3.4 --- Model Execution --- p.107 / Chapter 4.3.5 --- Data Postprocessing --- p.107 / Chapter 4.3.5.1 --- Import Model Result to GIS --- p.108 / Chapter 4.3.5.2 --- Iso-line of Concentration Map --- p.108 / Chapter 4.3.5.3 --- Discussions --- p.109 / Chapter 4.3.6 --- Model Performance Evaluation --- p.112 / Chapter 4.3.6.1 --- Program Execution --- p.113 / Chapter 4.3.6.2 --- Discussions --- p.113 / Chapter 4.3.7 --- Visualization --- p.116 / Chapter 4.3.7.1 --- Surface Mesh --- p.116 / Chapter 4.3.7.2 --- Multi-window Approach for 4D Data set --- p.117 / Chapter 4.3.7.2.1 --- Overview --- p.117 / Chapter 4.3.7.2.2 --- Overall Controls and Relations between Viewers --- p.121 / Chapter 4.3.7.2.3 --- Independent Controls within Each Viewers --- p.122 / Chapter 4.3.7.2.4 --- "The x,y,z-volume Viewer" --- p.123 / Chapter 4.3.7.2.5 --- "x,y,t-volume in ViewerZ" --- p.128 / Chapter 4.3.7.2.6 --- Other Viewers --- p.132 / Chapter 4.3.7.3 --- Discussions --- p.134 / Chapter 4.4 --- Conclusion --- p.137 / Chapter CHAPTER 5. --- CONCLUSION --- p.138 / Chapter 5.1 --- System Design Summary --- p.138 / Chapter 5.2 --- Summary of the Functions --- p.139 / Chapter 5.2.1 --- Data Preprocessing --- p.139 / Chapter 5.2.2 --- Data Postprocessing --- p.140 / Chapter 5.2.3 --- Model Evaluation --- p.140 / Chapter 5.2.4 --- Visualization --- p.141 / Chapter 5.3 --- Further Research --- p.143 / BIBLIOGRAPHY --- p.145

The Fincastle Bison Kill Site (DlOx-5), located in Southern Alberta, Canada, yielded a significant number of archaeological remains, including projectile points, lithic tools, debitage, fire broken rock (FBR) and fauna. The large 81 m2 East Block excavation area provided an opportunity to spatially analyze the remains from this part of the site using a Geographic Information System (GIS), a program that is becoming more widely employed and accepted in archaeology. This research explored the benefits of using a GIS to spatially analyze archaeological sites by using the data collected from the excavations carried out at the Fincastle Site. The process of applying spatial statistical tests and creating distribution maps within the GIS software was outlined, and the results were archaeologically interpreted. It was confirmed that a GIS can perform all of the tasks needed to spatially analyze an archaeological site and the additional benefits make a valuable component of archaeological research. / x, 144 leaves : ill. (chiefly col.) ; 29 cm

Leasing of state land under control of the Department of Land Affairs takes place, due to historical reasons, in a manner that is unconformable with the cadastre. The Department (and the State) is obliged to manage its assets efficiently and promote land reform. How can such leases be described spatially, and captured on a land information system? The author argues that it is indeed possible to develop a method, system or convention of spatial description for leased areas unconformable with the cadastre by relating it to the cadastre and capture and maintain data on such areas on a spatially and text-based database. In order to identify relevant best practices, available technology, a review was carried out on methodologies from other countries within the fields of land administration and land information systems, focussing on parcel-based cadastral systems. Fieldwork consisted firstly of interviews with officials and specialists in these fields for more information on the management of leases in the Department and available technology. A full set of active leases (52) from a District Office was acquired for analysis on current spatial descriptions. In a second visit some of these leased areas were surveyed by GPS to construct maps to aid with the development of a convention. Based on this work, the author developed a methodology/convention for indexing and spatial description of unconformable leases, with the current South African cadastre and embedded 21-character land parcel identifier as basis. It was demonstrated that basic technology could be used in the field, supported by an advanced land information system. The value of the convention lies in the fact that it relates the unconformable leases back to the formal cadastre within a land information system. Administration of leases will be more effective. Also that it could be applied to other spheres of land reform and non-parcel based geocoding of centroids indicating occupational or communal rights on land. / Thesis (M.Sc.)- University of Natal, Pietermaritzburg, 2003.

Leasing of state land under control of the Department of Land Affairs takes place, due to historical reasons, in a manner that is unconformable with the cadastre. The Department (and the State) is obliged to manage its assets efficiently and promote land reform. How can such leases be described spatially, and captured on a land information system? The author argues that it is indeed possible to develop a method, system or convention of spatial description for leased areas unconformable with the cadastre by relating it to the cadastre and capture and maintain data on such areas on a spatially and text-based database. In order to identify relevant best practices, available technology, a review was carried out on methodologies from other countries within the fields of land administration and land information systems, focussing on parcel-based cadastral systems. Fieldwork consisted firstly of interviews with officials and specialists in these fields for more information on the management of leases in the Department and available technology. A full set of active leases (52) from a District Office was acquired for analysis on current spatial descriptions. In a second visit some of these leased areas were surveyed by GPS to construct maps to aid with the development of a convention. Based on this work, the author developed a methodology/convention for indexing and spatial description of unconformable leases, with the current South African cadastre and embedded 21-character land parcel identifier as basis. It was demonstrated that basic technology could be used in the field, supported by an advanced land information system. The value of the convention lies in the fact that it relates the unconformable leases back to the formal cadastre within a land information system Administration of leases will be more effective. Also that it could be applied to other spheres of land reform and non-parcel based geocoding of centroids indicating occupational or communal rights on land. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

The Ferncliffe Catchment Conservancy has been identified, within the context of Pietermaritzburg, KwaZulu-Natal, for its important geographical and ecological features. The mapping and communication of these features to the broader community resident within the Conservancy have been envisaged as an important undertaking. A most effective way of achieving this goal was to use a Geographic Information System in the mapping exercise and in creating an inventory of the resources in the Conservancy and a monitoring database. Such spatial information would then provide stakeholders with a spatial context within which to appreciate the natural resources available and the problems associated with them. In undertaking this task, spatial data were acquired in digital form as well as from aerial photographs and 1:50000 topo-cadastral maps. These data were imported into ArcView GIS Version 3.1 where the mapping of the various resources was done. An inventory of the resources was created and a spatial database linking attributes that describe the physical environment, the natural vegetation, agricultural activities and the built environment, was set up. It became evident that using a Geographic Information System for natural resource management provides for integration of spatial information which would otherwise be contained in several separate databases and maps. Further, these data can be readily accessed, queried, upgraded and manipulated. For conservancies in urban and rural KwaZulu-Natal, and indeed, the rest of South Africa, to achieve their aims in natural resource management and monitoring, such an approach would be most efficient and effective. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2000.

<p>Dental caries is a multi-factorial disease that affects everyone irrespective of race, class or gender, however, the burden of the disease is often found in children from lower socio-economic backgrounds. The nature of the disease is such that it can be prevented. Various international studies on fluoride have shown a reduction in the prevalence of dental caries. By using geographical information systems, oral health data can be linked to the fluoride levels and further analysis could be done to identify areas at risk of dental caries as well as show patterns in the distribution of dental caries. The aim of this study was therefore to assess the effects of different levels of fluoride on the prevalence of dental caries in selected towns in the Northern Cape and Westen Cape. It also examined the application of Geographical Information Systems (GIS) to oral health data.</p>

Geographic information systems and remote sensing software were used to analyze data to determine the area and volume of the proposed Fastrill Reservoir, and to examine seven alternatives. The controversial reservoir site is in the same location as a nascent wildlife refuge. Six general land cover types impacted by the reservoir were also quantified using Landsat imagery. The study found that water consumption in Dallas is high, but if consumption rates are reduced to that of similar Texas cities, the reservoir is likely unnecessary. The reservoir and its alternatives were modeled in a GIS by selecting sites and intersecting horizontal water surfaces with terrain data to create a series of reservoir footprints and volumetric measurements. These were then compared with a classified satellite imagery to quantify land cover types. The reservoir impacted the most ecologically sensitive land cover type the most. Only one alternative site appeared slightly less environmentally damaging.

The purpose of the project was to develop a Web application using GIS data that would map addresses or coordinate information and then find any hazardous areas that may fall within a given distance to this location. The geographic area of this project covers the extent of cities San Bernardino, Redlands, and Yucaipa, California.