Variograms, Trend removal and Universal Kriging in Advanced Spatial Analysis and Modeling

Introduction

The main objectives of this study are i) to learn how to use ArcGis‟s GeoStatistical Analyst to examine spatial structure and to interpolate surfaces using GeoStatistical techniques, and ii) to explore GeoStatistical technique using S-Plus (variograms, trend removal, Universal Kriging). The data available for this study include a GeoDatabase that contains a random spot heights feature class for an area in the northwest of the City of Calgary and the City Limits for the City of Calgary. Additionally, a 25m Digital Elevation Model (DEM) for the same area is also included. In this study, we are interpolating the random spot heights surface so as to predict the elevation of the surrounding areas. The software packages used for interpolation are ArcGis and S-Plus. ArcGis is used for Ordinary Kriging interpolation and S-Plus for Universal Kriging. This study aims at evaluating the results performed by two software packages. It also highlights the strengths and weakness of the software packages used for the analysis. This study includes many maps, figures, tables and command lines created in Arcgis and S-Plus; however, the end product of this study is to match the Ordinary Kriging performed in ArcGis and Universal Kriging performed in S-Plus and to understand how different software packages perform the interpolation.

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Interpolation and Trend Surface Analysis in Advanced Spatial Analysis and Modeling

Introduction

'In the mathematical subfield of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points. Surface interpolation functions make predictions from sample measurements for all locations in a raster dataset whether or not a measurement has been taken at the location. There is a variety of ways to derive a prediction for each location; each method is referred to as a model. With each model, there are different assumptions made of the data, and certain models are more applicable for specific data. The Interpolation tools are
generally divided into deterministic and geostatistical methods' (ArcGis 2004). In this study IDW is used as the deterministic interpolator and Global Polynomial interpolation as geostatistical interpolator.

'Trend surface analysis is a method used for the analysis of change over space which attempts to decompose each observation on a spatially distributed variable into acomponent associated with any regional trends present in the data and a component associated with purely local effects. This separation into two components is accomplished by fitting a best-fit surface of a previously specified type using standard regression techniques' (Unwin, 1975). In this study, our main objective is to interpolate the average income for the City of Calgary using ArcGis and calculate a First and Second Order Trend Surface using S-Plus.

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Point Pattern Analysis in Advanced Spatial Analysis and Modeling

Introduction

The analysis of point data in space, in order to obtain patterns in the points that inform something about the underlying process that generated the points, is often termed as point pattern analysis (Fotheringham et al. 2000). The objective in learning more about spatial patterns is to assess spatial dependence so that we may ultimately correct our statistical analyses based upon dependent spatial data and to learn whether geographic phenomena cluster in space. The need of the quantitative measures of spatial pattern is because it is simply not sufficient to rely on one’s visual interpretation of a map (Rogerson 2006, 224). Point pattern analysis is particularly popular in the fields of biology (Diggle, 1983 in Fotheringham et al., 2000), epidemiology (Diggle et al. in Fotheringham et al., 2000) and the analysis of crime patterns (Bailey and Gatrell, 1995 in Fotheringham et al., 2000). This study focuses on the spatial pattern of the Park centers in the residential areas of Calgary.

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Insurance Risk Profiling in Alberta

The main objective of this study is to develop an “Atmospheric Risk Composite Score” and then a “Catastrophic Risk for Alberta – Atmospheric Hazard” score as per the FSA boundaries for the Alberta province, Canada. This is based on three atmospheric natural hazards viz. 50 Year Return Wind-speed, Average Number of Days with Hail, Number of Tornadoes per Year (per 10,000 sq. km.). This exercise is set to explore natural hazards data for Alberta and develop a summary of atmospheric risks similar to the type of risk scoring that is used by the insurance industry.

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Geodemographic Segmentation: Social vulnerability index

Social vulnerability is one of a series of indicators that are commonly used to assess risk or vulnerability in a geographic population. It is a useful tool for agencies such as Regional Health and Child and Family Services for use in long-term planning, policy development and resource allocation. The Social vulnerability Index is a very specific tool to measure need of a population through highlighting stress and disadvantage as evidenced in the 2001 census. Demographically, the Social vulnerability Index is based on nine census variables. The main purpose of this study is to work with the 2001 Statistics Canada census data at the Dissemination Area (DA) level, and develop a Social vulnerability Index map for the Calgary CMA.

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Practical application of GIS in Business planning and operations

The main purpose of this study is to explore the creation of trade area customer profiles and undertake trade area analysis in the city of Calgary, Canada. The data available for the analysis is a customer survey data for ABC sporting goods store which was created through interviewing customers as they left three stores during a one week period in the month of September. The three ABC sporting goods outlets in Calgary market are located in three different malls viz. Crowfoot centre as store A, Westhills as Store B and Bankers Hall as Store C. The customer locations were geocoded by matching postal codes. ABC sporting goods store are new to Calgary market and was first opened in the year 1993. ArcGIS software package is used for the analysis. This study focuses on the trade area analysis of the ABC sporting goods store.

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Developing a landuse real estate GIS model

The main purpose of this study is to develop a demo land use real estate model for Advanced Real Estate Solutions (ARES) Ground in Calgary. A typical request from a young family is provided for the neighborhood search criteria to use in the demo model. The potential client request includes a) existing residential areas b) within 1000 meters to an elementary school c) house price between $200,000 to $300,000 d) Average Income greater than $100,000 e) On average, thee or more bedrooms, and f) at least 500 meters from a major road. The data available for analysis are ‘Calgary communities’, ‘Calgary community land use 2001’, ‘Calgary major roads 2001’, ‘Calgary elementary schools 2001’ as shape files and ‘Calgary community average bedrooms’, ‘Calgary community average house price’ and ‘Calgary community average income’ as ‘.dbf’ files. ArcGIS is used for analysis. 

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GIS Mapping and Cartography to map possible sightings of Caribou in Revelstoke National Park

The International Cartographic Association defines cartography as the art, science, and technology of making maps, together with their study as scientific documents and works of art which can include all types of maps, plans, charts, and sections, three-dimensional models and globes representing the Earth or any celestial body at any scale (Dent 1993). According to Longley et al. (2005) GIS has fundamentally changed cartography and the way we create, use and think about maps. This study is intended to use ArcGIS software package and create high quality cartographic maps. The datasets available for analysis are the general land cover map of Revelstoke (British Columbia) 1997, the Revelstoke forest cover shape file, and other ArcGIS format files such as boundary, digital elevation model, highways, lakes, glaciers, streams etc. These datasets are used to create two high quality cartographic maps. The first map outlines the general land cover map area clipped with features such as roads, lakes, highways and glaciers. The second map shows the possible sightings of Caribou in the study site during the early winter. The purpose of the first map is to give a general idea of the Revelstoke national park for the tourists and visitors. The purpose of the second map is to assist the conservationist and concerned authorities about the possible sightings of Caribou during the early winter. The main objectives of this study are to i) gain familiarity with ArcGIS, specifically ArcMap,
ArcCatalog, and ArcToolbox and ii) create informative, visually pleasing, well balanced maps using established cartographic principles.

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