Spatial Data Collection Research Articles

U.S. Census Bureau Geographic Support: A Response to Changing Technology and Improved Data

The TIGER system was developed by the Geography Division of the U.S. Census Bureau to support agency censuses and surveys. The system has been crucial to meeting the demands placed on the U.S. Census Bureau. It has been widely used by the public for a large and diverse number of uses. As public uses evolved, demands evolved. In parallel, technology and spatial data collection evolved. TIGER should now support a larger purpose. This article discusses some developments of the TIGER system and presents some of the key components of TIGER modernization: improvement of positional accuracy, connection to the National Spatial Data Infrastructure (NSDI), and improved geographic analysis.

Integrating Social Preference in GIS-Aided Planning for Forestry and Conservation Activities: A Case Study from Rural SE Asia

Land-use planning using geographic information systems (GIS) commonly emphasizes biophysical spatial data; however planning can be improved by integrating spatial sets of socioeconomic data into the GIS. As an example, we compared a traditional GIS-aided forestry planning protocol that considered only biophysical suitability, with an integrated GIS-aided approach that incorporated both biophysical and socioeconomic suitability. The analyses were conducted for the planning of plantation investments in the Kyaukpadaung Township in the dry zone of central Myanmar. The traditional approach used three biophysical layers for suitability: land use, slope, and accessibility. In contrast, the integrated GIS approach included biophysical suitability data, perceptions and preferences of local villagers towards forestry (social suitability), and quantitative socioeconomic data. The results indicated that the integrated approach provided two principal benefits over the traditional method. First, the integrated method resulted in a more precise idea of suitable sites for plantation investment that could benefit more rural people and also lead to greater investment efficiency. Second, incorporating social preference into the GIS takes into account the crucial element of social capital (viz., social preference), which should lead to higher levels of community acceptance of plantation projects because those plantations would be established on socially suitable land. A second GIS exercise showed how conservation investment decisions could be informed using the integrated method. The results of this study support the idea that GIS-aided planning activities can be enhanced through the incorporation of social data into the analysis. When applicable, spatial data collection efforts for GIS-based planning exercises should incorporate spatial socioeconomic data.

LAND-BASED INTEGRATED SYSTEMS FOR MAPPING AND GIS APPLICATIONS

An emerging solution to the problems faced in modern data collection campaigns is the integration of various navigation and remote sensing technologies together on a common land-based platform. These land-based Mobile Mapping Systems (MMS) are capable of providing fast, efficient, cost-effective, and complete data collection. Their development has been motivated by a desire to overcome the problems with alternative methods of spatial data collection. These alternative methods include point-wise GPS and traditional terrestrial surveying — which are ill suited for rapid or dense data collection — and aerial photogrammetric surveys — which do not provide complete coverage. Land-based MMS share none of these disadvantages, while still being capable of providing similar object space accuracies.This paper provides a brief history of land-based MMS, including a summary of nearly all systems developed up to now. It then details the development of the geo-referencing formulas used by MMS and shows how such formulas can be used to determine the accuracies of points measured by the system. The paper concludes with a closer examination of two land-based mobile mapping systems — one vanbased, the other person-based. Both systems demonstrate that MMS are able to achieve absolute object-space accuracies between 10–20 em.

MapLibrarian—Map Index Querying

MapLibrarian is a digital and online solution for interactive spatial querying and management of map and spatial data collections. MapLibrarian opens access to map collections to a global audience and offers searching services twenty-four hours a day. The MapLibrarian software solution removes the burden of paper-based index maintenance and improves the accuracy of collection inventory data. Built using industry standards and an open-architecture design, MapLibrarian is a unique application of spatial information technology in the traditional world of map collection management.

Designing a visualization system for hydrological data

The field of hydrology is, as any other scientific field, strongly affected by a massive technological evolution. The spread of modern information and communication technology within the last three decades has led to an increased collection, availability and use of spatial and temporal digital hydrological data. In a two-year research period a working group in Muenster applied and developed methods for the visualization of digital hydrological data and the documentation of hydrological models. A low-cost multimedial, hydrological visualization system (HydroVIS) for the Weser river catchment was developed. The research group designed HydroVIS under freeware constraints and tried to show what kind of multimedia visualization techniques can be effectively used with a nonprofit hydrological visualization system. The system's visual components include features such as electronic maps, temporal and nontemporal cartographic animations, the display of geologic profiles, interactive diagrams and hypertext, including photographs and tables.

The Tarrawarra project: high resolution spatial measurement, modelling and analysis of soil moisture and hydrological response

Detailed spatial patterns of soil moisture were measured for 13 dates at the 10·5 ha Tarrawarra catchment in southern Victoria, Australia. Several analyses of the data are summarized. These include: hydrological behaviour, including preferred states, spatial organization and the performance of terrain indices; geostatistical properties of the soil moisture patterns; and remote sensing of the soil moisture patterns. In the second part of the paper, the patterns along with surface runoff and meteorological data are used in applications of the Thales and VIC models at Tarrawarra. Thales is a process-based distributed parameter hydrological model which explicitly simulates the spatio-temporal patterns of soil moisture, while VIC uses a lumped statistical distribution approach to model the spatial variability of soil moisture storage. Both models simulate saturation excess runoff and are forced by rainfall and potential evapotranspiration. VIC was calibrated to observed runoff at the catchment outlet. Limited manual calibration of Thales to runoff and the soil moisture patterns was performed. Internal testing was achieved by comparison of predicted and observed spatial soil moisture patterns for the Thales model and of predicted and observed cumulative distributions of active soil moisture storage for the VIC model. With limited calibration effort, Thales was able to to simulate the seasonal changes in characteristics of the spatial soil moisture patterns. Detailed examination of the errors in the simulated patterns allowed identification of structural problems in the model, including problems with simulating lateral redistribution as the catchment wets in autumn. For the VIC model, time-series of spatially averaged internal state variables (total storage) were consistent with observations. However, the statistical distribution of soil moisture storage assumed in the model differed from that observed. The collection of detailed spatial data for soil moisture patterns provided a basis for testing the internal states relevant to each model formulation (spatially distributed for Thales and statistically lumped for VIC), as well as improving the identification of the dominant runoff processes. Copyright © 1999 John Wiley & Sons, Ltd.

Map librarianship: an introduction

Providing the basics for working with spatial-data collections in libraries, this book describes in detail the processes and procedures of map selection, acquisition, classification, cataloging, everyday storage, care, preservation, reference, public relations, and education. Focus is on practicalities of handling both hard copy and digital forms of atlases, maps, remote-sensing images, globes, and so forth. Larsgaard has thoroughly revised and updated the book, addressing major changes resulting from the shift of spatial data to digital forms, and she has added significant new material to the chapters on selection, cataloging, and reference.

An approach for greenway suitability analysis

Greenway analysis is designed to identify and measure the suitability of potential sites for greenway development. This evaluation can be regarded as an extremely difficult task due, in part, to the large number of criteria and large volume of data that may be required for the determination. The purpose of this paper is to present an approach to greenway analysis that integrates suitability analysis with geographic information system (GIS) technology to identify suitable sites for greenway development in the town of Prescott Valley, AZ, USA. This approach identified five major steps involved in the greenway analysis, these include: identification of land-use functions, spatial data collection, development of weighting values, data integration and analysis using GIS, and output evaluation. Land-use function identification, and weighting values were developed from a wide range of resources including the Prescott Valley General Plan, surveys, expert opinion and published literature. Spatial data were obtained from federal, state, and local agencies. Where specific data were not available, these data were collected from the site using inventory techniques. Three land-use functions were identified for the Prescott Valley study area, wildlife habitat, recreation, and riparian corridor. For each of these functions, four or five primary factors were determined. Additionally, for each factor, a land capability rating was established. Results of the surveys indicated that normalized weightings for the functions were 1.0 for wildlife habitat, 0.862 for recreation, and 0.653 for riparian corridor. Rankings for the primary factors within the functions ranged from a high of 0.468 to a low of 0.049, with the sum of weighting values for all factors within a function equal to 1.0. Land capability values for attributes within factors were set as high, moderate, low, and no capability. All data were integrated into a vector-based GIS software and a total of 14 coverages were created, Spatial analysis was performed using an overlay technique combining all factors within a function, and then by combining all resulting factor outputs to produce an overall greenway suitability analysis. The final analysis was then evaluated by a panel of experts to determine its accuracy and potential for use in a greenway development plan.

Traffic Engineering Recurrent Spatial Knowledge Base: Design and Implementation

Several regional and environmental agencies record spatial data continuously at fixed time intervals such as hourly, daily, monthly, and annually. Such a data collection is termed a recurrent spatial data collection. This paper reports experiences from the implementation of a recurrent spatial knowledge base for traffic analysis. The knowledge base consists of a database, a function library, and a procedure collection. The knowledge is either retrieved directly from the database or computed using functions from the function library. The procedure collection stores various procedures that can be used for statistical and artificial intelligence analysis. The knowledge base organization is transparent to its users. A scientific analysis language is used to provide a spreadsheet-like interface for the knowledge base. Selection of an appropriate data model for the database and its design and implementation is also discussed in detail. The discussion focuses on issues such as knowledge retrieval, access time, and storage requirements. It is argued that the NF 2 relational model provides a better data model for representing the recurrent spatial hierarchy than the relational model. It is shown that the NF 2 model is more efficient in terms of access time and storage requirements.

GIS Approaches to Regional Analysis: A Case Study of the Island of Hvar. By Vincent Gaffney and Zoran Stančič.

Gaffney and Stancic publish preliminary results of a regional studies project on the Dalmatian island of Hvar (4 km from the Croatian coast, 68-km long, and 15-km wide at most). A geographical information system (GIS) program was fundamental to the design of the Hvar project. Case studies from Hvar show how archaeologists can employ GIS. GIS facilitates the collection, storage, retrieval, analysis, and presentation of spatial data. Section 1 describes the methods of GIS and the equipment (including computer hardware and software) needed. Section 2 applies GIS techniques to problems of territorial boundary definition, the analysis of communication routes, and the relationship of archaeological sites to agricultural land within their economic territories. Five topics are discussed as examples of GIS applications in archaeology. GIS could be an invaluable tool for government archaeological services entrusted with managing archaeological heritage.

Correlated Versus Uncorrelated Hydrologic Samples

Spatial data are collected at various locations. Two cases are considered: (1) The observations are independent; and (2) the observations are correlated. If the data are assumed to be normally distributed with constant mean and variance, it is shown that the optimal sample sizes under the independent assumption discussed in this note provide further details correlated case (nó) are related by the expression n*=[(nó2]/(n*+2ΣΣΣSrij), where rij denotes the correlation coefficient between observations at locations i and j. This note derives the preceding expression and provides further details concerning the statistical inference of correlated spatial variables. The importance of the relationship between correlated and uncorrelated sample sizes for hydrologic spatial data collection is emphasized in this work.

Analysis of a Cylindrical Hybrid Positron Camera with Bismuth Germanate (BGO) Scintillation Crystals

Theoretical design studies of a multilayer hybrid computed tomographic system which could perform both X-ray transmission computed tomography (XCT) and positron computed tomography (PCT) are presented. Use of BGO scintillation crystals makes it possible to achieve the highest spatial resolution and coincident data collection efficiency possible with the present technology. In the new hybrid system, the multilayer positioning is achieved by use of one dimensional Anger principle with BGO crystals. The ultimate resolution and counting rate attainable with the system is discussed in reference to the true to random ratio. Present study indicates that the resolution and efficiency that can be achieved in PCT mode are 5-6 mm fwhm with efficiency gain of over a hundred in comparison to the existing NaI(Tl) ring system at UCSD.