Raster Database Research Articles

Scale-independent Land-use Allocation Modeling in Raster GIS

: A common application of raster-based geographic information systems (GIS) is as an aid in multi-criteria, multi-objective land-use decision problems. However, as the cell resolution increases by reducing cell size, the number of rows and columns in the raster representation also increases. The size of raster representations of land-use problems is often a determining factor in the type of methodology used in solving such problems. Previous land-use allocation models integrated with a raster GIS have used either decision heuristics or exact methods based on linear programming models. The former is fairly scale independent but produces only approximate answers, whereas the latter produces optimal solutions but remains more scale dependent. This paper presents a specialized dual simplex method adapted to the generalized assignment problem that can be used to solve large-scale land-use allocation problems. The dual approach only requires that information for one pixel be stored at a time thus allowing the solution of problems based on any size raster database.

The land use and land cover change database and its relative studies in China

In the mid-1990s, we established the national operative dynamic information serving systems on natural resources and environment. During building the land-use/land-cover change (LUCC) database for the mid-1990s, 520 scenes of remotely sensed images of Landsat Thematic Mapper (TM) were interpreted into land-use/land-cover categories at scale of 1:100,000 under overall digital software environment after being geo-referenced and ortho-rectified. The vector map of land-use/land-cover in China at the scale of 1:100,000 was recently converted into a 1-km raster database that captures all of the high-resolution land-use information by calculating area percentage for each kind of land use category within every cell. Being designed as an operative dynamic information serving system, monitoring the change in land-use/land-cover at national level was executed. We have completed the updating of LUCC database by comparing the TM data in the mid-1990s with new data sources received during 1999–2000 and 1989–1990. The LUCC database has supported greatly the national LUCC research program in China and some relative studies are incompletely reviewed in this paper.

Temporal and spatial prediction of radiocaesium transfer to food products.

A recently developed semi-mechanistic temporal model is used to predict food product radiocaesium activity concentrations using soil characteristics available from spatial soil databases (exchangeable K, pH, percentage clay and percentage organic matter content). A raster database of soil characteristics, radiocaesium deposition, and crop production data has been developed for England and Wales and used to predict the spatial and temporal pattern of food product radiocaesium activity concentrations (Bq/kg). By combining these predictions with spatial data for agricultural production, an area's output of radiocaesium can also be estimated, we term this flux (Bq/year per unit area). Model predictions have been compared to observed data for radiocaesium contamination of cow milk in regions of England and Wales which received relatively high levels of fallout from the 1986 Chernobyl accident (Gwynedd and Cumbria). The model accounts for 56% and 80% of the observed variation in cow milk activity concentration for Gwynedd and Cumbria, respectively. Illustrative spatial results are presented and suggest that in terms of food product contamination areas in the North and West of England and Wales are those most vulnerable to radiocaesium deposition. When vulnerability is assessed using flux the spatial pattern is more complex and depends upon food product.

The Climate Information System of China

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 18:229-247 (2001) - doi:10.3354/cr018229 The Climate Information System of China Zongbo Shang1,*, Qiong Gao2, Dianan Yang1 1Laboratory of Quantitative Vegetation Ecology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China 2MOE Key Laboratory of Environmental Change and Natural Disaster, Institute of Resources Science, Beijing Normal University, Beijing 100075, China *Present address: Nanxincun 20, Xiangshan, Beijing 100093, China. E-mail: shangzb@sohu.com ABSTRACT: The Climate Information System of China (CISC) was built using Visual C++ and Java to perform 4 main functions: (1) to describe the variation in the spatial distribution of particular climatic variables with minimal digital information; (2) to separate the impacts of large-scale factors and local factors on climatic distribution and generate a raster database from the data collected from dispersed stations; (3) to share the climatic data on the Internet; and (4) to evaluate the impact of global change on Chinese water conditions under a number of prescribed climate scenarios. The establishment of CISC is described in detail. A digital elevation model and some meteorological (climatic) equations were used to calculate raster radiation data. Trend surface analysis and the interpolation method were used to analyze the spatial distribution of temperature, precipitation, relative humidity, sunshine fraction, and wind velocity and to generate the raster database. Penman¹s equation was amended and parameterized to calculate the potential evapotranspiration over China. An aridity index was calculated under present situations and 12 prescribed climate scenarios (raising mean temperature by 1.5, 3.0 and 4.5°C and changing precipitation by 0, +10, +20 and -10%) to assess the sensitivity of Chinese water conditions to global change. Some Java applets were written to make it possible to share Chinese climate information on the Internet. KEY WORDS: Climate Information System of China (CISC) · Trend surface analysis · Aridity index · Global change Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 18, No. 3. Online publication date: November 02, 2001 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2001 Inter-Research.

THE BIODIVERSITY DATABASE IN LITHUANIA—DISTRIBUTIONAL AND ENVIRONMENTAL APPLICATIONS

Abstract The DBMS software, currently being used for the Biodiversity database management, developed by the project group “Ecological diversity of Lithuania” and currently maintained at the Institute of Ecology (Vilnius, Lithuania), is Borland® Paradox®, mainly Paradox® for DOS ver. 4.5. The relational structure of the database contains minimum of coding and allows to perform data management and all basic outputs, using forms and reports of the standard interface, it does not require special programs or applications in DBMS environment. The database contains a taxonomic and literature citation blocks, species distribution data files (Budrys, 1998, in press). Particular data block of the database contains lists of geographic names, and habitat information. These files are linked to a master file with records related to 1×1 km grid of territory, designed as a raster database. For particular purposes of inexperienced user, a minimized regional version of the database (RBIDB) with a user-friendly interface wa...