GIS (geographic information system) technology is commonly described as a computerised system for the compilation, access, retrieval, analysis and display of geographic and geographic-related data. Modern GIS is much more than computerised mapping - it provides the technology basis for an information infrastructure for bringing all manner of data together geographically to support integrated and multi-sector decision-making at many levels. It also consist of 5 Components, the people, the software, the hardware, the data and the standards.

A spatial data infrastructure (SDI) is a data infrastructure implementing a framework of geographic data, metadata, users and tools that are interactively connected in order to use spatial data in an efficient and flexible way. Another definition is "the technology, policies, standards, human resources, and related activities necessary to acquire, process, distribute, use, maintain, and preserve spatial data

The BNSDI (Belize National Spatial Data Infrastructure) is to provide an enabling environment for the CRIP project preparation facility, providing critical information infrastructure to support more effective formulation, design, development, monitoring and evaluation of targeted retrofitting, rehabilitation and reconstruction activities that are needed to strengthen the resilience of critical infrastructure to natural hazards and the anticipated impacts of climate variability. Beyond the immediate CRIP program requirements the study is also addressing a broader range of development concerns across all major sectors in Belize.

The Spatial Data Center develops state-of-the-art methods for geospatial analysis, spatial econometrics, and geo-visualization; implements them through open source software tools; applies them to policy-relevant research in the social sciences; and disseminates them through training and support to a growing Belize community of spatial analysts.

Fundamental geospatial data sets (FGDS) are those data types that are most commonly needed by multiple entities within the BNSDI community. These often include, among other issues, topographic information, cadastral information, ortho-rectified aerial photography, elevation data, transportation, hydrography, governmental administrative units, land use/land cover, demographics, soils, climatology, air and water quality, community facilities and service areas. International experience has revealed a range of information types that are often needed in common within an NSDI, and this list has been used as a starting point for further refinement and extension to a form that is specific to Belize.

Scale is the relationship that the depicted feature on map has to its actual size in the real word (more: map scale). All maps are modeled representations of the real world and therefore the features are reduced in size when mapped. In other words, scale is the measurement of the amount of reduction a mapped feature has to its actual counterpart on the ground.

All maps will have an indicator of the scale of the map. A map that doesn’t conform to a specific scale will be indicated by the words “not to scale” (or NTS).

Different applications of geospatial data have different requirements for geographic scale and levels of spatial detail and accuracy. The geographic scale at which information is compiled can be indicative of the level of detail and accuracy that can be reliable achieved. The BNSDI geospatial data can be grouped into three scale ranges:

• • Large scale. 1:1,000 to 1:5,000 – typical scales for an urban neighborhood or for detailed engineering works, or to view a whole village.
• • Medium scale. 1:10,000 to 1:25,000 – more suitable at the city level, or for a large area of relatively distributed human development;
• • Small scale. 1:50,000 and above – used to visualize large parts of the country. Much smaller scales may be used to depict data at the national and international scales, but these are too general as FGDS for most applications, and are therefore not specifically addressed here;

Positional (horizontal and vertical) accuracy can be of crucial importance, and there is a relationship between this and scale, whereby the level of accuracy generally increases at larger scales. Attribute accuracy is also important to the overall accuracy of a geospatial dataset. This refers to the consistency and accuracy of the information that has been entered into tabular database fields.

Scale is the relationship that the depicted feature on map has to its actual size in the real word (more: map scale). All maps are modeled representations of the real world and therefore the features are reduced in size when mapped. In other words, scale is the measurement of the amount of reduction a mapped feature has to its actual counterpart on the ground.