What is GIS?

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.


What is GIS?

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.

What is Spatial Data Infrastructure (SDI)?

A Spatial Data Infrastructure (SDI) provides a framework of standards, policies, data, procedures, and technology to support the effective coordination and sharing of spatial information among a community of stakeholders. Extensive national SDI programmes are now underway in North America, Europe, Australia and elsewhere, and a Global Spatial Data Infrastructure (GSDI) programme has been formed. These existing programmes have established important groundwork, but some countries with rapidly transforming economies are not organisationally ready to adopt these models at a similar rate of development, and many have special political, economic and legal contexts that require a unique approach. For most countries in the world, SDI involves a step-by-step, incremental process that must acknowledge the special circumstances of each nation.

What is the Abu Dhabi Spatial Data Infrastructure (AD-SDI)?

The Abu Dhabi Spatial Data Infrastructure (AD-SDI) is conceived as a national programme to harmonise, integrate and optimise the development and sharing of fundamental geographical and statistical information across all government agencies and institutions. The development of this programme is being carried out through a step-by-step, practical process that will establish a strategic and evolving framework for a long term AD-SDI, and provide coordination and support to the development of its various components through a carefully conceived and guided incremental process. It is recognised that this infrastructure can only be as strong as the community of agency stakeholders that comprise it, thus each component of the programme will seek to build on and leverage the many good works being carried out in many of the more progressive agencies in Abu Dhabi, across all sectors. This programme is being sponsored in Abu Dhabi by the Abu Dhabi Systems and Information Centre (ADSIC), under leadership of HE Rashed Lahej Al Mansoori.

For more information concerning the AD-SDI programme, please contact us.

Who is involved in the AD-SDI?

The AD-SDI programme is meant to develop into a broad and inclusive effort, starting with public sector agencies but eventually encompassing the private sector and civil society. In the foundation stage of building the AD-SDI, a number of key agencies have been selected to participate in the initial AD-SDI programme. Most of these agencies are either those that have a mandate to provide critical geospatial data, or that are currently involved in major projects that involve the production of this information. Coordinators from each agency are to be assigned to work with the AD-SDI team. The key agencies include:

  • Abu Dhabi Systems and Information Centre (ADSIC)
  • The Department of Municipal Affairs (DMA)
  • Abu Dhabi Municipality (ADM)
  • Al Ain Municipality (AAM)
  • Western Region Municipality (WRM)
  • Military Survey Department (MSD)
  • Environmental Agency Abu Dhabi (EAD)
  • Department of Economic Development (DED)
  • Abu Dhabi Water and Electricity Authority (ADWEA)
  • Etisalat
  • Abu Dhabi National Oil Company (ADNOC)
  • Urban Planning Council (UPC).

Other government agencies that may provide less important geospatial data or that have a lighter use of such data will also participate in this foundation stage.

What is the Spatial Data Centre (SDC)?

The SDC (Spatial Data Centre) is a unit that has been set up within the e-Government Programme to facilitate, coordinate, and support the foundation building stage of the AD-SDI.  It comprises a team of GIS and SDI professionals, strategic planning specialists, outreach specialists, and GIS technicians that have been assembled to operate the SDC through its important initiation stage. The form, function, staffing, and administrative position of the SDC will be shaped according to the AD-SDI Strategic Plan, Programme Design, and Implementation Plan, all now under development.

What are Fundamental Geographic Data Sets (FGDS)?

The FGDS framework is a set of essential data themes which are the building blocks for planning and design of a national spatial data infrastructure. There already exist international data model standards that address many of the fundamental data topics that will be developed through large or emirate-wide projects. Because these models reflect the experiences and results of trial-and-error to many considerations by a broad group of users, they are often quite comprehensive, large and complicated. The AD-SDI Team reviewed many of these models for their applicability to the situation in Abu Dhabi and crafted an overall Data Framework to meet the needs of the broader AD-SDI, inclusive of ongoing and planned emirate-wide projects. A data framework and model research report was generated previously that presents the results of this research and developed an FGDS framework for Abu Dhabi. It is expected that this initial framework will be periodically updated and refined as the AD-SDI development progresses.

What is the difference between Fundamental and Framework Data Sets?

FGDS can be characterized as ‘fundamental’ or ‘framework’.

Fundamental Data Sets. These are topics that are commonly needed by many organizations, and it is this common need that makes them fundamental. They may be geospatial "primitives" (i.e. basic spatial information upon which other information can be linked or derived), or they may be derived. For example, average rainfall depicted with isoline rainfall contours may be fundamental information for agriculturalists and water managers, but is derived from information gathered at meteorological stations.

Framework Data Sets. These are topics that are geospatial primitives to which other topical data sets and statistics can be linked. As such, all framework data sets are fundamental, but the opposite is not true. For example, a parcel boundary database can provide a framework for linking many other types of data such as ownership, building permits, student records, and utility customer records. Framework data sets are, by definition, fundamental data sets as well.

What is scale?

Scale refers to measurements on a map, as compared to measurements in the real world. For example, the distance represented by one centimeter on a 1:20,000 scale map would be equivalent to 20,000 centimeters, or 200 meters, on the face of the earth. It is best to think of scale as a fraction in determining whether a particular scale is small or large. For example, data at 1:1,000 or 1:5,000 would be referred to as large scale, while data at 1:100,000 or 1:1,000,000 would be referred to as small scale. In fractional terms, 1:1,000 equals 0.001, while 1:1,000,000 equals 0.000001, and therefore, the 1:1,000 scale data is at a larger scale because the resulting value (0.001 versus 0.000001) is larger. This distinction can be confusing because the amount of area depicted at smaller scales increases, while the amount of detail decreases.

small scale and large scale

Does scale matter?

In a GIS, data can be physically displayed at any scale desired; however, the compilation scale of the information will often dictate the level or resolution of mapped features that is appropriate. Large scale mapping tends to be more accurate and detailed than small scale mapping. The more detailed the mapping, the greater the effort to collect, store, maintain, manipulate and display the information. Also, displaying very detailed information as a regional level may be slow in a GIS because of the amount of coordinate information involved, and the inappropriate detail may graphically clutter the resulting map view. Conversely, information compiled at a gross scale may not be detailed enough to support local applications.

Based on the above, compiling the geographic information at an appropriate level of resolution involves a careful balance between application needs for accuracy and detail, and the resulting constraints related to building and maintaining the database at that level. On the other hand, display rules can be configured within GIS applications to help users in locating and accessing information depending on the geographic extent of their viewing and purpose of specific applications.

What is relationship between accuracy and scale?

The relative accuracy of linear and aerial measurements may vary from one place to another but on the other hand, accuracy requirements become less stringent as we move up to smaller scales. Therefore, maintaining a comprehensive metadata on the various data sources with their accuracy levels is very crucial. Also, when linear features such as roads and highways are compiled at a relatively large scale, it is recommended that a generalized version of those features be derived when they are displayed at smaller scale in order to reduce GIS application performance degradation. However, when facility data has been compiled as point features at a given scale, they can be re-projected at the smaller scale “on-the-fly” by the application software without excessive performance degradation.

What scales are relevant for the AD-SDI?

All scales are relevant for the AD-SDI. However, for the purpose of organizing this foundation stage, scales will be grouped in the FGDS in three levels or ranges:

Large. The mapping scale for this level is 1:1,000 – 1:5,000+. This scale is required primarily for engineering level works including facility mapping and management, streetscape design, urban and architectural design and localized environmental inventory and assessment. This scale is suitable for all aspects of engineering planning and design, but does not preclude the need for site specific engineering work, including site surveys and the locating of underground utilities, before actual implementation.

Medium. The mapping scale for this level is 1:10,000 – 1:50,000+. This scale mapping includes urban and peri-urban areas. Data compilation for this scale may be carried out at 1:1,000 and generalized to this level. This level of data is often used for urban land use planning, transportation planning and analysis and boundary delineation.

Small. The mapping scale for this level is 1:100,000 and above. This scale mapping includes the urban hinterland, rural areas and other areas of distributed human settlement, farms, plantations and related issues, and usually depicts relatively generalized information for the entire emirate. Such mapping may be carried out using data compiled at 1:10,000 to 1:25,000 and generalized to this level. This level of data is often used for land use planning, natural resource inventory and assessment, toxic release modeling, localized groundwater modeling, soils and superficial geology mapping, and for assessing such issues as climate, emirate-wide groundwater assessment, and urban growth projections.