SDI Convergence - Nederlandse Commissie voor Geodesie - KNAW

This distinction is also reflected in the generation analogy that has been used to highlight
the main structural changes that have taken place in the notion of spatial data infrastructures
over the last fifteen years. Some features of the first generation of eleven
SDIs that had emerged during the first half of the 1990s were described by Masser
(1999). What distinguished these from other GI policy initiatives was that they were all
explicitly national in scope and their titles all referred to geographic information, geospatial
data or land information and included the term 'infrastructure', 'system' or
'framework'.
The development of a second generation of SDIs began around 2000 (Rajabifard et al.,
2003). The most distinctive feature of the second generation of SDIs was the shift that
was taking place from the product model that characterised most of the first generation
to a process model of a SDI (Table 2). Database creation was to a large extent the key
driver of the first generation and, as a result, most of these initiatives tended to be data
producer, and often national mapping agency, led. The shift from the product to the
process model is essentially a shift in emphasis from the concerns of data producers to
those of data users.
This shift had profound implications for this involved in SDI development in that it has
resulted in data users becoming actively involved in SDI development and implementation.
The main driving forces behind the data process model are data sharing and reusing
data collected by a wide range of agencies for a great diversity of purposes at various
times. Also associated with this change in emphasis is a shift from the centralised
structures that characterised most of the first generation of national SDIs to the decentralised
and distributed networks that are a basic feature of the WWW.
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Table 2: Current trends in SDI development (Masser, 2005, p. 257).
From a product to a process model From formulation to implementation
From data producers to data users
From database creation to data sharing
From centralised to decentralised structures
From coordination to governance
From single to multilevel participation
From existing to new organisational structures
There has also been a shift in emphasis from SDI formulation to implementation as
those involved gained experience of SDI implementation and a shift from single level to
multi level participation, often within the context of an administrative hierarchy of SDIs.
As a result of these developments the coordination models that had emerged for single
level SDIs have been substantially modified and more complex and inclusive models of
governance have emerged. They may also require the creation of new kinds of organisational
structure to facilitate effective SDI implementation.
In the last few years there are also signs that a third generation of SDIs is emerging.
The most important difference between the second and third generation is that the balance
of power in the latter has shifted from the national to the sub national level (Rajabifard
et al., 2006). Most large-scale land related data is collected at this level where
it is used for collecting land taxes, land use planning, road and infrastructure development,
and day-to-day decision making. Alongside these developments there has been
a shift from government led approaches to whole of industry models where the private
sector operates on the same terms as its government partners. One consequence is
that national SDI activities are likely to be increasingly restricted to the strategic level
while most of the operational level decisions are handled at the sub national levels by
local government agencies in conjunction with the private sector.