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Integration of Topographic Digital Vector Data into National (Natural) Resources Information System Database
S.A.Shah, B.G.Vaishnav, Ketki
Kharod, R.K.Goel
Geomatics Technologies Division, Signal Image
Information Processing Area, Space Applications Centre, Ahmedabad
Department of Space (DOS),
Government of India has taken up, a major programme on realization of the
National (Natural) Resources Information System (NRIS) catering to the natural
resources development planning needs of the planners and decision makers at a
district, state and center. The NRIS is visualized as a nationwide network of
Spatial Information System nodes inter linked with each other under a
Center-State-District hierarchy. Each of the NRIS nodes is built around a
Geographical Information System (GIS) core and includes an integrated database
known as NRIS database. This NRIS database consists of data elements in both
spatial and non-spatial form on natural resources, infrastructure and
socioeconomic aspects. Realization of such an integrated system will aid for
monitoring, analyzing, planning and decision making on any query using available
spatial information with association of non-spatial information, i.e. NRIS
database. For such systematic resources utilization and conservation plan under
NRIS, the basic and important requirement is to establish a methodology for
easy, accurate database creation and timely updation under the NRIS standards
and its environment. In the context of accommodating variety of input sources,
like remote sensing data, conventional maps and data on socioeconomic and
infrastructure aspects mentioned in Ref. 1, certain techniques in the
form of software interface (Shells) are to be designed and implemented so that
the NRIS database can be managed easily, accurately and automatically towards
effective operationalization of NRIS database creation, updation and maintenance
activity. Topographic information from Survey Of India (SOI) is one of the
standard and reliable source for developing spatial database to meet NRIS
project requirement. Recently, SOI has started making base maps information on
topographic maps available in specific standard exchange format in digital form
known as Digital Vector Data (DVD) format. Thus, there is a need to have this
digital vector form data from SOI for nationwide base maps/Color separate
information in 1:50000 scale covering about 5084 toposheets. On comparative
study of design elements between NRIS database and SOI-DVD data, it is found
that about 20% of total NRIS database elements can be prepared as base layers.
It includes roads, railways, drainage, administrative boundaries, contours,
elevation points etc.
This software interface (Shell) is primarily
designed to eliminate huge manual effort required for digitizing about 5084
topographic maps and corresponding digitization errors. This also automates
process of generating thematic information in NRIS database as per NRIS
standards. Thus the Shell is designed to integrate these relevant base maps
information from different categories available in DVD formats.
The
software Shell comprises of procedures for look up table generation between DVD
elements and NRIS elements, importing DVD data base category wise and extraction
of topological data, generation of thematic coverages, integration to mappable
workspace, mosaicing them with area of interest and their visualization. It is
also planned to extend this Shell for maintaining up-to-date databases both for
NRIS and DVD in their respective standards and formats. The spatial data of
different scales and projections are also planned to be handled. To accommodate
and automate the said functionality under a software package as a Shell, such
process is termed as DVD data integration with NRIS database.
A
comparative study has been made between the NRIS spatial database and the DVD
data for their standards, structures, file formats, base categories, associated
features codification scheme etc., and mentioned in Ref.2 &
Ref.3. Thus, a Look Up Table (LUT) is generated by establishing
relational linkage between the features of DVD data and NRIS themes mentioned in
Ref.4.
This Shell is developed to retrieve the topographic data
distributed in various categories provided in respective DVD formats and imports
the various features available to meet NRIS project requirement into NRIS
spatial database. Finally, the Shell generates the thematic layers information
as per NRIS standards e.g. Wells, Drainage, Canals, Settlements, Roads,
Railways, Contours, Elevation points, Villages, Talukas Districts, States and
Forests Boundaries, etc. This software interface is also planned to extend its
capability to generate up-to-date, high resolution topographical DVD data kit in
its customized format from latest NRIS databases information, containing
modified topographical features using temporal satellite data. The user
interface is user friendly, provides point and click operation.
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