G.S.Vatsa1, Rajesh Kumar2
1Assistant Chief Civil Hydrographic Officer
2Principal Civil Hydrographic Officer
National Hydrographic Office, Dehradun
Email: [email protected]
Geographical information (GI) today is vital for the functioning of modern society. Its use is essential for almost all decisions concerning infrastructure development and maintenance, trade, and a large number of other socio-political and economic matters relating to the administration of territory. Geographical information is only of use when it is reliable, timely, accurate, appropriate, and presented to the right person at the right time and in the right manner. Under such conditions, geographical information (GI) becomes a resource, of great value to an organization.
Computer-based geographical information systems (GIS) are increasingly being used in order to assist in the process of capturing spatial data, storing and retrieving them, processing relevant information from them, and making this information available as required. The use of GIS, therefore, has great potential to optimize the value of information as a resource within an organization. The application of GIS technologies and methods to problems of coastal zone management embodies many of these difficulties, and it has even been suggested that, to date, any success that has been achieved in harnessing GIS to the solution of coastal issues has often been reached almost in spite of, rather than because of, the current state-of-the-art in operational geoinformation systems (Bartlett, 1993a).
We all are familiar with land -based maps and its application in GIS environment supported by aerial photography and Remote Sensing. As in the land based GIS application, Marine GIS application requires input in the form of a map of the water area. The input is a Nautical Chart or a Navigation Chart; the use of Nautical Chart at sea by the mariners for navigating at sea is a typical example of GIS in Marine environment. On the land we can move around without the aid of map but Navigation at Sea requires safety under IMO/IHO regulations, which is provided to mariners in the form of a Navigational Chart showing various aid to Navigation and Symbols for safe navigation.With greater quantities of marine and coastal data being acquired today there is an urgent need to evolve information technologies used in these fields.
Marine GIS system is a new type of digital information system with the capability to combine a wide range of four-dimensional oceanographic and coastal data to create environmental scenarios adaptable to a wide range of uses. It is based on the proven methodology of the Electronic Chart Display and Information System (ECDIS), which has been developed for navigational purposes.
The roles and objective of Hydrographic Service
Hydrographic applications in marine coastal development and environmental preservation, is a growth area, the world over. According to an UN study, approximately 50% of the coastal states have no hydrographic capabilities. Another 25% have only limited capabilities. Only the remaining 25%, including India, have adequate hydrographic capabilities. Therefore there is immense scope among the hydrographic offices to conserve/protect our coastal regions and develop and evolve spatial technologies for less developed. The Hydrographic Offices of the world have the responsibility towards their maritime states to provide an essential service within the national transport infrastructure. Hydrographic Services support safe and efficient navigation, foster national maritime development, help to safeguard life and property at sea, facilitate the protection of the marine environment and support the administration and sustainable development of the national maritime zones. A Hydrographic Office plays this multidisciplinary role. These Important roles can be listed as follows:
1. To collect, with systematic surveys at sea and along the coast, georeferenced data related to:
- Coastal configuration, including man made infrastructure for maritime navigation (Aids to navigation and port configuration)
- Depths of the seas in the area of national interest (including all potential hazards to navigation and other marine activities.
- Sea bottom composition
- Tides, currents
- Physical properties of the water column
- Gravity and Magnetic Observations at Sea
2. To process the information collected in order to create organized databases capable of feeding the production of thematic maps, nautical charts and other types of documentation for the following most common uses :
- Maritime navigation (and traffic control);
- Naval operations;
- Coastal management and defence;
- Marine environment preservation;
- Exploitation of marine resources and laying of Submarine cables/pipelines
- Maritime boundaries definition (Law of the Sea implementation);
- Scientific studies connected to the sea and near-shore zone.
3. To update the databases through re-survey when and where needed,gathering supplementary information from other maritime authorities.
4. To ensure the production, distribution and updating of charts and Electronic navigational Charts(ENC)
5. To ensure the timely dissemination of maritime safety information. Role of Indian Hydrographic Office
Our corporate objective is to ensure total satisfaction of the customer needs for precise and accurate hydrographic and oceanographic products and services to the international & national agencies, duly updated by a reliable mechanism.
Customer aspirations and needs
- Precise, accurate & detailed surveys for safety at sea,for offshore development work (Ports and Harbours), Maritime Routes, Fishing, Offshore Exploration, Coastal Recreation.
- Updating service round the year.
- Availability of charts & publications in paper & digital formats(ENC)
- Technological updating.
- Affordable cost of the products and services.
- Assistance to R&D agencies for Marine related projects.
The NHD is committed to respond to national & international regulations/conventions relating to the safety at sea and offshore development work by furnishing accurate and reliable Hydrographic products & services. The department can undertake surveys in the coastal/inland waters and in the deep seas for the following :-
- Navigational safety
- Oceanographic/Environmental parameters.
- Pipeline & Cable route
- Geophysical & Geotechnical
- EEZ/Continental Shelf/Maritime Boundary delineation with baselines.
- Pre & Post Dredging.
In addition, the NHD offers its well-developed management expertise in the form of contract surveys, establishment of Hydrographic Offices and training facilities for other agencies.
National Hydrographic Office
Hydrographic services are controlled from Dehradun. The Office is located in the Doon Valley at the foothills of the Himalayas and the Shivalik ranges. The services include: –
- Planning of operations
- Issue of field directives to ships
- Examination & Review and Chart Production(Paper charts and ENCs)
- Printing Navigational Warning
- Archival of data
- Sale of products & Services
- Custody of historical data
The Office maintains 350 charts and 15 publications covering the Indian waters and adjoining seas. Mariners are fully supported by round the year navigational warning services for NAVAREA VIII. The department is oriented to paper/digital products & services and constantly strives to meet the present and future chart specifications for varied users.
Provision of Charts
Ideally, every Maritime State should be responsible for charting its maritime areas as well as for the distribution of the relevant nautical information. In fact, many States do not yet have the appropriate structures and organization required to handle this task. For historical reasons, some countries (notably: France, Portugal,Spain, UK and USA) have continued to play this role on behalf of the international community for territories, which are now independent. This means that they continue to maintain a portfolio of nautical documents, which are often the only reference available.
The main service provided by a hydrographic department is the national chart series. The department should therefore have access to a production facility. A production facility has a number of key features. These include;
- Facilities for the compilation of new charts, including cartographers and computing equipment.
- Facilities for the maintenance and updating of these charts on a fortnightly basis.
- Facilities for the publication of charts in digital and analoge form.
- Facilities for compiling and publishing supporting texts such as Sailing Directions, Tide Tables, etc.
- Facilities for distribution of information and products to users around the world
The National Chart Series of India is published by Indian Hydrographic Department which is divided into 3 groups:.
- Small Scale charts are provided for passage planning and for navigation out of sight of land. These charts are typically of a scale between 1:10 million and 1: 1 million.
- Medium Scale charts are provided for making landfall and for passage along the coast. These charts are typically at a scale of 1:300,000 or 1:150,000.
- Large Scale charts are provided for port approaches, ports, and other areas where navigation is constrained by land formations, navigational hazards, traffic density etc.
The number of charts in the national chart series will depend upon the length of the national coastline and the extent of the national EEZ. Often the national chart scheme will be linked to the international chart scheme of the region, compiled by Member States within the International Hydrographic Organization. The purpose of the international chart scheme is to ensure that the needs of international shipping are met in an economical and efficient way by co-ordination of the chart schemes of neighboring regional nations.
The coast is a distinct, and extremely important, feature of the earth’s surface. It marks the three-way boundary between the main environmental domains of our planet: land, sea and air. Carter (1988) defines the coast as ‘that space in which terrestrial environments influence marine (or lacustrine) environments and vice versa’. Although in popular terminology, the term coastline is frequently used, in practice the coast has width and depth as well as length, so the term coastal zone is to be preferred.
The coastal zone also provides access to physical and other resources. For many countries of the world the oceans, and especially the continental margins, provide an important primary source of protein. Minerals and vital hydrocarbons also come from many of our coastal waters while we also use the off-shore zone as a convenient disposal ground for sewage and for domestic and industrial wastes, including toxic and/or radioactive materials. As well as attracting industry, the coastal fringes of our landmasses are also becoming increasingly sought after for leisure and tourism developments, both organized and informal. All of these activities may contribute significantly to regional, national and international economic performance (Bartlett, 1993).
A coastal State must declare & publish a catalogue of its coastal charts as its is the prime requisite of the maritime state for managing its marine coastal resources. The Technological Developments in the field of sub sea explorations to gradually explore and utilize submarine resources have increased tremendously in the recent times. It is nothing new that new technologies enable new applications, which, in turn, open markets for new technologies. This has happened also with hydrography: Satellite positioning, sophisticated high power computer technology and electronic communications have made hydrographic surveying and oceanographic data observations more efficient and hence there is a need to combine all these technologies and Data into a seamless database for the purpose of extracting spatial and attribute information for efficient use in Coastal Zone Management and finally into Electronic Charts.
The National Hydrographic Office of India has this national responsibility for mapping/charting its coastal areas for the purpose of production of Navigational charts. It is the only Charting organization in India which is well equipped in coastal mapping techniques The Hydrographic Office of India situated at Dehradun has fleet of Eight Modern survey ships to carry out Hydrographic Surveys for Coastal waters of India. Each survey ships collects bathymetric data using state-of-the art equipments to collect this data for preparing the end products i.e. Nautical Chart. So far, only analogue charts are available, but in view of international commitments by the Indian Hydrographic Office and being a signatory of International Hydrographic Office (IHO), which is fulfilling IMO/IHO/UNEP conventions of Navigational Safety Services at Sea it is obligatory to provide all the coastal charts in a Digital format called ENC i.e. Electronic Navigational Chart. The Productions of ENCs has started three years back and now it has reached to an advanced stage. So far 262 ENCs have been completed and the ENCDB is also nearing completion. Presently only issues pertaining to encryption and marketing needs to be resolved.
Coastal Charts Database
The acquisition of Hydrographic Data for coastal Mapping and creation of Hydrographic Data Bases are the primary requirement to provide safety in navigation. The hydrographic data for coasts is not only required for preparation of navigational chart and publications but it is also used by variety of other specialist users. In view of its national role in field of hydrography.,it is worth mentioning that in past 20 years, most of the ports, harbours and their coastal approaches of India, have been re-surveyed to high standards using modern surveying equipment. The era of automation and digital cartography initially started since 1981 with acquisition of new ships, modern automated equipments, Automated Data Logging & Plotting System, Automated Cartographic & Printing Systems.
The NHO has always adopted the changing technology and India will soon be one of the first few Hydrographic Offices in the world to enter in the field of Digital cartography with confidence at the start of 2003. In order to adapt the wind of change, dynamics of technology and to meet expectations of new Offshore marine ventures, developments of private ports, commercial imperatives, changing international scenario of Hydrography and Nautical Cartography, the NHO is in the process of moving way ahead in field of creating digital data base.
The Hydrographic Data Base System at NHO
The Hydrographic Data in Indian Waters has been collected for centuries, which is contained in Analogue Data Base at NHO.
National Hydrographic office presently holds two types of databases
- Analogue chart Data Base System
- Digital chart Data Base System
The Hydrographic source Database which is used in the preparation of charts & publications and is also used by other specialist users, consists principally of the following, which are maintained in the Archives of NHO :-
Analogue Chart Data Base System
- Results of local Surveys from Port Trusts & Other ports
- Oceanic Soundings (GEBCO)
- Indian Nautical Charts and Publications
- Foreign Nautical Charts and Publications
- Survey of India Topographical maps
- Air-Photographs & Satellite Imageries
- Geodetic Control Data
- Tidal Stream & Currents Data (Ocean Dynamics)
- Publications such as sailing Directions, Light Lists, List of Radio Signals, List of Wrecks and Shoals, etc.
- Reports from Maritime Agencies, Port Trusts etc.
Digital Chart Data Base System
The development of digital chart Data Base System at NHO started with the installation of Computer Plotting System at NHO in 1995. Initially a five year Plan was proposed for following :-
- To create Digital Chart data base by Digitization of Paper charts/Compilations and production of .dgn files for paper chart generation
- Digital hydrographic data base creation and further creation of ENCDB for ENC in DX 90 (IHO S-57) format for use in ECDIS.
- Customization of Software package for symblology , line style and various limits, and attachment of feature table for various object classes.
Development of Digital Chart Databases During Last Five Years
On successful completion of this Five Year plan and as the result of digitization National Hydrographic Office has created Digital Data bases for the following:-
- Paper Chart Database(PCDB)
- Electronic Navigational Chart Database(ENCDB)
- Geographic Information System (GIS) as available on related sub-themes
- Digital Sailing Directions are planned to be linked with ENCDB as text file and picture file as per S.57 Specifications.
- WGS-84 Positional Digital Data Base which is being created at NHO based on latest DGPS observations for giving information on Everest/WGS 84 differences both in paper charts & ENC’s.
- Digital Data Base for Base lines and other UNCLOS aspects is being created at NHO which is the certifying agency for bathymetric & seismic data and which is responsible for preparation of documentation for submitting India’s claim to CLCS.
Futuristic Plans for Digital Chart Databases
At present times the important challenges for National Hydrographic Office in this post economic liberalization policy of the Government of India is the spurt in offshore activities especially along the coastal belt. Th trend is welcome phenomenon in view of the importance of commerce and energy requirement of our country through oceans and the Naval Hydrographic Department is ever committed to provide Navigational Safety at Sea. The NHD is constantly being modernized to keep pace with the revised IMO/IHO procedures, standards and technology to make high content charts, including Electronic Navigational Charts and Integrating GIS technologies.
NHD during the next five years plans to lay emphasis on the following:-
- Updation and maintaince of Digital Database(PCDB & ENCDB)
- Digital Reprinting (already commenced)
- Promulgation’s of N to M’s via web (already commenced)
- Creation of Digital Data Base for General Bathymetric Charts of the Oceans under IHO Data Center for digital Bathymetry and GEBCO Digital Atlas (GDA) project of IHO.
- NHO being one of the 13 Data Centers under National Ocean Information system (NOIS) will collect Bathymetric data under National Marine Data Center (NMDC)
- To work for Real Time Tidal information database, which will play a key role in ENCDB
- Coastal Zone Management (CZM) Digital Data base will be created at NHO as national agency for validation of HTL/LTL for use in Coastal Zone Regulation (CZR) Plans of MOEF.
- Digital Compilations
- Increase in Human Resources Developments
- Use State of the art equipment’s such as Laser Bathymetric System (LBS), Multi Beam Echo sounders, Mobile Carvan etc.
- Integration of Under water Systems (IUWS).
- Explore uses of Digital Photogrammetry and Remote Sensing for updation of Nautical Charts.
- Integration of GIS technology for Navigational Charts
- Prepare and submit claim under UNCLOS on extended Continental Self of India.
- Print on Demand
Integration of Coastal Database with GIS
National Hydrographic office being a leading hydrographic service provider for the nation feels the need to evolve information technologies in the coastal mapping in a GIS system (COMGIS) by combining a wide variety of four-dimensional oceanographic and coastal data to create an environmental scenario adaptable to wide range of uses. The digital data bases created at NHO are quite extensive and varied in nature. The need is to examine and analyze this temporal and spatial relationship within these GIS systems. Coastal area being a place of constant dynamics therefore requires special attention. NHO presently has rich database of Electronic Navigational Chats, but before we must develop a basic understanding of “What is an ENC?” Unfortunately, it is not necessarily based on what is defined in Section 2.2 of the IMO Performance Standards for ECDIS:
Electronic Navigational Chart (ENC) means the database, standardized as to content; structure and format, issued for use with ECDIS on the authority of government authorized hydrographic offices. The ENC contains all the chart information necessary for safe navigation, and may contain supplementary information in addition to that contained in the paper chart (e.g., sailing directions) which may be considered necessary for safe navigation.
Electronic Navigational Chart Database uses S-57 is the International Hydrographic Organization Transfer Standard for Digital Hydrographic Data. It consists of a feature dictionary, a data model, and an exchange format called DX-90. S-57 is an object-based data structure; its feature dictionary describes the geometry and attributes of all features that may appear on an electronic navigation chart (ENC).
In defining what is an ECDIS, Section 2.1 of the IMO Performance Standards states:
Electronic chart display and information system (ECDIS) means a navigation information system which, with adequate back-up arrangements, can be accepted as complying with the up-to-date chart requirement by regulation V/20 of the 1974 SOLAS Convention, by displaying selected information from a system electronic navigational chart (SENC) with positional information from navigation sensors to assist the mariner in route planning and route monitoring, and by displaying additional navigation-related information if required.
ECDIS supports most of the GIS requirements including an ability to accept additional objects necessary for new objects, and handling of the temporal variability of the dynamic objects.
ECDIS, helps navigate the ship safely in all weather conditions .ENC is a replacement of conventional paper chart, which is used as tool for navigation provides in-put for detailed information about depth, hazards and navigational aids within the area. This supported by visual and audio alarms of ECDIS provide the navigator on bridge sufficient means to navigate the vessel safely. The display is used to provide selective information either spatial or textual information to the navigator for safe passage. ENC is the database for GIS operations and ECDIS is the real time GIS application in marine environment.
Many Marine GIS companies are developing intuitive and easy to use client interface, customizing solution for integrating GIS datasets using Client wizards, template and code examples combining speed with flexibility. They are development into Spatial Fusion mapping engine which supports a variety of industry standard spatial data formats such as CARIS, Shapefiles, Oracle8i, MapInfo, S-57, and many more.
Spatial Fusion engines provide the ability to integrate multiple sources of data into one seamless map view without the need for conversion. Powerful GIS functionality will be available to all users without the need for additional infrastructure. Furthermore these applications are scale-friendly pricing model allows you to grow without the need for a costly upgrade, allowing you to easily add mapping to your web site.
New developments in ECDIS promise a quick progress of integration of various datasets. Integration of some oceanographic variables, like tides and currents is already possible in ECDIS and hence objects and attributes for meteorological and various oceanographic data are also possible to merge.
As the hydrographic community all over the worlds generates multi-dimensional environmental data within a coastal and/or oceanic area there is significant requirement of developing a GIS based spatial and dynamic data system for resources planning and decisions making for use of in coastal zone and oceanographic applications. There has to be some actions influenced by present priorities and opportunities. Integration of these databases will provide the necessary flexibility to adapt to these future needs of coastal Zone and oceanographic applications. This will provide scientists a new tool to advance and understand interaction of many temporally variable parameters within the oceans, in the coastal zone and on dry land.