M.C. Gupta, O.M. Murali, Prakash Mantry *, S.R. Oza* and Shailesh Nayak
Marine and Water Resources Division, Space Applications Centre (ISRO), Ahmedabad
Remote Sensing and Communication Centre, Gandhinagar *
Email : [email protected]
A Coastal Zone Information System (CZIS) is designed and developed in GIS environment to prepare an effective Coastal Zone Management Plan (CZMP) for entire Gujarat state, at the behest of the Forests and Environment Department, Government of Gujarat, Gandhinagar.
In a world of rapid population growth and diminishing natural resources, each country has to plan for economic growth in balance with resource conservation and environmental management if it is to make progress in health, food, housing, energy and other critical national needs ( “Coastal Zone Management Handbook” J. R. Clark, 1996). In the coastal areas, high population densities, linked with urban growth, expanding tourism and industrialisation, pose major threats to natural resources and biological diversity. The uncontrolled development is destabilising ecosystems, changing land use patterns and are making communities vulnerable to sea storms. Sustainable use is the only alternative to resource depletion that accompanies excessive exploitation for short-term profit. This requires an integrated coastal zone management information system to plan and coordinate all the varied interests in coastal resource uses.
Gujarat state has about 1600 km, long coast line in the country. It supports a variety of habitats such as mangroves, coral reefs, sea grass beds, algae/ sea weeds, gulfs, estuaries, beaches etc. There are number of activities going on along the coast viz. salt industries, cement industries, import of oil & natural gas besides the pressure of growing population. This puts a tremendous pressure on the coastal zone and thus requires a proper Coastal Zone Management Plan (CZMP) for developmental planning to sustain the environment. In view of this, Coastal Zone Information System (CZIS) has been developed.
In order to protect and conserve the coastal environment, the Ministry of Environment and Forest (MOEF), has defined Coastal Regulation Zone (CRZ) (Notification, MOEF, New Delhi, 1999). Prohibited and permissible activities in CRZ, procedure for monitoring and enforcement, classification of CRZ into CRZ-I, CRZ-II, CRZ-III and CRZ-IV and guidelines for various activities such as setting up of industries, beach resorts, hotels, lodging houses in coastal areas are given in the notification. The main objective of CZIS is to design and develop a data base, and to provide a user friendly GIS software to retrieve spatial and non-spatial information to generate a Coastal Zone Management Plan (CZMP). This will provide decision support tool for implementing CRZ notification to planners and administrators to create user specific outputs. CZIS has three distinct capabilities. It acts as
Design, Organization & Creation of a Data Base
Data base design and organisation is one of the important task prior to creation of a data base. This is the key factor for any information system to be successful as an efficient management and planning tool . This includes various aspects of data base such as basic framework of the spatial data sets, standard coordinate system, proper linkage of spatial and non-spatial data and standard registration procedure etc., along with its ultimate use. For the present CZIS, a basic framework (master grid) is prepared on 1:25,000 scale in the polyconic projection in GIS environment. This covers entire Gujarat coast and consists 52 X 38 rectangular grids or cells where each cell represents one SOI toposheet on 1:25,000 scale. To create data base, SOI standard is used and four corners of the grid are taken as the TICs or registration points to digitize each map taking master grid as the reference. Shades / symbols and unique IDs for polygons and line features are standardised. Attributes are assigned to spatial data sets and linked with shades/ symbols using Look-Up Tables (LUTs). Land use maps were prepared for CRZ along with administrative boundaries (district, taluka), transports etc for entire Gujarat on 1:25,000 scale using IRS LISS-II and SPOT data of 1988-1989. These maps are digitized to create corresponding thematic coverages (layers) using the standard procedure (“Brackish Water Aquaculture Site Selection using Techniques of GIS” M.C. Gupta , S.R. Nayak et. al. 1995. Published as SAC Scientific Note.).
CZIS as an Information Retrieval System (IRS)
As an IRS, CZIS can be used to retrieve all the information created in the data base in a user friendly manner. This is the first menu of CZIS named as “General Info”. This has the following Sub-menus
|Fig. 1 Information Retrieval for Land use for entire Gujarat and an enlarged area of Gulf of Khambht|
The first and the second Sub-menus provide composite information about various existing overlay coverages which can optionally be superimposed on Land use and Coastal Regulation Zone themes respectively by an user. The information about different polygons of land use (in sq. kms) and linear features such as transport, boundaries (in meters) can be obtained interactively using ‘Query’ button of CZIS. The desired area can be selected and enlarged using either cursor or by providing longitudes and latitudes. The scale and full legend is displayed automatically after enlargement. Third and fourth Sub-menus provide information about individual overlay coverages. ‘Thematic Maps’ Sub-menu allows to select a map composition in the data base on a popup menu and display it with a desired page size. Fig. 1 shows land use of Gujarat area comprising 244 maps on 1:25,000 scale with a composite view of all the coverages of an enlarged area in lower right corner.
CZIS as an Analysis/ Modeling Tool for CZMP
As an Analysis Tool, CZIS takes up the tasks of generating land use information up to 500 m from HTL and wetland information between LTL and HTL and zoning the coastal area into distinct zones (CRZ-I, II, III & IV) using analysis/ modeling based on criteria as per MOEF notification in GIS environment. The ‘Theme-wise’ ( Selected land use categories) or ‘Zone-wise’ (Selected CR Zones viz. CRZ-I, CRZ-II, CRZ-III & CRZ-IV) information can be generated for the entire state, district or a SOI toposheet area on 1:25,000 scale as shown in Fig. 2.The user can select any number of land use categories or coastal regulation zones in any order. These information and the final map outputs (from Output Map Generation System) can be used for locating critical areas, imposing certain restrictions on setting up and expansions of industries, operations and process etc. in CRZ for CZMP.
CZIS as Output Map Generation System (OMGS)
As an OMGS, CZIS can be used for output map generation for land use and / or coastal regulation zone. This is ‘Map-Output’ menu of CZIS, which requires SOI toposheet number as an input and has the following sub-menus
|Fig. 2 Flow Chart of CZMP|
OMGS has three distinct capabilities a) Map Specific Legend Generation – Entire Gujarat coastal zone area is covered by about 244 maps on 1:25,000 scale. The total land use categories and the line features in the study area are 26 and 15 respectively (Fig. 1). An individual map may consist only a few of these categories/ featuresThus it is necessary to generate the legend of only those categories which exists on the individual map to avoid confusion. OMGS has an in built facility to generate only these categories/ features automatically on the individual maps b) Map Index Generation – OMGS has also the capability to generate the map index that is the SOI map numbers of the output map and its surrounding maps automatically and c) Map Scale Generation – OMGS also generate the map scale automatically.The standard output map format is taken up as decided by all collaborating agencies. However, it can be modified if required. The coastal land use and coastal regulation zones maps generated by OMGS are shown in Fig. 3 and Fig. 4 respectively. An Atlas covering entire Gujarat is to be prepared using OMGS.
|Fig 3 Coastal Land use Map of SOI Map No.46B04/SE of Amdabad & Bhavnagar District (Gujarat)|
|Fig. 4 Coastal Regulation Zone Map of SOI Map No.46B04/SE of Amdabad & Bhavnagar District (Gujarat)|