Sunderban a GIS approach
Webstar Infotech (P) Ltd.
The Sunderban region is located between 21deg 32 MIn.latitude & 22deg.40Min. attitude north and between 88deg.&05Min.and 89deg.longtitude east and Constitutes the watermost part of the gangetic delta.
Bio-spheres Reserve throughout the world
The region is demarcated by the river Hoogly on the west, the Bay of Bengal on the south, the Ichhamati-Kalindi-Raimongol rivers on the east. It comprises nineteen blocks of north & south 24-parg. Districts of West Bengal.
There are 54 islands in this region. The land area measures about 9629 sq.km. of which 4493 sq.km inhabitated by people and the rest is reserve forest. The total number of mouzas under the region is 1093. major ecosystem type is tropical humid forest, mangroves. habitat and land cover types are tropical semi-evergreen forest including mangrove such as avicennia albs, bruguiery gymnorrhiza, ceriopstagal, rhizophoraapiculataetc, agroecosystems, silviculture, pisciculture, prawn culture etc. water and soil characteristics of estuaries mechanism of situation in the tidal river system soil related problems and fertility of coastal soils and a wide diversity of flora, fauna and medicinal values of mangrove species, plankton composition and its population density also a very important issue for sustainable development. Socio economic status is mainly dependent on the fishery resources of sunderban.
There is a vast difference between the other bio-sphere reserve and sunderban, because it is world heritage site as well as largest mangrove area in the world. ecologically it is a very important place as well as it is under MAB(Man and Bio-sphere) project.
Bio-spheres Reserve throughout the India
Major objectives of GIS application in Sunderban
Main object to create a GIS based data base for the following information’s To generate various reports for the management as a decision support system.
Till the end of march 92,840 km. of brick paved road has been constructed by the board in sunderban area. This has opened up new horizons for the local people. It has brought about considerable mobility in the remote sunderban areas where transport and communication was previously difficult specially during the monsoon season. The GIS based information system can help in making future development and logistics planning for local community development.
Since 1981-1982 the construction of 37 jettis has been completed. The provision of jettis has been made for promotion of landing facilities in the riverine sunderban areas. The Jettis are serving an estimated population of 15.6 lacs spread over about 250 villages from 60 to 3500 persons per day. Apart from this GIS can develop a proper system at Chemaguri and Kachuberia points cater to needs the pilgrims from all over India during the Gangasagar Mela.
About 427.7 kms of channels have been re-excavated till the end of March 1992. It is estimated that more than 6000 ha. of land have been brought under the fold of a second crop in the dry season with the sweet water stored in this re-excavated channels. In all probabilities, in the coming years, this figure will move upward. The farmers within the command areas of re-excavated channels are always advised to cultivate those ravi crops which reasonably less irrigation water. Conditions of these channels along with the re-excavation of Govt. bonds can be monitored through GIS and remote sensing application along with a proper model of development.
The program element “Brackish aqua culture” the Fish Farm Activities were introduced by the SDB (Sunderban Development Board). GIS based model can help the objective of boosting the production of Brackish Water Fish and to provide technical supervision and marketing facilities in the area.
Under this Social Forestry Program (SFP),SDB was initiated in 1981-1982 . At the outset the program size was small compared to the other program elements of the project. The initial program was as follows:-
Experimental Mangrove plantation 100 ha.
The economy of the Sunderban Region is dependent primarily on Agricultural activity. About 90 % of the people of the region fall back on agriculture alone for the livelihood. The Sunderban Region having a total Geographical area of 431893 ha. With a cultivable area of 299419 ha. Is mainly monocrop, the main crop being kharif paddy. Over 50 % of the people are landless laborers while over 40% of the farming house holds of the region operate in less than 2 ha. of agricultural land. The problem of agriculture in sunderban is initially related to salinity and water logging. Inadequate drainage, during monsoon, affects the paddy crop adversely. A huge portion of land remains follow land during the dry season for want of irrigational facility. A GIS based drainage and irrigation program can create potential farming activities for the region. The cropping intensity, drainage system, irrigation potentiality can be judged distinctly through GIS system. Apart from this the economic condition of small and marginal farmers can be measured and a master data base with the help of spatial information can introduce for the decision support system.
Animal Resource program was introduced in the year of 1991-92. For improving the breeding stocks, bucks and rams were distributed in 9 blocks and for creating veterinary aid in the sunderban region 48 lacs rupees in the forms of transport subsidies was provided to the Veterinary Services Directorate. With the help of GIS technology we can understand the current status and identify the developing segment of the region. Also with the help of GIS monitoring of tiger project can also possible.
During 1990 -91 the SDB undertook a scheme of sinking tube well under its Rural Water Supply program in the sunderban region aiming at providing safe drinking water in deficient mouzas in the region. A sum of Rupees 36 lacs was allotted to Zilla parishad of south and north 24 paraganas for execution of the scheme. If we can use GIS to locate the safe drinking water zones more and more people will be benefited by this program.
The department of non conventional energy sources, Govt. of India, was started this program in the year 1986 –87 with street lights (25 units). Today they are also using bio-mass gasifier for rural electrification. To identify the potential areas for these types of system GIS and Remote Sensing is a very effective tool. In a remote area like sunderban these technologies is very helpful to understand the natural resource balance and their equitable uses as an energy source.
Under this program the district rural development agency (DRDA) of south and north 24 paraganas districts have been imparting vocational training to the village women folk in group also there are different production centers for the region. With the help of our system they can understand the growing needs of the people and locate different skills & resources for further improvement.
Since sunderban is a world heritage site, there are different development programs from state and central government also programs funded by different foreign agencies. Ngo’s are playing a vital role for the development for this region. They became catalyst between local people and government. So a comprehensive development model (gis based) can help them to integrate different information’s and give them clear view in understanding the objectives of different development programs for the people.
Methodology of the proposed conservation project
The development planning of such a vast area for identification of degraded stretches of sunderban requires various data information to identify the terrain, slope of the river, affected land areas in order to draw, on the block map and the bank of the river, the proper passage of channel to prevent loss of land as well as to maximize potential.
Implementation of GIS Application development with the Remote Sensing data (Satellite images), layering of Topo Survey data from Topo maps (1:25000 to 1:50,000 scales) available from the Survey of India and digitization of relevant block maps, as well as verification of draft contour maps in the field will only be able to prepare micro-distribution system within a short time and with more economy.
The accessibility of the different parts of the local bodies can also be studied and mapped with the help of GIS.
Planning is done with the assumption of future population. With the application of GIS the local planners can assume the environment, health & education conditions of the local bodies in future and take policy decisions accordingly.
In order to satisfy water demands of today and tomorrow and protect the resources in long term, the decision makers need tools to make decisions based on reliable data. It would therefore be imperative to view the facts of water management as:
GIS based PBR format will be used for natural resource estimation in sunderban area. Following points are included in the PBR format for the estimation.
All of the pictures received from remote sensing and which we view on the computer are 8-bit digital images, which means that they have 256 colors (2^8). The image in the right illustrates this principle. Digital images are tables of numbers, which in this case range from 0 to 255. The "bright" squares (called pixels) have high number values (ie. 200 to 255), while the "dark" pixels, have low number values (ie. 50-100). This image is an extreme close-up of a satellite image of West Hancock. The dark region is a stream valley, which has low reflectance, while the bright area is a gravel pit, which has high reflectance. The satellite sensor records the reflectance in its field of view, and then scales the signal to an 8-bit number (0 to 255).
Remote sensing is the science and art of obtaining information about a phenomenon without being in contact with it. It provides a unique perspective from which to observe large regions. Sensors can measure energy at wavelengths which are beyond the range of human vision (ultra-violet, infrared, microwave).
Compared to traditional satellite remote sensing IRS-1D also, provides significantly higher resolution. It has the ability to collect both panchromatic and multispectral images of the same object from the same perspective. The collected imagery can be output as one-metre pan-sharpened (color) and 4 metre multispectral (color). These images provide excellent accuracy for mapping surface of the earth. Remotely sensed images contain both spectral and spatial information. The spectral information provides various properties and characteristics about the surface cover at a given location or pixel (that is, vegetation and/or soil type). The spatial information gives the distribution, variation, and topographic relief of the cover types from pixel to pixel. Therefore, the main characteristics that determine a pixel's brightness/reflectance and, consequently, the digital number (DN) assigned to the pixel, are the physical properties of the surface and near surface, the cover type, and the topographic slope. In this application, the ability to detect and map lineaments, especially those related to fractures and faults, is critical. Therefore, the extraction of spatial information from the digital images was of prime interest.
Cadastral Level Mapping is needed for this type of projects, which is only possible with Arial Survey. We can create 1:10,000 level map with the help of this survey.
The Satellite Remote Sensing data has proved to be a highly reliable for extracting the land use, land cover, the river and its bank etc. of any region in a given time and also in a cost effective manner due to their inherent capability of providing very high spectral and radio-metric integrity and consistency. Due to these capabilities satellite remote sensing also facilitates rapid but accurate changed detection studies which also forms an integral components of environmental impact assessment and to site a location for sustainable developmental growth of the entire conservation area.
GIS in land mapping:
With GIS techniques, maps are produced that are similar in appearance to hand-drawn maps; to the eye, each elevation map may appear not to conflict with the elevation maps of other stratographic units. However, to develop a truly internally consistent set of maps, the maps are processed into a raster (gridded) format. Then, conflicts in elevation between horizons (and larger conflicts across several horizons) detected in reference to block maps. The Topo survey maps always provide some benchmark and are therefore very useful in contour preparation either manually or electronically. Topographical maps of India made by Survey of India were started more than hundred years ago. Since then the land information is based on the Topo Maps of Survey Of India for various purpose. But there is some constraint in Topo maps as information is little bit older. So Topo Maps could be very helpful to read with the Remote Sensing Images, which is today’s scenario.
Now, it is needless to say that anyone can derive contour maps at various intervals from various Topo maps at various scales. According to Survey of India 10m, 20m and 30m interval contour data are available from 1:25000 and 1:50,000 scale maps
Digitized block maps provide the necessary frame of the map to be drawn and also help in physical verification in the field for the errors that might occur inspite of high precision of the imaging. In mapping a terrain especially when in plane it is highly possible that errors may occur in defining the slope and elevation through imaging. On the other hand reliance on entire manual process may also lead to error due to failure of estimation through human eyes.
Creating a Vector Map
For creating a vector map we create three products: a three-dimensional perspective view, an elevation map of the upper surface, and a thickness map. Mapping of each unit was an iterative process that, through re-examination of stratigraphic data and maps, gradually refines the understanding of the vertical and lateral distribution of each unit. To map a unit, we should plot the stratigraphic control data, then prepare a hand-contoured map based on the data and an understanding of the regional distribution of the materials and geologic history.
Consideration in Micro Level Planning
Micro level planning with MIS with GIS Application is to visualize upto block level data, various related information, and contour maps at layout plan of Sunderban area. But for execution or implementation of a project planning, detailed information about drawings/maps are required to work at ground level.
To prepare a detailed map of layout plan of Channels at each block level, the following tasks are required to be carried out .
In order to prepare authentic base maps, a pre – requisite to any Conservation Plan, the use of Satellite images in conjunction with contour maps are essential planning task, which has been addressed here.
Information available from Topo maps are as follows:
Consideration in Micro Level Planning
Micro level planning with MIS & GIS Application is to visualize upto block level information, data, and contour maps on layout plan. But for execution or to implement a project planning, a detailed information and drawings/maps are required to work at ground level. To prepare a detailed map of layout plan of Micro ploanning at each block level the following tasks are required to be carried out .
The proposed Application Software will follow three tier architecture where oracel-9i will work as database, ASP as front-end and IIS as web server.
So, initially it will be an independent domain based Network which will graduate incrementally for connectivity and integration for remote client interface to the main application domain and centralized data repository.
As a backend database oracle-9i will be used on TCP/IP as the underlying protocol with provision for scalability and upgradability. The Software will conform to the Microsoft Windows NT platform specification. The same Networking protocol (TCP/IP) shall be established among all operating areas in future. Primarily the data will be captured at block Office. will be required to set up. WBSWAN (West Bengal State Wide Area Network) will be used for connectivity among the server and the nodes in the system. Alternatively, for remote connectivity to server at Microsoft RAS based connection will be used with telephone lines and dial-up modems
Backend Database : Oracle 9i
Client End Operating System : MS Windows 98 / 2000
Network Operating System : Microsoft Windows 2000 Server
There will be two applications software for this project
For system application and users, security meas, security measures will be taken care of at different levels, explicitly at the administrative, functional database and operating system level.
Officers and staff of the Authority will be provided with proper on hand training for operation of the software along with the following works which will be necessary to produce contour maps and for the preservation of data and the output generated from the computer.
Computer mapping requires two types of databases interacting with each other. One is cartographic database showing, for example, coast lines, administrative boundaries, roads, rivers, location and shape of houses and buildings. The information sources for acquiring these types of data are satellite and other remote sensing data, existing maps, and land survey data.
The other database is an attribute or thematic database. It may include the names of places and buildings, statistical data such as demographic information, land use classification, and others. These types of data are supplied in various forms such as printed statistical reports, digital tape data, or cd- rom.
The advantages of computer mapping are the reduced time and costs of data updating and management. Initial data creation and input to develop the geographic database requires long hours of work. We have researched the latest equipment and technology available to produce a workflow system for higher efficiency and improved accuracy.
In order to acquire data directly from satellite data, we use a suite of various hardware and software components to operate systems: such as high-resolution precision photo-scanner and soft-copy-ortho-photo mapping system. Other software and hardware components control digitizing tables used to convert existing paper maps into digital form. Other systems process land survey data from gps and total stations, which collect land, survey data. Original image enhancement and geometric correction of image data are performed with the aid of an image processing system to meet requirements in the latter phase of mapping works.