National Land Use Land Cover Mapping Using Multi-Temporal Satellite Data For Year 2005

Objectives: 

The main objectives  outlined in the project are:

  1. To generate land use/ land cover data base for the period 2005-2006 using three seasons (kharif, rabi & zaid) IRS P6, LISS-III satellite data and repeat the exercise at every 5 year interval.
  2. To create digital data base based on standard codification and integration with base details and to generate seamless digital data at district/state/national level.
  3. To provide a state wise land use report for the whole country with details for each district/state. This can be input for planning exercises at various levels
  4. To generate district-wise tables of the natural resources  parameters and the changes over the previous census cycle.
  5. To prepare  land use / land cover information system for easy query and retrieval of geo-database
  6. To report the areas of major land use change with appropriate scale maps and assessment report on causative factors and remedial measures.
Description:

The growing biotic pressure coupled with increasing human demands exerts tremendous pressure on the available land resources all over the country. In order to optimally use the land, it is necessary to have the information on the existing land use / land cover, which  permits a better understanding of the land utilization aspects on cropping pattern, fallow lands, forests, grazing lands, wasteland and surface water bodies forming vital areas for developmental planning.  One of the basic requirements of planning is to have accurate and timely information on land use within the shortest possible time.  This can be achieved from satellite based high resolution remotely sensed data on cost effective basis.  Although the conventional land use statistics data is available it is inadequate.  This data, therefore, can be integrated with satellite data to evaluate the agriculture and urban land use, forest and plantation, extent of wastelands and pasture lands, land suitability for optimum utilization besides season wise availability of surface water for irrigation prospects etc.  Digital image analysis techniques have been found more useful in land use / land cover inventories since segregates of different land use / land cover classes is feasible due to its synoptic coverage, near real time base line information, multi-spectral mode of data acquisition and its relative economy over other methods of survey. 

 

Data Used

In LU/LC 50K project, the IRS P6 LISS III data was used. This data provides information in 4 spectral bands- green, red, near infra red (NIR) and short wave infra red (SWIR), with 23 m spatial resolution and 24 day repeat cycle. The spatial resolution is suitable for 1:50,000-scale mapping. 

Methodology: 

The broad steps involved in the generation of LU/LC database are listed below:

  1. The multi-temporal LISS-III data covering kharif, rabi, and zaid seasons are used to address spatial and temporal variability in land cover classes.
  2. Ortho rectification of multi-temporal datasets are made, to correct the effect of relief and geo-referencing is then done with reference to framework using LCC / TM projection and WGS 84 datum.
  3. Preliminary interpretation:   The land use / land cover polygons as seen in the satellite image are delineated on-screen  using heads-up digitisation  using standard classification system adopted and preliminary interpretation map has been prepared.
  4. Preparation for fieldwork:  This involved identification of statistically sound sample grids that have been verified on the ground. On the basis of the interpretative uncertainty highlighted during the preliminary interpretation a portion of map units have been selected for field checking. These first sets of points have been integrated, if necessary, by an extra set of checks to assure a good statistical representation of the land cover classes.
  5. Fieldwork: Fieldwork has been executed using a fully standardized methodology. The fieldwork involved establishing the relationship between image elements and the tentatively identified LU/LC categories during preliminary interpretation. “Intermediate” interpretation accuracy was done using field data, which has allowed us to evaluate, in a rather objective way, the work done in the preliminary phase of interpretation. 
  6. Final Interpretation: The delineation of LU/LC categories made during the preliminary interpretation phase was  based on information collected during the fieldwork, existing maps such as wasteland, biodiversity, LU/LC data, etc. During this phase the classes with similar accuracies could be aggregated to the nearest LU/LC class.
  7. The Minimal Mapping Area: Is a concept applied by cartographers when addressing the smallest area that can be shown on a map. Historically, the cartographers determined one particular minimum size of area to be mapped.  This was applied to all classes contained in the legend. The minimum mappable polygon of 3mm x 3mm which is equivalent to 2.25 ha. on 1: 50000 scale has been considered. However, for few important classes variable mapping area can be adopted to preserve the local variations.
  8. Digital Database: This step involves the finalization of land cover layer through editing, digitization, coding and geographic referencing of land cover polygons to facilitate their follow-up GIS processing and integration of land cover and basic topographic layers in a comprehensive digital land cover database.
  9. To implement process based quality assurance to regulate the data flows and outputs as per the standards.
  10. To develop implementation document to monitor the progress.
Project Deliverables: 

Seamless land use/ land cover database for the entire State

Districtwise land use/land cover maps along with statistics

Land use/ land cover Atlas

Beneficiaries: 
  • Agriculture Department
  • Rural Development Department
  • Govt. Departments
  • NGO’s, etc
Quantum of work: 
33
Districts