An Introduction to Geospatial Approach: Land Use Map of Mining area and Analysis of Time Sequential Surface Changes

Land is the solid cover of the earth .It is a non–renewable, finite natural resource to be used by human beings for all purposes, essentials and extras of life .Information on landuse- land cover and possibilities for their optimal use is essential for the selection, planning and implementation of land use schemes to meet the increasing demands for basic human needs and for welfare purposes. Land degradation due to several anthropogenic activities such as urbanization, deforestation & desertification, conversion of productive agricultural land for industrial use and surface mining activities have become a fundamental environmental problem. Land degradation due to surface & sub-surface mining has become a serious threat to the environment over the recent years. As mining is a site specific activity, it alters the entire land use pattern rapidly within a very short span of time. Land use conditions are bound to change in any area where some amount of mining activity is going on everyday (Ghosh R, 1990).

Surface & sub-surface mining activities have resulted in a huge change in the land use pattern. Remote Sensing has evolved as an important tool for land use mapping. Remote Sensing with the recent advancement in sensors spatial resolution helps in better understanding of the key causes behind the change in land use.

MATERIAL AND METHODS

Primary Data

NRSC remote sensing data in digital format was received in False Colour Composite (FCC) comprising of three different bands. Spectral mismatching problem are faced. These are overcome majorly by Histogram Matching technique during merging of different scenes into a single frame.

Secondary Data:

1) Survey of India (SoI) toposheet

2) Geological Maps, Mine Plans

Data Processing (Methodology)

Data processing involves the major steps:-

1) Radiometric Correction

2) Geometric correction, rectification and geo-referencing.

3) Image Enhancement

4) Training set selection;

5) Signature generation and classification;

6) Validation of Classified Image

7 )Thematic map preparation.

Interpretation

Digital Classifications are done to interpret the raw satellite data. The image sets are analyzed based on interpretation keys. These keys are fundamental image elements such as colour, tone, shape, size, texture, pattern, location, association and shadow.

Based on the image elements and other geo-technical elements like land form, drainage pattern and physiography; training sites are selected/identified for each land use/cover class. Field survey has to be  carried out in order to collect ground information so that training sets were selected accurately in the image .These are done as an aid for subsequent classification.

Conclusion

Thus, we see how remote sensing can become an effective tool and can reduce the man power thereby saving costs for such analysis purposes. It is a convenient approach and is increasingly becoming significant in varied fields where actual ground analysis is cumbersome and time consuming.

Article by Mr. Arghya Niyogi

Author’s Bio- Associated with M.N.Dastur & Company (P) Limited as an Environmental Engineer.
Assists clients in protecting the environment & enhancing their shareholder value by advising them on various environmental issues.

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