Geo-Spatial Technology in Landslide Management – A Case Study in Nilgiris District

Geo-Spatial Technology in Landslide Management – A Case Study in Nilgiris District

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D. Vidhya
Student
Institute of Remote Sensing,Anna University,
Email: [email protected]

R.Vandana Varshini
Student
Institute of Remote Sensing,Anna University
Email: [email protected]

Environmental degradation and human of exploitation of natural resources of hilly region are triggering many disasters like excessive soil erosion and sedimentation, landslide etc. Landslides constitute one of the major natural catastrophes of the Nilgiris District, which account for a considerable loss of life and damage to communication routes, human settlements, agricultural and forestland. The problem of landslides becomes more aggravated, especially during the rainy season in Nilgiris District. As such, there is an urgent need on part of the scientific community to formulate strategies for minimizing the occurrence of landslides.
Aerial photography, which gives high-resolution horizontal and vertical spatial information, can be employed in Land Hazard Zonation (LHZ) A small area in Nilgiris district has been taken to demonstrate the utility of the aerial photographs and photogrammetric technique in pinpointing the landslide hazard zones.
Prohibitive cost and substantial delays are major disadvantages of photogrammetric techniques. This paper reviews the effective use of remote sensing data for landslide management inorder to replace the expensive photogrammetric techniques.
As a case study, a watershed has been taken for landslide zonation mapping using from Survey Of India toposheets and IRS LISS-III + PAN data. Slope and land use are the two parameters used for LHZ mapping.
The result shows that 10-meter contour interval of toposheets and 6-meter spatial resolution of IRS PAN data can only give broad and qualitative ideas for landslide risk
Management.
For effective zonation and management, Contour interval of 2 meters is necessary and spatial resolution of 1 meter is needed. Though optical resolution data is increasing day-by-day (Quick bird, Cartosat, etc.), getting vertical resolution is still challenging in passive remote sensing.
The authors felt during the study that Interferometric techniques can be effectively employed to improve the existing DEM and to monitor minor changes in terrain. The RISAT mission of government of India, RADARSAT of Canada, ENVISAT of ESA (European Space Agency) will provide necessary spatial data for such analysis.