Micro Landslide Hazard Zonation Mapping of Lunglei town using Remote Sensing & GIS

The project “Micro Landslide Hazard Zonation Mapping of Lunglei Town using Remote Sensing and GIS” was undertaken by the Mizoram Remote Sensing Application Centre (MIRSAC), Science & Technology, Planning Department, Government of Mizoram, as an in-house study to support disaster-risk reduction and safer urban development in Lunglei. The study was initiated in response to recurrent landslides associated with the town’s steep and dissected terrain, weak sedimentary formations, heavy monsoon rainfall and increasing anthropogenic disturbances such as road cutting, slope modification and unplanned construction. Its main objectives were to analyse land use/land cover, slope, geomorphology, lithology and geological structure, and to integrate these parameters for preparation of a micro-level landslide hazard zonation map.

The study covered the 55.08 sq. km notified area of Lunglei Town. High-resolution QuickBird imagery with 0.8 m spatial resolution formed the primary database, supplemented by IRS-P5 Cartosat-I stereo imagery of 2.5 m resolution, Survey of India topographic maps, field observations and ancillary information. Cartosat-I stereo data were used for contour and slope generation, while QuickBird imagery supported detailed thematic interpretation. The hazard assessment adopted a qualitative, expert-weighted methodology modified from the NRSA approach, in which the controlling terrain parameters were rated according to their relative influence on slope instability.

The terrain analysis revealed the dominance of steep slopes: 55.41% of the study area lies within the 40–60° slope class, while another 33.60% falls within 20–40°; only about 9% of the area has slopes below 20°. Geomorphologically, Medium Structural Hills occupy 71.94% of Lunglei, followed by Low Structural Hills at 21.18%, demonstrating the strong structural control over the town’s rugged landscape.

The final landslide hazard zonation classified Lunglei into five susceptibility classes. Very High Hazard Zones occupy 1.01 sq. km (1.84%), while High Hazard Zones account for 7.67 sq. km (13.92%). The largest proportion falls within the Moderate Hazard Zone—19.76 sq. km or 35.87%—followed by Low Hazard at 17.05 sq. km (30.96%) and Very Low Hazard at 9.59 sq. km (17.41%). Thus, approximately 51.6% of the town falls within Moderate to Very High hazard categories, highlighting the significance of terrain instability for future urban planning.

The study also documented field evidence of slope instability associated with crumpled shale, jointed rock, quarrying, road widening, retaining-wall failure and soil saturation. Overall, the project demonstrated the effectiveness of high-resolution Remote Sensing and GIS for micro-level landslide assessment. The resulting thematic layers, hazard zonation map and 1:20,000 grid-wise maps provide an important scientific baseline for land-use regulation, infrastructure planning, slope stabilization, disaster preparedness and prioritization of mitigation measures in Lunglei Town.

Summarized Metadata

Mapping Scale: 1:5,000 

Satellite data & Year: Quickbird & Cartosat-1 (2007)

Thematic sub-category: Disaster Management, Geology

Collaborating/Funding Agency: Science, Technology & Environment Wing, Planning Department, Government of Mizoram

Report Publication Month/Year: February, 2009