This presentation is about the how we can use Remote sensing and GIS using Analytical Hierarch System for Landslide Susceptibility Map.

1. Presentation on Landslide Prone
site and their identification using
Remote sensing
By Atif Hussain Malla
Roll No 21064120001

7. Landslide Hazard Zonation
The Division of the Land in areas and their ranking according to degree of
actual/Potential hazard caused by mass movement.
Landslide hazard is commonly shown on maps, which displays the spatial
distribution of hazard classes in terms of landslide Hazard Zonation

8. Identification of areas prone to landslide and
their categorization are the key elements for
suggesting mitigation measures for
minimizing the losses caused by landslides.
• Landslide prone areas are to be delineated on the maps by
integrating multiple database.
• When assessing the probability of landslide within an area,
recognition of the conditions that caused the slide and the
processes that triggered the movement is of primary importance.

9. Intrinsic Factors
These make the slope susceptible to failure
Geology
Structures
Slope and Aspect
Relative relief
Soil
Drainge Pattern
Landcover/Landuse
Triggering Factors: These initiate the Failure
Rainfall
Earthquake
Shaking of Land by vehicles
Factors affecting the Landslide

10. For the Preparation of Landslide susceptibility map, we prepare
thematic layers of potential sources.
• Different type of primary and secondary data used to prepare the
landslide susceptibility map is taken from satellite imagery and some
of the data is developed or collected from potential sources.

11. Case Study
In this case study, eight different eight factors were taken into consideration, LuLc, lithology, drainage, distance
from rivers, rainfall and soil type.

12. Method:
• Integration of Remote sensing with GIS.
• The slope map and drainage density map of the area
understudy were generated from the SRTM DEM using spatial
analyst tool in ArcGIS. Maps showing the distances from rivers
and roads were generated from the DEM using the Euclidean
distance tool in ArcGIS. Average rainfall maps for three different
seasons such as pre-monsoon (March to May), monsoon (June
to October) and post-monsoon (November to February) were
prepared from the daily rainfall data of seven rain gauge
stations (Agartala, Amarpur, Dharmanagar, Khowai, Sabroom,
Sakhan, and Sonamura) within the study area. The rainfall data
for a period of 22 years (1998 to 141 2019) was downloaded
from the NASA Power Data Access Viewer website. The daily
data was converted to seasonal data considering three seasons
as stated above.Inverse distance weighting (IDW) interpolation

13. Table 1 Summary of data sources
Sr. No Data Source Year
Scale/Resolution
1 SRTM DEM USGS Earth Explorer 2014 30 m
2 LULC map National Remote Sensing Centre(NRSC), Hyderabad 2015-16
1:50,000
3 Geology map Geological survey of India (GSI) 2018
1:50,000
4 Soil map FAO harmonized world soil database 2007
1:5,00,000
5 Road map MapCruzin website -
1:50,000
6 Daily Rainfalldata NASA Power data access viewers portal 1998-2019 -

18. These maps are scanned and introduced into ArcGIS for the generation of
Landslide susceptibility map.
Analytical Hierarchy process(AHP), a multi-criteria decision making(MCDM)
method is used to assign weightage to different thematic layers. In this
method, relative weights were determined after consulting with the
Experts and following the past studies. The weights were then
assigned to different thematic layers and their features on the scale of
1 to 9 based on their influence on landslide susceptibility. Higher
weights represent higher influences and the weight reduces with the
reduction in landslide susceptibility.

20. Results and conclusions
During pre-monsoon season 73.2 and 18.7% of the area comes under low and
moderate landslide susceptible zones covering about 7679 and 1957 km2,
respectively. During the monsoon season the susceptibility to landslide increases
with the moderate landslide susceptible area increasing to about 62% and the low
landslide susceptible area reduces to about 29%. Though the state is not highly
susceptible to landslides, still its percentage is 8.3% during the monsoon season
covering an area of around 870 km2. As the monsoon recedes the susceptibility
to landslides reduces following almost the similar trend as the pre-monsoon
season resulting in low to very low landslide susceptibility. The landslide
susceptibility maps will help the scientists/planners to undertake precautionary
measures to handle the hazard so that the possible cause of casualty and
economic losses can be avoided up to certain extent.

21. Thank You