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2. INTRODUCTION Landslide is the movement of earth, mass of rock or debrisalong the slope Gharwal Himalaya is a part of extra peninsula Structural disturbances like folding, faulting, and shearingare very common in this region This area exhibits variety of landslides because of variousnatural as well as artificial activities2 3. INTRODUCTION Landslides may be ignored if they occur in the area ofno human interest But if it occur in areas like roads, agricultural lands,human inhabited areas then it leads to loss of life andproperty Minor to major landslides that are very common nearPipalkoti area on the road of Chamoli to Joshimaththat have increased the maintenance cost of RishikeshMana Highway3 4. INTRODUCTION There is need to study and classify the Himalayanlandslides from road network point of view inMountain terrain This study is done by available Base maps of area andtheir interpolation with RS and GIS to form thelandslide hazard zonation maps of respective studyareas4 5. STUDY AREA 3 areas have been selecteda ) Gopeshwar city of Chamoli districtb ) Stretch of Chamoli-Joshimath road nearPipalkotic ) Area around Nandprayag Area lies in Survey of India toposheet covering26.18 sq.km, 21 sq.km and 17.63 sq.km respectively5 6. 6 7. GEOLOGY OF AREA There is an intense metamorphosis in area Land consist of rocks such as quartzite, gneisses,marbles and various types of micaceous schist andslates All these rocks have weak cohesion along the plains Physiographically the area lies in tectonic , folded andover thrust mountainous chain.7 8. LANDSLIDE Geography and Geology of this area makes it prone tolandslides Besides this area comes under zone IV of earthquake High flow of rivers and ice melting triggers the actionof landslides Besides this road development across slopes anddeforestation adds effect to landslide.8 9. LANDSLIDESFollowing types of landslide was observed in study area1. Slides2. Falls3. Flow4. Topples9 10. ROCKFALL10 11. TOPPLES11 12. SLIDE12 13. FLOW13 14. RS AND GIS TECHNIQUE Field survey is most accurate way to study landslides But to study large and remote area it is consumingtime and money RS and GIS are most effective tools in such conditionto obtain results with good accuracy Various satellite images provided by IKONOS, IRS P6,QUICK BIRD etc can be used as base to studylandslides.14 15. REMOTE SENSING (RS) RS data like satellite images and aerial photographs areused to extract terrain information. Satellite data of different years gives information aboutchanges in geomorphology of area. Various factor maps like land use map, drainage mapetc can be prepared from processing of RS data15 16. GEOGRAPHICAL INFORMATIONSYSTEM (GIS) GIS has information about different terrain factors inthe form of layers With use of GIS software like ILWIS it is possible tocombine the factor map produced by RS withlandslide map. This will visualize landslide density in survey area .16 17. ILWIS ILWIS (Integrated Land and Water InformationSystem) is a GIS software developed by ITC,Netherland. It contains both the modules of GIS and imageprocessing It is very fast and accurate tool for processing,analyzing and representing spatial data. It is a useful tool for landslide analysis17 18. Landslide hazard zonation mapping There is no basis available to forecast the probability oflandslide occurrence in given time period But landslide hazard assessment is possible Hazard assessment is the estimation of an area to itssusceptibility to landslide based on few key factors18 19. Landslide hazard zonation mappingFollowing data used to measure landslide hazard of anarea: Past landslides and their distribution Bed rock properties Slope of area Hydrology of area Human factors19 20. Applications of hazard zonation It helps to decide land use capability of area It shows risk to current land use development It shows area vulnerable to landslide Based on surveys it helps to predict future landslides20 21. METHODOLOGY Remote sensing and GIS are two main methodologiesadopted for landslide hazard zonation Remote sensing data used in the form of satelliteimageries GIS software is used to interpolate both satellite dataand base maps to form hazard zonation map21 22. RS DATA INTERPRETATION Digital data of IKONOS is procured fromwww.earth.google.comof all study areas. The color composite is prepared in ILWIS in RGBbands. The satellite data is geo-referenced and rectified withbase map of study area. Base map is prepared by use of toposheets.22 23. 23 24. GENERATION OF DIGITAL ELEVATEDMODEL (DEM) Base map is imported to ILWIS and converted toILWIS data format Geo coding and Geo referencing is done to generate araster (Images in Geo-Informatics) The segment maps are digitized in respective domainboundaries of area, contours and drainage.24 25. GENERATION OF DIGITAL ELEVATEDMODEL (DEM) DEM is prepared after interpolating the contoursegment data DEM is analyzed by spatial filtering and slope mapsare derived From DEM flow direction and flow accumulation mapis also prepared Degree of map was classified as per Young'sClassification25 26. 26 27. 27 28. Generation of hazard zonation map Satellite data was imported and geo referenced withbase map The data is then interpreted by image interpretationkeys and pre occurred landslides and landslide hazardzones are located The slope map layer, flow map layer, drainage layer areadded on RS data to predict the landslide prone zones28 29. 29 30. 30 31. Preparing stereo pairs From DEM stereo pairs are prepared to view forvarious rasters like slope degree map, satellite data etc The generated stereo pairs are viewed as ANAGLYPH.31 32. 32 33. CONCLUSION Landslides are Force Majeure. When occurred, landslides causes great losses to bothHuman and Infrastructure. Remote Sensing data has proved to be an effective toolfor landslides study in remote areas like Himalayanranges. RS and GIS based Hazard Zonation Maps givesaccurate information about the Risk levels in aparticular area. GIS techniques found to be very economical for fieldstudy in inaccessible areas.33 34. 34THANK YOU!!!