Present study was related to land degradation after landslide and risk analysis of Lower Kosi watershed in Central Himalaya using RS and GIS. The study was aimed to identifying the relation of land use with landslide activity in Himalayan terrain and landslide management. The landslide inventory map was prepared for the detailed study with the help of Google Earth Image and field verifications. Landslide had been sub-categorized into two categories; natural and road induced. The land use map was prepared from Google Earth image followed by toposheets. Statistical analysis of landslide frequency and density as well as frequency and density ratios were applied. The collected data was evaluated in combination with GIS. The relationship between land use categories and landslide occurrences was determined. The landslide frequency ratio (FR) and density ratio (DR) were analyzed. The FR and DR value of 1 is an average value. Hence, the value of ratio more than 1 signifies a strong relationship between landslides and the given factor while ratio values less than 1 registers a poor relationship. The FR and DR values were >1.0 in the areas of fallow land, barren/rocky land, agricultural land and open forest revealing a strong relation to landslide processes while the lesser values of FR and DR in ‘dense forest’ area determines the impact of sufficient vegetation cover on the least occurrence of landslides. This study may be applicable for new and existing land use planning projects as the adopted methodology provides rapid estimation of landslide vulnerability of the area.
With the increase in the pace of development, the demand for tunnels has increased in recent years. Analysing the stability of a tunnel in a fractured rock mass is a very challenging and cumbersome activity. The tunnel stability depends on the strength of the rock, joints bolt strength, in-situ stresses, and their orientation. This paper focuses on constructing tunnels in fractured/jointed rock mass. Three different software namely Rocscience Phase2 (finite element based), FLAC3D (finite volume based) and PFC3D (distinct element based), were used to analyse the performance and stability under static and dynamic loading conditions. The geomaterial properties used for the analysis were taken from data obtained after laboratory testing and based on available literature. The effect of joint orientation and bolt length was analysed using Phase 2 assuming plain strain conditions. The effect of earthquake and performance of fully grouted, energy absorbing and deformation-controlled bolts under seismic loading conditions were compared using FLAC3D. While the 3D distinct element analysis of geometry was performed using PFC3D to evaluate the effect of joints and their orientation. The performance of the different types of bolts was also analysed numerically. The behaviour of bolts can be customised using the ‘fish‘function. The results indicate that analysis must incorporate the fusion of various numerical simulation techniques like finite element-, finite volume- and distinct element-based methods for more reliable results.