Faculty Publications
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Item Assessing the impact of 2018 tropical rainfall and the consecutive flood-related damages for the state of Kerala, India(Elsevier, 2021) Kulithalai Shiyam Sundar, K.S.S.; Deka, P.C.; Subbarayan, S.; Devanantham, D.; Jacinth Jennifer, J.Flood is the relatively high flow in the river, markedly than the usual resulting in the inundation of low land. Usually, river floods when the river can no longer contain its discharge from its catchments. Flood is the costliest as well as a common natural disaster in the world devastating both life and economy to a greater extent. The state of Kerala has faced an unprecedented rainfall followed by severe floods in August 2018 with a death toll for 504. Kerala is the southernmost narrow strip of the coastal territory that slopes down the Western Ghats to reach the Arabian Sea with 14 districts in the state. According to the Central Water Commission (CWC), the state received 2346.6 mm of rain from June to 19th of August, which is 42% more than the average rainfall. The state received a tremendous rainfall of 758.6 mm in the first 20 days of August which is 164% more than the actual rainfall. With the heavy rainfall all over the state, floods prevailed by the end of July. Once again a massive spell of rainfall happened at 8th and 9th of August which led to further flooding in Wayanad district. Due to the continuous rainfall from the first week of June to August, water levels were almost near the Full Reservoir Level. So, the water was released from several dams due to the heavy rainfall in the catchment. Another intense spell of rainfall took place by the 14th of August and continued till 19th of August resulting in the massive flood throughout the state affecting 13 of the 14 districts leading to the evacuation of about 3.4 million people to the 12, 300 relief camp across the state making the worst flood in the century. 2018 Kerala flood caused extensive damage to the crops, building, and infrastructure; its associated aftermath of the flood resulted in a huge loss to its economic, social, and natural environment, accompanied by the 331 landslides across 10 districts. After ravaging by the flood, the state has faced communicable diseases leptospirosis, chicken pox, hepatitis A, malaria, and dengue resulting in a death toll for 180. Thus, this paper is tried to understand the impact of the tropical rainfall followed by the devastating flood that occurred in the state of Kerala in August 2018 and to understand the impact on the socioeconomic disturbances, its resilience aftermath the flood. © 2021 Elsevier Inc. All rights reserved.Item A NDVI Based Approach To Detect The Landslides By Using Google Earth Engine(Institute of Electrical and Electronics Engineers Inc., 2023) Vishnu Vardhan, M.; Harish Kumar, S.; Mohan Kumar, S.; Kundapura, S.Detection of landslide-prone areas plays an important role in planning urban connectivity like roads, bridges, etc. Landslides are generally caused by a variety of factors, the most important of which is rainfall. In this paper, the detection is carried out in four taluks of Chikkamagaluru district, namely Koppa, Sringeri, Mudigere, and Narashimarajpur; these four taluks are located in the Western Ghat region. Landslides are primarily caused by heavy rainfall during the monsoon season. For the detection of landslides, Sentinel optical and SAR data are used because of their 10metre resolution and revisiting period of two to five days. The entire methodology for detecting landslides is carried out in Google Earth Engine due to its large collection of data, which aids in multi-temporal studies. This paper attempts to investigate the capabilities of remote sensing and GIS techniques in the detection of landslides. For the detection of landslides, Normalized Difference Vegetation Index (NDVI) is used for Sentinel-2 data and the SAR backscatter change approach is used for Sentinel-1 images, and I thresholding is applied to both methods to detect areas where landslides had occurred. The main thing is that no previous landslide inventory data is used for detection. The previous landslide inventory is used for validation purposes only. Finally, the performance of both approaches was compared using accuracy assessment properties such as overall accuracy and kappa coefficient to determine which approach is superior. © 2023 IEEE.Item Use of geoinformatics and geophysical applications in landslide studies: An overview(World Research Association Vijay Nagar A.B. Road Indore 452 010, 2019) Thejashree, G.; Lokesh, K.N.; Dwarakish, G.S.Landslide is one of the hazardous geological phenomena which is gaining attention worldwide because of destruction caused by it. Due to the drastic increase in urbanization and human intervention in hilly regions, the destruction caused by mass wasting is increasing day by day. Landslides are far from the control of humans. But the destruction and losses caused by these calamites can be minimized, if their occurrence is known before time. This review paper aims at discussing how remote sensing, GIS and geophysical techniques can be utilized for investigation of landslides and mapping of landslide susceptible areas. Geophysical techniques can provide important information on physical characteristics linked with landslide mechanism. Complementarily, remote sensing and Geographical Information System (GIS) techniques play an important role in the generation of thematic layers related to landslide occurrences which aid to produce susceptible, hazard zonation and landslide inventory maps. Such integrated approach on landslides studies can bring about better understanding and help to take up mitigation measures to reduce the landslide hazards. © 2019, World Research Association. All rights reserved.Item A note on the occurrence of landslides in Araku valley and its environs, Visakhapatnam district, Andhra Pradesh, India(2010) Balaji, P.; Pavanaguru, R.; Venkat Reddy, D.The occurrence of landslides in Araku valley and its environs of Visakhapatnam district of Andhra Pradesh have been studied. The slides occurred in a rugged hilly terrain which is a part of Eastern Ghats Mobile Belt. The slides are predominantly debris slides of varying dimensions and occurred in khondalitic country having slopes of the order of 30°. The debris are composed mostly of scree, soil, boulders and weathered rock. The significant causative factor of triggering slides was manifested through heavy rainfall associated with cyclonic storm. The causes of the slope failure include toe erosion, debris accumulation that resulted in blockade, overtopping and changes in the stream courses. The present paper is aimed to identify damage assessment, magnitude of slides and causes of slides with an attempt to suggest some long term corrective and control measures in the area. © 2010 Cafet-Innova Technical Society.Item Analyzing landslide susceptibility, health vulnerability and risk using multi-criteria decision-making analysis in Arunachal Pradesh, India(Springer Science and Business Media Deutschland GmbH, 2023) Rehman, S.; Azhoni, A.Landslides being a widespread disaster are associated with susceptibility, vulnerability and risk. The physical factors inducing landslides are relatively well-known. However, how landslide susceptibility will be exacerbated by climate change, impede the attainment of the sustainable development goals and increase health vulnerability is relatively less explored. We present an integrated assessment of landslide susceptibility, health vulnerability and overall risk to understand these interconnected dimensions using Arunachal Pradesh, India, as a case study, which is susceptible to landslides due to its topography and climate conditions. Landslide susceptibility was examined using twenty landslide conditioning parameters through the fuzzy analytical hierarchy process (FAHP). The susceptibility map was validated using the area under the ROC curve (AUC). National Family Health Survey (NFHS 4) data were used to analyze the health vulnerability, while the overall risk was computed through the integration of susceptibility and vulnerability. Landslide susceptibility analysis indicated that nearly 22% area of the state is characterized by moderate susceptibility followed by high (17%) and very high susceptibility (13%). High elevation, slope, rainfall, SPI, drainage density and complex geology were identified as the causative factors of landslides. In the case of health vulnerability, East Kameng and Lohit districts were found to be very highly vulnerable, while Papum Pare, Changlang and Tirap districts experience high health vulnerability due to high degree of exposure and sensitivity. Overall risk analysis revealed over 16.8% area of the state is under moderate risk followed by high (9.8%) and very high (4.2%) risk. Linking this analysis with the climate change projections and SDG goals attainment revealed that Papum Pare, Upper Subansiri, Tirap and West Kameng require priority for lessening susceptibility, vulnerability and risk for achieving sustainable development. A strong correlation (99%) between HVI and risk further demonstrates the need for lessening health vulnerability and risk in the study area. Furthermore, our study contributes additional insights into landslide susceptibility by considering heal vulnerability and risk which may help in planning sustainable development strategies in a changing climate. © 2022, The Author(s) under exclusive licence to Institute of Geophysics, Polish Academy of Sciences & Polish Academy of Sciences.Item Multihazard Assessment of the Sutlej-Beas River Basin Using Bivariate Statistical Frequency Ratio (FR) Model and Management Barriers of Land-River Interface(Springer Science and Business Media Deutschland GmbH, 2023) Rehman, S.; Azhoni, A.Climate change coupled with increased anthropogenic activities intensifies the potency and frequency of extreme weather events. While multihazard assessments of these extreme weather events enhance the estimation of hazard susceptibility, it must be coupled with identifying institutional barriers of managing the land-river interface. Thus, this study has carried out a multihazard susceptibility assessment based on landslide and flood susceptibility in the Sutlej-Beas River basin and prepared flood and landslide susceptibility maps using eleven causative parameters through a bivariate statistical frequency ratio (FR) model. This statistical evaluation of hazard susceptibility from multiple factors is supplemented by identifying the key barriers of managing the land-river interface, producing a more comprehensive understanding of the challenges of mitigating extreme weather-related hazards in a river basin. Nearly 51% of the study area was identified as susceptible to landslide while 43% was under flood and 48% area was observed under multihazard susceptibility. Landslides, floods, and multihazard followed a similar pattern of spatial distribution where elevation, population, drainage density, stream power index (SPI), and rainfall were identified as the contributing parameters. Changing attitudes of people toward rivers, lack of coordination among different stakeholders, and deficit funds were identified as prominent barriers in the case of land-river management. Susceptibility maps generated in this study will help in identifying the areas under hazard susceptibility while the identified institutional barriers may guide towards contextual sustainable planning of the basin and attainment of sustainable development goals. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Item An Appraisal of the Mechanism and Research Development Status of Anti-slide Piles as Effective Technique for Landslide Risk Reduction(Springer, 2024) Jose, D.; Kolathayar, S.; Nayak, S.The increased frequency of landslides and associated devastations necessitates developing sustainable mitigation measures. The present paper aims to appraise the research developments in enhancing slope stability using anti-slide piles for landslide mitigation. The previous researchers made an immense effort to identify the soil–structure interaction of the anti-slide pile. The soil arching between the piles was identified as the soil–pile interaction mechanism. A detailed review of the soil arching between the piles is performed, and the observations are presented in detail. Recently, different sustainable methods for the analysis and design of anti-slide piles have been developed. An attempt was made to carry out a comprehensive review of the analysis methods and their critical features, and the observations are provided. The parameters affecting the performance of the anti-slide piles were identified, and the influence of those parameters on the behavior of piles is also discussed. Finally, the novel designs developed by researchers to overcome the limitations of conventional anti-slide piles and the utilization of sustainable materials as anti-slide piles were appreciated. The authors like to highlight that anti-slide piles are an effective solution for landslide risk reduction, and there is further scope for research in this field. © The Author(s), under exclusive licence to Indian Geotechnical Society 2024.Item Influence of Angle of Internal Friction and Slope Face Angle on Kinematic Failures in Marble Mines: A Predictive Approach(Springer, 2025) Sinha, S.; Tripathi, A.K.; Akhil, A.; Kumar, M.This study investigates the kinematic stability of slopes in two opencast marble mines, focusing on the variation of dip angles of the slope and angles of internal friction on overall slope stability. The research draws on joint orientation data collected from the mines to perform detailed kinematic analyses, examining different slope faces at various dip directions that gave a probability of failure. A crucial part of the study involved statistical analysis by curve-fitting model to establish a relationship between the dip angle (or overall pit angle) and the angle of internal friction. The relationship was found to be nonlinear following a trend of 3rd-degree polynomial equation. Additionally, sensitivity analysis was conducted to further understand the relationship between these critical parameters. The sensitivity index was calculated by finite difference method where the parameters dip angle and angle of internal friction were taken into consideration by keeping one of the parameter constants and varying the other parameter and vice versa to find out the dependency of the varying parameter on the probability of failure. This multifaceted approach not only validates the importance of these variables, but also provides a predictive framework for assessing slope failure risks. © The Author(s), under exclusive licence to Indian Geotechnical Society 2025.Item Rainfall-Induced Slope Instability in a Tilting Flume: Analysis of Pore Pressure Variations and Surface Crack Percentage(Springer, 2025) Menon, V.; Kolathayar, S.This study investigates the relationship between surface crack development and excess pore water pressure (EPWP) during rainfall-induced debris flow conditions. A custom-designed tilting flume integrated with a rainfall simulator was fabricated to replicate slope failure scenarios. Silty sand was tested under controlled conditions on 45° and 60° slopes with identical rainfall intensities. Surface cracks were quantified using an image processing algorithm to calculate crack percentages, and real-time EPWP measurements were recorded to assess their correlation. The results demonstrate that surface crack formation significantly influences EPWP, suggesting a potential interdependence between these parameters. Furthermore, the study evaluates whether EPWP can serve as an effective threshold parameter for landslide early warning systems (LEWS). These findings contribute to a better understanding of landslide mechanics and provide critical insights for enhancing LEWS design and implementation. © The Author(s), under exclusive licence to Indian Geotechnical Society 2025.Item 3D Finite Element Analysis of Anti-slide Pile Performance for Slope Stabilization(Springer Science and Business Media Deutschland GmbH, 2025) Jose, D.; Kolathayar, S.; Nayak, S.The stability of the slope plays a significant role in the formation and development of landslides. Among numerous slope stabilizing techniques, the reinforcement using anti-slide piles is an efficacious method for mitigating slope failures. These piles are usually installed in a row with uniform spacing, which will anchor the unstable zone to the deeper stable strata, thus maintaining the stability of the slope. In this study numerical analysis of the pile reinforced was carried out using the finite element software PLAXIS 3D to appraise the performance of anti-slide piles for controlling landslides. The variation of the factor of safety with the pile position, pile spacing, pile length, and shape of the pile was identified based on the safety analysis using the strength reduction method. The anti-slide pile effectively stabilized the slope and enhanced the safety factor by 1.4 times. The fixity of the pile head influences the performance of anti-slide piles, and fixed-head piles excels than free-head piles. The optimum position for placing the pile was observed as the middle of the slope for fixed head piles and near the toe of the slope for free head piles. The optimum spacing between the piles is recommended to be five times the diameter of the pile. A critical pile length of 0.8 times the height of the slope is suggested for attaining the maximum factor of safety and effective anchoring, and square-shaped piles are recommended. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.