Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
5 results
Search Results
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 Rainfall trend analysis in coastal region of karnataka(Springer Science and Business Media Deutschland GmbH, 2021) Ashwin, S.; Kemmannu, K.; Doranalu Chandrashekar, D.C.Climate can be defined as the weather conditions or the weather patterns that is present in the particular geographical area for a very lengthy period. It can be assessed by the important factors like temperature, humidity, wind, precipitation. The climate of the region also depends on the latitude, terrain, water bodies, etc. Coastal Karnataka receives an average rainfall of 3456 mm; at summer, the temperature lies between 33.5 and 40 °C and the minimum temperature of 23.3 and 27.9 °C. Tropical monsoon climate covers whole coastal places of Karnataka and other nearby places too. Rainfall time series is divided into four periods. This region has a very hot climate with extreme rainfall in monsoon season, i.e., June to September. These drastic changes in the climate severely affect the various activities throughout the coastal area of Karnataka. Understanding the variability of climate in the region is essential. In this study, the variation in the climate for a period of 1984–2017 is observed and investigated and changes in the trend in the grid points can be noticed. Mann–Kendall trend test is applied for the precipitation to find trend patterns, and the magnitude of the trend is determined by Sen’s slope estimator. Increase in trend was found in the grid point 3 and grid point 4. © Springer Nature Singapore Pte Ltd 2021.Item Review of Experimental Studies on Rainfall-Induced Landslide Using the Laboratory Flume Technique(Springer Science and Business Media Deutschland GmbH, 2024) Menon, V.; Kolathayar, S.Rainfall-induced landslides are one of the most influential disasters in the monsoon season for rainfall-rich parts of India, primarily southern and northeastern. Landslides are geotechnical phenomena that can be studied by conducting field experiments, laboratory experiments, and numerical modeling. Various methods can be adopted to study landslides, and the landslide flume seems to be one of the most widely used techniques for laboratory simulation of the landslides. The scaled models created in a flume can represent the real-world situations so far, which will be reviewed here. The essential aspects of this review include the practicality of the flume experiments from the previous findings, how they can be related to the real-world scenarios, the difference between field instrumentations and laboratory instrumentations, discrepancies that can occur due to the scaled effect of laboratory simulation, and recommended techniques for the future development of laboratory simulated landslides with tilting type flume incorporated with a rainfall simulator. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Travel Decisions and Experiences of Bus Passengers During Extreme Rainfall Conditions(Springer Science and Business Media Deutschland GmbH, 2024) Nithin, K.S.; Mulangi, R.H.; Kumar, A.The public transit system becomes unreliable during extreme weather conditions due to demand fluctuations caused by changes in the travel decision of people. To develop a sustainable public transit system, there is a need to understand the perception of people towards it during extreme weather conditions. The present study aims to study the influence of rainfall on the travel decision, waiting time and travel time of Bengaluru Metropolitan Transport Corporation (BMTC) bus passengers. Responses of people are collected by carrying out a questionnaire survey in Bengaluru City, and analysis is done using the multinominal logistic regression model. From the analysis, it is observed that 60% of people want to prepone or postpone or cancel the trip which may result in demand fluctuations. It is also observed that the waiting time of people at bus stops has got increased by 45% and also 70% of people encountered increased travel time during extreme rainfall. This study edifies the transport policy-makers regarding the travel behaviour of people during extreme weather conditions which can assist them to carry out managerial changes in operational strategies of the public transit system to make it more reliable. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Characterization of climatic parameters in the perspective of irrigated agriculture in Uttar Kannada district of Karnataka, India(India Meteorological Department mausamps@gmail.com, 2020) Yallurkar, S.; Nayak, S.; Nandagiri, L.A rainfall and potential evapotranspiration characteristics together determine the agro-meteorological regime of a region and influences decision concerning the magnitudes and timing of irrigation application. In the present study, historical rainfall and climate data pertaining to the study area, Uttar Kannada district, Karnataka, was analyzed with a view to characterizing irrigation water requirements. In addition to rainfall input, an important aspect of the water balance model is the crop evapotranspiration (ETcrop), which is the main factor in determining the irrigation schedule. ETcrop could be estimated by reference evapotranspiration (ET0) and crop coefficient. Atmospheric demand for water is represented by ‘potential evapotranspiration’ (PET) and calculated from climatic variables which is crucial for irrigation planning. It has been reported that the Penman-Monteith method gives more consistently correct ET0 estimates to other ET0 methods. While recognizing the importance of both rainfall and PET, an effective measure is known as the ‘Moisture Availability Index’ (MAI), which is computed as the ratio of 75% dependable rainfall and potential evapotranspiration. An MAI value of 1.00 indicates that dependable precipitation is equal to potential evapotranspiration. An MAI value of 0.33 or less for one month during the crop growing season is considered to be a signal of water deficit resulting reduction in crop yield. The findings of this study on MAI are used to decide the selection of the sowing period of crops so as to avoid water stress during the critical harvesting period. © 2020, India Meteorological Department. All rights reserved.