Faculty Publications
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Item Hydraulic Modeling of River Discharge Subjected to Change in Riverbed Morphology(Springer, 2020) Kappadi, P.; Nagaraj, M.K.In natural channels such as rivers, the flow behavior is highly complicated phenomenon due to unsteady and nonuniform flow. Hydraulic modeling is essential for the study of characteristics of unsteady flow in rivers. Changes in riverbed morphology influence the increase in depth of flow in rivers. In the present study, the roughness coefficient is varied to match the natural condition. The objective of the paper is to study the effect of the change in riverbed morphology on the river discharge using a hydraulic model. The study is carried out using the Hydrologic Engineering Center—River Analysis System (HEC-RAS). A river length of 12 km of the Nethravathi river regime, Karnataka from Uppinangadi to Bantwal is considered for the study. Daily river stage and discharge data are collected from Central Water Commission (CWC) gaged at Bantwal station. GIS interface of HEC-GeoRAS is also used to extract the cross section, bed slope, and length of the river channel from Digital Elevation Model (DEM) data of resolution 30 m. The cross sections are represented for each kilometer length of the river. Since accurate data is unavailable in the study area, cross sections are simplified. HEC-RAS model was used for the simulation of surface water levels and discharge values. Manning’s roughness coefficient and river cross sections were defined for the calibration of observed river stage and discharge data. The predicted discharge was in good agreement with that of the observed discharge value. Study results illustrated that accuracy of predicted maximum water depth, and surface water level depends upon the precise representation of Manning’s roughness. The study is useful for the prediction of the flood dynamics in the river regime with the change in riverbed morphology. © Springer Nature Singapore Pte Ltd. 2020.Item Study on Processed Granulated Blast Furnace Slag as a Replacement for Fine Aggregates for the Greener Global Construction(Springer Science and Business Media Deutschland GmbH, 2023) Arpitha, D.; C, C.; Kappadi, P.As innovation in concrete technology advances and the environment weakens, it is currently evident that the boundless utilization of construction materials and its initial expense being the common determination model has become a routine with regard to the past. Since there is great interest for raw materials and natural resources are rare, it is expected to utilize a high volume of alternative materials in concrete that would be monetarily beneficial like crushed sand, blast furnace slag, etc. An experimental investigation was carried out to examine the behaviour of mortars incorporating partial volumes of secondary material to fine aggregates. Processed granulated blast furnace slag (PGBS), newly processed slag which had overcome the limitations of granulated blast furnace slag obtained as a by-product during the extraction of steel was tested for fine aggregate (FA) replacement. Several combinations of mortar mixes were prepared using Lignosulfonate (LS), Sulphonated Naphthalene Formaldehyde (SNF) and Polycarboxylate Ether (PCE)-based superplasticizers (SP) for 0 and 50% replacement levels of FA by PGBS to recognize the feasible optimum dosage of SP required to achieve desired flow characteristics of mortars. Based on the optimum dosage of SP and w/c obtained, mortar cubes were prepared and cured for 3, 7, and 28 days. These cubes were tested for compressive strength periodically, the results revealed that PCE-based SP exhibited better performance concerning flow behaviour and strength gain parameters along with the effective reduction in w/c for both 0 and 50% FA replaced mixes. PGBS exhibited higher strength when compared to 0% replaced mixes though there was a slight increase in water content required for the cohesive mix. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Crop pattern change and crop water requirement judgment using remote sensing and gis techniques: A research on tungabhadra dam right canal(Blue Eyes Intelligence Engineering and Sciences Publication, 2019) Yadav, A.; Hafeezunnisa; Kappadi, P.Agriculture is most important resources of any country worldwide which is a major renewable source and is dynamic. The study area selected was command area under Basavanna canal which is one of the canals to Tungabhadra river on right side bank. This selected canal for cropping pattern analysis has a command of 1240.00 hectare and is located at Vallabhpur, Bellary district. Basavanna canal has a designed discharge capacity of 125 cusecs for serving the cropping area. Every irrigation project has planned cropping pattern, the crop water requirement (CWR) for which is calculated based on Duty / Delta method. However due to growing population and increase demand for food products crop violation is found in every command leading to more irrigation. Remote Sensing (RS) and Geographical Information System (GIS) techniques have emerged as powerful tools for crop water management. Remotely sensed land use-land cover data was used for analysing the cropping pattern in the area and also to estimate the change in the cropping pattern. This study was performed using ArcGIS 9.3 and ERDAS 9 software. Crop water requirement was calculated using Modified Penman Equation for present cropping pattern. The study finds that, approximately 50% of water could be saved using modified Penmen method compared to crop water requirement calculated using Duty Delta method as adopted in project report and the same water may be diverted to meet other needs. © BEIESP.Item Effect of roughness coefficient on discharge and flow depth by using hydraulic model for nethravathi river Basin, India(Inderscience Publishers, 2021) Kappadi, P.; Nagaraj, M.K.; Deka, P.C.The river stage and discharge are dynamic due to various factors affecting the flow characteristics in a natural channel. The channel roughness plays an important role since it is not a constant parameter and varies along the length of the river. The objective of the present study is to assess the variation of Manning's roughness coefficient on flow characteristics of Nethravathi River. In the study, 1D Saint-Venant equation-based HEC-RAS hydraulic model was used to simulate the effect of roughness coefficient (Manning's coefficient n) on discharge and stage of river flow. The model result showed good consensus between model computed flow discharge values and observed flow discharge measured at downstream gauging station. The study found that the computed stage values increased whereas the associated peak discharge decreased with the increase in Manning's roughness coefficient. The stage-discharge rating curves revealed that Manning's n value is relatively more sensitive at higher discharge values. © 2021 Inderscience Enterprises Ltd.