Browsing by Author "Harish Kumar, S."

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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. Â© 2023 IEEE.
Assessment of Interactions between River and Aquifer in the Gowri-hole Sub-catchment
(Geological Society of India, 2018) Harish Kumar, S.; Nagaraj, M.K.
Surface water interacts with groundwater in many types of physiographic and hydrogeological conditions. Exchange of water varies spatially and temporally due to the effect of natural and anthropogenic factors. Interactions between a river and the underlying aquifer systems are often difficult to observe and measure. The objective of the present study is to analyze the spatial and temporal variation of river-aquifer interactions in the Gowri hole sub-catchment and quantify the amount of flow exchange between river and aquifer. In the study, a new conceptual model is developed using RIVER package of Three-Dimensional Finite-Difference Modular Groundwater Flow Model (MODFLOW) for the simulation of river-aquifer interaction processes. The subcatchment of Gowri hole, which is a tributary of Kumaradhara river spread across an area of 134 km2 is considered. The model was calibrated from June 2004 to May 2010 under the transient condition with a daily step input of all necessary hydro-geological data. The calibrated model was validated from June 2010 to October 2012 from two monthly observation wells of Department of Mines and Geology and one seasonal observation well of Central Ground Water Board (CGWB). Gowri hole acted as a gaining river during the monsoons due to aquifer discharge and acted as a losing river due to river leakage during post-monsoon and summer months. River leakage continued to occur upto the end of summer months resulting in fragmentation of few river segments. Aquifer discharge sustained to exist even in the summer period avoiding the low flow river segments from drying. © 2018, Geological Society of India.
Minimum superficial fluid velocity in a gas-solid swirled fluidized bed
(2010) Harish Kumar, S.; Murthy, D.V.R.
A swirl flow is achieved in a bed of solids by passing air through multiple fluid inlets, which are tangentially located at the base of a flat-based circular column. The minimum superficial velocities needed to achieve swirling of the bed are measured experimentally under varied conditions. An empirical correlation for the minimum swirl velocity has been proposed. The results indicate that a stable swirling regime operation of the bed is possible. There exists an upper limit of static bed depth beyond which stable swirling of entire bed is not possible. The minimum swirl velocities are found to be 1.2-1.3 times the minimum fluidization velocities predicted for conventional fluidized beds. © 2010 Elsevier B.V.