scholarly journals 226Ra and 210Po concentration in drinking water of Cauvery river basin south interior Karnataka State, India

2017 ◽  
Vol 10 (1) ◽  
pp. 20-23 ◽  
Author(s):  
E. Kavitha ◽  
M.S. Chandrashekara ◽  
L. Paramesh
2017 ◽  
Vol 314 (1) ◽  
pp. 321-331 ◽  
Author(s):  
R. S. Niranjan ◽  
C. Ningappa ◽  
T. Yashaswini ◽  
N. A. Chamaraja ◽  
D. R. Rangaswamy ◽  
...  

2020 ◽  
Author(s):  
Gowri Reghunath ◽  
Pradeep Mujumdar

<p>Catchments are complex self-organizing environmental systems for which the form, drainage network, channel geometries, soil and vegetation, are all an outcome of co-evolution and adaptation to the ecological, geomorphologic and land-forming processes. Quantification of hydrological signatures provides vital information about the complex system properties and the functional behaviour of catchments. This work aims at evaluating catchment similarity with respect to geomorphology and hydrological signatures such as runoff ratio, flow duration curves and peak flows for calibrating and upscaling model parameters. The study is carried out on the sub-catchments of Cauvery river basin which is a major river basin in Peninsular India. The basin is characterized by extensive regional variability in surface and groundwater availability and large-scale shift in land use patterns in recent decades. With a significant number of anthropogenic interventions such as check dams and reservoirs, the basin faces water management challenges at the local, regional and basin scales. Hydrological signatures derived from elevation, streamflow and meteorological data are used to evaluate geomorphologic and hydrological similarity between the sub-catchments. We employ the physically based macroscale Variable Infiltration Capacity (VIC) model coupled with a routing model to simulate the streamflow. Streamflow simulations are carried out for various sub-catchments delineated based on discharge gauging stations. Model parameters are estimated and hydrological signatures are assessed for effective model calibration. Impact of interventions on flow signatures at the catchment scale is also assessed. This work can significantly improve the scientific understanding of variability of hydrological processes at various scales and provide useful insights for development of scaling relationships. It can also aid in examining the model parameter transferability across scales.</p>


2020 ◽  
Author(s):  
Sagar Chavan ◽  
Shobhit Maheshwari

<p>The mechanism of sediment transport is mainly governed by surface water flow within the river basins. Excessive sediment transport plays an important role in reducing the carrying capacity of channel networks, storage capacity of reservoirs/dams. An important task for most of the hydrologists is to determine the reliable stream flow estimate which causes majority of the sediment transport within river basins/stream channels. The transport effectiveness of a stream flow event of a particular magnitude in carrying a sediment load is defined as the product of the effect of that event (i.e. sediment transport rate corresponding to the stream flow event) and the frequency with which the event occurs. This approach is famously known as magnitude frequency analysis (MFA). MFA provides a mathematical framework to determine various discharge indices such as effective discharge, fraction-load discharge and functional-equivalent discharge. These indices provide information on long-term transport of sediments through river networks and are linked to the exponent of sediment rating curve (which is correlated to the size of sediments, bed armouring and river morphology). Effective discharge index represents that single discharge which carries the most amounts of sediments, whereas fraction-load discharge and functional-equivalent discharge indices deal with mean sediment load which considers the contribution of entire probability distribution of discharge. There is a dearth of attempts to study these discharge indices for Indian catchments. In the present study, lognormal distribution and Gamma distribution -based MFA approaches are used to estimate discharge indices for Cauvery River basin, India. Effectiveness of the approaches was assessed based on their ability to predict discharge indices for 12 catchments in the river basin. Results indicate that Gamma distribution-based approach provides reliable estimates of fraction-load discharge and functional-equivalent discharge. The fraction-load discharges were computed for the catchments by considering various fractions of sediment loads ranging from 10% to 90%. Plots of cumulative sediment yield were prepared for both approaches and compared with empirical cumulative sediment yield. It was observed that the Gamma distribution-based MFA approach tends to provide close match with the empirical yield.</p>


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