Trend Analysis of Water Flow and Suspended Sediment Flow of Lower Godavari Basin, India

2021 ◽  
pp. 261-275
Author(s):  
Madhura Aher ◽  
S. M. Yadav
Keyword(s):  
Trend Analysis ◽  
Suspended Sediment ◽  
Water Flow ◽  
Sediment Flow ◽  
Godavari Basin

scholarly journals Vertical Distribution of Suspended Sediments above Dense Plants in Water Flow

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 12 ◽  
Author(s):  
Yanhong Li ◽  
Liquan Xie ◽  
Tsung-chow Su
Keyword(s):  
Vertical Distribution ◽  
Flow Velocity ◽  
Suspended Sediment ◽  
Plant Height ◽  
Water Flow ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Turbulent Momentum ◽  
Different Diameters ◽  
Plane Displacement

Plants in natural water flow can improve water quality by adhering and absorbing the fine suspended sediments. Dense plants usually form an additional permeable bottom boundary for the water flow over it. In the flow layer above dense plants, the flow velocity generally presents a zero-plane-displacement and roughness-height double modified semi-logarithmic profile. In addition, the second order shear turbulent moment (or the Reynolds stress) are different from that found in non-vegetated flow. As a result, the turbulent momentum diffusivity of flow and thus the diffusivity of sediment will shift, which will cause the vertical profile of suspended sediment and the corresponding Rouse formula deform. A set of physical experiments with three different diameters of fine suspended sediments was conducted in an indoor water flume. These experiments investigated a new distribution pattern of suspended sediment and the correspondingly deformed Rouse formula in the flow layer over the dense plants. Experimental results showed that above the dense plants, the shear turbulent momentum of flow presented a plant-height modified negative linear profile, which has been proposed by a previous study, and the vertical distribution of fine suspended sediments presented an equilibrium pattern. Based on the plant-modified profiles of flow velocity and the shear turbulent momentum a new zero-plane and plant-height double modified Rouse formula were analytically derived. This double-parameter modified Rouse formula agrees well with the measured profile of suspended sediment concentration experimentally observed in the present study. By adjusting the Prandtl–Schmidt number, i.e., the ratio of sediment diffusivity to flow diffusivity, the double-parameter modified Rouse formula can be applied to submerged dense plant occupied flow.

Study on the Plants Growth Effect of the Sediment-Laden Flow Turbulence Characteristics

2012 ◽  
Vol 518-523 ◽  
pp. 4771-4777
Author(s):  
Jun Ning Li ◽  
Ju Rui Yang ◽  
Jing Luo
Keyword(s):  
Suspended Sediment ◽  
Plant Height ◽  
Suspended Sediment Concentration ◽  
Flow Direction ◽  
Sediment Concentration ◽  
Growth Effect ◽  
Vertical Orientation ◽  
Turbulence Characteristics ◽  
Sediment Flow ◽  
Flow Turbulence

Abstract: The effect on Sediment-laden flow turbulence characteristics of Wetland plants simulated by flexible plastic tree growing and distribution of suspended sediment concentration were studied through the flume experiment under a certain hydraulic condition. The experimental results showed that the vertical velocity distribution of sediment flow with plant was no longer consistent with logarithm distribution with no plants in sediment flow, but for the "S"-type distribution. The turbulent intensity and Reynolds stress in longitudinal,transversal and vertical orientation were anisotropic, and the maximum and the location of the maximum increased with increasing plant height. Plant growth effects of sediment removal was significant. The vertical suspended sediment concentration increased with plant height decrease, the suspended sediment concentration gradually decreased along the flow direction.

scholarly journals Impact of land use-land cover change on spatio-temporal trends in seasonal stream flow and suspended sediment load of Godavari basin from 1969 to 2019

2021 ◽  
Author(s):  
Madhura Chetan Aher ◽  
Sanjay Yadav
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Suspended Sediment ◽  
Land Cover Change ◽  
Stream Flow ◽  
Sediment Load ◽  
Land Use Land Cover ◽  
Suspended Sediment Load ◽  
Post Monsoon ◽  
Godavari Basin

Abstract Assessment of long-term trend in stream flow and sediment load is important for adopting soil and water conservation measures and for predicting morphological changes in rivers. In the present study, detailed quantification of the nature of trend in stream flow and suspended sediment load of Godavari basin, India is reported for the period of 1969 to 2019. The Mann–Kendall test is used to check trend of stream flow and sediment load for different seasons, namely, spring, monsoon, post-monsoon and winter. The land use-land cover of the whole basin is prepared for four decades (1980–2020). The maximum and minimum water and sediment discharge is detected in monsoon and winter season, respectively. The stream flow is found significantly decreased during monsoon and post-monsoon season. The sediment load is significantly decreased for monsoon and spring season. The nature of trend in sediment load is attributed to the land use and land cover change of the basin. The significant reduction suspended sediment load is mainly due to increase in water bodies and planned agricultural area. The findings of the research would help to manage water resources as well as sustainable development in the Godavari basin.

scholarly journals On the Issue of Calculation of the Suspended Sediment Load Discharge

2020 ◽  
Author(s):  
Keyword(s):  
Suspended Sediment ◽  
Error Probability ◽  
Analytical Formula ◽  
Calculation Error ◽  
Flow State ◽  
Lower Error ◽  
Sediment Size ◽  
Calculated Probability ◽  
Sediment Flow ◽  
Load Discharge

The article deals with the questions of the contribution of suspended sediment in the processes of formation of the channel, and includes several formulas of suspended sediment discharge calculation and the results of calculations by these formulas. An analytical formula of sediments, in which the absolute exponent of the degree of arguments is equal to one shown the lower error probability. The calculated probability of calculation error is explicitly related to the average relative deviation between the calculated and observed values of sediment flow: the formulas with a lower error probability show better correspondence to the observed values. At the same time, the parameters of the analytical formula of sediment flow integral with respect to the type of bottom sediments represent a more stable dependence of the hydraulic variables of the flow state and sediments in contrast to the formulas of a similar purpose with data on sediment size included in them. This is explained by the fact that even quantum estimates of particle size are often unreliable and have high variability within one phase of water content, whereas the parameters focused on the qualitative state of the system (category of sediment size) characterize the properties of the bottom soil on average (integrally) over the cross-section of the flow.

scholarly journals Trend analysis of heavy metals, Ni, Pb, Cd and As in marine sediments – A case study of ONGC Block (KG OSN 2009/2) in Krishna-Godavari Basin, Bay of Bengal

2021 ◽  
Vol 02 (01) ◽  
pp. 051-059
Author(s):  
Pramod Kumar ◽  
G. L. Das ◽  
Atul Garg
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Trend Analysis ◽  
Metal Concentration ◽  
Bay Of Bengal ◽  
Anthropogenic Activities ◽  
Heavy Metal Concentration ◽  
Trend Line ◽  
Increasing Trend ◽  
Godavari Basin

Heavy metals can be termed as conservative pollutants, introduce into the aquatic systems as a result of the weathering of soils and rocks, from under water volcanic eruption and other anthropogenic activities. Thereby it changes the natural concentration of metals in seawater resulting in a ten or even hundred fold increase near the source of an effluent discharge. While some metals like manganese (Mn), copper (Cu), iron (Fe) and zinc (Zn) are biologically important for marine life, others like Nickel (Ni), Lead (Pb), Cadmium (Cd), and Arsenic (As) are non-essential and become toxic at higher concentrations. Associated to particulate matters, heavy metals tends to stay in solution for a very long time, but they will end up in the sediments, Therefore concentrations in the sediments are often higher than those in solution. In the sediments, these particles may form an important secondary source of contamination, even after the primary source has disappeared. Therefore, there is a need for timescale monitoring of the levels of these metals in all the marine resources, so as to establish the trends that could be linked to anthropogenic activities. In this paper, the effect of E&P activities of ONGC Block (KG OSN 2009/2) in Krishna-Godavari Basin, Bay of Bengal is studied, by carrying out a trend analysis of heavy metal concentration (60Ni, 208Pb, 111Cd, and 75As) in the sediments from this block. Sediments samples were collected from the ONGC Block (KG OSN 2009/2) using OSPAR commission guidelines and the heavy metal concentration values averaged out. These average values are used to analyze the trend for a period extending from 2015 up to 2019. In the years 2016, the pollution level recorded was minimum. Overall, from 2015 to 2019, 208Pb shows a decreasing trend line, but 60Ni, 111Cd, and 75As shows an increasing trend line. Albeit the increasing trend of 60Ni, 111Cd, and 75As concentration are a matter of concern, but all the values are below the ERL (effects range low) set by the National Oceanographic and Atmospheric Administration (NOAA), USA. Hence, it can be concluded that the oil field activity of ONGC in the Eastern Offshore has not made any significant impact on the marine environment, in terms of heavy metal pollution. A statistical analysis in terms of Relative Contamination Factors and Pollution Load Index has also been done in the paper.

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