scholarly journals Spatio Temporal Variation in Streamflow and Sediment Discharge in Middle Godavari Basin During 1969-2016

2019 ◽  
Vol 8 (4) ◽  
pp. 4780-4786
Keyword(s):  
Stream Flow ◽  
Water Discharge ◽  
Sediment Concentration ◽  
Sediment Discharge ◽  
Daily Data ◽  
Spatio Temporal ◽  
Slope Estimator ◽  
Annual Water ◽  
Present Case Study ◽  
Godavari Basin

The present study focuses to investigate the trend in the annual water and sediment discharge for Middle Godavari Basin. Daily data of stream flow and suspended sediment concentration is collected from 19 hydrometric stations. The trend was determined by applying Mann-Kendall and Sen’s slope estimator. The analysis of stream flow revealed that out of 19 stations, 17 stations reported decreasing trend and analysis of sediment discharge revealed that all 19 stations reported decreasing trend. Pettit test is carried out to identify the abrupt change in water discharge and sediment discharge. The present case study would be useful to the policy maker’s for effective management of water resources in the area.

Spatio-temporal analysis of the sediment yield and water turbidity at the right-bank tributaries of the Pripyat River within Ukraine

2020 ◽  
Author(s):  
Yuliia Filippova
Keyword(s):  
Sediment Yield ◽  
Sediment Load ◽  
Water Discharge ◽  
Sediment Discharge ◽  
Water Turbidity ◽  
Spatio Temporal ◽  
Annual Water ◽  
Annual Water Discharge ◽  
The Right ◽  
Annual Sediment

<p>Regularities of the river channel processes are closely related to the magnitude and variability of the river load, and the sediment yield, and the sediment yield is one of the principal factors of the riverbed formation. Cycling and dynamics of the sediment yield need to be taken into account when making hydrotechnical calculation, project work and investigating of the riverbed processes. The amount of the river loads, which find their way into the sub-basin of the Pripyat River each year, depends more on the meteorological conditions of the year. That’s why sediment yield and water turbidity are non-permanent from year to year. Since the rivers of the investigated region belong to different hydrological zones and regions, characterized by the uniqueness of water regime, which is caused by the peculiarities of hydrographic and orographic territory indexes, the content of the sediment yield and the amount are also not the same.</p><p>The water turbidity at the right-bank tributaries of the Pripyat River, which flow within the Ukrainian Polesie, is not large. The water turbidity of the Turia, Ubort River and Vyzhivka is especially small. In certain years the concentration of sediment yield can be bigger. Much more suspended particles are observed in the Styr, Sluch, and Horyn, the upper catchments of which are strongly cut and partially covered with easily washable sediments. The biggest annual average water turbidity was recorded on the Ikva River. Within the accumulative lowland in the downstream river sections, the right-bank tributaries of the Pripyat River carry cleaner water than in the upstream section since the part of sediment load of the river is build up on the riverbeds and creeks. It occurs as a result of the slope and speed reducing. However, on some right-bank rivers of Pripyat, which flow down from small local terrain uplands with cover of loamy forest and sandy sediments, water turbidity can be quite large.</p><p>The estimation of the spatio-temporal dynamics of the sediment load is accomplished by difference integral curves taking into account an average annual water discharge, maximum annual water discharge and also average annual sediment discharge and the biggest annual sediment discharge during the whole period of investigation of current hydrological posts for the right-bank tributaries of the Pripyat River within Ukraine. The analysis of synchronicity and equiphase condition of these oscillations had made it possible to identify general noticeable opposite orientation of the set of curves to the oscillation curve of general sediment load. Constructed graphs show interdependence of maximum annual water discharge, average annual sediment discharge, maximum annual sediment discharge because the sediment discharge has to react to hydraulic fluctuation in the flow.</p>

scholarly journals Pertinent spatio-temporal scale of observation to understand suspended sediment yield control factors in the Andean region: the case of the Santa River (Peru)

2013 ◽  
Vol 17 (11) ◽  
pp. 4641-4657 ◽  
Author(s):  
S. B. Morera ◽  
T. Condom ◽  
P. Vauchel ◽  
J.-L. Guyot ◽  
C. Galvez ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Spatial Data ◽  
Sediment Yield ◽  
Water Discharge ◽  
Daily Rainfall ◽  
Sediment Concentration ◽  
Suspended Sediment Yield ◽  
Control Factors ◽  
Daily Water ◽  
Spatio Temporal

Abstract. Hydro-sedimentology development is a great challenge in Peru due to limited data as well as sparse and confidential information. This study aimed to quantify and to understand the suspended sediment yield from the west-central Andes Mountains and to identify the main erosion-control factors and their relevance. The Tablachaca River (3132 km2) and the Santa River (6815 km2), located in two adjacent Andes catchments, showed similar statistical daily rainfall and discharge variability but large differences in specific suspended-sediment yield (SSY). In order to investigate the main erosion factors, daily water discharge and suspended sediment concentration (SSC) datasets of the Santa and Tablachaca rivers were analysed. Mining activity in specific lithologies was identified as the major factor that controls the high SSY of the Tablachaca (2204 t km2 yr−1), which is four times greater than the Santa's SSY. These results show that the analysis of control factors of regional SSY at the Andes scale should be done carefully. Indeed, spatial data at kilometric scale and also daily water discharge and SSC time series are needed to define the main erosion factors along the entire Andean range.

scholarly journals Field methods of a near-bed suspended sediment experiment in the Yangtze River, China

2020 ◽  
Vol 13 (21) ◽  
Author(s):  
Caiwen Shu ◽  
Guangming Tan ◽  
Yiwei Lv ◽  
Quanxi Xu
Keyword(s):  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Dynamic Equilibrium ◽  
Water Discharge ◽  
Sediment Concentration ◽  
Common Method ◽  
Sediment Discharge ◽  
Improved Method ◽  
The Common ◽  
The Impact

AbstractUsing experimental data of near-bed suspended sediment concentrations at five typical hydrometric stations of the Three Gorges Reservoir at the early reserving stage, the differences were investigated between the common method and improved method during flood seasons and non-flood seasons. The impact of taking measurements below 0.2 times the water depth on the results was discussed. The results show that the average discharges and velocities at each station calculated by the common method were slightly larger than those calculated by the improved method. Regarding the suspended sediment concentration at each station, the errors in the reservoir and downstream channels in dynamic equilibrium state were small, and the largest errors occurred where the river bed was strongly scoured in the downstream reach below the large dam. There was no significant relationship between water discharge and flow velocity, and the missed measurement phenomenon also occurred. The sediment discharge error was affected by the suspended sediment concentration, implying that errors usually occurred in channels with serious erosion during flood seasons. The correction coefficients (R2) of sediment discharge at each station were given during the experiment, which showed that the sediment discharges at the hydrometric stations where a large amount of sediment transport occurred near the river bottom, needed to be modified. Furthermore, the test methods proposed in this study were applied to calculate the sediment discharges of three rivers, and the results indicate that this method can narrow the gap between bathymetric comparisons and sediment load measurements.

Formulating an elasticity approach to quantify the effects of ecological restoration and climate variability on streamflow and sediment discharge changes in the Loess Plateau of China

2020 ◽  
Author(s):  
Guangyao Gao
Keyword(s):  
Climate Variability ◽  
Suspended Sediment ◽  
Ecological Restoration ◽  
Loess Plateau ◽  
Yellow River ◽  
Water Discharge ◽  
Sediment Concentration ◽  
Sediment Discharge ◽  
The Loess Plateau ◽  
Check Dams

<p>Ecological restoration (ER) has strong consequences on hydrological responses. The China’s Loess Plateau (LP) contributed nearly 90% of sediment load in the Yellow River, which was once the world’s largest carrier of fluvial sediment. ER efforts including the soil and water conservation measures (SWCMs, especially terracing and construction of check dams) since 1950s and large-scale ecological restoration campaigns such as Grain-for-Green project (i.e., returning sloping cropland to afforestation and pasture reestablishment) in 1999, has resulted in extensive land use/cover change, leading to considerable decreases of streamflow (Q), suspended sediment yield (SSY) and sediment concentration (C) in the LP over the past 60 years. However, it remains challenging to quantify the impacts of ER and climate variability on declines of Q and especially SSY. In this study, we formulate the notion of elasticity of sediment discharge, by associating SSY change to climate variability and ER over the period 1950s to 2014. Our results strongly support the hypothesis that changes to both streamflow volumes and to the suspended sediment concentration versus water discharge (C-Q) relationships result in reduced SSY, so that streamflow is reduced but runs clearer. We find that two of the ER strategies resulted in weaker relative impacts of climate variability, largely by reducing streamflow (by 55% to 75%). Meanwhile, ER predominantly decreased SSY (by 63% to 81%). Regarding ER practices, (i) the predominant measure acting to reduce SSY changed, over time, from engineering to reforestation; (ii) check-dams preferentially act to regulate the C-Q relationships whereas reforestation preferentially acts to moderate streamflow. Overall, our results suggest that a combination of engineering and vegetation measures is critical to achieving high-efficiency ER. While change to the ER strategy increased the efficiency of streamflow for SSY control, the lost water discharge per unit SSY reduction increased from 5.2 to 6.4 m<sup>3</sup>·t<sup>-1</sup>. Conflicting demands for water necessitate that further ER should target precision management by revegetation of targeted areas in the Loess Plateau.</p>

scholarly journals Estimating River Sediment Discharge in the Upper Mississippi River Using Landsat Imagery

2020 ◽  
Vol 12 (15) ◽  
pp. 2370
Author(s):  
Jonathan A. Flores ◽  
Joan Q. Wu ◽  
Claudio O. Stöckle ◽  
Robert P. Ewing ◽  
Xiao Yang
Keyword(s):  
Mississippi River ◽  
Landsat Imagery ◽  
Water Discharge ◽  
Absolute Error ◽  
Sediment Concentration ◽  
Hydraulic Geometry ◽  
Upper Mississippi River ◽  
Sediment Discharge ◽  
River Channels ◽  
Fluvial Systems

With the decline of operational river gauges monitoring sediments, a viable means of quantifying sediment transport is needed. In this study, we address this issue by applying relationships between hydraulic geometry of river channels, water discharge, water-leaving surface reflectance (SR), and suspended sediment concentration (SSC) to quantify sediment discharge with the aid of space-based observations. We examined 5490 Landsat scenes to estimate water discharge, SSC, and sediment discharge for the period from 1984 to 2017 at nine gauging sites along the Upper Mississippi River. We used recent advances in remote sensing of fluvial systems, such as automated river width extraction, Bayesian discharge inference with at-many-stations hydraulic geometry (AMHG), and SSC-SR regression models. With 621 Landsat scenes available from all the gauging sites, the results showed that the water discharge and SSC retrieval from Landsat imagery can yield reasonable sediment discharge estimates along the Upper Mississippi River. An overall relative bias of −25.4, mean absolute error (MAE) of 6.24 × 104 tonne/day, relative root mean square error (RRMSE) of 1.21, and Nash–Sutcliffe Efficiency (NSE) of 0.49 were obtained for the sediment discharge estimation. Based on these statistical metrics, we identified three of the nine gauging sites (St. Louis, MO; Chester, IL; and Thebes, IL), which were in the downstream portion of the river, to be the best locations for estimating water and sediment discharge using Landsat imagery.

scholarly journals Discharge and sediment loads of two streams in the mid-hills of central Nepal

1970 ◽  
Vol 2 (3) ◽  
pp. 51-54 ◽  
Author(s):  
Roshan M Bajracharya ◽  
Subodh Sharma ◽  
Roberto Clemente
Keyword(s):  
Land Use ◽  
Stream Flow ◽  
Management Practices ◽  
Nutrient Loading ◽  
Water Discharge ◽  
Sediment Concentration ◽  
Sediment Yields ◽  
Growing Seasons ◽  
Sediment Loads ◽  
Land Use And Management

Stream flow, nutrient loading, and sediment yield closely reflect land use and management practices in relation to growing seasons in mid-hill watersheds of the central Himalaya. A preliminary study was conducted to determine approximate total water discharge and sediment yields from the Galaundi and Pokhare catchments. Mean discharge and sediment loads during the 2002 rainy season were 2.1 m3?s-1 and 0.9 kg?s-1 for Galaundi Khola and 0.45 m3 s-1 and 0.28 kg?s-1 for Pokhare Khola. Estimates of total annual discharge of water and sediment were, respectively, 27.8 million m3 and 11,400 t (Galaundi) and 6.4 million m3 and 3,500 t (Pokhare). These corresponded to about 71.6% and 60.4% of total rain volumes and soil loss rates of 5.18 t?ha-1 and 5.83 t?ha-1 for Galaundi and Pokhare sub-watersheds, respectively. Good correlations were observed for stream discharge vs. sediment concentration (R2 = 0.83 and 0.94 respectively) and rainfall amount vs. discharge (R2 = 0.94 and 0.96 respectively) for both streams. Key words: stream flow, sediment concentration, land use, pre-monsoon, sub-watershed Himalayan Journal of Sciences 2(3): 51-54, 2004

СALCULATED CHARACTERISTICS OF THE AVERAGE ANNUAL RUNOFF OF THE RIGHT-BANK AND LEFT-BANK PARTS OF THE RIVER BASIN DNIESTER TO THE CITY OF ZALISHCHYKY

2020 ◽  
pp. 58-72
Author(s):  
A.I. Boiko ◽  
O.V. Lobodzinskyi ◽  
О.I. Lukіanets
Keyword(s):  
River Water ◽  
River Basin ◽  
Water Flow ◽  
Stream Flow ◽  
Water Discharge ◽  
Continuous Series ◽  
Left Bank ◽  
Average Annual Runoff ◽  
Annual Water ◽  
The Right

The Dniester River is the second longest and most watery river in Ukraine, which is characterized by heterogeneity and diversity of conditions for the formation of water flow, both in terms of its length and numerous tributaries. The right-bank and left-bank parts of the Dniester River basin are quite different in terms of physical and geographical conditions, drainage network density, water regime and river water content. The object of the study is the average annual water flow of the rivers of the Dniester River basin, the subject is its calculated characteristics of different probabilities of exceeding. The purpose of the study is to analyze, systematize, generalize and compare the calculated characteristics of the average annual water flow of rivers of the right-bank and left-bank parts of the Dniester basin. Input data is based on the average annual river water discharge from 50 stream flow measuring stations in the Dniester River basin (to Zalishchyky). The data bank was formed from the beginning of observations until 2016. 89% of 28 right-bank stream flow measuring stations have a continuous series of more than 50 years, and 86% of 22 left-bank stream flow measuring stations have a continuous series of observations of more than 50 years. As for the catchment areas of rivers in the closing areas, the right bank is dominated by small ones – 64% of 28 stations have an area of less than 500 km2 and 25% – from 500 to 1,000 km2. 37% of 22 stations on the left bank have a catchment area of less than 500 km2 and 41% – from 500 to 1,000 km2. According to statistical criteria, the series of observations of the average annual river water discharge in both parts were mainly homogeneous and representative. Analytical distribution curves were calculated by the method of moments, as the coefficients of variation do not exceed 0.50. Generalization and comparison of the calculated characteristics of the average annual water flow of different probabilities of exceeding the rivers of the right-bank and left-bank parts of the Dniester basin have shown that the smallest scatter of certain analytical ordinates is observed for the probability of exceeding 50%, the transition coefficients from the norm are close to 1. The greatest spread of variation of ordinates is observed at extreme probabilities of excess of distributions, that is 0,01 % and 99 %. Analysis of the ranges of variability of transition coefficients from the norm of average annual water consumption has shown that the intensity of their change in the region of rare probabilities (0.01, 0.1, 1 %%) on the left bank is more significant than on the right bank of the Dniester basin. As for low-water supplies (95, 97, 99 %%), their ranges of variability coincide in both studied parts.

SPATIAL-TIME VARIABILITY OF THE ILE RIVER RUNOFF UNDER CONDITIONS OF ANTHROPOGENIC ACTIVITY

2021 ◽  
Vol 101 (2) ◽  
pp. 40-51
Author(s):  
Zh.S. Mustafayev ◽  
◽  
A.T. Kozykeyeva ◽  
L.M. Ryskulbekova ◽  
◽  
...  
Keyword(s):  
Catchment Area ◽  
Anthropogenic Activities ◽  
Water Discharge ◽  
Hydrological Regime ◽  
Temporal Scale ◽  
Anthropogenic Activity ◽  
Time Variability ◽  
Spatio Temporal ◽  
Annual Water ◽  
Annual Water Discharge

To solve the problems of sustainable management of water resources in the catchment area of the Ili River basin, it is becoming demanded to study the dynamics of the average annual water discharge, taking into account anthropogenic activities, since their intensity is constantly growing. At the same time, the integral indicator of natural conditions in the catchment is the average annual water discharge of river basins, and the importance of this parameter lies in the fact that they can be considered as a function of the response to any changes in the catchment. In this regard, the analysis of changes in the average annual water discharge of the Ili River basin's catchment area was carried out on a spatio-temporal scale, where linear trends were used to assess and plot graphs, the method of multiple regression analysis and processing of time series were carried out on the basis of Microsoft Excel. Analysis of the dynamics of the average annual water discharge in the Ili River basin's catchment area on a spatio-temporal scale showed that, despite significant variability over the years, all studied hydrological stations are characterized by general patterns of changes in the hydrological regime under the influence of anthropogenic and natural factors.

Neural networks approached for modelling river suspended sediment concentration due to tropical storms

2013 ◽  
Vol 11 (4) ◽  
pp. 457-466
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Time Series Data ◽  
Water Discharge ◽  
Sediment Concentration ◽  
Series Data ◽  
Generalized Regression Neural Network ◽  
Event Based

Artificial neural networks are one of the advanced technologies employed in hydrology modelling. This paper investigates the potential of two algorithm networks, the feed forward backpropagation (BP) and generalized regression neural network (GRNN) in comparison with the classical regression for modelling the event-based suspended sediment concentration at Jiasian diversion weir in Southern Taiwan. For this study, the hourly time series data comprised of water discharge, turbidity and suspended sediment concentration during the storm events in the year of 2002 are taken into account in the models. The statistical performances comparison showed that both BP and GRNN are superior to the classical regression in the weir sediment modelling. Additionally, the turbidity was found to be a dominant input variable over the water discharge for suspended sediment concentration estimation. Statistically, both neural network models can be successfully applied for the event-based suspended sediment concentration modelling in the weir studied herein when few data are available.

scholarly journals Dissolved and particulate nutrient transport dynamics of a small Irish catchment: the River Owenabue

2014 ◽  
Vol 18 (6) ◽  
pp. 2191-2200 ◽  
Author(s):  
S. T. Harrington ◽  
J. R. Harrington
Keyword(s):  
Suspended Sediment ◽  
Water Discharge ◽  
Nutrient Transport ◽  
Sediment Concentration ◽  
Coefficient Of Determination ◽  
Available Phosphorus ◽  
Nitrogen And Phosphorus ◽  
Particulate Nitrogen ◽  
Monitoring Period ◽  
Nitrogen Concentrations

Abstract. The objective of this research was to investigate the relationship between water and sediment discharge on the transport of nutrients: nitrogen and phosphorus. Water discharge, suspended sediment concentration and dissolved and particulate forms of nitrogen and phosphorus were monitored on the 105 km2 River Owenabue catchment in Ireland. Water discharge was found to have an influence on both particulate and dissolved nutrient transport, but more so for particulate nutrients. The particulate portion of N and P in collected samples was found to be 24 and 39%, respectively. Increased particulate nitrogen concentrations were found at the onset of high discharge events, but did not correlate well to discharge. High concentrations of phosphorus were associated with increased discharge rates and the coefficient of determination (r2) between most forms of phosphorus and both discharge and suspended sediment concentrations were observed to be greater than 0.5. The mean TN yield is 4004 kg km−2 yr−1 for the full 29-month monitoring period with a mean PN yield of 982 kg km−2 yr−1, 25% of the TN yield with the contribution to the yield of PN and PP estimated to be 25 and 53% respectively. These yields represent a PN and PP contribution to the suspended sediment load of 5.6 and 0.28% respectively for the monitoring period. While total nitrogen and total phosphorus levels were similar to other European catchments, levels of bio-available phosphorus were elevated indicating a potential risk of eutrophication within the river.

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