scholarly journals Two approaches to hydrograph separation of the glacial river runoff using isotopic methods

2016 ◽  
Vol 56 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Yu. N. Chizhova ◽  
E. P. Rets ◽  
Yu. K. Vasil'chuk ◽  
I. V. Tokarev ◽  
N. A. Budantseva ◽  
...  
Keyword(s):  
River Runoff ◽  
Isotope Fractionation ◽  
Hydrograph Separation ◽  
Snow Melting ◽  
Runoff Hydrograph ◽  
Total Runoff ◽  
Solution Of Equations ◽  
Isotopic Methods ◽  
Runoff Regime ◽  
Field Works

Application of the stable isotope method in the balance equations used to calculate separation of the runoff hydrograph from the Djankuat Glacier basin is demonstrated. Simultaneous solution of equations of water, isotope and ion balances is applied to estimate contributions of different components and processes to formation of the Djankuat River runoff regime. For June 2014, we made calculations for the purpose to separate contributions of the spring (isotopically weighted) snow and winter (isotopically depleted) snow. Field works in the glacial basin Djankuat were performed during two ablation seasons, i.e. from June to September of 2013 and 2014. Two approaches were used when calculating separation of the runoff hydrograph by means of solution of systems of equations for isotopic and ion balances: 1) taking account of the isotope fractionation during snow melting, and 2) with no account for the fractionation. Separation of the hydrograph for June 2014 have shown that about 15–20% of the Djankuat River runoff is formed by spring snow melting, sometimes increasing up to 36%. Contribution of spring meltwater to the total runoff increases when the isotope fractionation during the snow melting is taken into account for the calculations. In this case, the contribution of spring snow changes from 30 to 50%.

Quantitative estimation of genetic components in the seasonal runoff of a small river by the graphoanalytic and isotopic method

2020 ◽  
Author(s):  
Julia Chizhova ◽  
Maria Kireeva ◽  
Natalia Tebenkova ◽  
Alexey Kositsky
Keyword(s):  
River Runoff ◽  
Quantitative Estimation ◽  
Isotope Composition ◽  
Atmospheric Precipitation ◽  
Weighted Average ◽  
Hydrograph Separation ◽  
Snow Melting ◽  
Flow Forming ◽  
Important Indicator ◽  
Genetic Components

<p>The processes of spring flood formation associated with intensive snow melting are becoming less and less predictable, and forecasts of such important characteristics as maximum discharge and water level do not fit into the allowable ranges of error. In some areas, a sharp decrease in river runoff was observed, followed by catastrophic floods, associated with the anomalous hydrometeorological conditions and an unfavorable combination of flow-forming factors. All this testifies to the change in runoff formation processes in regions with a significant share of snow-fed rivers. A new method of storing processing and visualizing of the information is developed to bridge the gap between point data on river runoff and globally distributed data on characteristics affecting the genetic components of runoff. The use of new model for separating runoff into genetic components was verified by isotope hydrograph separation.</p><p>Under unsteady climate conditions, the isotope signature of river water within a year and on a multi-year scale is an important indicator of the response of hydrological system to change (associated with different amounts of snow in the winter and different contributions of snow melting to the river and groundwater reservoir). Observations at the local site of the Protva River catchment on the European Plain showed that over 9 years (in 2009-2010 and in 2019), the groundwater component did not change its isotopic characteristics: δ18О = -12.3 ‰. The intra- and interannual fluctuations associated with different amounts of atmospheric precipitation entering the upper groundwater horizon practically did not shift oxygen isotope composition of water. In 2014, the weighted average annual value δ18О of the precipitation for Moscow was -12.1‰ (Chizhova et al., 2017). The δ18О value of precipitation in the summer months varies from -3 to -10 ‰. In Protva river runoff in mid-summer the contribution of precipitation is from 16 to 34% according to the isotope hydrograph separation. This work was supported by RSF project 19-77-10032.</p>

Automatic hydrograph separation approach provides possibility to look at less-studied characteristics of water regime

2020 ◽  
Author(s):  
Ekaterina Rets ◽  
Maria Kireeva ◽  
Timophey Samsonov
Keyword(s):  
River Runoff ◽  
Flash Flood ◽  
Flash Floods ◽  
European Part ◽  
Hydrograph Separation ◽  
North Caucasus ◽  
Russian Science ◽  
European Part Of Russia ◽  
Snowmelt Flood ◽  
Runoff Regime

<p>The study presents an approach to automatic river hydrograph separation and analysis implemented in GrWat open source package for R programming language. In the proposed scheme of hydrograph separation, river hydrograph is separated into base and quick flow. For plain rivers quick flow is further separated into seasonal snowmelt flood quick flow; rain quick flow and thaw quick flow. For mountainous rivers seasonal snowmelt flood quick flow component is divided into “basic snowmelt flood” component and overlapping rain floods. Base and quick runoff is separated by a critical gradient. Flash-floods are separated from the seasonal snowmelt wave by critical values of air temperature and precipitation on the event for the plain rivers and using a critical gradient concept for mountainous rivers. More than 30 characteristics of river runoff regime are calculated for each water resource year: characteristics of annual and seasonal runoff, contribution of each genetic component, characteristics of maximum runoff, n-day minimum discharges and dates when they are observed. Additionally, more than 50 characteristics of each flash-flood are calculated:  characteristics of shape, volume, timing of flash-floods, the values of meteorological parameters that bring about different types of floods. The presented approach to automatic river hydrograph separation and analysis was tested on 45 plain rivers in the European part of Russia in different climatic zones and on 10 mountainous rivers in the North Caucasus. The result of application provides a possibility for analyzing previously unstudied characteristics of river runoff regime and its climate-related transformation on the European part of Russia.</p><p>The study was supported by the Russian Science Foundation grant No. 19-77-10032</p>

scholarly journals Comparing Bayesian and traditional end-member mixing approaches for hydrograph separation in a glacierized basin

2019 ◽  
Author(s):  
Zhihua He ◽  
Katy Unger-Shayesteh ◽  
Sergiy Vorogushyn ◽  
Stephan M. Weise ◽  
Doris Duethmann ◽  
...  
Keyword(s):  
Bayesian Approach ◽  
Model Uncertainty ◽  
Temporal Variability ◽  
Isotope Fractionation ◽  
Cold Season ◽  
Water Sampling ◽  
Hydrograph Separation ◽  
Total Runoff ◽  
Spatio Temporal ◽  
The Bayesian Approach

Abstract. Water tracer data have been successfully used for hydrograph separation in glacierized basins. However, uncertainties in the hydrograph separation are large in these basins, caused by the spatio-temporal variability in the tracer signatures of water sources, the uncertainty of water sampling and the mixing model uncertainty. In this study, we used electrical conductivity (EC) measurements and two isotope signatures (δ18O and δ2H) to label the runoff components, including groundwater, snow and glacier meltwater, and rainfall, in a Central Asia glacierized basin. The contributions of runoff components (CRC) to the total runoff, as well as the corresponding uncertainty, were quantified by two mixing approaches: a traditional end-member mixing approach (TEMMA) and a Bayesian end-member mixing approach. The performance of the two mixing approaches were compared in three seasons, distinguished as cold season, snowmelt season and glacier melt season. Results show that: 1) The Bayesian approach generally estimated smaller uncertainty ranges for the CRC compared to the TEMMA. 2) The Bayesian approach tended to be less sensitive to the sampling uncertainties of meltwater than the TEMMA. 3) Ignoring the model uncertainty caused by the isotope fractionation likely leaded to an overestimated rainfall contribution and an underestimated meltwater share in the melt seasons. Our study provides the first comparison of the two end-member mixing approaches for hydrograph separation in glacierized basins, and gives insights for the application of tracer-based mixing approaches for similar basins.

scholarly journals A Comparison of Continuous and Event-Based Rainfall–Runoff (RR) Modelling Using EPA-SWMM

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 611 ◽  
Author(s):  
Sharif Hossain ◽  
Guna Alankarage Hewa ◽  
Subhashini Wella-Hewage
Keyword(s):  
Goodness Of Fit ◽  
Model Performance ◽  
South Australia ◽  
Comparative Performance ◽  
Direct Runoff ◽  
Continuous Simulation ◽  
Runoff Hydrograph ◽  
Total Runoff ◽  
Event Based ◽  
Runoff Hydrographs

This study investigates the comparative performance of event-based and continuous simulation modelling of a stormwater management model (EPA-SWMM) in calculating total runoff hydrographs and direct runoff hydrographs. Myponga upstream and Scott Creek catchments in South Australia were selected as the case study catchments and model performance was assessed using a total of 36 streamflow events from the period of 2001 to 2004. Goodness-of-fit of the EPA-SWMM models developed using automatic calibration were assessed using eight goodness-of-fit measures including Nash–Sutcliff efficiency (NSE), NSE of daily high flows (ANSE), Kling–Gupta efficiency (KGE), etc. The results of this study suggest that event-based modelling of EPA-SWMM outperforms the continuous simulation approach in producing both total runoff hydrograph (TRH) and direct runoff hydrograph (DRH).

scholarly journals Contribution of glacial melt to river runoff as determined by stable isotopes at the source region of the Yangtze River, China

2015 ◽  
Vol 47 (2) ◽  
pp. 442-453 ◽  
Author(s):  
Zhaofei Liu ◽  
Zhijun Yao ◽  
Rui Wang
Keyword(s):  
Yangtze River ◽  
Meteoric Water ◽  
Stream Water ◽  
Source Region ◽  
Upstream Region ◽  
The Yangtze River ◽  
Hydrograph Separation ◽  
Water Line ◽  
Total Runoff ◽  
Meteoric Water Line

The primary objective of this study was to quantify the contribution of glacial melt to total runoff in the Gaerqu River catchment, which is located in the source region of the Yangtze River, China. The isotope hydrograph separation method was used to separate glacier melt runoff from total runoff in the catchment. The degree-day method was used to investigate temporal variations in glacial melt runoff. The results showed that the contribution of glacial melt runoff to total runoff was 15.0%. The uncertainty of the separation was ± 3.7% at the confidence level of 95%. Glacial melt runoff was mainly generated in June, July, and August. The runoff coefficient was 0.23 for the catchment. Precipitation-induced runoff constituted 19.9% of the total precipitation, meaning that precipitation loss was >80% across the study period (a hydrological year). The Local Meteoric Water Line (LMWL) of the catchment was fitted as δ2H = 7.75 δ18O + 5.93. This line has a smaller slope and intercept than the Global Meteoric Water Line. The regression-lines for the δ18O and δ2H values of stream water indicated that evaporation was greater over the entire catchment than it was for the upstream region alone.

Year-to-year changes in the salinity of the eastern English Channel, 1948–1973: a budget

1981 ◽  
Vol 61 (2) ◽  
pp. 489-507 ◽  
Author(s):  
A. H. Taylor ◽  
P. C. Reid ◽  
T. J. Marsh ◽  
T. D. Jonas ◽  
J. A. Stephens
Keyword(s):  
North Atlantic ◽  
River Runoff ◽  
Atlantic Water ◽  
English Channel ◽  
Local Wind ◽  
Local Data ◽  
The North ◽  
Total Runoff ◽  
Flow Through ◽  
Local Wind Forcing

A model has been used to assess the relative importance of the various factors contributing to changes in the salinity of the eastern English Channel between 1948 and 1973. As part of the data input to the model, monthly means (1948–73) of total runoff into the eastern English Channel and monthly estimates of evaporation and precipitation for the same area (1961–73) were calculated. The results of this study have shown that river runoff is an important factor contributing to the variability of salinity in the eastern English Channel; rainfall over and evaporation from the Channel may also be important at certain times. The model can predict satisfactorily more than 80% of the variation of salinity from local data inputs. While Atlantic water movements and salinities may contribute to variability at the entrance to the English Channel, variations of flow through the Channel, caused by local wind forcing or originating further out in the Atlantic, have little effect on the fluctuations of salinity in the eastern English Channel. Furthermore, fluctuations in the salinity of the North Atlantic do not correspond to those observed at the entrance to the English Channel. River runoff and mixing due to the wind and tides appear to be the main factors responsible for the seasonal changes of salinity in the eastern English Channel.

scholarly journals Comparing Bayesian and traditional end-member mixing approaches for hydrograph separation in a glacierized basin

2020 ◽  
Vol 24 (6) ◽  
pp. 3289-3309
Author(s):  
Zhihua He ◽  
Katy Unger-Shayesteh ◽  
Sergiy Vorogushyn ◽  
Stephan M. Weise ◽  
Doris Duethmann ◽  
...  
Keyword(s):  
Bayesian Approach ◽  
Model Uncertainty ◽  
Cold Season ◽  
Spatiotemporal Variability ◽  
Water Sampling ◽  
Hydrograph Separation ◽  
Total Runoff ◽  
Central Asian ◽  
Insight Into ◽  
The Bayesian Approach

Abstract. Tracer data have been successfully used for hydrograph separation in glacierized basins. However, in these basins uncertainties of the hydrograph separation are large and are caused by the spatiotemporal variability in the tracer signatures of water sources, the uncertainty of water sampling, and the mixing model uncertainty. In this study, we used electrical conductivity (EC) measurements and two isotope signatures (δ18O and δ2H) to label the runoff components, including groundwater, snow and glacier meltwater, and rainfall, in a Central Asian glacierized basin. The contributions of runoff components (CRCs) to the total runoff and the corresponding uncertainty were quantified by two mixing approaches, namely a traditional end-member mixing approach (abbreviated as EMMA) and a Bayesian end-member mixing approach. The performance of the two mixing approaches was compared in three seasons that are distinguished as the cold season, snowmelt season, and glacier melt season. The results show the following points. (1) The Bayesian approach generally estimated smaller uncertainty ranges for the CRC when compared to the EMMA. (2) The Bayesian approach tended to be less sensitive to the sampling uncertainties of meltwater than the EMMA. (3) Ignoring the model uncertainty caused by the isotope fractionation likely led to an overestimated rainfall contribution and an underestimated meltwater share in the melt seasons. Our study provides the first comparison of the two end-member mixing approaches for hydrograph separation in glacierized basins and gives insight into the application of tracer-based mixing approaches in similar basins.

scholarly journals Temporal variation of water discharges in the lower course of the Danube River across the area from Reni to Izmail under the influence of natural and anthropogenic factors

Energetika ◽  
2019 ◽  
Vol 65 (2-3) ◽  
Author(s):  
Yelyzaveta Romanova ◽  
Zhannetta Shakirzanova ◽  
Valeriya Ovcharuk ◽  
Olena Todorova ◽  
Iuliia Medvedieva ◽  
...  
Keyword(s):  
Temporal Variation ◽  
River Runoff ◽  
Water Exchange ◽  
Water Discharge ◽  
Hydrological Regime ◽  
Danube River ◽  
Anthropogenic Factors ◽  
The Danube River ◽  
Runoff Regime ◽  
Natural And Anthropogenic Factors

The Danube River mouth is a main source for fresh water used for water supply and irrigation purposes in the arid southern part of Ukraine. In addition, the water of the mouth is used for filling the Danube Lakes. Climate change and numerous social and economic factors reduce the area and the water level of the Danube Lakes and increase their salinity. Under these circumstances the water exchange between the Danube River and the lakes is a very important process which allows maintenance of the water–salt balance of the latter. Such water exchange massively depends on the Danube River regime. The paper presents research of temporal variation of typical water discharges in the lower course of the Danube River associated with assessment of natural and anthropogenic factors affecting river runoff fluctuations. Time series of annual average water discharge at the water gauging stations of such cities as Reni and Izmail were considered uniform for the selected periods. They cover the period of conventionally natural river runoff regime (1840–1920), the period of the least altered river runoff regime (1921–1960) and the most altered river runoff regime under a heavy anthropogenic influence (1961–1989). The analysis of the impact of climate changes on the river runoff allowed introduction of a new, modern period of the Danube River hydrological regime (1990–2015). It is established that the series of maximum and minimum water discharges are characterized by the lack of their uniformity from the beginning of the period of initial influence of hydraulic engineering structures on the hydrological regime (since 1961). The analysis of the aggregate multi-year series (1840–2015) of average annual, maximum and minimum water discharges of the Danube River across its length from Reni to Izmail showed the presence of positive trends. At the same time the period of climatic changes (after 1989) is characterized by a less intensive growth of maximum water discharges. The research resulted in establishing the periodicity and synchronism of water discharge fluctuations in the lower course of the Danube River from Reni to Izmail within the territory of Ukraine. In particular, the study showed for the first time that from the 2000s onwards the redistribution of river runoff between the Danube River branches led to unsynchronization of minimum river runoff in different parts of the Danube Delta. The research shows that comprehensive analysis of the Danube River hydrological regime under modern climatic conditions is required to ensure efficient engineering regulation of the Danube Lakes filling pattern. Such regulation, in its turn, will ensure that the water supply and irrigation purposes are achieved.

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