New Use of Hydrograph Separation Method for Hydrological Process Identification

2019 ◽  
pp. 33-35
Author(s):  
Asma Dahak ◽  
Hamouda Boutaghane
Keyword(s):  
Separation Method ◽  
Hydrological Process ◽  
Hydrograph Separation ◽  
Process Identification

scholarly journals Does discharge time source correspond to its geographic source in hydrograph separations? Toward identification of dominant runoff processes in a 300 square kilometer watershed

2014 ◽  
Vol 11 (9) ◽  
pp. 10931-10963
Author(s):  
Y. Yokoo
Keyword(s):  
Electric Conductivity ◽  
Moving Average ◽  
Source Separation ◽  
Surface Flow ◽  
Separation Method ◽  
Filter Method ◽  
Hydrograph Separation ◽  
Discharge Time ◽  
Discharge Data ◽  
Flow Components

Abstract. This study compared a time source hydrograph separation method to a geographic source separation method, to assess if the two methods produced similar results. The time source separation of a hydrograph was performed using a numerical filter method and the geographic source separation was performed using an end-member mixing analysis employing hourly discharge, electric conductivity, and turbidity data. These data were collected in 2006 at the Kuroiwa monitoring station on the Abukuma River, Japan. The results of the methods corresponded well in terms of both surface flow components and inter-flow components. In terms of the baseflow component, the result of the time source separation method corresponded with the moving average of the baseflow calculated by the geographic source separation method. These results suggest that the time source separation method is not only able to estimate numerical values for the discharge components, but that the estimates are also reasonable from a geographical viewpoint in the 3000 km2 watershed discussed in this study. The consistent results obtained using the time source and geographic source separation methods demonstrate that it is possible to characterize dominant runoff processes using hourly discharge data, thereby enhancing our capability to interpret the dominant runoff processes of a watershed using observed discharge data alone.

scholarly journals Technical note: Analytical sensitivity analysis and uncertainty estimation of baseflow index calculated by a two-component hydrograph separation method with conductivity as a tracer

2019 ◽  
Vol 23 (2) ◽  
pp. 1103-1112 ◽  
Author(s):  
Weifei Yang ◽  
Changlai Xiao ◽  
Xiujuan Liang
Keyword(s):  
Time Series ◽  
Sensitivity Analysis ◽  
Measurement Errors ◽  
Uncertainty Estimation ◽  
Separation Method ◽  
Analytical Sensitivity ◽  
Hydrograph Separation ◽  
Time Step ◽  
Sensitivity Indices ◽  
Two Component

Abstract. The two-component hydrograph separation method with conductivity as a tracer is favored by hydrologists owing to its low cost and easy application. This study analyzes the sensitivity of the baseflow index (BFI, long-term ratio of baseflow to streamflow) calculated using this method to errors or uncertainties in two parameters (BFC, the conductivity of baseflow, and ROC, the conductivity of surface runoff) and two variables (yk, streamflow, and SCk, specific conductance of streamflow, where k is the time step) and then estimates the uncertainty in BFI. The analysis shows that for time series longer than 365 days, random measurement errors in yk or SCk will cancel each other out, and their influence on BFI can be neglected. An uncertainty estimation method of BFI is derived on the basis of the sensitivity analysis. Representative sensitivity indices (the ratio of the relative error in BFI to that of BFC or ROC) and BFI′ uncertainties are determined by applying the resulting equations to 24 watersheds in the US. These dimensionless sensitivity indices can well express the propagation of errors or uncertainties in BFC or ROC into BFI. The results indicate that BFI is more sensitive to BFC, and the conductivity two-component hydrograph separation method may be more suitable for the long time series in a small watershed. When the mutual offset of the measurement errors in conductivity and streamflow is considered, the uncertainty in BFI is reduced by half.

Hydrological analysis of runoff formation in a small forested mountain catchment using δ2H and δ18O ratios

2020 ◽  
Author(s):  
Lisa Rommel ◽  
Thomas Wöhling
Keyword(s):  
Comprehensive Evaluation ◽  
Process Analysis ◽  
Model Development ◽  
Flood Event ◽  
Hydrological Process ◽  
Hydrograph Separation ◽  
Catchment Scale ◽  
Delayed Reaction ◽  
Runoff Formation ◽  
Mountain Catchment

<p>The identification of origin, flow paths and transit times of water in catchments is an important component for process-based model development for runoff prediction. Hydrological studies offer, combined with isotope data, the possibility to quantify interactions between different compartments in catchments. In the context of this work it is examined to what extent event sampling of precipitation, streamflow, soil water and groundwater and the evaluation of their isotopic ratios δ<sup>2</sup>H and δ<sup>18</sup>O enable complex hydrological process investigations in the small forested mountain catchment of the river Große Ohe in the Bavarian Forest National Park. Within this study process analyses are carried out on small scales, e.g. runoff formation on hill slopes and on catchment scale as integrative process analysis. The water samples were collected during a small flood event and analysed for the isotope ratios δ<sup>2</sup>H and δ<sup>18</sup>O using a Picarro. A hydrograph separation was carried out through a comprehensive evaluation of the concentration profiles during the event. In combination with further hydrological and soil hydrological observations possible areas of origin and retention times of the water were determined. A strongly delayed reaction of the groundwater was observed which suggests that groundwater is not contributing to stream flow during a flood event, but a possible mobilization of pre-event water in the riparian zone can be observed as a response to precipitation events. The knowledge gained hereby is the basis for further process analysis and model development.</p>

scholarly journals Technical note: Analytical sensitivity analysis and uncertainty estimation of a two-component hydrograph separation method which uses conductivity as a tracer

2018 ◽  
Author(s):  
Weifei Yang ◽  
Changlai Xiao ◽  
Xiujuan Liang
Keyword(s):  
Time Series ◽  
Sensitivity Analysis ◽  
Relative Error ◽  
Measurement Errors ◽  
The United States ◽  
Uncertainty Estimation ◽  
Separation Method ◽  
Hydrograph Separation ◽  
Sensitivity Indices ◽  
Two Component

Abstract. The conductivity two-component hydrograph separation method is cheap and easy to operate and is favored by hydrologists. This paper analyzes the sensitivity of the baseflow index (BFI, the long-term ratio of baseflow to streamflow) calculated by this method to errors or uncertainties of the two parameters (BFC, the conductivity of baseflow; ROC, the conductivity of surface runoff) and of the two variables (yk, the specific streamflow; Qck, the specific conductivity of streamflow), and then estimates the uncertainty of BFI. The analysis shows that when the time series is longer than 365 days, the random measurement errors of yk or Qck will cancel each other, and the influence on BFI can be neglected. Dimensionless sensitivity indices (the ratio of the relative error of BFI to the relative error of BFC or ROC) can well express the propagation of errors or uncertainties of BFC or ROC into BFI. Based on the sensitivity analysis, the uncertainty estimation method of BFI is derived. Representative sensitivity indices and BFI' uncertainties are yielded by application of the resulting equations to 24 watersheds in the United States. The results indicate that BFI is more sensitive to BFC, and the conductivity two-component hydrograph separation method may be more suitable for the long time series in a small watershed. After considering the mutual offset of the measurement errors of conductivity and streamflow, the uncertainty of BFI is reduced by half.

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