Recession Curve Research Articles

Evaluation of Water Supply Capacity of a Small Forested Basin Water Supply Facilities Using SWAT Model and Flow Recession Curve

This study develops a system for calculating the number of days of availability at upstream water intake sources for drought response in the Mullo stream basin in Gangwon-do, a multistage sand dam construction project's candidate site, in response to Korea's lack of water supply and demand calculation system for upstream intake sources. The Soil and Water Assessment Tool (SWAT) model calculated the upstream water supply capacity, and the automatic water level gauges measured the flow rate at three points in the target area: the stream, intake weir, and water tank. The SWAT parameter test and correction result using the daily flow rate measurements showed a coefficient of determination of 0.74, which was used to calculate the streamflow over 10 years. Based on daily streamflow data, 53 rainfall reduction events were identified, deriving a curve equation for the number of days of availability following the flow rate during drought seasons. This study's results can be used to compare data before and after constructing the sand dam. In addition, the results can be considered primary data for priority selection and efficiency analysis when expanding and distributing structural drought measures, such as sand dams, through national reviews.

Estimation of Groundwater Recharge in the Lobo Catchment (Central-Western Region of Côte d’Ivoire)

Determination of groundwater recharge is a major challenge in areas where rainfall is generally abundant. Variability and uncertainty are inherent in the estimation of recharge, and several methods are therefore recommended for its estimation at a regional level. In this study, we evaluated several methods for estimating recharge: the web GIS-based automated hydrological analysis tool (WHAT), water table fluctuation (WTF), hydrograph analyses, a recession curve displacement method, graphical separation, and empirical formulas. The annual recharge estimated by combining direct recharge and base-flow varied from 84 mm in 2019 to 66.4 mm in 2020. The mean direct recharge was about 44 mm in 2018 and 57.3 mm in 2019, representing about 4% and 5% of the respective rainfall. In 2020, this direct recharge was 43 mm, or about 6% of rainfall, around 25% lower than in 2019. Base-flow separation methods and recession curve displacement generally gave low results, whereas modified empirical formulas gave results close to those of the WTF method and were considered more consistent and reasonable. The regression curve displacement method implemented in the United States geologic survey (USGS) RORA program was found to be unsuitable for the study area. However, the other methods presented more reasonable results and could be used to estimate groundwater recharge in the study area.

Estimation of baseflow recession constant and regression of low flow indices in eastern Japan

ABSTRACT We propose a convenient procedure for the matching strip method in determining the recession constant of the master recession curve using the ratio of flow over successive days (Qn+1/Qn). The method is applied to 29 basins (6.1–740 km2) in eastern Japan to develop linear regression models that estimate low flow indices through the recession constant (λ), and either mean annual precipitation or mean annual runoff. Significant models were developed for Q710 (seven-day 10-year low flow), and Q9710 (10-year low flow exceeded 97% of the time) in the case of all basins, and in particular for basins classified into sedimentary or igneous geology (adjusted R2 up to 0.784). When basins were not classified by geology, models based on mean annual runoff as the second independent variable performed better than those based on mean annual precipitation, with adjusted R2 values of 0.705 and 0.717 for the Q710 and Q9710 models, respectively.

Tracking the hydrologic response of agricultural tile outlet terraces to storm events

Agricultural practices in intensively managed landscapes are thought to be shifting hydro-bio-geochemical behavior from transformation to transport dominated systems. Here we explore the impacts of a best management practice known as tile-outlet-terraces (TOT). Tiles at this site are a set of perforated vertical pipes that can receive direct surface water, soil water and groundwater inputs that are connected to horizontal pipes that transport water to a receiving pond. Terraces are constructed, horizontal areas created to divide sloping terrains to reduce slope steepness and erosion, and in so doing they redirect surface water toward standpipes and promote soil and groundwater discharge as a result bisecting local flowpaths. While the impact of tiles on hydrologic behavior has been well studied, the combined impact of TOTs has not been well quantified. To address this knowledge gap, we focus on the response of TOT discharge and biogeochemical behavior across three adjacent agroecosystems in Kansas over three growing seasons (2016–2018). TOT discharge was measured every minute at each location and discharge during storm events was collected and analyzed for dissolved and total nutrients as well as major anion and cation chemistry. Additionally, suction cup lysimeters were installed at the ridges and depression of the terraces to capture soil water solute chemistry prior to storm events. Recession curve analysis revealed that tile inlet density was not directly related to the proportion of quickflow, mixing models showed that antecedent conditions played a critical role in the degree of connectivity of event water to the tiles, and concentration discharge behavior showed the dominant behavior for all constituents was chemostatic across all tile densities. Interestingly, these findings suggest that while TOTs shift the hydrology of agroecosystems away from natural conditions, the storm event size and antecedent conditions can still dominate the hydrologic and biogeochemical response to storm events.

Performance evaluation of an automated method for hydrograph separation in Mellah catchment, Northeastern Algeria

This paper explains a procedure based on the master recession curve (MRC) for hydrograph separation into individual flow components, using the recession constant K. To evaluate the performance of this computational technique, the results of the baseflow component were compared to the baseflow component obtained from the recursive digital filter (RDF) method. The study has revealed that the results of baseflow achieved by both methods show similarity to a great extent, and the baseflow values agree better with (R2 > 0.77). Moreover, automated baseflow separation underestimates the simulated baseflow from RDF method by as much as 2.35%, or overestimates it by up to 23.55%, during rainfall. These methods were applied to a set of hydrometric measures in the Mellah catchment, Algeria. The results proved that the proposed method gives a better estimate of flow components.

Improving Hillslope Link Model Performance from Non-Linear Representation of Natural and Artificially Drained Subsurface Flows

This study evaluates the potential for a newly proposed non-linear subsurface flux equation to improve the performance of the hydrological Hillslope Link Model (HLM). The equation contains parameters that are functionally related to the hillslope steepness and the presence of tile drainage. As a result, the equation provides better representation of hydrograph recession curves, hydrograph timing, and total runoff volume. The authors explore the new parameterization’s potential by comparing a set of diagnostic and prognostic setups in HLM. In the diagnostic approach, they configure 12 different scenarios with spatially uniform parameters over the state of Iowa. In the prognostic case, they use information from topographical maps and known locations of tile drainage to distribute parameter values. To assess performance improvements, they compare simulation results to streamflow observations during a 17-year period (2002–2018) at 140 U.S. Geological Survey (USGS) gauging stations. The operational setup of the HLM model used at the Iowa Flood Center (IFC) serves as a benchmark to quantify the overall improvement of the model. In particular, the new equation provides better representation of recession curves and the total streamflow volumes. However, when comparing the diagnostic and prognostic setups, the authors found discrepancies in the spatial distribution of hillslope scale parameters. The results suggest that more work is required when using maps of physical attributes to parameterize hydrological models. The findings also demonstrate that the diagnostic approach is a useful strategy to evaluate models and assess changes in their formulations.

Estimation of groundwater recharge in a shallow sandy aquifer using unsaturated zone modeling and water table fluctuation method

Quantification of groundwater recharge is one of the most important issues in hydrogeology, especially in view of the ongoing changes in climate and land use. In this study, we use numerical models of 1D vertical flow in the vadose zone and the water table fluctuation (WTF) analysis to investigate local-scale recharge of a shallow sandy aquifer in the Brda outwash plain in northern Poland. We show that these two methods can be jointly used to improve confidence in recharge estimation. A set of preliminary numerical simulations based on soil water content measurements from 4 grassland and pine forest profiles provided a wide range of recharge estimates (263 mm to 839 mm for a 3-year period). Additional simulations were performed with the lower boundary condition specified as a functional relationship between the groundwater table elevation and the rate of groundwater outflow from the vertical profile (horizontal drains boundary condition). In this way, we could reproduce the water table fluctuations resulting from recharge and lateral discharge to nearby lakes. The agreement between simulated and observed groundwater levels differed depending on the specific set of parameters characterizing vadose zone flow, which allowed us to find the most representative parameter sets and refine the range of plausible recharge estimates (501 mm to 573 mm per 3 years). The recharge rates from WTF (410 mm to 606 mm per 3 years) were in good agreement with numerical simulations, providing that the effect of the natural recession of groundwater table due to lateral outflow was considered (master recession curve method). Our results show that: (i) the proposed approach combining 1D vadose zone modeling and WTF improves recharge estimation, (ii) multiple types of observations, including groundwater table positions, are needed to calibrate and validate vadose zone flow models, and (iii) extended periods of observations and simulations are necessary to capture year-to-year variability in the recharge rates.

Critical-load calculation method of bolt competitive failure under composite excitation

A competitive failure model of a bolt was established based on the clamping force recession curve of the bolt under composite excitation. By analyzing the force on the thread surface, we propose a numerical method for calculating the critical load for bolt competitive failure under combined excitation. Competitive failure experiments of bolts were performed to verify the competitive failure model and the numerical calculation method of the critical load. The results revealed that the competitive failure model can accurately predict the failure type of bolts, and the numerical calculation method of the critical load can accurately predict the critical failure load of bolts. Finally, based on the numerical calculation method of the critical load, the influence of bolt structure parameters on the critical load ratio was studied, which can provide guidance for the reasonable selection of bolt structure parameters in engineering applications.

Prediction of Streamflow Recession Curves in Gauged and Ungauged Basins

AbstractPrediction of the time for perennial outflow from a natural basin to recede from the mean to some low flow value is an important practical and difficult problem in water resource management. This study aims to gain further understanding of this complex problem and to put forward new practical and accurate methods for predicting flow recessions between nominated limits in both gauged and ungauged basins. For a gauged basin, a three parameter recession model is employed to estimate the recession time, from day‐to‐day, as flow recedes from mean flow using previously measured site recession curves and a library of recession curve shapes generated by the RObust Parameter Estimation algorithm. The model is tested using data from 10 New Zealand basins which are diverse in low flow hydrological behavior and yields a Median Absolute Error (MAE) of 1 day. Another new model is also developed to predict recession time in an ungauged basin using catchment characteristics and information from master recession curves in a suite of 10 reference basins geologically and hydrologically similar to the ungauged basin, as assessed by a Random Forest model. Model performance is robust with a MAE of 1 day and the models advance the use of past flow records to enable more accurate predictions to be obtained. They can be applied elsewhere with confidence although further testing is desirable.

On the use of modified Boussinesq equation for studying double-layered hillslope recession characteristics

Recession flow analysis based on the Boussinesq equation has been widely used to estimate hydraulic parameters of hillslope aquifers. However, previous studies mainly focused on homogeneous hillslope aquifers and showed that the recession curves satisfy the power law, with two transition points and three power law regimes (b1, b2 and b3). Since the variation trends of b for homogeneous hillslopes are inconsistent and even opposite, it is necessary to investigate the law of recession curves of double-layered hillslope aquifers. In the current study, a modified Boussinesq equation applicable to double-layered hillslope aquifers was proposed. After validating against laboratory experiments and numerical simulations, this modified Boussinesq equation was used to examine the recession characteristics of double-layered hillslope aquifers. The results show that the recession curves of double-layered hillslope aquifers also follow three power law regimes. However, the variations of b values are more complex than those of homogeneous hillslopes. Specifically, while b monotonically changes with slope angle for homogeneous hillslopes, the variations of b are non-monotonic for double-layered hillslopes, depending on the soil configuration, e.g., the thickness of subsoil. These findings are of great significance for determining the hydraulic parameters of hillslopes.

Identification of relevant indicators for the assessment of karst systems hydrological functioning: Proposal of a new classification

Classification is a first-line tool for understanding the main characteristics of a natural system’s response. We propose a new classification of karst systems hydrological functioning that is based on spring discharge time series and takes profit of spring discharge databases to encompass the high diversity of karst hydrological functioning. It discriminates six different classes based on three relevant indicators of karst hydrological functioning.A core dataset made of 10 karst systems was first considered for the set-up of the classification. The spring discharge time series were investigated according to recession curves, statistical and signal analyses to identify relevant indicators of hydrological functioning. The selection of the most relevant indicators and the proposal of the classification were based on multivariate analyses. The classification was then tested on spring discharge time series of 78 karst systems located worldwide.All the systems homogeneously spread among the six proposed classes, which highlights the relevance of the approach and the representativeness of the various classes of hydrological functioning. Results from the proposed methodology were finally discussed to explore its limitations and define guidelines for its application.

A comparative evaluation of automated recession extraction methods to determine the late-time recession characteristics of karst spring hydrographs

Recession Curve Analysis is a common method to characterize karstic aquifers and their discharge dynamics. Although this technique provides crucial information on quantifying system hydrodynamic properties, the manually selected recession curves analysis is neither a practical technique to cover all candidate recession curves, nor it allows extracting the entire hydrological diversity of the recession behavior. This study aimed to comparatively evaluate the applicability of automated recession selection procedures to the late-time recession analysis of karst spring hydrograph. For the comparative evaluation of the three automated recession extraction methods (Vogel Method, Brutsaert Method, and Aksoy and Wittenberg Method), we quantified the late-time recession parameters of spring hydrographs by combining three extraction methods with four recession analysis methods (Maillet, 1905; Boussinesq, 1904; Coutagne, 1948; and Wittenberg, 1999). By applying our experimental design into the five karst springs located in Austria, we identified the possible weaknesses of the automated recession extraction procedures for the late-time recession analysis for spring hydrographs. To explore the value of the karst spring’s physicochemical data (electrical conductivity and water temperature) as a completion data for the recession curve analysis, we carried out the hydro-chemograph analysis to examine the recession time and its duration. The research provides a research direction as to how the automated recession extraction procedures for the karst spring hydrographs could be improved by the physicochemical signatures of karst springs.

Automatic procedure for selecting flood events and identifying flood characteristics from daily streamflow data

The selection of flood events and determination of flood characteristics (e.g. start and end dates, peak discharge, volume, and duration) are the first critical steps for flood analyses. To obtain the key flood information accurately, we used the automatic peak over threshold (POT) model for flood sampling and proposed an automatic approach to determine flood characteristics using the master recession curve analysis (MRC) method. We further developed a graphical user interface (GUI) and toolbox for this procedure in MATLAB. Model parameter estimation experiment (MOPEX) data from 423 stations were used to evaluate the proposed method. Our results suggest that the proposed procedure performs well for watersheds with diverse characteristics. The developed toolbox can be conveniently applied to other watersheds for flood sampling and the characterisation of flood events, thus helping reduce the uncertainty in subsequent flood analyses, such as multivariable flood frequency and trend analyses.

Analysis of competitive failure life of bolt loosening and fatigue

Bolt joints are often subjected to combined loading conditions, and there exists a competitive failure relationship between bolt loosening and fatigue under combined loading. To study the competitive failure characteristics of bolt loosening and fatigue and predict the competitive failure life, a competitive bolt failure test was conducted. According to the test data, the clamping force recession, load-life prediction, and critical-value prediction curves of the axial load to restrain bolt failure under combined loading were obtained. The bolt failures were categorized as loosening, critical state of loosening and fatigue, and fatigue, and the failure types were determined by the load ratio. The transverse load always accelerated the bolt failure, while the effects of axial load varied according to the magnitude. Additionally, a reasonable form of load combination in the bolt connection design and a competitive failure-life prediction model were proposed, thus providing a reference for the failure-life prediction of bolts under combined loading.

ANALISIS KARAKTERISTIK DAN FORMULASI RAWA DENGAN PENDEKATAN VARIABEL HIDROLOGI RAWA

The characteristics of wetlands can be recognized through their hydrological and ecological conditions. The hydrology of a wetland determines whether it can function initially or change. Research on the hydrology of wetlands can start from applying an appropriate water balance and a runoff generation formula for a wetland. Hydrological analysis of wetlands, including peatlands as part of watersheds, requires proper research according to the circumstances. A water balance formula calculating the equilibrium between rainfall, evapotranspiration, surface water, and groundwater is essential for recognizing wetland conditions. Analysis of the watershed flow where the wetland is located can use the rational formulas and the unit hydrograph methods of generated flow that consider suitability for the wetland conditions. This analysis is carried out by calculating the influence of variables on the wetland; rainfall, surface flow, and water detention. Other variables related to soil properties have an influential aspect in determining flow generation. The overall variables effect is reflected in the changes in the downstream flow hydrograph of a watershed. It mainly seems in the recession curve of the flood hydrograph. The peak of the flow decreases in order to wetland presence. This change is a composite of the upstream flow alteration and wetland storage influence. The influence of wetland areas is also found in flood volume, which shows a proportional relationship, namely that the increase in wide wetland areas affects the decrease in flood volume.

Groundwater-Surface Water Interaction in the Nera River Basin (Central Italy): New Insights after the 2016 Seismic Sequence

The highest part of the Nera River basin (Central Italy) hosts significant water resources for drinking, hydroelectric, and aquaculture purposes. The river is fed by fractured large carbonate aquifers interconnected by Jurassic and Quaternary normal faults in an area characterized by high seismicity. The 30 October 2016, seismic sequence in Central Italy produced an abrupt increase in river discharge, which lasted for several months. The analysis of the recession curves well documented the processes occurring within the basal aquifer feeding the Nera River. In detail, a straight line has described the river discharge during the two years after the 2016 seismic sequence, indicating that a turbulent flow characterized the emptying process of the hydrogeological system. A permeability enhancement of the aquifer feeding the Nera River—due to cleaning of fractures and the co-seismic fracturing in the recharge area—coupled with an increase in groundwater flow velocity can explain this process. The most recent recession curves (2019 and 2020 periods) fit very well with the pre-seismic ones, indicating that after two years from the mainshock, the recession process recovered to the same pre-earthquake conditions (laminar flow). This behavior makes the hydrogeological system less vulnerable to prolonged droughts, the frequency and length of which are increasingly affecting the Apennine area of Central Italy.

Groundwater flow velocities in karst aquifers; importance of spatial observation scale and hydraulic testing for contaminant transport prediction.

We review scale dependence of hydraulic conductivities and effective porosities for prediction of contaminant transport in four UK karst aquifers. Approaches for obtaining hydraulic parameters include core plug, slug, pumping and pulse tests, calibration of groundwater flow models and spring recession curves. Core plug and slug tests are unsuitable because they do not characterize a large enough volume to include a representative fracture network. Pumping test values match regional-scale hydraulic conductivities from flow modelling for the less intensively karstified aquifers: Magnesian Limestone, Jurassic Limestone and Cretaceous Chalks. Reliable bulk hydraulic conductivities were not available for the intensively karstified Carboniferous Limestone due to dominance of flow through pipe conduits in Mendips. Here, the only hydraulic conductivity value found from spring recession is one order of magnitude higher than that indicated by pumping tests. For all four carbonate aquifers, effective porosities assumed for transport modelling are two orders of magnitude higher than those found from tracer and hydrogeophysical tests. Thus, a combination of low hydraulic conductivities and assumed flowing porosities resulted in underestimated flow velocities. The UK karst aquifers are characterized by a range of hydraulic behaviours that fit those of karst aquifers worldwide. Indeed, underestimation of flow velocity due to inappropriate parameter selection is common to intensively karstified aquifers of southern France, north-western Germany and Italy. Similar issues arise for the Canadian Silurian carbonates where the use of high effective porosities (e.g. 5%) in transport models leads to underestimation of groundwater velocities. We recommend values in the range of 0.01-1% for such aquifers.

Responses of Spring Discharge to Different Rainfall Events for Single-Conduit Karst Aquifers in Western Hunan Province, China.

It is a challenge to describe the hydrogeological characteristics of karst aquifers due to the complex structure with extremely high heterogeneity. As the response of karst aquifers to rainfall events, spring discharge variations after precipitation can be used to identify the internal structure of karst systems. In this study, responses of spring discharge to different kinds of precipitations are investigated by continuously monitoring precipitation and karst spring flow at a single-conduit karst aquifer in western Hunan province, China. Recession curves were used to analyze hydrodynamic behaviors and separate recession stages. The results show that the shape of the recession curve was changed under different rainfall conditions. Recession processes can be divided in to three recession stages under heavy rain conditions due to water drainage mainly from conduits, fracture, and matrix at each stage, but only one recession stage representing drainage mainly from matrix in the case of light rain. With the change in amount and intensity of precipitation, the calculated recession coefficient at each stage changes in an order of magnitude. The influence of precipitation on the recharge coefficient and the discharge composition at each recession are discussed, and then the conceptual model diagram of water filling and releasing in the single-conduit karst aquifers is concluded. The findings provide more insight understand on hydraulic behaviors of karst spring under different types of rainfall events and provide support for water resource management in karst regions.

Development and Verification of the Available Number of Water Intake Days in Ungauged Local Water Source Using the SWAT Model and Flow Recession Curves

Climate change significantly affects water supply availability due to changes in the magnitude and seasonality of runoff and severe drought events. In the case of Korea, despite a high water supply ratio, more populations have continued to suffer from restricted regional water supplies. Though Korea enacted the Long-Term Comprehensive Water Resources Plan, a field survey revealed that the regional government organizations limitedly utilized their drought-related data. These limitations present a need for a system that provides a more intuitive drought review, enabling a more prompt response. Thus, this study presents a rating curve for the available number of water intake days per flow, and reviews and calibrates the Soil and Water Assessment Tool (SWAT) model mediators, and found that the coefficient of determination, Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS) from 2007 to 2011 were at 0.92%, 0.84%, and 7.2%, respectively, which were “very good” levels. The flow recession curve was proposed after calculating the daily long-term flow and extracted the flow recession trends during days without precipitation. In addition, the SWAT model’s flow data enables the quantitative evaluations of the number of available water intake days without precipitation because of the high hit rate when comparing the available number of water intake days with the limited water supply period near the study watershed. Thus, this study can improve drought response and water resource management plans.

Impact of reservoirs on baseflow recession analysis: a case study of the Chaersen Reservoir in Northeast China

ABSTRACT The number of reservoirs worldwide increases annually, and there are growing concerns regarding their potential effects on runoff and baseflow. In this study, the impact of the recently constructed Chaersen Reservoir on downstream baseflow recession is analysed using the pre–post comparison method. Additionally, the potential causes of these effects are investigated. Reservoir construction is found to cause the baseflow at the recession stage to increase by a relatively constant value (approximately 1 m3/s), which makes the log(−dQ/dt) vs. log(Q) points at the low-flow stage shift to the right. This eventually results in a decrease of ~70% in recession coefficient a and an increase of ~27% in coefficient b. Consequently, the master recession curve and storage–discharge curve deviate significantly from those before construction. Finally, a baseflow recession analysis strategy suitable for a basin with reservoirs is proposed; it ensures that recession coefficients (a, b) agree well with practical values.