Flow Recession Curve Research Articles

Characterising the discharge of hillslope karstic aquifers from hydrodynamic and physicochemical data (Sierra Seca, SE Spain)

Groundwater flow has been investigated in the Sierra Seca, Spain. Maximum recharge to the central core of the mountain occurs at high elevations, which provides recharge to two overlapping karst aquifers constituting a groundwater storage zone at a lower elevation break in slope. Both karst aquifers are associated with three springs arising from the upper part of the permeable formations. The climate is characterized by long and intense periods of drought and short periods of rainfall, which trigger discharges from the springs. Spring flow recession curve analysis, cross-correlation and monitoring of groundwater temperature and electrical conductivity have demonstrated contrasts observed in the hydrodynamic and physicochemical response of the three springs during flood events. One spring records floods with narrow and short peaks of high discharge accompanied by sharp drops in temperature and electrical conductivity. Another spring records floods with somewhat wider peaks and sharp increases in temperature and electrical conductivity (piston effect), whereas the third spring shows great consistency in all monitored characteristics. It is concluded that the absence of a piston effect in the spring with the highest flow rates is due to the contribution of rapidly circulating water that is expelled by semi-active karst networks (overflow) before reaching the saturated zone, which does not occur in the other springs due to the absence of overflow hydrological pathways. The most regular spring owes its functioning to the contribution of infiltrated water in the bed of an upstream riverbed, which explains this regularity.

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.

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.

Improved Model Parameter Transferability Method for Hydrological Simulation with SWAT in Ungauged Mountainous Catchments

The sustainability of water resources in mountainous areas has a significant contribution to the stabilization and persistence of the ecological and agriculture systems in arid and semi-arid areas. However, the insufficient understanding of hydrological processes in ungauged mountainous catchments (UMCs) is not able to scientifically support the sustainable management of water resources. The conventional parameter transferability method (transplanting the parameters of the donor catchment model with similar distances or attributes to the target catchment model) still has great potential for improving the accuracy of the hydrological simulation in UMC. In this study, 46 river catchments, with discharge survey stations and multi-type catchment characteristics in Xinjiang, are separated into the target catchments and donor catchments to promote an improved model parameter transferability method (IMPTM). This method synthetically processes the SWAT model parameters based on the distance approximation principle (DAP) and the attribute similarity principle (ASP). The performance of this method is tested in a random gauged catchment and compared with other traditional methods (DAP and ASP). The daily runoff simulation results in the target catchment have relatively low accuracy by both the DAP method ( N S = 0.27, R 2 = 0.55) and ASP method ( N S = 0.36, R 2 = 0.65), which implies the conventional approach is not capable of processing the parameters in the target regions. However, the simulation result by IMPTM is a significant improvement ( N S = 0.69, R 2 = 0.85). Moreover, the IMPTM can accurately catch the flow peak, appearance time, and recession curve. The current study provides a compatible method to overcome the difficulties of hydrological simulation in UMCs in the world and can benefit hydrological forecasting and water resource estimation in mountainous areas.

Assessment of Water Balance for Russian Subcatchment of Western Dvina River Using SWAT Model

The study provides a new assessment of the water balance components of the catchment (evapotranspiration, surface and lateral flow etc. and its spatial distribution and temporal variability) for the transboundary catchment of Western Dvina river within the poorly gauged Russian part of the catchment.The study focuses on modeling the inland flow generation processes using open source data and the SWAT (Soil Water Assessment Tool) hydrological model. The high interannual variability of river flow and impact of snowmelt processes were especially taken into account when setting up the model and processing the calibration. The database of daily meteorological data for the period 1981 – 2016 was prepared using global atmospheric reanalysis ERA-Interim data and observed station data from the GSOD NCDC/NOAA and ECA&D datasets. The considered datasets were tested on plausibility and regionalized. The catchment model was built on the basis of open land use / land cover (LULC) data sets, topography and soil, so that the entire transboundary catchment area could be easily implemented in the next step. For the daily model calibration, 19 sensitive parameters were chosen manually. The most sensitive are the parameters which consider snow melting processes and flow recession curve number. The highest impact on water balance components has the area and distribution of wetlands. Lakes strongly affect the evapotranspiration rate. The study provides further research with uncertainty analysis and recommendations for model improvement and model limitations. The developed modelling approach can be used to assess water resources, climate change impacts, and water quality issues in comparable regions.

ANALISIS KURVA RESESI ALIRAN DASAR MENGGUNAKAN MODEL RESERVOIR LINIER RECESSION CURVE HYDROOFFICE PADA DAS WURYANTORO KABUPATEN WONOGIRI PROPINSI JAWA TENGAH

The hydrograph recession curve expresses the theoretical relationship between the aquifer structure and the flow of groundwater flowing into the river basin channel. These theoretical relationships are often empirically depicted using the base flow recession curve. The hydrograph recession curve is commonly used to estimate the recessionary parameters, aquifer properties and to evaluate alternative hydrological hypotheses. The river basin hydrograph recession curve records the behavior of the relationship between the aquifer structure and its association with groundwater outflow to the river channel. This research was conducted with the aim: to analyze the characteristics of the baseflow recession based on the parameters and coefficients of the recession, and the shape of the individual recession curve and the master recession curve. The characteristics of the baseflow recession to research sub-watershed have the recession curves tend to sloped, describing the water storage well enough. The parameter Q0 (recession early), α and the recession constant Krb ranging from 0,80 – 0,90 for the individual and master recession curve in all three research sub-watershed. This calculation result indicates that the recession characteristics in three research sub-watershed have the condition of water storage is excellent, because they are supported by the aquifer characteristics dominated by the geological structures are more permeable (porous).

The influence of the measurement errors on the Brutsaefrt and Nieber analysis of flow recession curves

The paper presents the problem of mathematical form of the hydrological recession in rivers when using conceptual models to describe the catchment behavior. One of the well-known ways of this analysis is the Brutsaert and Nieber method which is based on graphical comparison of flow values and its derivatives. It has been proved that the classical interpretation of these results does not reflect the possible influence of measurement errors which strongly affects the flow derivatives values.

Water resources assessment and prediction in China

Abstract. Water resources assessment in China, can be classified into three groups: (i) comprehensive water resources assessment, (ii) annual water resources assessment, and (iii) industrial project water resources assessment. Comprehensive water resources assessment is the conventional assessment where the frequency distribution of water resources in basins or provincial regions are analyzed. For the annual water resources assessment, water resources of the last year in basins or provincial regions are usually assessed. For the industrial project water resources assessment, the water resources situation before the construction of industrial project has to be assessed. To address the climate and environmental changes, hydrological and statistical models are widely applied for studies on assessing water resources changes. For the water resources prediction in China usually the monthly runoff prediction is used. In most low flow seasons, the flow recession curve is commonly used as prediction method. In the humid regions, the rainfall-runoff ensemble prediction (ESP) has been widely applied for the monthly runoff prediction. The conditional probability method for the monthly runoff prediction was also applied to assess next month runoff probability under a fixed initial condition.

Quantifying changes of effective springshed area and net recharge through recession analysis of spring flow

AbstractThe average flow of Silver Springs, one of the largest magnitude springs in Central Florida, declined 32% from 2000 to 2012. The average groundwater head in the springshed declined 0.14 m, and the spring pool altitude increased 0.24 m during the same period. This paper presents a novel explanation of the spring flow recession curve for Silver Springs using the Torricelli model, which uses the groundwater head at a sentinel well, the spring pool altitude and the net recharge to groundwater. The effective springshed area and net recharge (defined as recharge minus groundwater pumping and evapotranspiration) were estimated based on the observed recession slopes for spring flow, groundwater head and spring pool altitude. The results indicate that the effective springshed area continuously declined since 1989 and the net recharge declined since the 1970s with a significant drop in 2002. Subsequent to 2002, the net recharge increased modestly but not to the levels prior to the 1990s. The reduction in net recharge was caused by changes in hydroclimatic conditions including precipitation and air temperature, along with groundwater withdrawals, which contributed to the declined spring flow. Copyright © 2016 John Wiley & Sons, Ltd.

Watershed model calibration to the base flow recession curve with and without evapotranspiration effects

AbstractCalibration of watershed models to the shape of the base flow recession curve is a way to capture the important relationship between groundwater discharge and subsurface water storage in a catchment. In some montane Mediterranean regions, such as the midelevation Providence Creek catchment in the southern Sierra Nevada of California (USA), nearly all base flow recession occurs after snowmelt, and during this time evapotranspiration (ET) usually exceeds base flow. We assess the accuracy to which watershed models can be calibrated to ET‐dominated base flow recession in Providence Creek, both in terms of fitting a discharge time‐series and realistically capturing the observed discharge‐storage relationship for the catchment. Model parameters estimated from calibrations to ET‐dominated recession are compared to parameters estimated from reference calibrations to base flow recession with ET‐effects removed (“potential recession”). We employ the Penn State Integrated Hydrologic Model (PIHM) for simulations of base flow and ET, and methods that are otherwise general in nature. In models calibrated to ET‐dominated recession, simulation errors in ET and the targeted relationship for recession (−dQ/dt versus Q) contribute substantially (up to 57% and 46%, respectively) to overestimates in the discharge‐storage differential, defined as d(lnQ)/dS, relative to that derived from water flux observations. These errors result in overestimates of deep‐subsurface hydraulic conductivity in models calibrated to ET‐dominated recession, by up to an order of magnitude, relative to reference calibrations to potential recession. These results illustrate a potential opportunity for improving model representation of discharge‐storage dynamics by calibrating to the shape of base flow recession after removing the complicating effects of ET.

An investigation of flows and losses within the alluvial sands of ephemeral rivers in Zimbabwe

Ephemeral rivers are common hydrological features in Southern Africa where periods of up to 9 months occur with no significant rainfall. In many cases, they have well-defined channels in-filled with alluvial sands in which significant quantities of water flow, even when the surface flow has ceased. This water resource is commonly exploited either by shallow pits dug in the sand or by well-points, infiltration galleries or collector wells in the river bank and provides a valuable, readily available supply for local people [Hussey, S.W., 1997. Small-scale sand abstraction systems, 23rd WEDC Conference Water and Sanitation for All, Durban, WEDC]. The processes involved in the flow in these so-called ‘sand rivers’ present interesting hydrological and hydraulic questions. From a hydrological perspective, it could be argued that the flow in the alluvium is an extension of the surface flow and could be estimated by extrapolating the surface flow recession curve. Hydraulically, the flow can be visualised as a closed conduit, which has a slope to its base approximating to the sand surface but more irregular. Although the flow may follow the well-known Darcy formula, the conventional methods of analysis of groundwater systems may not apply as they normally assume horizontally bedded deposits of infinite lateral extent. This paper presents the results of a study of four sites in the Matabeleland Province of Zimbabwe over a period of about 3 years. At each site, water level readings were recorded from a number of piezometers in the alluvium together with an estimation of the bedrock profile. The velocity of flow was estimated from the slope of the phreatic surface as well as from salt dilution experiments. A simple model has been developed based on a ‘closed conduit’ concept, which estimates the recession of the water levels and flow rates in the alluvium, including the effects of evaporation from the sand surface as well as recharge by intermittent rainfall during the dry season. This model has been calibrated and validated against the field observations from the four sites.

Baseflow recession and recharge as nonlinear storage processes

Discharge in many rivers is often fed by outflow from a shallow groundwater reservoir. It is becoming clear that the outflow from this aquifer is not linearly proportional to storage as is commonly assumed in many algorithms. Numerical analysis of flow recession curves from about 100 river gauging stations instead reveals a nonlinear relationship between baseflow, Q, and storage, S, for which the equation S=aQb was adopted. Values of the exponent b are found by calibration to be between 0 and 1 but with a high concentration around 0·5, which is in accordance with the findings of other studies and theoretical approaches yielding b=0·5 for unconfined aquifers and relating the coefficient a to catchment properties, primarily area and shape of basin, pore volume and transmissivity. This non-linear reservoir function is proposed as a more realistic alternative to the linear reservoir function. The relatively fast response of groundwater flow to rainfall is mainly a result of the increase of hydraulic head of the groundwater reservoir accelerating the exfiltration of ‘old’, pre-event water into the river bed. As fissure and pore volumes communicate hydraulically, it appears physically reasonable to model the system by one non-linear reservoir for catchments, or parts of them, instead of applying independent parallel linear reservoirs. The non-linear reservoir algorithms are supported by an analytical derivation. They are extended for the automatic separation of baseflow from a time-series of daily discharge in rivers and the computation of storage and effective recharge of groundwater in river basins by inverse nonlinear reservoir routing. The time-series obtained allow the identification and quantification of long-term changes to the water balance. Relationships between computed groundwater storage and observed groundwater level can also be established. Copyright © 1999 John Wiley & Sons, Ltd.

Application of a Generalized TOPMODEL to the Small Ringelbach Catchment, Vosges, France

This paper describes the application of the revised parabolic transmissivity profile form of TOPMODEL, leading to a second‐order hyperbolic base flow recession curve, to four years of 18 minute data from the 36 ha Ringelbach research catchment in the Vosges, France. The model is completed by evapotranspiration, snowmelt and runoff routing components. As far as possible the parameters of this form of the model, or their ranges, are estimated a priori. Results are given that compare the original and revised forms of TOPMODEL, with and without optimization. One particular feature of this catchment is the availability of measurements of saturated areas. These are taken into account by using a modified distribution of the soil‐topographic index, in a first attempt to relax the assumption of uniform transmissivity in the catchment. It is shown that the reasonably good results obtained with the original model are improved with the revised model, particularly in the simulation of dry weather flows, and that further improvements are obtained with the modified soil‐topographic index distribution.

Toward a Generalization of the TOPMODEL Concepts: Topographic Indices of Hydrological Similarity

Preliminary studies of the application of TOPMODEL to the 36‐ha Ringelbach catchment suggested that the original form of exponential transmissivity function leading to the In (a/tan β) topographic index and first‐order hyperbolic base flow recession curve is not appropriate to this catchment. Two alternative forms of topographic index and soil‐topographic index are developed based on parabolic and linear transmissivity functions, leading to the more frequently observed second‐order hyperbolic and exponential recession curves, respectively. It is shown how these can be used in the same way as the original to relate catchment average water table depths to local water table depths so that patterns of saturation can be evaluated. Two companion [Ambroise et al., this issue; Freer et al., this issue] papers show how the new parabolic index is used in the prediction of Ringelbach discharges, and how the limitations of the model are reflected in the estimated predictive uncertainties using the Generalised Likelihood Uncertainty Estimation (GLUE) approach.

Automated Base Flow Separation and Recession Analysis Techniques

AbstractAn automated base flow separation technique has been developed and tested. Base flow is considered to be the ground‐water contribution to stream flow. Estimates of the amount of base flow can be derived from stream flow records. Such estimates are critical in the assessment of low flow characteristics of streams for use in water supply, water management, and pollution assessment. An automated base flow separation technique using a digital filter has been tested against three other automated techniques and manual separation methods. The filter appears to be comparable to other automated techniques in its ability to reproduce the results produced from graphical separation techiques. The filter technique is easy to use and has the added advantage in that it can be adjusted by the user to take into account personnel preferences in separation of stream flow into surface flow and base flow.The slope of the base flow recession has been used to estimate the volume of water in storage in the basin above the level of the stream channel, the amount of recharge to the shallow aquifer, and as an input into water budget models. A second automated technique was developed to calculate the slope of the base flow recession curve from stream flow record. This technique is an adaptation of the Master Recession Curve procedure. The results of this method were compared to manual estimates with an efficiency of 74 percent.

Analysis of hydrological recession curves

This paper develops a model for stream flow recession curves. Data from three Australian rivers are used to illustrate how the effects of seasonality and storm input can be catered for by a relatively simple estimation procedure. It is suggested that a master recession curve does not give an adequate description of recession flows for a river.

The hypsometric integral and low streamflow in two Pennsylvania provinces

Summer streamflow duration and base flow recession curves for eight watersheds draining sandstone‐siltstone‐shale terranes in the Appalachian Plateau and Folded Appalachian Mountains of Pennsylvania reflect variations in areal distribution and state of structural deformation of shallower lithologic units. The hypsometric integral (HI) has been used as a rapid reconnaissance technique to evaluate hydrology characteristics and to quantify the effects of lithology and structural deformation on low streamflow. The HI provides a measure of the areal extent of sandstone in each watershed, and the magnitude of summer streamflow (ft3/s/mi2) increases as the value of the integral increases, to indicate a higher percent of sandstone. Streamflow duration data from the two provinces show that siltstone‐shale areas in the mountain province can produce as much low streamflow per unit area as sandstone areas in the plateau province.

Derivation of Base Flow Recession Curves and Parameters

The Boussinesq equation is used to show that base flow recession is an exponential decay function. For a single peaked hydrograph, the storage delay factor Kb, the time for base flow to decrease by a factor of 10, is estimated. The parameter Kb is adjusted by trial so that surface flow, or the observed total flow minus base flow, is also an exponential decay function after the point of inflection on the hydrograph recession. Surface flow Ks is so determined. For 22 basins in Illinois, dormant season Kb ranges from 15–100 days and is associated with physiography. Ks varies from 1.8–6.0 days.