scholarly journals Groundwater surface mapping informs sources of catchment baseflow

2015 ◽  
Vol 19 (4) ◽  
pp. 1599-1613 ◽  
Author(s):  
J. F. Costelloe ◽  
T. J. Peterson ◽  
K. Halbert ◽  
A. W. Western ◽  
J. J. McDonnell
Keyword(s):  
Digital Filter ◽  
Groundwater Discharge ◽  
Independent Data ◽  
Groundwater Extraction ◽  
Shallow Flow ◽  
Surface Mapping ◽  
Flow Paths ◽  
Data Set ◽  
Groundwater Mapping ◽  
Regional Groundwater

Abstract. Groundwater discharge is a major contributor to stream baseflow. Quantifying this flux is difficult, despite its considerable importance to water resource management and evaluation of the effects of groundwater extraction on streamflow. It is important to be able to differentiate between contributions to streamflow from regional groundwater discharge (more susceptible to groundwater extraction) compared to interflow processes (arguably less susceptible to groundwater extraction). Here we explore the use of groundwater surface mapping as an independent data set to constrain estimates of groundwater discharge to streamflow using traditional digital filter and tracer techniques. We developed groundwater surfaces from 88 monitoring bores using Kriging with external drift and for a subset of 33 bores with shallow screen depths. Baseflow estimates at the catchment outlet were made using the Eckhardt digital filter approach and tracer data mixing analysis using major ion signatures. Our groundwater mapping approach yielded two measures (percentage area intersecting the land surface and monthly change in saturated volume) that indicated that digital filter-derived baseflow significantly exceeded probable groundwater discharge during most months. Tracer analysis was not able to resolve contributions from ungauged tributary flows (sourced from either shallow flow paths, i.e. interflow and perched aquifer discharge, or regional groundwater discharge) and regional groundwater. Groundwater mapping was able to identify ungauged sub-catchments where regional groundwater discharge was too deep to contribute to tributary flow and thus where shallow flow paths dominated the tributary flow. Our results suggest that kriged groundwater surfaces provide a useful, empirical and independent data set for investigating sources of fluxes contributing to baseflow and identifying periods where baseflow analysis may overestimate groundwater discharge to streamflow.

scholarly journals Groundwater surface mapping informs sources of catchment baseflow

2014 ◽  
Vol 11 (11) ◽  
pp. 12405-12441 ◽  
Author(s):  
J. F. Costelloe ◽  
T. J. Peterson ◽  
K. Halbert ◽  
A. W. Western ◽  
J. J. McDonnell
Keyword(s):  
Digital Filter ◽  
Water Resource Management ◽  
Groundwater Discharge ◽  
Groundwater Extraction ◽  
Shallow Flow ◽  
Surface Mapping ◽  
Flow Paths ◽  
Independent Dataset ◽  
Groundwater Mapping ◽  
Regional Groundwater

Abstract. Groundwater discharge is a major contributor to stream baseflow. Quantifying this flux is difficult, despite its considerable importance to water resource management and evaluation of the effects of groundwater extraction on streamflow. It is important to be able to differentiate between contributions to streamflow from regional groundwater discharge (more susceptible to groundwater extraction) compared to interflow processes (arguably less susceptible to groundwater extraction). Here we explore the use of unconfined groundwater surface mapping as an independent dataset to constrain estimates of groundwater discharge to streamflow using traditional digital filter and tracer techniques. We developed groundwater surfaces from 98 monitoring bores using Kriging with external drift. Baseflow estimates at the catchment outlet were made using the Eckhardt digital filter approach and tracer data mixing analysis using major ion and stable isotope signatures. Our groundwater mapping approach yielded two measures (percentage area intersecting the land surface and monthly change in saturated volume) that indicated that digital filter-derived baseflow significantly exceeded probable groundwater discharge during the high flow period of spring to early summer. Tracer analysis was not able to resolve contributions from ungauged tributary flows (sourced from either shallow flow paths, i.e. interflow and perched aquifer discharge, or regional groundwater discharge) and regional groundwater. Groundwater mapping was able to identify ungauged sub-catchments where regional groundwater discharge was too deep to contribute to tributary flow and thus where shallow flow paths dominated the tributary flow. Our results suggest that kriged unconfined groundwater surfaces provide a useful, empirical and independent dataset for investigating sources of fluxes contributing to baseflow and identifying periods where baseflow analysis may overestimate groundwater discharge to streamflow.

scholarly journals The influence of hyporheic fluxes on regional groundwater discharge zones

2021 ◽  
Author(s):  
Brian Babak Mojarrad ◽  
Anders Wörman ◽  
Joakim Riml ◽  
Shulan Xu
Keyword(s):  
Groundwater Modeling ◽  
Groundwater Discharge ◽  
Water Fluxes ◽  
Flow Paths ◽  
Spectral Solution ◽  
Scale Modeling ◽  
Naturally Occurring ◽  
Boreal Landscape ◽  
Regional Groundwater

Abstract. The importance of hyporheic water fluxes induced by hydromorphologic processes at the streambed scale and their consequential effects on stream ecohydrology have recently received much attention. However, the role of hyporheic water fluxes in regional groundwater discharge is still not entirely understood. Streambed-induced flows not only affect mass and heat transport in streams but are also important for the retention of solute contamination originating from deep in the subsurface, such as naturally occurring solutes as well as leakage from the future geological disposal of nuclear waste. Here, we applied a multiscale modeling approach to investigate the effect of hyporheic fluxes on regional groundwater discharge in the Krycklan catchment, located in a boreal landscape in Sweden. Regional groundwater modeling was conducted using COMSOL Multiphysics constrained by observed or modeled representations of the catchment infiltration and geological properties, reflecting heterogeneities within the subsurface domain. Furthermore, streambed-scale modeling was performed using an exact spectral solution of the hydraulic head applicable to streaming water over a fluctuating streambed topography. By comparing the flow fields of watershed-scale groundwater discharge with and without consideration of streambed-induced hyporheic flows, we found that the flow trajectories and the distribution of the travel times of groundwater were substantially influenced by the presence of hyporheic fluxes near the streambed surface. One implication of hyporheic flows is that the groundwater flow paths contract near the streambed interface, thus fragmenting the coherent areas of groundwater upwelling and resulting in narrow “pinholes” of groundwater discharge points.

scholarly journals Virologic Response to Lopinavir-Ritonavir-Based Antiretroviral Regimens in a Multicenter International Clinical Cohort: Comparison of Genotypic Interpretation Scores

2008 ◽  
Vol 52 (11) ◽  
pp. 4050-4056 ◽  
Author(s):  
Philip Grant ◽  
Eric C. Wong ◽  
Richard Rode ◽  
Robert Shafer ◽  
Andrea De Luca ◽  
...  
Keyword(s):  
Viral Load ◽  
Multivariate Analyses ◽  
Virologic Response ◽  
Receiver Operator Characteristic ◽  
Independent Data ◽  
Data Set ◽  
Clinical Cohort ◽  
Multicenter Cohort ◽  
Mutation Score ◽  
Clinical Breakpoints

ABSTRACT Several genotypic interpretation scores have been proposed for the evaluation of susceptibility to lopinavir/ritonavir (LPV/r) but have not been compared using an independent data set. This study was a retrospective multicenter cohort of patients initiating LPV/r-based therapy. The virologic response (VR) was defined as a viral load of <500 copies/ml at week 24. The genotypic interpretation scores surveyed were the LPV mutation score, the ViroLogic score, the ATU score, the Stanford database score, and the International AIDS Society-USA mutation list. Of the 103 patients included in the analysis, 76% achieved VR at 24 weeks. For scores with clinical breakpoints defined (LPV mutation, ATU, ViroLogic, and Stanford), over 80% of the patients below the breakpoints achieved VR, while 50% or less above the breakpoints responded. Protease mutations at positions 10, 54, and 82 and at positions 54, 84, and 90 were associated with a lack of VR in the univariate and multivariate analyses, respectively. The area under the receiver-operator characteristic curves for the five genotypic interpretation scores studied ranged from 0.73 to 0.76. The study confirms that the currently available genotypic interpretation scores which are widely used by clinicians performed similarly well and can be effectively used to predict the virologic activity of LPV/r in treatment-experienced patients.

Predicting lean meat yield in beef cattle using ultrasonic muscle depth and width measurements

2003 ◽  
Vol 83 (3) ◽  
pp. 429-434 ◽  
Author(s):  
R. Bergen ◽  
D. H. Crews ◽  
Jr., S. P. Miller ◽  
J. J. McKinnon
Keyword(s):  
Beef Cattle ◽  
Carcass Composition ◽  
Ultrasound Measurement ◽  
Independent Data ◽  
Data Set ◽  
Meat Yield ◽  
Lean Meat ◽  
Ultrasound Measurements ◽  
Width Measurements ◽  
Highly Correlated

The value of live ultrasound longissimus dorsi depth and width measurements as predictors of estimated carcass lean meat yield of steers (CARLEAN-S) and bulls (CARLEAN-B) was studied. In trial 1, equations were developed to predict estimated lean meat yield of steers (n = 116) from carcass weight (Eq. 1) or liveweight (Eq. 2), fat depth and l. dorsi area or liveweight, fat depth and l. dorsi depth × width (Eq. 3). Equation 1 was most precise (RSD = 25.6 g kg-1), followed by Eq. 2 (RSD = 27.8g kg-1) and Eq. 3 (RSD = 30.2g kg-1). Equations 2 and 3 predicted CARLEAN-S with similar accuracy (SEP = 23.8 vs. 24.9 g kg-1, respectively) and were highly correlated with each other (r = 0.89) in an independent data set (n = 118). Repeatability and accuracy of pre-slaughter l. dorsi depth and width measurements were studied in yearling bulls (trial 2; n = 191). When ultrasound measurements were expressed as a percentage of the average ultrasound measurement, repeatabilities of l. dorsi depth (SER = 6.2 to 7.8%) and width (SER = 4.2 to 6.1%) measurements were similar to fat depth and l. dorsi area measurements (SER = 17.9 and 4.5%, respectively). When ultrasound measurements were compared to the corresponding carcass measurements, l. dorsi depth (SEP = 10.3 to 13.9%) and width (SEP = 6.7 to 8.5%) measurements were as accurate as fat depth and l. dorsi area measurements (SEP = 32.9 and 8.4%, respectively). Equations were developed to predict CARLEAN-B of yearling bulls (n = 82) from liveweight, 12th rib ultrasound fat depth and either l. dorsi depth × width measurements (Eqs. 4 and 5) or two l. dorsi depth measurements (Eq. 6). All equations had similar precision (RSD = 19.4 to 19.5 g kg-1) and predicted CARLEAN-B similarly (SEP = 25.0, 24.6 and 26.1g kg-1 for Eqs. 4, 5 and 6, respectively) in an independent data set (n = 109). All equations were highly correlated (r ≥0.97) with an equation using ultrasound fat depth and l. dorsi area in the independent data set. Longissimus muscle depth and width measurements were as valuable as l. dorsi area for predicting carcass composition of yearling beef bulls in the present study. Key words: Ultrasound, beef cattle, carcass traits

Modeling the Effect of Prior Sublethal Thermal History on the Thermal Inactivation Rate of Salmonella in Ground Turkey

2008 ◽  
Vol 71 (2) ◽  
pp. 279-285 ◽  
Author(s):  
M. J. STASIEWICZ ◽  
B. P. MARKS ◽  
A. ORTA-RAMIREZ ◽  
D. M. SMITH
Keyword(s):  
Thermal History ◽  
Thermal Inactivation ◽  
Mean Squared Error ◽  
Inactivation Rate ◽  
Prediction Errors ◽  
Independent Data ◽  
Validation Data ◽  
Data Set ◽  
Dependent Model ◽  
Path Dependent

Traditional models for predicting the thermal inactivation rate of bacteria are state dependent, considering only the current state of the product. In this study, the potential for previous sublethal thermal history to increase the thermotolerance of Salmonella in ground turkey was determined, a path-dependent model for thermal inactivation was developed, and the path-dependent predictions were tested against independent data. Weibull-Arrhenius parameters for Salmonella inactivation in ground turkey thigh were determined via isothermal tests at 55, 58, 61, and 63°C. Two sets of nonisothermal heating tests also were conducted. The first included five linear heating rates (0.4, 0.9, 1.7, 3.5, and 7.0 K/min) and three holding temperatures (55, 58, and 61°C); the second also included sublethal holding periods at 40, 45, and 50°C. When the standard Weibull-Arrhenius model was applied to the nonisothermal validation data sets, the root mean squared error of prediction was 2.5 log CFU/g, with fail-dangerous residuals as large as 4.7 log CFU/g when applied to the complete nonisothermal data set. However, by using a modified path-dependent model for inactivation, the prediction errors for independent data were reduced by 56%. Under actual thermal processing conditions, use of the path-dependant model would reduce error in thermal lethality predictions for slowly cooked products.

scholarly journals Individual Tree Volume Equations for Red Pine in Michigan

1997 ◽  
Vol 14 (2) ◽  
pp. 53-58 ◽  
Author(s):  
Gary W. Fowler
Keyword(s):  
Red Pine ◽  
Data Sets ◽  
Regression Equations ◽  
Independent Data ◽  
Data Set ◽  
Individual Tree ◽  
Standing Trees ◽  
Pine Stands ◽  
Volume Estimates ◽  
Volume Equations

Abstract New total, pulpwood, sawtimber, and residual pulpwood cubic foot individual tree volume equations were developed for red pine in Michigan using nonlinear and multiple linear regression. Equations were also developed for Doyle, International 1/4 in., and Scribner bd ft volume, and a procedure for estimating pulpwood and residual pulpwood rough cord volumes from the appropriate cubic foot equations was described. Average ratios of residual pulpwood (i.e., topwood, cubic foot or cords) to mbf were developed for 7.6 and 9.6 in. sawtimber. Data used to develop these equations were collected during May-August 1983-1985 from 3,507 felled and/or standing trees from 27 stands in Michigan. Sixteen and 11 stands were located in the Upper and Lower Peninsulas, respectively. All equations were validated on an independent data set. Rough cord volume estimates based on the new pulpwood equation were compared with contemporary tables for 2 small cruise data sets. The new equations can be used to more accurately estimate total volume and volume per acre when cruising red pine stands. North. J. Appl. For. 14(2):53-58.

A logit analysis of private woodlot owner's harvesting decisions in New Brunswick

1988 ◽  
Vol 18 (3) ◽  
pp. 330-336 ◽  
Author(s):  
M. S. Jamnick ◽  
D. R. Beckett
Keyword(s):  
Maximum Likelihood ◽  
New Brunswick ◽  
Logit Model ◽  
Screening Tool ◽  
Logit Analysis ◽  
Independent Data ◽  
Data Set ◽  
Extension Personnel

A maximum likelihood logit model of New Brunswick's private woodlot owner's harvesting decisions indicates that these decisions are related to owner and ownership characteristics. The model was able to correctly classify 75.2% of the observations from the data used to construct the model and 75.7% of the observations from an independent data set. Examples of how the model can be used to develop policies to encourage or discourage harvesting or as a screening tool for forest extension personnel are discussed.

scholarly journals A Review of Caveats in Statistical Nuclear Image Analysis

1998 ◽  
Vol 16 (2) ◽  
pp. 63-82 ◽  
Author(s):  
Helene Schulerud ◽  
Gunner B. Kristensen ◽  
Knut Liestøl ◽  
Liljana Vlatkovic ◽  
Albrecht Reith ◽  
...  
Keyword(s):  
Image Analysis ◽  
Statistical Evaluation ◽  
Large Body ◽  
Classification Rule ◽  
Independent Data ◽  
Limited Data ◽  
Data Set ◽  
Minimum Requirement ◽  
Prognostic Features ◽  
Multiple Test

A large body of the published literature in nuclear image analysis do not evaluate their findings on an independent data set. Hence, if several features are evaluated on a limited data set over‐optimistic results are easily achieved. In order to find features that separate different outcome classes of interest, statistical evaluation of the nuclear features must be performed. Furthermore, to classify an unknown sample using image analysis, a classification rule must be designed and evaluated. Unfortunately, statistical evaluation methods used in the literature of nuclear image analysis are often inappropriate. The present article discusses some of the difficulties in statistical evaluation of nuclear image analysis, and a study of cervical cancer is presented in order to illustrate the problems. In conclusion, some of the most severe errors in nuclear image analysis occur in analysis of a large feature set, including few patients, without confirming the results on an independent data set. To select features, Bonferroni correction for multiple test is recommended, together with a standard feature set selection method. Furthermore, we consider that the minimum requirement of performing statistical evaluation in nuclear image analysis is confirmation of the results on an independent data set. We suggest that a consensus of how to perform evaluation of diagnostic and prognostic features is necessary, in order to develop reliable tools for clinical use, based on nuclear image analysis.

Sign in / Sign up

Export Citation Format

Share Document