Sensitivity analysis and parameter estimation for an approximate analytical model of canal-aquifer interaction applied in the C-111 basin

The goal of this study was to better characterize parameters influencing the exchange of surface water in south Florida’s C-111 canal and Biscayne aquifer using the analytical model STWT1. A three-step model evaluation framework was implemented as follows: (1) qualitative parameter ranking by comparing two Morris method sampling strategies, (2) quantitative variance-based sensitivity analysis using Sobol’s method, and (3) estimation of parameter posterior probability distributions and statistics using the Generalized Likelihood Uncertainty Estimator (GLUE) methodology. Results indicated that the original Morris random sampling method underestimated total parameter effects compared to the improved global Morris sampling strategy. However, parameter rankings from the two sampling methods were similar. For the STWT1 model, only four out of the six parameters analyzed were important for predicting water table response to canal stage and recharge fluctuations. Morris ranking in order of decreasing importance resulted in specific yield (ASY), aquifer saturated thickness (AB), horizontal hydraulic conductivity (AKX), canal leakance (XAA), vertical hydraulic conductivity (AKZ), and half-width of canal (XZERO). Sobol’s sensitivity indices for the four most critical parameters revealed that summation of first-order parameter effects was 1.0, indicating that STWT1 behaved as an additive model or negligible parameter interactions. We estimated parameter values of 0.07 to 0.14 for ASY, 11,000 to 14,300 m d-1 for AKX, 13.4 to 18.3 m for AB, and 99.8 to 279 m for XAA. The estimated values were within the range of values estimated using more complex methods at nearby sites. The Nash-Sutcliffe coefficient of efficiency and root mean square error for estimated parameters ranged from 0.66 to 0.95 and from 4 to 7 cm, respectively. This study demonstrates a simple and inexpensive way to characterize hydrogeological parameters controlling groundwater-surface interactions in any region with aquifers that are highly permeable without using standard pumping tests or canal drawdown experiments. Hydrogeological parameters estimated using this approach could be used as starting values in large-scale numerical simulations

Systematic review of dexketoprofen in acute and chronic pain

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Dexketoprofen, an NSAID used in the management of acute and chronic pains, is licensed in several countries but has not previously been the subjected of a systematic review. We used published and unpublished information from randomised clinical trials (RCTs) of dexketoprofen in painful conditions to assess evidence on efficacy and harm. Methods: PubMed and Cochrane Central were searched for RCTs of dexketoprofen for pain of any aetiology. Reference lists of retrieved articles and reviews were also searched. Menarini Group produced copies of published and unpublished studies (clinical trial reports). Data were abstracted into a standard form. For studies reporting results of single dose administration, the number of patients with at least 50 % pain relief was derived and used to calculate the relative benefit (RB) and number-needed-to-treat (NNT) for one patient to achieve at least 50 % pain relief compared with placebo. Results: Thirty-five trials were found in acute pain and chronic pain; 6,380 patients were included, 3,381 receiving dexketoprofen. Information from 16 trials (almost half the total patients) wa

Effets d'une nappe peu profonde sur le transport d'eau, sédiments et pesticides dans une bande enherbée: part B. Couplage du modèle, application, analyse de sensibilité et d'incertitude

International audienceVegetative filter strips are often used for protecting surface waters from pollution transferred by surface runoff in agricultural watersheds. In Europe, they are often prescribed along the stream banks, --where a seasonal shallow water table (WT) could decrease the buffer zone efficiency. In spite of this potentially important effect, there are no systematic experimental or theoretical studies on the effect of this soil boundary condition on the VFS efficiency. In the companion paper (Munoz-Carpena et al., 2018), we developed a physically based numerical algorithm (SWINGO) that allows the representation of soil infiltration with a shallow water table. Here we present the dynamic coupling of SWINGO with VFSMOD, an overland flow and transport mathematical model to study the WT influence on VFS efficiency in terms of reductions of overland flow, sediment, and pesticide transport. This new version of VFSMOD was applied to two contrasted benchmark field studies in France (sandy-loam soil in a Mediterranean semicontinental climate, and silty clay in a temperate oceanic climate), --where limited testing of the model with field data on one of the sites showed promising results. The application showed that for the conditions of the studies, VFS efficiency decreases markedly when the water table is 0 to 1.5 m from the surface. In order to evaluate the relative importance of WT among other input factors controlling VFS efficiency, global sensitivity and uncertainty analysis (GSA) was applied on the benchmark studies. The most important factors found for VFS overland flow reduction were saturated hydraulic conductivity and WT depth, added to sediment characteristics and VFS dimensions for sediment and pesticide reductions. The relative importance of WT varied as a function of soil type (most important at the silty-clay soil) and hydraulic loading (rainfall + incoming runoff) at each site. The presence of WT introduced more complex responses dominated by strong interactions in the modeled system response, reducing the typical predominance of saturated hydraulic conductivity on infiltration under deep water table conditions. This study demonstrates that when present, the WT should be considered as a key hydrologic factor in buffer design and evaluation as a water quality mitigation practice

Effets d'une nappe peu profonde sur le transport d'eau, sédiments et pesticides dans une bande enherbée. Part A. infiltration non-uniforme et redistribution de l'eau dans le sol

International audienceVegetation buffers like vegetative filter strips (VFS) are often used to protect water bodies from surface runoff pollution from disturbed areas. Their typical placement in bottomland often results in the presence of a seasonal shallow water table (WT) that can decrease soil infiltration and increase surface pollutant transport during a rainfall/runoff event. Simple and robust components of hydrological models are needed to analyse the impacts of WT in the landscape. To simulate VFS infiltration under realistic rainfall conditions with WT, we propose a generic infiltration solution (Shallow Water table INfiltration algorithm: SWINGO) based on a combination of approaches by Salvucci and Entekhabi (1995) and Chu (1997) with new integral formulae to calculate singular times (time of ponding, shift time, and time to soil profile saturation). The algorithm was tested successfully on 5 distinct soils both against Richards’s numerical solution and experimental data in terms of infiltration and soil moisture redistribution predictions, and applied to study the combined effects of varying WT depth, soil type, and rainfall intensity and duration. The results show the robustness of the algorithm and its ability to handle various soil hydraulic functions, and initial non-ponding conditions under unsteady rainfall. The effect of a WT on infiltration under ponded conditions was found effectively decoupled from surface infiltration/excess runoff processes for depths larger than 1.2 to 2 m, shallower for fine soils and shorter events. For non-ponded initial conditions, the influence of WT depth also varies with rainfall intensity. Also, we observed that soils with a marked air entry (bubbling pressure) exhibit a distinct behaviour with WT near the surface. The features and good performance of SWINGO support its coupling with an existing VFS model in the companion paper, where the potential effects of seasonal or permanent WTs on VFS pollutant transport and control are studied

Evaluation of the WAVE model

WAVE (Water and Agrochemicals in soil, crop and Vadose Environment) is a software package developed by the Institute for Land and Water Management of the K.U.Leuven (Belgium) and the Department of Environmental Sciences and Land Management (Unité Génie Rural) of the Université Catholique de Louvain. The objetive of the model is to describe the transport and transformations of matter and energy in the soil, crop and vadose environment. It simulates the behavior of water, heat, non-reactive solutes, nitrogen and pesticide species in the soil-crop continuum. The current version of the model integrates several packages developed earlier: i) a revised version of the SWATNIT-model (Vereecken et al., 1990; 1991), which integrates the SWATRER-model (Feddes et al., 1978; Belmans et al., 1983; Dierckx et al, 1986), a heat and solute transport model based on the LEACHN-model (Wagenet and Hutson, 1989), and a nitrogen turn-over routine; ii) the universal crop growth model SUCROS (van Keulen et al., 1982; Spitters et al., 1988); and iii) a pesticide fate model. The program is written in FORTRAN 77 and can be run either under UNIX or MS-DOS platforms. Although the program can be run on 486-based computers, Pentium processors are recommended

Modeling as a tool for the characterization of soil water and chemical fate and transport

Modeling is the basis for any experimental characterization and is therefore a key in the characterization of soil water and chemical fate and transport processes. Before undertaking any process of characterization, it is necessary to use a conceptual model rather than a numerical model. This point of view considers modeling to be the starting point for any soil characterization process. It is important to note that the end result of characterization efforts is to describe how the processes will evolve in space and time through a mathematical model. The characterization process is based on modeling while soil process simulation modeling builds on the results of the soil characterization. This chapter discusses the characterization of water content and soil process