Dissolved organic carbon (DOC) transported by rivers represents an important link between carbon pools of terrestrial and oceanic ecosystems. However, it is unclear how frequent DOC must be sampled to obtain reasonable load estimates. Here, we used continuous records of the specific UV absorption coefficient (SAC) and discharge from a headwater stream at the Ore Mountains (Germany) to calculate load errors depending on DOC sampling frequency. SAC was used as a proxy for DOC. The results show that the load was underestimated by 13-19% with monthly, 10-13% with bi-weekly and 7-9% with weekly DOC samplings, respectively. We conclude that collecting additional data from high discharge events decrease the error significantly.
A one-dimensional dual-continuum model (also known as dual-permeability model) was used to simulate the lateral component of subsurface runoff and variations in the natural 18O content in hillslope discharge. Model predictions were analyzed using the GLUE generalized likelihood uncertainty estimation procedure. Model sensitivity was evaluated by varying two separate triplets of parameters. The first triplet consisted of key parameters determining the preferential flow regime, i.e., the volumetric proportion of the preferential flow domain, a first-order transfer coefficient characterizing soil water exchange between the two flow domains of the dual-continuum system, and the saturated hydraulic conductivity of the preferential flow domain. The second triplet involved parameters controlling exclusively the soil hydraulic properties of the preferential flow domain, i.e., its retention curve and hydraulic conductivity function. Results of the analysis suggest high sensitivity to all parameters of the first triplet, and large differences in sensitivity to the parameters of the second triplet. The sensitivity analysis also confirmed a significant improvement in the identifiability of preferential flow parameters when 18O content was added to the objective function. and K simulacím laterální složky podpovrchového proudění a změn koncentrace izotopu kyslíku 18O ve vodě vytékající ze svahu byl použit jednorozměrný model využívající přístupu duálního kontinua. Nejistota modelových předpovědí byla odhadnuta s využitím metody zobecněné věrohodnosti (GLUE). Citlivost modelu byla zjišťována pomocí variací dvou samostatných trojic parametrů. První trojice sestávala z klíčových parametrů pro určení režimu preferenčního proudění, tj. objemového podílu preferenční domény proudění, přenosového koeficientu charakterizujícího výměnu vody mezi oběma doménami duálního systému a nasycené hydraulické vodivosti preferenční domény. Druhá trojice zahrnovala výhradně parametry určující hydraulické charakteristiky preferenční domény proudění, tj. retenční křivku a funkci hydraulické vodivosti. Z výsledků analýzy vyplývá vysoká citlivost modelu na všechny parametry z první trojice a velké rozdíly v citlivostech parametrů druhé trojice. Analýza dále potvrdila významné zlepšení zjistitelnosti parametrů preferenční domény v případě, kdy je do cílové funkce přidána koncentrace izotopu kyslíku 18O.
Flow in compound channels with overbank flows becomes more complex because of shear interactions between flows in main channel and flood plains, lateral momentum transfer and secondary flows. Compound channels have interesting applications in flood control, civil engineering and environmental management. Because it is difficult to obtain sufficiently accurate and comprehensive understandings of flow in natural compound rivers, the developed models of flow in overbank flows have many uncertainties. The main aims of this paper are to analysis and quantify the uncertainty results of quasi two dimensional flow modeling in compound channels. In this paper a quasi two dimensional depth averaged model, known as Shiono and Knight Model (SKM), in compound channel is used and uncertainty analysis of its simulation results is done based on Monte-Carlo simulations. Results indicated that although the SKM model can simulate quasi-two-dimensional flow accurately but it has many uncertainties in simulation results. The uncertainties of model results in high are greater than low flows. Also uncertainties in discharge capacity and shear stress are greater than those for velocity profiles. Overall results cleared that the SKM model, beyond from its strong physical basics, requires rigorous effort on local calibration processes, especially for high flood flows and these limit its global applicability and generalities. and Prúdenie vody v kanáli so zloženým profilom a s prúdením mimo koryta je javom zložitým, predovšetkým pre interakcie medzi prúdením v hlavnom toku a prúdením v zaplavenom území, ktoré spôsobujú laterálny transport momentu a sekundárne prúdenie. Zložené kanály sa často používajú najmä pri protipovodňovej ochrane, v staviteľstve a v oblasti životného prostredia. Pretože je zložité získať dostatok pesných informácií o prúdení vody v zložených korytách prirodzených tokov, existujúce modely prúdenia vody v zložených profiloch s mimobrehovým prúdením obsahujú veľa neistôt. Cieľom tohto príspevku je analýza a kvantifikácia neistôt vo výsledkoch simulácie kvázi-dvojrozmerného prúdenia v zloženom kanáli s prúdením mimo koryta. V tejto práci používame kvázi-dvojrozmerný vertikálne spriemerovaný model, známy ako model Shiona a Knighta (SKM) pre zložený profil. Analýza neurčitosti je realizovaná metódou Monte-Carlo. Výsledky naznačujú, že model SKM je schopný simulovať kvázi-dvojrozmerné prúdenie pomerne presne, výsledky simulácií sú však značne neurčité. Tieto neistoty sú väčšie ako minimálne prietoky. Taktiež neurčitosti v prietokoch a v tangenciálnych silách sú väčšie ako neurčitosti pre rýchlostné profily. Celkovo výsledky ukazujú, že model SKM, nehľadiac na jeho silný fyzikálny základ, si vyžaduje kalibráciu, predovšetkým pre vysoké prietoky, čo limituje rozsah jeho použitia.
Predicting surface deformations caused by underground mining is an issue of significance both for the safety of overlaying facilities and for economic purposes. There are many different models for predicting the impact of underground mining on the land surface. One of them is the Knothe model commonly used in Poland and in the world. The paper presents two methods of estimating Knothe model parameters uncertainty. The parallel application of two methods enables the mutual verification of the results obtained and the identification of the potential errors and their sources in the case of any discrepancies. The first method is based on the so-called law of propagation of uncertainty, which in essence is the approximation based on the first-order Taylor series expansion. The second presented method is based on the Monte Carlo simulation.
This article describes statistical evaluation of the computational model for precipitation forecast and proposes a method for uncertainty modelling of rainfall-runoff models in the Floreon+ system based on this evaluation. The Monte-Carlo simulation method is used for estimating possible river discharge and provides several confidence intervals that can support the decisions in operational disaster management. Experiments with other parameters of the model and their influence on final river discharge are also discussed.
Knowledge on soil moisture is indispensable for a range of hydrological models, since it exerts a considerable influence on runoff conditions. Proper tools are nowadays applied in order to gain in-sight into soil moisture status, especially of uppermost soil layers, which are prone to weather changes and land use practices. In order to establish relationships between meteorological conditions and topsoil moisture, a simple model would be required, characterized by low computational effort, simple structure and low number of identified and calibrated parameters. We demonstrated, that existing model for shallow soils, considering mass exchange between two layers ( the upper and the lower), as well as with the atmosphere and subsoil, worked well for sandy loam with deep ground water table in Warsaw conurbation. GLUE (Generalized Likelihood Uncertainty Estimation) linked with GSA (Global Sensitivity Analysis) provided for final determination of parameter values and model confidence ranges. Including the uncertainty in a model structure, caused that the median soil moisture solution of the GLUE was shifted from the one optimal in deterministic sense. From the point of view of practical model application, the main shortcoming were the underestimated water exchange rates between the lower soil layer (ranging from the depth of 0.1 to 0.2 m below ground level) and subsoil. General model quality was found to be satisfactory and promising for its utilization for establishing measures to regain retention in urbanized conditions.
Area of the Czech Republic is located in headwater area of central Europe. As a result a flood concentration and travel times are quite short (generally from hours to 2 or 3 days). Therefore QPF must be used to provide sufficient lead-time of the hydrological forecast. In addition, the significant orography influence demands rather detailed spatial resolution of NWP model. ALADIN NWP precipitation forecast is used for hydrological models. ALADIN produces only deterministic QPF. Hence the evaluation of QPF uncertainty from the hydrological point of view is necessary. For different basins, time intervals and QPF intervals the difference of QPF and MAP was made and exceedance curves were derived. Using these curves we can post-process determinant QPF to obtain different QPF variants which input hydrological model. Despite its simplicity this approach provides some additional probabilistic information to main model run. and Česká republika z hydrologického pohledu leží ve zdrojové oblasti střední Evropy. Následkem toho doba koncentrace povodní a dotokové doby jsou relativně krátké (maximálně 2 až 3 dny). Z toho důvodu je pro dosažení dostatečného předstihu hydrologické předpovědi nezbytné využívat kvantitativní předpověď srážek (QPF) s relativně vysokým prostorovým rozlišením. Do hydrologického předpovědního systému AquaLog vstupují deterministické předpovědi srážek meteorologického modelu ALADIN. Nezbytné je vyhodnocení vstupujících QPF z hlediska hydrologických potřeb. Pro 88 povodí byly pro různé časové intervaly odvozeny křivky překročení odchylek QPF a MAP (průměrná srážka na povodí). Na jejich podkladě jsou z deterministické QPF odvozeny variantní srážkové předpovědi, které vstupují jako výpočtové varianty do hydrologického modelu. Výsledkem jsou hydrologické variantní předpovědi s určitou pravděpodobností dosažení. Přes jednoduchost daného přístupu tento poskytuje jakousi přidanou pravděpodobnostní informaci k hlavní deterministické předpovědi.
The Weinstein transform satisfies some uncertainty principles similar to the Euclidean Fourier transform. A generalization and a variant of Cowling-Price theorem, Miyachi's theorem, Beurling's theorem, and Donoho-Stark's uncertainty principle are obtained for the Weinstein transform.
This study investigates the identity of hookworms parasitising the Australian sea lion, Neophoca cinerea (Péron), from three colonies in South Australia, Australia. The Australian sea lion is at risk of extinction because its population is small and genetically fragmented. Using morphological and molecular techniques, we describe a single novel species, Uncinaria sanguinis sp. n. (Nematoda: Ancylostomatidae). The new species is most similar to hookworms also parasitic in otariid hosts, Uncinaria lucasi Stiles, 1901 and Uncinaria hamiltoni Baylis, 1933. Comparative morphometrics offered limited utility for distinguishing between species within this genus whilst morphological features and differences in nuclear ribosomal DNA sequences delineated U. sanguinis sp. n. from named congeners. Male specimens of U. sanguinis sp. n. differ from U. lucasi and U. hamiltoni by relatively shorter anterolateral and externodorsal rays, respectively, and from other congeners by the relative lengths and angulations of bursal rays, and in the shape of the spicules. Female specimens of U. sanguinis sp. n. are differentiated from Uncinaria spp. parasitic in terrestrial mammals by differences in vulval anatomy and the larger size of their eggs, although are morphologically indistinguishable from U. lucasi and U. hamiltoni. Molecular techniques clearly delimited U. sanguinis sp. n. as a distinct novel species. Obtaining baseline data on the parasites of wildlife hosts is important for the investigation of disease and the effective implementation and monitoring of conservation management.
Let $X$ be a Banach space. We give characterizations of when ${\cal F}(Y,X)$ is a $u$-ideal in ${\cal W}(Y,X)$ for every Banach space $Y$ in terms of nets of finite rank operators approximating weakly compact operators. Similar characterizations are given for the cases when ${\cal F}(X,Y)$ is a $u$-ideal in ${\cal W}(X,Y)$ for every Banach space $Y$, when ${\cal F}(Y,X)$ is a $u$-ideal in ${\cal W}(Y,X^{**})$ for every Banach space $Y$, and when ${\cal F}(Y,X)$ is a $u$-ideal in ${\cal K}(Y,X^{**})$ for every Banach space $Y$.