Modellierung und Prognose der Bodenfeuchtigkeit mithilfe von Boden und Meteodaten am Beispiel einer Lysimeteranlage

Böden bilden einen wichtigen Zwischenspeicher im Wasserkreislauf. Das Wasser, welches im Boden in Grob und Feinporen vorliegt, dient als Lösungsmittel und Transportmedium für Nährstoffe und wird beim Gasaustausch mit der Atmosphäre transpiriert. So verändert sich der im Boden befindende Bodenwasservorrat ständig, abhängig von Niederschlägen, Transpiration und Evaporation. Die Quantifizierung des Bodenwasservorrats ist für die Landwirtschaft wichtig, weil es Hinweise zur mengenmassigen und zeitlichen Bemessung von Bewässerungsgaben liefert. Da die flachendeckende Messung von Bodenwassergehalt und Matrixpotenzial teuer und arbeitsaufwändig ist, kann mithilfe von Modellen die Bodenwasserbilanz eines Standorts berechnet werden. Dabei werden Daten zu Meteorologie und Bodenbeschaffenheit verwendet, um die Evapotranspiration (ET), Infiltration und Versickerung mathematisch zu beziffern. In dieser Arbeit sollen Berechnungen der Wasserbilanz sowie des Bodenwassergehalts vorgenommen und mit Messdaten der Lysimeteranlage auf dem Campus der ZHAW in Wädenswil verglichen werden. Da die Exposition und Hangneigung aufgrund des sich verändernden Einstrahlungswinkels einen Einfluss auf die Evapotranspiration hat, wurden zudem Tensiometer zur Überwachung der Bodenfeuchtigkeit an zwei unterschiedlich exponierten Flachen installiert, um diesen Effekt zu beobachten. Die mit HYDRUS-1D berechneten Komponenten der Wasserbilanz sowie Bodenwassergehalt und Matrixpotenzial zeigten eine gute Übereinstimmung mit den gemessenen Daten. Sickerwassermenge und Speicheränderung konnten gut nachvollzogen werden. Die Berechnung der ET wies jedoch Unstimmigkeiten auf, die teilweise durch die verwendeten Eingangs-Parameter erklärt werden konnten. Die Berechnungen des Matrixpotenzials in Abhängigkeit der expositionsabhängigen Einstrahlung konnte nur bedingt die gemessenen Werte abbilden. Im Unterboden wurde dabei eine bessere Übereinstimmung als im Oberboden erreicht. Die Genauigkeit des Modells konnte durch die Verwendung genauerer Daten über Boden und Vegetation verbessert werden.Abstract: Soils form an important intermediate reservoir in the water cycle. The water, which is present in the soils coarse and fine pores, serves as a solvent and transport medium for nutrients and is transpired during gas exchange with the atmosphere. The soil water supply changes constantly depending on precipitation, transpiration and evaporation. Quantifying the soil water provides information on the quantity and timing of irrigation for agricultural crops. Since the large-scale measurement of soil water content and matrix potential is expensive and labourintensive, models can be used to calculate the soil water balance of a site. Data on meteorology and soil composition are used to mathematically quantify evapotranspiration, infiltration and percolation. In this work, calculations of the water balance and the soil water content will be carried out and compared with measured data from the lysimeter facility on the campus of the ZHAW in Wadenswil. Since exposition and slope have an influence on evapotranspiration due to the changing irradiation angle, tensiometers for monitoring soil moisture were also installed on two differently exposed surfaces to observe this effect. The components of the water balance, soil water content and matrix potential calculated by HYDRUS-1D showed a good agreement with the measured data. The quantity of percolated and the change in stored water could be reproduced. However, the calculation of the evapotranspiration showed discrepancies, which could partly be explained by the input parameters used. The calculations of the matrix potential as a function of the exposure-dependent irradiation could only reproduce the measured values to a limited extent. A better agreement was achieved in the subsoil than in the topsoil. The performance of the model could be improved by using more accurate data regarding soil and vegetation cover

Morphology and temporal evolution of ground-nesting bee burrows created by solitary and social species quantified through X-ray imaging

Most research on wild bees has focused on their role as pollinators, while their importance as soil ecosystem engineers has been largely overlooked, despite the fact that most species nest in the soil. There is limited quantitative knowledge regarding the architecture of nests created by wild bees and the temporal evolution of bee burrows. The aim of this study was to evaluate the feasibility of repeatedly scanning ground-nesting bee nests using X-ray computed tomography to quantify the morphology and temporal evolution of burrow systems created by both solitary and social species. We installed eleven large cylinders at locations with ongoing nesting activity of ground-nesting bees, and repeatedly scanned these soil columns with a medical X-ray scanner over a period of 16 months. From the X-ray images, we extracted bee burrows to visualize and quantitatively characterize their morphology and temporal evolution. The architecture and temporal evolution of burrows strongly differed between the studied social and solitary ground-nesting bee species. Burrows created by the solitary species were simple, linear and unbranched burrows, which were not reused and decayed with time. The burrow systems created by the social species were more complex, with highly branched networks of horizontal and vertical burrows, which increased in complexity and size over time during the bee activity period. The persistence of burrows created by ground-nesting bees varied greatly, with some decaying within a few weeks and others remaining mostly intact for the entire 16-month study period. This study demonstrates the potential of X-ray imaging to provide new insights into the underground life of ground-nesting bees, and highlights the locally important role of ground-nesting bees as soil ecosystem engineers

SENSING THE LAND SUBSIDENCE IN THE VENICE LAGOON BY INTERFEROMETRIC POINT TARGET ANALYSIS

Land subsidence is a severe geologic hazard threading the lowlying coastal areas worldwide. Monitoring land subsidence has been significantly improved over the last few years by space borne earth observation techniques based on SAR (Synthetic Aperture Radar) Interferometry. Within the INLET Project, funded by Magistrato alle Acque di Venezia – Venice Water Authority (VWA) and Consorzio Venezia Nuova (CVN), we have used the Interferometric Point Target Analysis (IPTA) to characterize the ground displacements within the Venice Lagoon. IPTA measures the movement of backscattering objects (point targets, PT) at the ground surface which persistently reflect radar signal emitted by the SAR antenna. For this study 80 ERS-1/2 and 44 ENVISAT scenes recorded from 1992 to 2005 and from 2003 to 2007, respectively, have been processed by IPTA. High reliable land subsidence data have been detected for thousands of PT located on the lagoon margins, along the littorals, in major and small islands, and on single anthropogenic structures scattered within the lagoon. On the average, land subsidence ranges from less than 1 mm/year to 5 mm/year, with some PT that exhibit values also larger than 10 mm/year depending on both the local geologic conditions and anthropogenic activities. A network of few tens of artificial square trihedral corner reflectors (TCR) has been established before summer 2007 to monitor land subsidence in the inner lagoon areas where natural reflectors completely lack (e.g., on the salt marshes). The first interferometric results on the TCR appear very promising

Mechanical and Structural Characterization of Zn-Ti Colored Coatings

AbstractHot dip galvanizing is one of the most popular processes used to protect steel against corrosion. It produces a coating characterized by intermetallic phases with different hardness and resistance. In this work has been studied a coating provided by a zinc alloy with 0.2 wt% of titanium. Steel samples were coated for a dipping time of 3minutes at temperatures between 560-640°C. The high temperatures were chosen as it has been observed a color change on the surface. With this type of bath composition the coatings obtained were characterized by a considerable thickness. By means of EDX (Energy Dispersive X-ray spectroscopy) and XRD (X-ray diffraction) intermediate phases containing FeTiZn formed during the process have been identified.Indentation and impact tests were carried out to show that the ZnTi coating is better than the more used pure zinc hot dip galvanized in terms of hardness and it undergoes decay if subjected to dynamic stresses

An Integrated Approach for Evaluating the Restoration of the Salinity Gradient in Transitional Waters: Monitoring and Numerical Modeling in the Life Lagoon Refresh Case Study

Large lagoons usually show a salinity gradient due to fresh water tributaries with inner areas characterized by lower mean values and higher fluctuation of salinity than seawaterdominated areas. In the Venice Lagoon, this ecotonal environment, characterized in the past by oligo‐mesohaline waters and large intertidal areas vegetated by reedbeds, was greatly reduced by historical human environmental modifications, including the diversion of main rivers outside the Venice Lagoon. The reduction of the fresh water inputs caused a marinization of the lagoon, with an increase in salinity and the loss of the related habitats, biodiversity, and ecosystem services. To counteract this issue, conservation actions, such as the construction of hydraulic infrastructures for the introduction and the regulation of a fresh water flow, can be implemented. The effectiveness of these actions can be preliminarily investigated and then verified through the combined implementation of environmental monitoring and numerical modeling. Through the results of the monitoring activity carried out in Venice Lagoon in the framework of the Life Lagoon Refresh (LIFE16NAT/IT/000663) project, the study of salinity is shown to be a successful and robust combination of different types of monitoring techniques. In particular, the characterization of salinity is obtained by the acquisition of continuous data, field campaigns, and numerical modeling

Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial

Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe