420 research outputs found
On the use of spatially distributed, time-lapse microgravity surveys to inform hydrological modeling
No full textDataset: A multi-site, year-round turbulence microstructure atlas for the deep perialpine Lake Garda
No full textThis repository includes the dataset described in "A multi-site, year-round turbulence microstructure atlas for the deep perialpine Lake Garda", Scientific Reports, 2021, DOI: 10.1038/s41597-021-00965-0 A multi-site, year-round dataset comprising a total of 606 high-resolution turbulence microstructure profiles of shear and temperature gradient in the upper 100 m depth is made available for Lake Garda (Italy). Concurrent meteorological data were measured from the fieldwork boat at the location of the turbulence measurements. During the fieldwork campaign (March 2017-June 2018), four different sites were sampled on a monthly basis, following a standardized protocol in terms of time-of-day and locations of the measurements. Additional monitoring activity included a 24-h campaign and sampling at other sites. Turbulence quantities were estimated, quality-checked, and merged with water quality and meteorological data to produce a unique turbulence atlas for a lake. The dataset is open to a wide range of possible applications, including research on the variability of turbulent mixing across seasons and sites (demersal vs pelagic zones) and driven by different factors (lake-valley breezes vs buoyancy-driven convection), validation of hydrodynamic lake models, as well as technical studies on the use of shear and temperature microstructure sensors.</span
A multi-site, year-round turbulence microstructure atlas for the deep perialpine Lake Garda
No full textA multi-site, year-round dataset comprising a total of 606 high-resolution turbulence microstructure profiles of shear and temperature gradient in the upper 100 m depth is made available for Lake Garda (Italy). Concurrent meteorological data were measured from the fieldwork boat at the location of the turbulence measurements. During the fieldwork campaign (March 2017-June 2018), four different sites were sampled on a monthly basis, following a standardized protocol in terms of time-of-day and locations of the measurements. Additional monitoring activity included a 24-h campaign and sampling at other sites. Turbulence quantities were estimated, quality-checked, and merged with water quality and meteorological data to produce a unique turbulence atlas for a lake. The dataset is open to a wide range of possible applications, including research on the variability of turbulent mixing across seasons and sites (demersal vs pelagic zones) and driven by different factors (lake-valley breezes vs buoyancy-driven convection), validation of hydrodynamic lake models, as well as technical studies on the use of shear and temperature microstructure sensors.APHY
HYPERstream: A multi-scale framework for streamflow routing in large-scale hydrological model
No full textWe present HYPERstream, an innovative streamflow routing scheme based on the width function instantaneous unit hydrograph (WFIUH) theory, which is specifically designed to facilitate coupling with weather forecasting and climate models. The proposed routing scheme preserves geomorphological dispersion of the river network when dealing with horizontal hydrological fluxes, irrespective of the computational grid size inherited from the overlaying climate model providing the meteorological forcing. This is achieved by simulating routing within the river network through suitable transfer functions obtained by applying the WFIUH theory to the desired level of detail. The underlying principle is similar to the block-effective dispersion employed in groundwater hydrology, with the transfer functions used to represent the effect on streamflow of morphological heterogeneity at scales smaller than the computational grid. Transfer functions are constructed for each grid cell with respect to the nodes of the network where streamflow is simulated, by taking advantage of the detailed morphological information contained in the digital elevation model (DEM) of the zone of interest. These characteristics make HYPERstream well suited for multi-scale applications, ranging from catchment up to continental scale, and to investigate extreme events (e.g., floods) that require an accurate description of routing through the river network. The routing scheme enjoys parsimony in the adopted parametrization and computational efficiency, leading to a dramatic reduction of the computational effort with respect to full-gridded models at comparable level of accuracy. HYPERstream is designed with a simple and flexible modular structure that allows for the selection of any rainfall-runoff model to be coupled with the routing scheme and the choice of different hillslope processes to be represented, and it makes the framework particularly suitable to massive parallelization, customization according to the specific user needs and preferences, and continuous development and improvements
Ice Cover and Extreme Events Determine Dissolved Oxygen in a Placid Mountain Lake
No full textA decrease in hypolimnetic dissolved oxygen (DO) is a commonly seen effect of climate change. However, in oligotrophic Lake Tovel (Italy), a deep mountain lake, annual mean DO (% saturation) has increased from near anoxia to >20% in the bottom layer (35–39 m). We analyzed long‐term patterns of DO (1937–2019) using different methods (correlation and trend analysis, identification of extreme events) to link DO to drivers and indices of mixing. While spring mixing remained temporally limited, later ice‐in (5.1 days decade−1) and the positive relationship between ice‐in and DO the following year evidenced autumn mixing as the main driver for hypolimnetic DO increase. Extreme meteorological events also replenished hypolimnetic DO. Using DO and conductivity (1995–2019), we identified 14 deep mixing events with hypolimnetic DO > 40%. Density‐based indices (Schmidt stability, relative thermal resistance, Lake Number, and Wedderburn Number) only partially captured these events that were related to snowmelt, flooding, and cold spells during spring and autumn, with a carryover effect sometimes lasting >1 year. Recently, annual mean DO in the upper layer decreased beyond temperature‐dependent solubility. This decrease was not comprehensively confirmed by statistical tests but was possibly linked to atmospheric stilling. We suggest that Lake Tovel's shift from meromixis to dimixis was driven by climate warming (i.e., increasing air temperature 0.6°C decade−1) that delayed ice‐in and increased autumn mixing. Our work underlines the vulnerability of mountain lakes and their different response to climate change with respect to more studied lowland lake
HYPERStream: Un innovativo schema di routing per la modellazione idrologica a grande scala
No full textIl presente volume digitale ad accesso libero (licenza Creative Commons 4.0) raccoglie le memorie brevi pervenute al Comitato Scientifico di IDRA16 ed accettate per la presentazione al convegno a valle di un processo di revisione tra pari. Il volume articola dette memorie in sette macro-tematiche, che costituiscono i capitoli del volume stesso: I. meccanica dei fluidi; II. ambiente marittimo e costiero; III. criteri, metodi e modelli per l’analisi dei processi idrologici e la gestione delle acque; IV. gestione e tutela dei corpi idrici e degli ecosistemi; V. valutazione e mitigazione del rischio idrologico e idraulico; VI. dinamiche acqua-società: sviluppo sostenibile e gestione del territorio; VII. monitoraggio, open-data e software libero. Ciascuna macro-tematica raggruppa più sessioni specialistiche autonome sviluppatesi in parallelo durante le giornate del Convegno, i cui titoli vengono richiamati all’interno del presente volume. La vastità e la diversità delle tematiche affrontate, che ben rappresentano la complessità delle numerose sfide dell’Ingegneria delle Acque, appaiono evidenti dalla consultazione dell’insieme di memorie brevi presentate
Sebastiano Moruzzi, Vaghezza. Confini, cumuli e paradossi, Laterza, Bari 2012, pp. 196
No full textThe text offers a Critical Review of "Vaghezza. Confini, cumuli e paradossi" by Sebastiano Moruzzi. The author critically reflects on the book by considering its methodologies, its arguments, and its relation with other books of the same type and on the same subject.Il testo propone una Lettura Critica del libro "Vaghezza. Confini, cumuli e paradossi" di Sebastiano Moruzzi. L'autrice riflette criticamente sul libro considerandone le metodologie, gli argomenti e il nesso con altri libri dello stesso tipo e sullo stesso argomento
Client-consultant interaction practices: Sources of ingenuity, value creation and strategizing
No full textService providers increasingly choose to interact with their clients. Previous studies show that client’s resources and activities can influence the service provider’s ability to create value, to be creative, and to develop competitive strategies. Yet several gaps can be identified in the literature regarding how these abilities are impacted by client-consultant interaction (c-c-i) practices. The purpose of this doctoral thesis is to explain the service providers’ varying ability to offer highly valuable solutions to their clients’ problems, in terms of the practices through which consultants interact with their clients. The main research questions are;
How do client-consultant interaction practices influence a firm’s ability to offer unique value propositions and deliver ingenious solutions, and how do these practices influence the formation of the firm’s strategy? These questions are answered through four papers. Each paper answers a sub-question.
Paper 1 focuses on the impact of c-c-i practices on the service providers’ ingenuity capabilities. The paper asks how project teams shatter constraints in ill-structured problem-solving situations, and what implications this finding has for the understanding of creative action in organizations. This paper sheds light on the c-c-i practices through which project teams shatter their constraints and create ingenious solutions.
Paper 2 focuses on the creative aspects of c-c-i practices and presents the experiences of service providers who have been successful in capitalizing on the creative resources provided by their clients.
Paper 3 is an inquiry into the relationship between c-c-i practices and the service providers’ ability to offer unique value propositions. The paper provides a model to define and assess value created through c-c-i practices. The findings of this paper show that value creation is maximized through c-c-i practices that provide access to various forms of capital and practice that enable capital exploitation. Unique value offerings can be developed from knowing what c-c-i practices to enact in different circumstances.
Paper 4 focuses on the implications of c-c-i practices for the emergence of new strategies. The findings show that mundane business operations can be the locus of strategizing, and that clients can play a role in emergent strategy formation. Theoretical resources for this research are drawn from literature on practice theory, strategy, organizational creativity, and value creation. An explorative research design is used and qualitative data are gathered from 30 cases through extensive field work. Both in-depth and comparative case analyses are performed
Client-consultant interaction practices: Sources of ingenuity, value creation and strategizing
No full textService providers increasingly choose to interact with their clients. Previous studies show that client’s resources and activities can influence the service provider’s ability to create value, to be creative, and to develop competitive strategies. Yet several gaps can be identified in the literature regarding how these abilities are impacted by client-consultant interaction (c-c-i) practices. The purpose of this doctoral thesis is to explain the service providers’ varying ability to offer highly valuable solutions to their clients’ problems, in terms of the practices through which consultants interact with their clients. The main research questions are;
How do client-consultant interaction practices influence a firm’s ability to offer unique value propositions and deliver ingenious solutions, and how do these practices influence the formation of the firm’s strategy? These questions are answered through four papers. Each paper answers a sub-question.
Paper 1 focuses on the impact of c-c-i practices on the service providers’ ingenuity capabilities. The paper asks how project teams shatter constraints in ill-structured problem-solving situations, and what implications this finding has for the understanding of creative action in organizations. This paper sheds light on the c-c-i practices through which project teams shatter their constraints and create ingenious solutions.
Paper 2 focuses on the creative aspects of c-c-i practices and presents the experiences of service providers who have been successful in capitalizing on the creative resources provided by their clients.
Paper 3 is an inquiry into the relationship between c-c-i practices and the service providers’ ability to offer unique value propositions. The paper provides a model to define and assess value created through c-c-i practices. The findings of this paper show that value creation is maximized through c-c-i practices that provide access to various forms of capital and practice that enable capital exploitation. Unique value offerings can be developed from knowing what c-c-i practices to enact in different circumstances.
Paper 4 focuses on the implications of c-c-i practices for the emergence of new strategies. The findings show that mundane business operations can be the locus of strategizing, and that clients can play a role in emergent strategy formation. Theoretical resources for this research are drawn from literature on practice theory, strategy, organizational creativity, and value creation. An explorative research design is used and qualitative data are gathered from 30 cases through extensive field work. Both in-depth and comparative case analyses are performed
Measured temporal variations of CO2 concentration and atmospheric emissions in a hydropeaking-impacted river
No full textRivers are increasingly recognised as active players in the global carbon cycle. They are able to transport, transform, and exchange organic matter, and can emit considerable fluxes of greenhouse gases (e.g., CO2) into the atmosphere, with a magnitude comparable to the global carbon input to the oceans. However, the quantification of these processes is still affected by considerable uncertainties, driven by an incomplete understanding of the interplay between physical, geochemical, and biological parameters, and by a lack of spatially and temporally resolved high-quality data. For instance, and despite a potentially strong impact on kilometres of rivers worldwide, the effects of hydropeaking on riverine CO2 emissions have been almost completely neglected until recently (Calamita et al., Unaccounted CO2 leaks downstream of a large tropical hydroelectric reservoir, PNAS 2020). As a contribution to filling this knowledge gap, we present the results of a field-measurement campaign performed in a single-thread Alpine river (River Noce, Italy) during multiple hydropeaking events. Data of water-dissolved CO2, water temperature, and flow discharge, were collected sub-hourly both downstream and upstream of the outlets of a hydropower plant, revealing a complex pattern of variation in time at both locations. Water released from the hydropower plant during hydropeaking had oversaturated CO2 concentrations relative to the atmosphere, in close agreement with water samples collected in the hypolimnion of the upstream reservoir. Higher flow rates during hydropeaking events were associated with higher rates of gas exchange through the water-air interface. Higher exchange rates and higher CO2 concentrations in water during hydropeaking events enhanced CO2 fluxes, as confirmed by measurements with a floating CO2 flux chamber. Meanwhile, the CO2 concentration upstream of the outlets displayed strong diel fluctuations around the atmospheric equilibrium concentration, which were likely driven by primary production within the residual flow during the day. It is shown that the residual flow can have a previously unacknowledged added value as a CO2 sink during the day, fueled by its biological activity. Hydropower releases bypassed the residual flow and discharged hypolimnetic water oversaturated with CO2 at high flow rates during hydropeaking, offsetting CO2 concentration and fluxes downstream of the outlets and increasing emissions on average. These results highlight the ubiquity of hydropeaking impacts also with respect to greenhouse gas emissions. They illustrate the complexity of the riverine carbon cycle and demonstrate the importance of temporally and spatially-resolved data for the accurate assessment of the riverine carbon balance
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