| 1. |
- Blösch, Günter, et al.
(author)
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Twenty-three unsolved problems in hydrology (UPH) - a community perspective
- 2019
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In: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 64:10, s. 1141-1158
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Journal article (peer-reviewed)abstract
- This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.
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| 2. |
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| 3. |
- Liljedahl, Sophie, et al.
(author)
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Culture and personality disorders : Self-harm in Sweden: A national response with treatment implications for those with or without borderline perso- nality disorder
- 2016
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In: ; , s. 15-15
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Conference paper (peer-reviewed)abstract
- Objectives: The purpose of this presentation is to discuss Sweden’s national recommendations for mental health treatment provided to self-harming individuals in the country. The recommendations were based upon a Self-Harm Quality Standard (2013) published by the National Institute for Health and Care Excellence (NICE) adapted to Swedish health care and cultural context. Methods: A review and synthesis of scientific literature on self-harm; A review and synthesis of treatment guidelines for self-harm Results: The recommendations are referred to as a Quality Document within Swedish healthcare, published initially in 2014, with a scientific update in February 2016. The first and primary recommendation relates to meeting self-harming individuals with compassion, respect, and dignity across the individual’s continuum of care. Other recommendations summarize the leading practices and evidence-based literature in relation to acute assessment of mental and physical health, diagnostic evaluation, risk management, treatment planning, treatment itself and continuity of care. Conclusions: Sweden’s national Recommendations for the treatment of self-harm were published in the development phase of a multi-year national self-harm project. Emerging in part from the Recommendations has been the development of a number of new initiatives, which are summarized and discussed. References: NICE (2013b). QS34: Quality standard for self-harm. Retrieved from: http://publications.nice.org.uk/quality-standard-for-selfharm-qs34/introduction-and-overview Westling, S., Liljedahl, S. I., Holmqvist-Larsson M, Parnén, H., Zetterqvist, M., & Ershammar, D. (2014). Recommendationer för insatser vid självskadebeteende. Retrieved from: http://www.svenskabupforeningen.se/bibliotek/kunskapsoversikter_PM/behandlings_PM/Sjalvskade%20rekommendationer.pdf
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| 5. |
- Mineo, Claudio, et al.
(author)
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Assessment of Rainfall Kinetic-Energy-Intensity Relationships
- 2019
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In: Water. - : MDPI. - 2073-4441. ; 11:10
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Journal article (peer-reviewed)abstract
- Raindrop-impact-induced erosion starts when detachment of soil particles from the surface results from an expenditure of raindrop energy. Hence, rain kinetic energy is a widely used indicator of the potential ability of rain to detach soil. Although it is widely recognized that knowledge of rain kinetic energy plays a fundamental role in soil erosion studies, its direct evaluation is not straightforward. Commonly, this issue is overcome through indirect estimation using another widely measured hydrological variable, namely, rainfall intensity. However, it has been challenging to establish the best expression to relate kinetic energy to rainfall intensity. In this study, first, kinetic energy values were determined from measurements of an optical disdrometer. Measured kinetic energy values were then used to assess the applicability of the rainfall intensity relationship proposed for central Italy and those used in the major equations employed to estimate the mean annual soil loss, that is, the Universal Soil Loss Equation (USLE) and its two revised versions (RUSLE and RUSLE2). Then, a new theoretical relationship was developed and its performance was compared with equations found in the literature.
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| 6. |
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| 7. |
- Mineo, Claudio, et al.
(author)
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The areal reduction factor : A new analytical expression for the Lazio Region in central Italy
- 2018
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In: Journal of Hydrology. - Amsterdam : Elsevier. - 0022-1694 .- 1879-2707. ; 560, s. 471-479
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Journal article (peer-reviewed)abstract
- For the study and modeling of hydrological phenomena, both in urban and rural areas, a proper estimation of the areal reduction factor (ARF) is crucial. In this paper, we estimated the ARF from observed rainfall data as the ratio between the average rainfall occurring in a specific area and the point rainfall. Then, we compared the obtained ARF values with some of the most widespread empirical approaches in literature which are used when rainfall observations are not available. Results highlight that the literature formulations can lead to a substantial over- or underestimation of the ARF estimated from observed data. These findings can have severe consequences, especially in the design of hydraulic structures where empirical formulations are extensively applied. The aim of this paper is to present a new analytical relationship with an explicit dependence on the rainfall duration and area that can better represent the ARF-area trend over the area case of study. The analytical curve presented here can find an important application to estimate the ARF values for design purposes. The test study area is the Lazio Region (central Italy).
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| 8. |
- Montesarchio, Valeria, et al.
(author)
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Comparison of methodologies for flood rainfall thresholds estimation
- 2015
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In: Natural Hazards. - : Springer Netherlands. - 0921-030X .- 1573-0840. ; 75:1, s. 909-934
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Journal article (peer-reviewed)abstract
- A flood warning system based on rainfall thresholds makes it possible to issue alarms via an off-line approach. This technique is useful for mitigating the effects of flooding in small-to-medium-sized basins characterized by an extremely rapid response to rainfall. Rainfall threshold values specify the amount of precipitation that occurs over a given period of time and are dependent on both the amount of soil moisture and the spatiotemporal distribution of the rainfall. The precipitation generates a critical discharge in a particular river cross section. Exceeding these values can produce a critical situation in river sites that make them susceptible to flooding. In this work, we present a comparison of methodologies for estimating rainfall thresholds. Critical precipitation amounts are evaluated using empirical data, hydrological simulations and probabilistic methods. The study focuses on three small-to-medium-sized basins located in central Italy. For each catchment, historical data are first used to theoretically evaluate the empirical rainfall thresholds. Next, we calibrate a semi-distributed hydrological model that is validated using rain gauge and weather radar data. Critical rainfall depths over 30 min and 1, 3, 6, 12 and 24 h durations are then evaluated using the hydrological simulation. In the probabilistic approach, rainfall threshold values result from a minimization of two different functions, one following the Bayesian decision theory and the other following the informative entropy concept. In order to implement both functions, it is necessary to evaluate the joint probability function. The joint probability function is built up as a bivariate distribution of rainfall depth for a given duration with the corresponding flow peak value. Finally, in order to assess the performance of each methodology, we construct contingency tables to highlight the system performance.
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| 11. |
- Ridolfi, Elena, et al.
(author)
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A new methodology to define homogeneous regions through an entropy based clustering method
- 2016
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In: Advances in Water Resources. - : Elsevier BV. - 0309-1708 .- 1872-9657. ; 96, s. 237-250
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Journal article (peer-reviewed)abstract
- One of the most crucial steps in flow frequency studies is the definition of Homogenous Regions (HRs), i.e. areas with similar hydrological behavior. This is essential in ungauged catchments, as HR allows information to be transferred from a neighboring river basin. This study proposes a new, entropy-based approach to define HRs, in which regions are defined as homogeneous if their hydrometric stations capture redundant information. The problem is handled through the definition of the Information Transferred Index (ITI) as the ratio between redundant information and the total information provided by pairs of stations. The methodology is compared with a traditional, distance-based clustering method through a Monte Carlo experiment and a jack-knife procedure. Results indicate that the ITI-based method performs Well, adding value to current methodologies to define HRs.
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| 12. |
- Ridolfi, Elena, et al.
(author)
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Accuracy analysis of a dam model from drone surveys
- 2017
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In: Sensors. - St. Alban-Anlage 66, 4052 Basel, Switzerland : MDPI. - 1424-8220. ; 17:8
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Journal article (peer-reviewed)abstract
- This paper investigates the accuracy of models obtained by drone surveys. To this end, this work analyzes how the placement of ground control points (GCPs) used to georeference the dense point cloud of a dam affects the resulting three-dimensional (3D) model. Images of a double arch masonry dam upstream face are acquired from drone survey and used to build the 3D model of the dam for vulnerability analysis purposes. However, there still remained the issue of understanding the real impact of a correct GCPs location choice to properly georeference the images and thus, the model. To this end, a high number of GCPs configurations were investigated, building a series of dense point clouds. The accuracy of these resulting dense clouds was estimated comparing the coordinates of check points extracted from the model and their true coordinates measured via traditional topography. The paper aims at providing information about the optimal choice of GCPs placement not only for dams but also for all surveys of high-rise structures. The knowledge a priori of the effect of the GCPs number and location on the model accuracy can increase survey reliability and accuracy and speed up the survey set-up operations.
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| 13. |
- Ridolfi, Elena, et al.
(author)
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Coping with Extreme Events : Effect of Different Reservoir Operation Strategies on Flood Inundation Maps
- 2019
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In: Water. - : MDPI. - 2073-4441. ; 11:5
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Journal article (peer-reviewed)abstract
- The need of addressing residual flood risk associated with structural protection measures, such as levee systems and flood-control reservoirs, has fostered actions aimed at increasing flood risk awareness. Structural measures have lowered risk perception by inducing a false sense of safety. As a result, these structures contribute to an underestimation of the residual risk. We analyze the effect of different reservoir operations, such as coping with drought versus coping with flood events, on flood inundation patterns. First, a hydrological model simulates different scenarios, which represent the dam regulation strategies. Each regulation strategy is the combination of an opening of the outlet gate and of the initial water level in the reservoir. Second, the corresponding outputs of the dam in terms of maximum discharge values are estimated. Then, in turn, each output of the dam is used as an upstream boundary condition of a hydraulic model used to simulate the flood propagation and the inundation processes in the river reach. The hydraulic model is thus used to determine the effect, in terms of inundated areas, of each dam regulation scenario. Finally, the ensemble of all flood inundation maps is built to define the areas more prone to be flooded. The test site is the Casanuova dam (Umbria, central Italy) which aims at: (i) mitigating floods occurring at the Chiascio River, one of the main tributaries of Tiber River, while (ii) providing water supply for irrigation. Because of these two competitive interests, the understanding of different scenarios generated by the dam operations offers an unique support to flood mitigation strategies. Results can lead to draw interesting remarks for a wide number of case studies.
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| 14. |
- Ridolfi, Elena, et al.
(author)
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Optimal Cross-sectional Sampling for River Modelling with Bridges : an Information Theory-based Method
- 2016
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In: Proceedings Of The International Conference On Numerical Analysis And Applied Mathematics 2015 (ICNAAM-2015). - : Author(s). - 9780735413924
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Conference paper (peer-reviewed)abstract
- The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers' cross-sectional spacing.
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| 15. |
- Ridolfi, Elena, et al.
(author)
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Water level measurements from drones: A Pilot case study at a dam site
- 2018
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In: Water. - MDPI, St. Alban-Anlage 66, 4052 Basel, Switzerland : MDPI. - 2073-4441. ; 10:3
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Journal article (peer-reviewed)abstract
- Unmanned Aerial Vehicles (UAVs) are now filling in the gaps between spaceborne and ground-based observations and enhancing the spatial resolution and temporal coverage of data acquisition. In the realm of hydrological observations, UAVs play a key role in quantitatively characterizing the surface flow, allowing for remotely accessing the water body of interest. In this paper, we propose a technology that uses a sensing platform encompassing a drone and a camera to determine the water level. The images acquired by means of the sensing platform are then analyzed using the Canny method to detect the edges of water level and of Ground Control Points (GCPs) used as reference points. The water level is then retrieved from images and compared to a benchmark value obtained by a traditional device. The method is tested at four locations in an artificial lake in central Italy. Results are encouraging, as the overall mean error between estimated and true water level values is around 0.05 m. This technology is well suited to improve hydraulic modeling and thus provides reliable support to flood mitigation strategies.
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