| 1. |
- Blösch, Günter, et al.
(författare)
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Twenty-three unsolved problems in hydrology (UPH) - a community perspective
- 2019
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 64:10, s. 1141-1158
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Tidskriftsartikel (refereegranskat)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. |
- Di Baldassarre, Giuliano, et al.
(författare)
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Integrating Multiple Research Methods to Unravel the Complexity of Human-Water Systems
- 2021
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Ingår i: AGU Advances. - : American Geophysical Union (AGU). - 2576-604X. ; 2:3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Predicting floods and droughts is essential to inform the development of policy in water management, climate change adaptation and disaster risk reduction. Yet, hydrological predictions are highly uncertain, while the frequency, severity and spatial distribution of extreme events are further complicated by the increasing impact of human activities on the water cycle. In this commentary, we argue that four main aspects characterizing the complexity of human-water systems should be explicitly addressed: feedbacks, scales, tradeoffs and inequalities. We propose the integration of multiple research methods as a way to cope with complexity and develop policy-relevant science.Plain Language SummarySeveral governments today claim to be following the science in addressing crises caused by the occurrence of extreme events, such as floods and droughts, or the emergence of global threats, such as climate change and COVID-19. In this commentary, we show that there are no universal answers to apparently simple questions such as: Do levees reduce flood risk? Do reservoirs alleviate droughts? We argue that the best science we have consists of a plurality of legitimate interpretations and a range of foresights, which can be enriched by integrating multiple disciplines and research methods.
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| 3. |
- Di Baldassarre, Giuliano, et al.
(författare)
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Multiple hazards and risk perceptions over time : the availability heuristic in Italy and Sweden under COVID-19
- 2021
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Ingår i: Natural hazards and earth system sciences. - : Copernicus Publications. - 1561-8633 .- 1684-9981. ; 21:11, s. 3439-3447
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Tidskriftsartikel (refereegranskat)abstract
- The severe impact of global crises, such as COVID-19 and climate change, is plausibly reshaping the way in which people perceive risks. In this paper, we examine and compare how global crises and local disasters influence public perceptions of multiple hazards in Italy and Sweden. To this end, we integrate information about the occurrence of hazardous events with the results of two nationwide surveys. These included more than 4000 participants and were conducted in two different phases of the COVID-19 pandemic corresponding to low (August 2020) and high (November 2020) levels of infection rates. We found that, in both countries, people are more worried about risks related to experienced events. This is in line with the cognitive process known as the availability heuristic: individuals assess the risk associated with a given hazard based on how easily it comes to their mind. Epidemics, for example, are perceived as less likely and more impactful in Italy compared to Sweden. This outcome can be explained by cross-country differences in the impact of, as well as governmental responses to, COVID-19. Notwithstanding the ongoing pandemic, people in both Italy and Sweden are highly concerned about climate change, and they rank it as the most likely threat.
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| 4. |
- Mondino, Elena, et al.
(författare)
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Public perceptions of multiple risks during the COVID-19 pandemic in Italy and Sweden
- 2020
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Knowing how people perceive multiple risks is essential to the management and promotion of public health and safety. Here we present a dataset based on a survey (N = 4,154) of public risk perception in Italy and Sweden during the COVID-19 pandemic. Both countries were heavily affected by the first wave of infections in Spring 2020, but their governmental responses were very different. As such, the dataset offers unique opportunities to investigate the role of governmental responses in shaping public risk perception. In addition to epidemics, the survey considered indirect effects of COVID-19 (domestic violence, economic crises), as well as global (climate change) and local (wildfires, floods, droughts, earthquakes, terror attacks) threats. The survey examines perceived likelihoods and impacts, individual and authorities' preparedness and knowledge, and socio-demographic indicators. Hence, the resulting dataset has the potential to enable a plethora of analyses on social, cultural and institutional factors influencing the way in which people perceive risk.
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| 5. |
- Ridolfi, Elena, et al.
(författare)
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Hydrological risk : modeling flood memory and human proximity to rivers
- 2021
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 2224-7955 .- 0029-1277. ; 52:1, s. 241-252
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Tidskriftsartikel (refereegranskat)abstract
- Recent literature in sociohydrology has shown the important role of flood memory in shaping hydrological risk. In this paper, we present a system dynamics model of human–flood interactions that simulates how the river proximity of human settlements is altered by changes in flood memory. We also compare our model outcomes with an unprecedented dataset consisting of historical and archeological observations of human settlements in Czech Republic that have been affected by major flood events. This comparison allows us to evaluate the potentials and limitations of our sociohydrological model in capturing essential features of flood risk changes, including the process of resettling farther and closer to the river. Our results show that the accumulation (and decay) of collective memory has potential in explaining temporal changes of flood risk driven by the occurrence (or absence) of major events. As such, this study contributes to advancing knowledge about the complex dynamics of human–water systems, while providing useful insights in the field of flood risk reduction.
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| 6. |
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| 7. |
- Alonso Vicario, S., et al.
(författare)
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Unravelling the influence of human behaviour on reducing casualties during flood evacuation
- 2020
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 65:14, s. 2359-2375
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Tidskriftsartikel (refereegranskat)abstract
- Floods are the natural hazards that are causing the most deaths worldwide. Flood early warning systems are one of the most cost-efficient methods to reduce death rates, triggering decisions about the evacuation of exposed population. Although previous studies have investigated the effect of human behaviours on evacuation processes, studies analysing a combination of behaviours, flood onset and warning timing are limited. Our objective is to explore how changes on the aforementioned factors can affect casualties. This is done within a modelling framework that includes an agent-based model, a hydraulic model, and a traffic model, which is implemented for the case study of Orvieto (Italy). The results show that the number of casualties is most impacted by people's behaviour. Besides, we found that a delay of 30 min in releasing the warning can boost the number of casualties up to six times. These results may help managers to propose effective emergency plans.
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| 8. |
- Bertini, Claudia, et al.
(författare)
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An entropy-based approach for the optimization of rain gauge network using satellite and ground-based data
- 2021
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 2224-7955 .- 0029-1277. ; 52:3, s. 620-635
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Tidskriftsartikel (refereegranskat)abstract
- Accurate and precise rainfall records are crucial for hydrological applications and water resources management. The accuracy and continuity of ground-based time series rely on the density and distribution of rain gauges over territories. In the context of a decline of rain gauge distribution, how to optimize and design optimal networks is still an unsolved issue. In this work, we present a method to optimize a ground-based rainfall network using satellite-based observations, maximizing the information content of the network. We combine Climate Prediction Center MORPhing technique (CMORPH) observations at ungauged locations with an existing rain gauge network in the Rio das Velhas catchment, in Brazil. We use a greedy ranking algorithm to rank the potential locations to place new sensors, based on their contribution to the joint entropy of the network. Results show that the most informative locations in the catchment correspond to those areas with the highest rainfall variability and that satellite observations can be successfully employed to optimize rainfall monitoring networks.
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| 9. |
- Bertini, Claudia, et al.
(författare)
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On the Use of Satellite Rainfall Data to Design a Dam in an Ungauged Site
- 2020
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- The estimation of the design peak discharge is crucial for the hydrological design of hydraulic structures. A commonly used approach is to estimate the design storm through the intensity-duration-area-frequency (IDAF) curves and then use it to generate the design discharge through a hydrological model. In ungauged areas, IDAF curves and design discharges are derived throughout regionalization studies, if any exist for the area of interest, or from using the hydrological information of the closest and most similar gauged place. However, many regions around the globe remain ungauged or are very poorly gauged. In this regard, a unique opportunity is provided by satellite precipitation products developed and improved in the last decades. In this paper, we show weaknesses and potentials of satellite data and, for the first time, we evaluate their applicability for design purposes. We employ CMORPH-Climate Prediction Center MORPHing technique satellite precipitation estimates to build IDAF curves and derive the design peak discharges for the Pietrarossa dam catchment in southern Italy. Results are compared with the corresponding one provided by a regionalization study, i.e., VAPI-VAlutazione delle Piene in Italia project, usually used in Italy in ungauged areas. Results show that CMORPH performed well for the estimation of low duration and small return periods storm events, while for high return period storms, further research is still needed.
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| 10. |
- Bertini, Claudia, et al.
(författare)
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Optima Rain Gauge Network Design Based On Multi-Objective Optimization Approach
- 2020
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Ingår i: International conference on numerical analysis and applied mathematics ICNAAM 2019. - : AIP Publishing. - 9780735440258
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Konferensbidrag (refereegranskat)abstract
- Precipitation is a main input to many hydrological applications, such as water management, flood forecasting and hydrological modelling. The goodness of the rainfall field estimation can thus affect their performances. Despite radar-based and satellite-based measurements have nowadays become very common and accurate, rain gauges monitoring stations are still needed. The gauge density and its spatial distribution are two of the key factors influencing the accuracy in precipitation estimation. Even if in the last decades many studies proposed several methodologies for the design of optimal monitoring networks, only few studies use hydrological model performance as a design criterion. The purpose of this study is to define the optimal rain gauge network for the Mignone River catchment (Italy). The optimal network is defined through a multi-objective optimization approach, where the interpolation error of precipitation is minimised and the performance of a hydrological model based on the Width Function Instantaneous Unit Hydrograph theory is maximised. The optimization is run both without and with constraints, which are based on rainfall patterns. A score to choose the best set of points in the Pareto front is presented. The results suggest that there are preferential areas where sensors locations achieve optimal interpolation error and model performance.
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| 11. |
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| 12. |
- Garcia, Margaret, et al.
(författare)
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The interplay between reservoir storage and operating rules under evolving conditions
- 2020
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Ingår i: Journal of Hydrology. - : ELSEVIER. - 0022-1694 .- 1879-2707. ; 590
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Tidskriftsartikel (refereegranskat)abstract
- Reservoir storage helps manage hydrological variability, increasing predictability and productivity of water supply. However, there are inevitable tradeoffs, with control of high frequency variability coming at the expense of robustness to low frequency variability. Tightly controlling variability can reduce incentives to maintain adaptive capacity needed during events that exceed design thresholds. With multiple dimensions of change projected for many water supply systems globally, increased knowledge on the role of design and operational choices in balancing short-term control and long-term adaptability is needed. Here we investigated how the scale of reservoir storage (relative to demands and streamflow variability) and reservoir operating rules interact to mitigate shortage risk under changing supplies and/or demands. To address these questions, we examined three water supply systems that have faced changing conditions: the Colorado River in the Western United States, the Melbourne Water Supply System in Southeastern Australia, and the Western Cape Water Supply System in South Africa. Moreover, we parameterize a sociohydrological model of reservoir dynamics using time series from the three case studies above. We then used the model to explore the impacts of storage and operational rules. We found that larger storage volumes lead to a greater time before the shortage is observed, but that this time is not consistently used for adaptation. Additionally, our modeling results show that operating rules that trigger withdrawal decreases sooner tend to increase the probability of an adaptive response; the findings from this model are bolstered by the three case studies. While there are many factors influencing the response to water stress, our results demonstrate the importance of: i) evaluating design and operational choices in concert, and ii) examining the role of information salience in adapting water supply systems to changing conditions.
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| 13. |
- George, Oriangi, et al.
(författare)
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An assessment of climate extremes in Mbale Municipality in Eastern Uganda
- 2023
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Ingår i: Hydro-Meteorological Hazards, Risks, and Disasters. - 9780128191019 ; , s. 301-321
-
Bokkapitel (refereegranskat)abstract
- This study investigated historic and future characteristics of precipitation periods in Mbale Municipality. Observed historic (1982–2014) and modeled future (2021–50) precipitation data were analyzed using Standardized Precipitation Index (SPI). Modeled data depict a likelihood of more frequent extremely wet and dry periods in near future as compared to historic period. In particular, there is a likelihood of more frequent extremely wet periods in 2020s and 2030s and more frequent extremely dry periods during 2030s and 2040s as opposed to findings from regional z-indices. Both historic and future precipitation extremes are pronounced between August and January. These findings imply that livelihoods in Mbale are likely to be threatened by precipitation extremes. Thus, researchers, practitioners, and policy makers need to assess influential factors that can enhance resilience. In conclusion, localized rather than regional indices are more able to distill local conditions, at the same time provide more accurate predictions of future extremes.
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| 14. |
- Kreibich, Heidi, et al.
(författare)
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Panta Rhei benchmark dataset : Socio-hydrological data of paired events of floods and droughts
- 2023
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Ingår i: Earth System Science Data. - : Copernicus Publications. - 1866-3508 .- 1866-3516. ; 15:5, s. 2009-2023
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Tidskriftsartikel (refereegranskat)abstract
- As the adverse impacts of hydrological extremes increase in many regions of the world, a better understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is currently a lack of comprehensive, empirical data about the processes, interactions, and feedbacks in complex human-water systems leading to flood and drought impacts. Here we present a benchmark dataset containing socio-hydrological data of paired events, i.e. two floods or two droughts that occurred in the same area. The 45 paired events occurred in 42 different study areas and cover a wide range of socio-economic and hydro-climatic conditions. The dataset is unique in covering both floods and droughts, in the number of cases assessed and in the quantity of socio-hydrological data. The benchmark dataset comprises (1) detailed review-style reports about the events and key processes between the two events of a pair; (2) the key data table containing variables that assess the indicators which characterize management shortcomings, hazard, exposure, vulnerability, and impacts of all events; and (3) a table of the indicators of change that indicate the differences between the first and second event of a pair. The advantages of the dataset are that it enables comparative analyses across all the paired events based on the indicators of change and allows for detailed context- and location-specific assessments based on the extensive data and reports of the individual study areas. The dataset can be used by the scientific community for exploratory data analyses, e.g. focused on causal links between risk management; changes in hazard, exposure and vulnerability; and flood or drought impacts. The data can also be used for the development, calibration, and validation of socio-hydrological models. The dataset is available to the public through the GFZ Data Services (Kreibich et al., 2023, 10.5880/GFZ.4.4.2023.001).
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| 15. |
- Kreibich, Heidi, et al.
(författare)
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The challenge of unprecedented floods and droughts in risk management
- 2022
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 608:7921, s. 80-86
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Tidskriftsartikel (refereegranskat)abstract
- Risk management has reduced vulnerability to floods and droughts globally, yet their impacts are still increasing. An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data4,5. On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change.
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| 16. |
- Liljedahl, Sophie, et al.
(författare)
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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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Ingår i: ; , s. 15-15
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Konferensbidrag (refereegranskat)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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| 17. |
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| 18. |
- Mineo, Claudio, et al.
(författare)
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Assessment of Rainfall Kinetic-Energy-Intensity Relationships
- 2019
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Ingår i: Water. - : MDPI. - 2073-4441. ; 11:10
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Tidskriftsartikel (refereegranskat)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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| 19. |
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| 20. |
- Mineo, C., et al.
(författare)
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Mapping Monthly Rainfall Erosivity for the Lazio Region (Italy)
- 2020
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Ingår i: International conference on numerical analysis and applied mathematics ICNAAM 2019. - : AIP Publishing. - 9780735440258
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Konferensbidrag (refereegranskat)abstract
- Erosion is an exogenous phenomenon, antagonistic to the constructive forces both of an endogenous nature (i.e. orogeny) and of a biological nature (i.e. coral reef), leading to the dismantling of the earth's surface and filling, with the clastic material produced, sedimentary basins and depressions in order to level differences in altitude [1]. It is estimated that, in Europe, 25 million hectares of soil are subject to "accelerated erosion processes" [2] and that, in several areas, the magnitude of soil loss is around a few tens of tons per year. Approximately 77% of Italy is at risk of accelerated erosion [3], also due to the lack of conservative measures for soil (hydraulic-agrarian measures, drainage, grassing, etc.). The phenomenon takes on particular importance in cultivated areas, where drastic changes have been imposed in soil use and sometimes, instead of natural and stable land cover, bare soil is subject to erosive agents. In this paper, the erosivity density approach introduced in Revised Universal Soil Loss Equation 2 (RUSLE2 [4]), will be used to develop monthly erosivity maps for the Lazio region (in central Italy). This was achieved through a full investigation carried out on the monthly (P-md), daily (P-24h) and sub-daily (15-minute time-scale, P-15) precipitation amounts available from rain gauges deployed across the study area.
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| 21. |
- Mineo, C., et al.
(författare)
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On the reliability of gamma distributed dsds for modelling kinetic energy of rainfall(dagger)
- 2020
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Ingår i: Irrigation and Drainage. - : WILEY. - 1531-0353 .- 1531-0361. ; 69:5, s. 1176-1191
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Tidskriftsartikel (refereegranskat)abstract
- To retrieve the gamma drop size distribution (DSD) parameters from observed drop spectra, the most common approach is the method of moments (MM). However, the goodness of this method is still disputed. To assess its reliability, the aims of this paper are: (i) estimation of empirical values of rainfall rate (I) and kinetic energy (KE) from DSD measurements collected by a laser-optical disdrometer; (ii) estimation of gamma DSD parameters by MM and another widespread method, i.e. maximum likelihood (ML); (iii) evaluation of theoretical values of rainfall rate and KE and comparison between these values and measured ones. The novelty of this work is the assessment of both MM and ML using the rainfall intensity measured by the disdrometer as a benchmark, rather than the KE or a statistical test as done in common practice. The assessment of the goodness of the estimates was performed on variables most investigated in soil erosion studies (i.e.Iand KE). Results show that smaller error values are associated with ML and that MM does not provide reliable estimations ofI.On the other hand, both methods substantially underestimate KE with increasing rainfall intensity. (c) 2020 John Wiley & Sons, Ltd.
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| 22. |
- Mineo, Claudio, et al.
(författare)
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The areal reduction factor : A new analytical expression for the Lazio Region in central Italy
- 2018
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Ingår i: Journal of Hydrology. - Amsterdam : Elsevier. - 0022-1694 .- 1879-2707. ; 560, s. 471-479
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Tidskriftsartikel (refereegranskat)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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| 23. |
- Moccia, Benedetta, et al.
(författare)
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Probability distributions of daily rainfall extremes in Lazio and Sicily, Italy, and design rainfall inferences
- 2021
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Ingår i: Journal of Hydrology. - : Elsevier. - 2214-5818. ; 33
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Tidskriftsartikel (refereegranskat)abstract
- Study region: We investigate samples from two Italian regions, i.e. Lazio and Sicily, located in central and south Italy, respectively, and characterized by two diverse climates. Study focus: In engineering practice, the study of maxima daily rainfall values is commonly dealt with light-tailed probability distribution functions, such as the Gumbel. The choice of a distribution rather than another may cause estimation errors of rainfall values associated to specific return periods. Recently, several studies demonstrate that heavy-tailed distributions are preferable for extreme events modelling. Here, we opt for six theoretical probability distribution functions and evaluate their performance in fitting extreme precipitation samples. We select the samples with two common methods, i.e. the Peak-Over-Threshold and the Annual Maxima. We assess the best fitting distribution to the empirical samples of extreme values through the Ratio Mean Square Error Method and the Kolmogorov-Smirnov test. New hydrological insights for the region: The assessment of the best fitting distribution to daily rainfall of the two different areas investigated here leads to interesting remarks. Despite the diversity of their climate, results suggest that heavy-tailed distributions describe more accurately empirical data rather than light-tailed ones. Therefore, extreme events may have been largely underestimated in the past in both areas. The proposed investigation can prompt the choice of the best fitting probability distribution to evaluate the design hydrological quantities supporting common engineering practice.
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| 24. |
- Montesarchio, Valeria, et al.
(författare)
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A comparison of two rainfall disaggregation models
- 2012
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Ingår i: AIP Conference Proceedings. - : American Institute of Physics (AIP). - 0094-243X.
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Konferensbidrag (refereegranskat)abstract
- Whitin the context of flood management, and generally for performing environmental, climate, hydrological, and water resources analysis, it is useful and reliable to provide scenarios by rainfall simulation, in order to overcome data limitations in terms of time and spatial resolution. Generally, it is required that the stochastic model preservesimportant properties of the rainfall process, such as intermittency, seasonality and scaling behavior in space and time, so that there will be no substantial differences between historical rainfall data and synthetic records. In this work, two rainfall disaggregation models are evaluated in terms of their ability to reproduce rainfall hourly statistics in four sites in Central Italy. The considered models are an entropy based disaggregation model and Hyetos-R (Bartlett-Lewis rectangular pulses rainfall)
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| 25. |
- Montesarchio, Valeria, et al.
(författare)
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Comparison of methodologies for flood rainfall thresholds estimation
- 2015
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Ingår i: Natural Hazards. - : Springer Netherlands. - 0921-030X .- 1573-0840. ; 75:1, s. 909-934
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Tidskriftsartikel (refereegranskat)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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