1.
Blösch, Günter, et al.
(författare)
Twenty-three unsolved problems in hydrology (UPH) - a community perspective
2019
Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 64:10, s. 1141-1158
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.
2.
3.
Bertini, Claudia, et al.
(författare)
An entropy-based approach for the optimization of rain gauge network using satellite and ground-based data
2021
Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 2224-7955 .- 0029-1277. ; 52:3, s. 620-635
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.
4.
Bertini, Claudia, et al.
(författare)
On the Use of Satellite Rainfall Data to Design a Dam in an Ungauged Site
2020
Ingår i: Water. - : MDPI AG. - 2073-4441. ; 12:11
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.
5.
Bertini, Claudia, et al.
(författare)
Optima Rain Gauge Network Design Based On Multi-Objective Optimization Approach
2020
Ingår i: International conference on numerical analysis and applied mathematics ICNAAM 2019. - : AIP Publishing. - 9780735440258
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.
6.
Biella, Riccardo, et al.
(författare)
The 2022 Drought Needs to be a Turning Point for European Drought Risk Management
2024
Ingår i: Natural hazards and earth system sciences. - 1561-8633 .- 1684-9981.
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt) abstract
The 2022 European drought has underscored critical deficiencies in European water management. This paper explores these shortcomings and suggests a way forward for European drought risk management. Data for this study was gathered through a continent-wide survey of water managers involved in this event. The survey collected 481 responses from 30 European countries and is comprised of 19 questions concerning sectorial impact in the regions of the responders and drought risk management practices of their organizations. Information from the survey is enriched with climate-related information to offer a comprehensive overview of drought risk management in Europe. Our research focuses on four key aspects: the increasing risk of drought, its spatial and temporal impacts, current drought risk management approaches, and the evolution of drought risk management across the continent. Our findings reveal a consensus on the growing risk of drought, which is confounded by the rising frequency and intensity of droughts. While the 2022 event affected most of the continent, our findings show significant regional disparities in drought risk management capacity among the various countries. Our analysis indicates that current drought risk management measures often rely on short-term operational concerns, particularly in agriculture-dominated economies, leading to potentially maladaptive practices. An overall positive trend in drought risk management, with organizations showing increased awareness and preparedness, indicates how this crisis can be the ideal moment to mainstream European-wide drought risk management. Consequently, we advocate for a European Drought Directive, to harmonize and enforce drought risk management policies across the continent. This directive should promote a systemic, integrated, and long-term risk management perspective. The directive should also set clear guidelines for drought risk management at the national level and for cross-boundary drought collaboration.
7.
Biella, Riccardo, et al.
(författare)
The 2022 Drought Shows the Importance of Preparedness in European Drought Risk Management
2024
Ingår i: Natural hazards and earth system sciences. - 1561-8633 .- 1684-9981.
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt) abstract
Droughts in Europe are becoming increasingly frequent and severe, with the 2022 drought surpassing previous records and causing widespread socio-economic impacts. This study employs a Europe-wide survey that integrates data from 481 respondents from 30 European countries, involved in the management of the 2022 European drought, together with hydroclimatic data (i.e., Standardized Precipitation Evapotranspiration Index; SPEI), to provide a holistic assessment of the effect of drought preparedness on response effectiveness and timeliness during the 2022 drought through statistical methods. It specifically assesses the role of forecasting systems and Drought Management Plans (DMPs) in improving preparedness and in facilitating more effective and timely responses. Additionally, the study investigates how drought management practices and awareness have evolved as a consequence of the 2018 European drought and how recent experiences shape water managers’ perceptions. The findings emphasize the urgent need for a standardized, continent-wide drought risk management coordination to address the multifaceted nature of drought risk by integrating climatic and societal factors, and advocates for a Drought Directive as a means to achieve it. This research aims to inform policy development towards sustainable and holistic drought risk management, highlighting the crucial roles of preparedness, awareness, and adaptive strategies in mitigating future drought impacts.
8.
9.
Di Baldassarre, Giuliano, et al.
(författare)
Integrating Multiple Research Methods to Unravel the Complexity of Human-Water Systems
2021
Ingår i: AGU Advances. - : American Geophysical Union (AGU). - 2576-604X. ; 2:3
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.
10.
Garcia, Margaret, et al.
(författare)
The interplay between reservoir storage and operating rules under evolving conditions
2020
Ingår i: Journal of Hydrology. - : ELSEVIER. - 0022-1694 .- 1879-2707. ; 590
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.
