1,721,024 research outputs found
A methodology for assessing spatio-temporal dynamics of flood regulating services
Full text linkThe effects of land use alteration, migration and urbanization are key aspects in flood management, as human activities can strongly influence the capacity of ecosystems to provide flood regulating ecosystem services and determine their demand. This study analyzes spatio-temporal dynamics of flood regulating ecosystem services to support watershed management planning. A methodology for mapping the supply and demand of flood regulation is proposed and applied to the Arno River basin, in central Italy. The spatial explicit analysis of flood regulating ecosystem services supply is carried out with SWAT - Soil and Water Assessment Tool, whose outputs are synthetized by two indicators to evaluate the retention capacity of each land use class originating from CORINE data sets. Quantification of demand for flood regulating ecosystem services is based on flood hazard classes derived from the existing local flood management plans (i.e., PAI-Piano per l'Assetto Idrogeologico and PGRA-Piano di Gestione del Rischio Alluvioni). Supply and demand data are then combined to obtain budget maps of flood regulating ecosystem services and their evolution, between 1990 and 2018. The results show how both demand and supply of ecosystem services have changed in the last decades, highlighting the main hotspots at the catchment and subcatchment scales. With the increasing urbanization, the demand values have grown in the Arno floodplains, where residential, industrial and commercial zones are located. At the same time, land use changes have altered the water regulation supply, resulting in a generalized decrease of the basin capacity to provide flood regulation services. The maps and tables obtained show the fundamental role of forest and other vegetated areas whose protection is a priority to assure future flood regulation and associated co-benefits (e.g., regulation of air quality, reduction of erosion, improvement of water quality, wood fuel). The assessment of flood regulating here proposed is a powerful tool for decision makers to improve flood regulation and provides a sound base of knowledge to identify and locate flood prevention and mitigation measur
Innovative Probabilistic Methodology for Evaluating the Reliability of Discrete Levee Reaches Owing to Piping
No full textTraditionally, levees are a popular measure widely adopted for flood control, accepted and trusted by populations living in floodplain areas. The presence of levees sometimes might even induce a false sense of safety in the population, influencing their decision to develop further in floodplains, because they feel safer. Thus, failures of levee systems are potentially devastating, as they might induce loss of human lives, damages to properties, and economic loss. This study proposes an innovative methodology to estimate the reliability of levee systems, accounting for different sources of uncertainty, and to divide and classify discrete levee reaches, according to different fragility classes. The reliability analysis is performed by evaluating the probability of failure, as a function of a certain failure mechanism, conditioned by a given hydraulic load. Fragility curves are determined using two different methods: Monte Carlo data generation and the so-called approximate, first-order reliability method. Thus, once having assessed fragility curves for each discrete levee reach, different fragility indexes are introduced to assess the reliability of the levee system. As a test case, this methodology is applied to determine the probability of failure due to piping along a branch of the Po River (Italy), where the probability of failure in case of a synthetic 100-year return period flood event is additionally estimated. The computed fragility curves are in agreement with historical observations of levee breaches along the River
Debates - Perspectives on socio-hydrology: Capturing feedbacks between physical and social processes
Full text linkIn flood risk assessment, there remains a lack of analytical frameworks capturing the dynamics emerging from two-way feedbacks between physical and social processes, such as adaptation and levee effect. The former, "adaptation effect", relates to the observation that the occurrence of more frequent flooding is often associated with decreasing vulnerability. The latter, "levee effect", relates to the observation that the non-occurrence of frequent flooding (possibly caused by flood protection structures, e.g. levees) is often associated to increasing vulnerability. As current analytical frameworks do not capture these dynamics, projections of future flood risk are not realistic. In this paper, we develop a new approach whereby the mutual interactions and continuous feedbacks between floods and societies are explicitly accounted for. Moreover, we show an application of this approach by using a socio-hydrological model to simulate the behavior of two main prototypes of societies: green societies, which cope with flooding by resettling out of flood-prone areas; and technological societies, which deal with flooding also by building levees or dikes. This application shows that the proposed approach is able to capture and explain the aforementioned dynamics (i.e. adaptation and levee effect) and therefore contribute to a better understanding of changes in flood risk, within an iterative process of theory development and empirical research.</p
Flood-risk mitigation in the Soliette river basin: an international cooperation initiative (Haiti, Dominican Rep., Italy)
Full text linkIsla Hispaniola (Haiti and the Dominican Republic), one of the poorest regions of the planet, has
repeatedly been hit by catastrophic natural disasters that caused incalculable economic losses and killed
thousands of people. One striking example is the disastrous flood-event that occurred in the transnational
basin of River Soliette on May 24th, 2004. The event was produced by a severe tropical storm originated
over the Caribbean Sea from an intense low-pressure system, and killed over 1000 Haitian and
Dominican people, wiping out a number of rural villages. The General Direction for Development and
Cooperation of the Italian Department of Foreign Affairs funded through the Istituto Italo-Latino
Americano (IILA, www.iila.org) an international cooperation initiative (ICI), coordinated and directed by
the University of Bologna. The initiative involved Haitian and Dominican institutions and consisted in
two main components: (a) institutional capacity building on flood-risk management and mitigation
measures and policies; (b) hydrological and hydraulic analysis of the May 2004 flood event aimed at
formulating a suitable and affordable flood-risk mitigation plan. The second component of the
cooperation is the main focus of this paper and in particular, starting from some logistical and technical
constrains, a topographic survey based on GNSS technology that enabled us, in a short time, to survey
river cross sections and construct Digital Elevation Models for two areas where to conduct numerical
hydraulic modelling and to pre-design hypothetic flood-risk mitigation measures. The paper reports and
discusses the main phases of the project
The seventh facet of uncertainty: wrong assumptions, unknowns and surprises in the dynamics of human–water systems
No full text
Impacts of Climate Change and Adaptation Strategies for Rainfed Barley Production in the Almería Province, Spain
Full text linkMediterranean water-stressed areas face significant challenges from higher temperatures and increasingly severe droughts. We assess the effect of climate change on rainfed barley production in the aridity-prone province of Almería, Spain, using the FAO AquaCrop model. We focus on rainfed barley growth by the mid-century (2041–2070) and end-century (2071–2100) time periods, using three Shared Socio-economic Pathway (SSP)-based scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Using the paired t-test, Spearman and Pearson correlation coefficient, Root Mean Squared Error, and relative Root Mean Squared Error, we verified AquaCrop’s ability to capture local multi-year trends (9 or more years) using standard barley crop parameters, without local recalibration. Starting with a reference Initial Soil Water Content (ISWC), different soil water contents within barley rooting depth were modelled to account for decreases in soil water availability. We then evaluated the efficiency of different climate adaptation strategies: irrigation, mulching, and changing sowing dates. We show average yield changes of +14% to −44.8% (mid-century) and +12% to −55.1% (end-century), with ISWC being the main factor determining yields. Irrigation increases yields by 21.1%, utilizing just 3% of Almería’s superficial water resources. Mulches improve irrigated yield performances by 6.9% while reducing irrigation needs by 40%. Changing sowing dates does not consistently improve yields. We demonstrate that regardless of the scenario used, climate adaptation of field barley production in Almería should prioritize limiting soil water loss by combining irrigation with mulching. This would enable farmers in Almería’s northern communities to maintain their livelihoods, reducing the province’s reliance on horticulture while continuing to contribute to food security goals. QC 20240529</p
Insights from socio-hydrology modelling on dealing with flood risk - Roles of collective memory, risk-taking attitude and trust
No full textThe risk coping culture of a community plays a major role in the development of urban floodplains. In this paper we analyse, in a conceptual way, the interplay of community risk coping culture, flooding damage and economic growth. We particularly focus on three aspects: (i) collective memory, i.e., the capacity of the community to keep risk awareness high; (ii) risk-taking attitude, i.e., the amount of risk the community is collectively willing to be exposed to; and (iii) trust of the community in risk reduction measures. To this end, we use a dynamic model that represents the feedback between the hydrological and social system components. Model results indicate that, on the one hand, by under perceiving the risk of flooding (because of short collective memory and too much trust in flood protection structures) in combination with a high risk-taking attitude, community development is severely limited because of high damages caused by flooding. On the other hand, overestimation of risk (long memory and lack of trust in flood protection structures) leads to lost economic opportunities and recession. There are many scenarios of favourable development resulting from a trade-off between collective memory and trust in risk reduction measures combined with a low to moderate risk-taking attitude. Interestingly, the model gives rise to situations in which the development of the community in the floodplain is path dependent, i.e., the history of flooding may lead to community growth or recession
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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