92 research outputs found
Regional prediction of basin-scale brown trout habitat suitability
Abstract. In this study we propose a novel method for the estimation of ecological indices describing the habitat suitability of brown trout (Salmo trutta). Traditional hydrological tools are coupled with an innovative regional geostatistical technique, aiming at the prediction of the brown trout habitat suitability index where partial or totally ungauged conditions occur. Several methods for the assessment of ecological indices are already proposed in the scientific literature, but the possibility of exploiting a geostatistical prediction model, such as Topological Kriging, has never been investigated before. In order to develop a regional habitat suitability model we use the habitat suitability curve, obtained from measured data of brown trout adult individuals collected in several river basins across the USA. The Top-kriging prediction model is then employed to assess the spatial correlation between upstream and downstream habitat suitability indices. The study area is the Metauro River basin, located in the central part of Italy (Marche region), for which both water depth and streamflow data were collected. The present analysis focuses on discharge values corresponding to the 0.1-, 0.5-, 0.9-empirical quantiles derived from flow-duration curves available for seven gauging stations located within the study area, for which three different suitability indices (i.e. ψ10, ψ50 and ψ90) are evaluated. The results of this preliminary analysis are encouraging showing Nash-Sutcliffe efficiencies equal to 0.52, 0.65, and 0.69, respectively
Panta Rhei: an evolving scientific decade with a focus on water systems
Abstract. The paper presents an overview of the activity of Panta Rhei, the research decade launched in 2013 by the International Association of Hydrological Sciences. After one year of activity Panta Rhei has already stimulated several initiatives and a worldwide involvement of researchers in hydrology and sister disciplines. Providing an overview of the status of Panta Rhei is essential to further promote the participation of scientists and the completion of its structure, which is currently being shaped by receiving Research Theme and Working Group proposals from the community
Influence of Urban Areas on Surface Water Loss in the Contiguous United States
Urbanization is one of the main drivers of surface water loss, which implies a transition from water to land. However, it is still unclear how urban areas affect the spatial pattern of surface water loss. Here, we use remotely sensed data to analyze and model the decrease of surface water extent and, in particular, the frequency of surface water loss as a function of distance from urban areas across the contiguous United States (CONUS). We employ an exponential distance-decay model that confirms the presence of a higher frequency of surface water loss in the proximity of human settlements and provides innovative insights on surface water loss patterns at different spatial scales (i.e., river basins, water resource regions, and the CONUS). These spatial patterns are found to be influenced by climatic conditions, with more widely distributed losses in arid regions with respect to temperate and continental climates. Our results provide a new and deeper understanding of the spatial influence of urban areas on surface water loss, which could be effectively integrated in the definition of sustainable strategies for urbanization, water management, and surface water restoration, focused on both human and environmental water needs
Why the 2022 Po River drought is the worst in the past two centuries
The causes of recent hydrological droughts and their future evolution under a changing climate are still poorly
understood. Banking on a 216-year river flow time series at the Po River outlet, we show that the 2022 hydrological
drought is the worst event (30% lower than the second worst, with a six-century return period), part of an
increasing trend in severe drought occurrence. The decline in summer river flows (−4.14 cubic meters per
second per year), which is more relevant than the precipitation decline, is attributed to a combination of
changes in the precipitation regime, resulting in a decline of snow fraction (−0.6% per year) and snowmelt
(−0.18 millimeters per day per year), and to increasing evaporation rate (+0.013 cubic kilometers per year)
and irrigated areas (100% increment from 1900). Our study presents a compelling case where the hydrological
impact of climate change is exacerbated by local changes in hydrologic seasonality and water use
Distance between a native cofactor and a spin label in the reaction centre of Rhodobacter sphaeroides by a two-frequency pulsed electron paramagnetic resonance method and molecular dynamics simulation
Biological and Soft Matter Physic
Human signatures derived from nighttime lights along the Eastern Alpine river network in Austria and Italy
Understanding how human settlements and economic activities are distributed
with reference to the geographical location of streams and rivers is of
fundamental relevance for several issues, such as flood risk management,
drought management related to increased water demands by human population,
fluvial ecosystem services, water pollution and water exploitation. Besides
the spatial distribution, the evolution in time of the human presence
constitutes an additional key question. This work aims at understanding and
analysing the spatial and temporal evolution of human settlements and
associated economic activity, derived from nighttime lights, in the Eastern
Alpine region. Nightlights, available at a fine spatial resolution and for a
22-year period, constitute an excellent data base, which allows one to
explore in details human signatures. In this experiment, nightlights are
associated to five distinct distance-from-river classes. Our results clearly
point out an overall enhancement of human presence across the considered
distance classes during the last 22 years, though presenting some differences
among the study regions. In particular, the river network delineation, by
considering different groups of river pixels based on the Strahler order, is
found to play a central role in the identification of nightlight
spatio-temporal trends
TEMPORAL TRENDS IN THE DETECTION RATES OF HEPATITIS B IN THE SANTA CATARINA STATE, BRAZIL
Hepatitis B is a serious public health problem. The state of Santa Catarina presents areas of high endemicity. The aim of this study was to describe temporal trends in detection rates of hepatitis B in the period from 2002 to 2009 in Santa Catarina and in its regions. A time series study was carried out. Crude rates were calculated and standardized by age using the direct method. Annual variation percentages were estimated by Joinpoint regression. There were two distinct and significant trends in Santa Catarina. From 2002 to 2006 a significant increase of 5.9% per year was observed. From 2006, there was a significant decrease of 6.4% per year. In this same period the southern and far-western regions had significant increases of 15.9% and 4.6% and significant decreases of 7.5% and 4.8%, respectively. Greater Florianópolis and Northeast also showed significant increases until 2006, of 15.4% and 17.4%, respectively. In the following period, non-significant decreases of 5.8% and 9.8% respectively were observed. Foz do Rio Itajaí and Planalto Serrano showed non-significant increases up to half of the studied period of 21.1% and 12.0%, respectively and after, significant decreases of 21.5% and 18.0%, respectively. Vale do Itajaí showed a significant decrease of 9.7%; Planalto Norte showed a non-significant decrease of 0.6% and Midwest a non-significant increase of 2.7% per year, in the period from 2002 to 2009
Hydrologic Variability Affects Invertebrate Grazing on Phototrophic Biofilms in Stream Microcosms
The temporal variability of streamflow is known to be a key feature structuring and controlling fluvial ecological communities and ecosystem processes. Although alterations of streamflow regime due to habitat fragmentation or other anthropogenic factors are ubiquitous, a quantitative understanding of their implications on ecosystem structure and function is far from complete. Here, by experimenting with two contrasting flow regimes in stream microcosms, we provide a novel mechanistic explanation for how fluctuating flow regimes may affect grazing of phototrophic biofilms (i.e., periphyton) by an invertebrate species (Ecdyonurus sp.). In both flow regimes light availability was manipulated as a control on autotroph biofilm productivity and grazer activity, thereby allowing the test of flow regime effects across various ratios of biofilm biomass to grazing activity. Average grazing rates were significantly enhanced under variable flow conditions and this effect was highest at intermediate light availability. Our results suggest that stochastic flow regimes, characterised by suitable fluctuations and temporal persistence, may offer increased windows of opportunity for grazing under favourable shear stress conditions. This bears important implications for the development of comprehensive schemes for water resources management and for the understanding of trophic carbon transfer in stream food webs
Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019
Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin
Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017
Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning
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