scholarly journals WFD ecological status indicator shows poor correlation with flow parameters in a large Alpine catchment

2018 ◽  
Author(s):  
Stefano Larsen ◽  
Maria Cristina Bruno ◽  
Guido Zolezzi
Keyword(s):  
National Level ◽  
Ecological Status ◽  
Regulated River ◽  
Limiting Factors ◽  
Poor Correlation ◽  
Running Waters ◽  
Flow Parameters ◽  
Physico Chemical ◽  
The Relationship ◽  
Ecological Flows

SummarySince the implementation of the Water Framework Directive, the ecological status of European running waters has been evaluated using a set of harmonised ecological indicators that should guide conservation and restoration actions. Among these, the restoration of the natural flow regime (ecological flows) is considered indispensable for the achievement of the good ecological status, and yet the sensitivity of the current biological indicators to hydrologic parameters remains understudied. The Italian Star_ICMi well represents other similar WFD indicators; it is a macroinvertebrate-based multimetric index officially adopted to assess the ecological status of running waters at the national level. Recent legislation has also included the Star_ICMi as one of the indicators used to assess and prescribe ecological flows in river reaches regulated by water abstraction. However, the relationship between river hydrology and the Star_ICMi index is so far virtually unknown. Using data from the Trentino - Alto Adige Alpine region, we first assessed the relationship between the Star_ICMi and synthetic descriptors of the physico-chemical (LIMeco) and morphological (MQI) status of respectively 280 and 184 river reaches. Then, we examined the relation between the Star_ICMi and a set of ecologically-relevant hydrologic parameters derived from discharge time-series measured at 21 hydrometric stations, representing both natural and regulated river reaches. Although the Star_ICMi showed significant and linear relationships with the physico-chemical character and, slightly, with the morphological quality of the reaches, its response to flow parameters appeared weak or non-existent when examined with linear models. Mixed quantile regressions allowed the identification of flow parameters that represented limiting factors for macroinvertebrate communities and the associated Star_ICMi scores. In particular, the index showed ‘negative floors’ where lower values were observed in reaches with large temporal variation in flow magnitude as well as frequent low and high flow events. The modelled quantiles also tracked the transition of the index from acceptable to unacceptable conditions.The results suggest that while the central tendency of the Star_ICMi index is not strongly influenced by river flow character, some key flow parameters represent limiting factors that allow the index to reach its lowest values, eventually ‘pushing’ the site towards unacceptable ecological conditions. The identification of limiting flow parameters can aid the setting of hydrologic thresholds over which ecological impairment is likely to occur. Overall, however, results imply caution is needed in using biological indicator like the Star_ICMi for the quantitative assessment and design of ecological flows.

scholarly journals An environmental database for the status of freshwater in Greece

2013 ◽  
Vol 4 (1) ◽  
pp. 1-14
Keyword(s):  
National Level ◽  
Reference Conditions ◽  
Ecological Status ◽  
Anthropogenic Pressures ◽  
Environmental Pressures ◽  
Physico Chemical ◽  
Other Information ◽  
The Status ◽  
Freshwater Bodies ◽  
Status Data

An environmental database has been created, recording water bodies at a national level and assembling relevant data collected by various public services and institutions in charge of water resources management and research in Greece. Data consists of physico-chemical parameters, geomorphological descriptions, inventories of fauna and flora species, environmental pressures, vulnerability evaluation and other information useful for the assessment of current and future ecological status. Data gathering has proven to be a challenging task, due to the large number and the generally small size of the surface freshwater bodies as well as the numerous competent services and institutions and the multiple and sometimes conflicting responsibilities that therefore result. The latter is also partly the cause of lack of continuity of data, gaps or sometimes questionable reliability. Performing a global data overview, we note that (a) ecological status can be characterized as good for the majority of the sites, especially for small mountain streams, and (b) the general trend in most cases is degradation of current conditions, related either to anthropogenic pressures or to human activity combined with natural factors. This database, in a more completed and enriched form, could assist in the implementation of 2000/60/EC Directive in Greece and the establishment of reference conditions of surface freshwater systems.

scholarly journals WFD Ecological Quality Indicators Are Poorly Correlated with Water Levels in River Catchments in Tuscany (Italy)

Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 185
Author(s):  
Chiara Arrighi ◽  
Isabella Bonamini ◽  
Cristina Simoncini ◽  
Stefano Bartalesi ◽  
Fabio Castelli
Keyword(s):  
Central Italy ◽  
Ecological Status ◽  
Ecological Indicators ◽  
Water Levels ◽  
Poor Correlation ◽  
Anthropogenic Pressures ◽  
Ecological Sampling ◽  
Good Ecological Status ◽  
Environmental Agencies ◽  
Ecological Flows

The Water Framework Directive (WFD) requires European countries to achieve a good ecological status of surface water bodies and demands that River District Authorities define ecological flows consistently. Nevertheless, the relationship between ecological and hydrological indicators is not fully understood and not straightforward to apply because ecological and hydrological indicators are monitored by different institutions, with different timings and purposes. This work examines the correlation between a set of ecological indicators monitored by environmental agencies (STAR-ICMi, LIMeco, IBMR, and TDI) and water levels with assigned durations monitored by the hydrologic service in Tuscany (central Italy). Reference water levels are derived from stage-duration curves obtained by the statistical analysis of daily levels in the same year of ecological sampling. The two datasets are paired through a geospatial association for the same river reach and the correlation is measured through Pearson’s r. The results show poor correlation (r between −0.33 and −0.42) between ecological indicators and hydrologic variables, confirming the findings observed in other Italian catchments with different hydrologic regimes, climate, and anthropogenic pressures. Nevertheless, the negative correlations show a decreasing water quality with water depths, i.e., in the lower part of the catchments more affected by anthropogenic pressures. These findings suggests that the determination of ecological flows with a purely hydrological approach is not sufficient for achieving WFD objectives in the study area.

Identifying Physico-Chemical Laws from the Robotically Collected Data

2019 ◽  
Author(s):  
Liwei Cao ◽  
Danilo Russo ◽  
Vassilios S. Vassiliadis ◽  
Alexei Lapkin
Keyword(s):  
Experimental Data ◽  
Numerical Models ◽  
Predictor Variable ◽  
Physical Models ◽  
Training Data ◽  
Mixed Integer ◽  
Physico Chemical ◽  
Data Points ◽  
Future Work ◽  
The Relationship

<p>A mixed-integer nonlinear programming (MINLP) formulation for symbolic regression was proposed to identify physical models from noisy experimental data. The formulation was tested using numerical models and was found to be more efficient than the previous literature example with respect to the number of predictor variables and training data points. The globally optimal search was extended to identify physical models and to cope with noise in the experimental data predictor variable. The methodology was coupled with the collection of experimental data in an automated fashion, and was proven to be successful in identifying the correct physical models describing the relationship between the shear stress and shear rate for both Newtonian and non-Newtonian fluids, and simple kinetic laws of reactions. Future work will focus on addressing the limitations of the formulation presented in this work, by extending it to be able to address larger complex physical models.</p><p><br></p>

scholarly journals Assessment of the Impact of Small Hydropower Plants on the Ecological Status Indicators of Water Bodies: A Case Study in Lithuania

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 433
Author(s):  
Laima Česonienė ◽  
Midona Dapkienė ◽  
Petras Punys
Keyword(s):  
Water Quality ◽  
Benthic Macroinvertebrates ◽  
Suspended Solids ◽  
Ecological Status ◽  
Fish Abundance ◽  
Water Bodies ◽  
Small Hydropower ◽  
Hydropower Plants ◽  
Physico Chemical ◽  
The Impact

Hydropower plants produce renewable and sustainable energy but affect the river’s physico-chemical characteristics and change the abundance and composition of the aquatic organisms. The impact of large HPPs on the ecological conditions of surface water bodies have been extensively studied, but less attention has been paid to environmental impact studies of small hydropower plants (SHPs). The impact of hydropeaking on both the river flow regime and ecosystems has been well-studied for peaking mode plants, mainly medium to large-sized ones. However, for small hydroelectric power plants, and especially for those in lowland rivers, the available information on water quality, benthic macroinvertebrates communities and fish abundance, and biomass is not sufficient. Ten small hydropower plants were selected, and the ecological status of water bodies was assessed in different parts of Lithuania. The studies were performed at the riverbed upstream from the SHPs, where the hydrological regime has not changed, and downstream from the SHPs. It was found that the small hydropower plants do not affect the physico-chemical values of the water quality indicators. This study demonstrated that the total number of benthic macroinvertebrates taxa (TS) is influenced by the concentration of nitrogen and suspended solids, the water flow, the river area, and the current speed; the number of EPT (Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies)) taxa is influenced by the concentration of nitrogen and suspended solids. The studied indicators do not have a significant impact on biomass. The SHPs affect the fish abundance and biomass. The Lithuanian fish index (LFI) is influenced by the average depth and area of the river. Some SHPs operating in lowland areas may yield somewhat significant hydrograph ramping but more detailed investigation is needed to support the significance of this impact on the biological indices.

scholarly journals Investigating the Links between UK House Prices and Share Prices with Copulas

2021 ◽  
Author(s):  
Rakesh K. Bissoondeeal ◽  
Leonidas Tsiaras
Keyword(s):  
Stock Market ◽  
House Prices ◽  
National Level ◽  
Tail Dependence ◽  
Share Prices ◽  
Property Prices ◽  
Left Tail ◽  
The Uk ◽  
The Relationship ◽  
Shared Characteristic

AbstractWe investigate the nonlinear links between the housing and stock markets in the UK using copulas. Our empirical analysis is conducted at both the national and regional levels. We also examine how closely London house prices are linked to those in other parts of the UK. We find that (i) the dependence between the different markets exhibits significant time-variation, (ii) at the national level, the relationship between house prices and the stock market is characterised by left tail dependence, i.e., they are more likely to crash, rather than boom, together, (iii) although left tail dependence with the stock market is a prominent feature of some regions, it is by no means a universally shared characteristic, (iv) the dependence between property prices in London and other parts of the UK displays widespread regional variations.

The Relationship Between Genotype and Positive Psychological Development in National-Level Swimmers

2006 ◽  
Vol 11 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Jim Golby ◽  
Michael Sheard
Keyword(s):  
National Level ◽  
Psychological Theory ◽  
Self Esteem ◽  
Psychological Development ◽  
Mental Toughness ◽  
Positive Affectivity ◽  
Buccal Swabs ◽  
Preliminary Study ◽  
The Relationship ◽  
Psychological Questionnaires

We report a preliminary study of the relationship between genotype (using a functional polymorphism of the serotonin transporter 5-HTT gene) and positive psychological development in high-achieving adolescent swimmers. Thirty-one volunteers of both genders, aged 10-24 years, completed a battery of positive psychological questionnaires measuring hardiness, mental toughness, self-esteem, self-efficacy, dispositional optimism, and positive affectivity. DNA samples were obtained via buccal swabs. The sample was initially split into three groups on the basis of 5-HTT genotype: SS, SL, and LL. Multivariate statistics revealed a discernible trend of a relationship between LL genotype and higher levels of positive psychological development. The nonsignificant overall effect is interpreted in terms of sample size and age of participants. The implications of these results are discussed relative to previous findings and in terms of psychological theory.

scholarly journals Diurnal vertical migration of some cladocerans in relation to the physico-chemical factors in a fish pond

1970 ◽  
Vol 20 (2) ◽  
pp. 147-154 ◽  
Author(s):  
AS Bhuiyan ◽  
S Akhter ◽  
MMA Quddus
Keyword(s):  
Key Words ◽  
Vertical Migration ◽  
Fish Pond ◽  
Chemical Parameters ◽  
Surface Layers ◽  
Diurnal Vertical Migration ◽  
Physico Chemical ◽  
Chemical Factors ◽  
Diurnal Movement ◽  
The Relationship

Diurnal vertical migration of four genera of cladocerans, namely Diaphanosoma sp., Daphnia sp., Moina sp. and Bosmina sp., during March to December, 2007 showed that the number of Diaphanosoma sp. was 501 units/1 in the surface layers, 172 units/l in the middle layers and 190 units/l in the bottom layers. The yearly number of Daphnia sp. in surface, middle and bottom layerss was 362 units/l, 46 units/l and 189 units/l respectively. In surface, bottom and middle layers, the number of Moina sp. was 159, 71 and 32 units/l, respectively. Bosmina sp. was 78 units/l in surface, 31 units/l in the middle and 33 units/l in the bottom layers. The number of Diaphanosoma sp., Daphnia sp., Moina sp., Bosmina sp., were 455, 149, 259 and 358 units/l, respectively in the morning, 63, 176, 142, 43 units/l at noon and 107, 55, 28, 59 units/l, respectively in the evening. Throughout the study period the cladocerans were always abundant near the surface during morning and evening. Among the factors responsible for the diurnal movement of cadoceran, light played the most important factor. The relationship between the physico-chemical factors and the cladoceran occurrence in the pond was also explored. Key words: Cladocera; Diurnal migration; Physico-chemical parameters; Fish pond DOI: http://dx.doi.org/10.3329/dujbs.v20i2.8975 DUJBS 2011; 20(2): 147-154

To what extent are the fish compositions of a regulated river related to physico-chemical variables and habitat structure?

2013 ◽  
Vol 97 (6) ◽  
pp. 717-730 ◽  
Author(s):  
Taylan M. Mattos ◽  
Marcus R. Costa ◽  
B. C. T. Pinto ◽  
Joyce L. C. Borges ◽  
F. Gerson Araújo
Keyword(s):  
Habitat Structure ◽  
Regulated River ◽  
Physico Chemical

scholarly journals Agroecological Determinants of Potato Spatiotemporal Yield Variation at the Landscape Level in the Central and Northern Ukraine

2021 ◽  
Vol 4 (2) ◽  
pp. 34-47
Author(s):  
Anastasiia Zymaroieva ◽  
Tetiana Fedoniuk ◽  
Svitlana Matkovska ◽  
Olena Andreieva ◽  
Victor Pazych
Keyword(s):  
Crop Yields ◽  
Climatic Factors ◽  
High Sensitivity ◽  
Potato Yield ◽  
Limiting Factors ◽  
Forest Steppe ◽  
Yield Parameters ◽  
Bioclimatic Variables ◽  
Potato Yields ◽  
The Relationship

Global food security largely depends on the crop yield increase, so the study of the yield-limiting factors of potato (the second bread) is a pressing issue today. This study determines the contribution of the agroecological factors, namely, bioclimatic variables, soil indicators, and factors of landscape diversity, to the variation in potato yields. Conducted in Polissya and Forest-steppe zones of Ukraine during 1991–2017, this study has not only addressed the relationship between ecological determinants and potato yields, but also considered crop yields as a dynamic system. The dynamics of potato yields from the mid-1990s to the present is described by a log-logistic model. There are statistically significant regression dependencies between potato yield parameters and agroecological factors. Potato yield is dependent on the diversity of landscape cover. The relationship between yield parameters and landscape-ecological diversity is non-linear, which determines the presence of optimal landscape structure for the highest potato yields. Among climatic factors, the continental climate is of the greatest importance for potato yield. The high sensitivity of potato yield parameters to soil indices was found, and mostly the soil texture components (silt content), which largely determines the potato yield spatial variation.

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