Accounting for discharge simulation performances and observation quality for modelling sediment at global scale

2020 ◽  
Author(s):  
Alban de Lavenne ◽  
Alena Bartosova ◽  
Johan Strömqvist ◽  
Berit Arheimer
Keyword(s):  
Water Quality ◽  
Time Series ◽  
Large Scale ◽  
Global Scale ◽  
Limiting Factor ◽  
Simulation Performance ◽  
Sediment Loads ◽  
Discharge Simulation ◽  
Monitoring Stations

<p>Water quality modelling is very often constrained beforehand by the performance of discharge modelling. When the model is set up at global scale, this discharge performance usually greatly varies in space and can therefore be a limiting factor in many regions around the globe. Besides discharge performances, the quality of the observations themselves can also be highly heterogeneous in space and among datasets. Modeller then has to find a compromise between being restrictive on the quality of his dataset or having a good spatio-temporal representativeness of the various hydrological conditions at global scale. This often relies on subjective thresholds.</p> <p>This work proposed a more objective calibration strategy that aims to consider both aspects explicitly: observation quality and model performance on discharge. It leads to the construction of two scores that are assigned to each water quality station quantifying their reliability for model calibration and evaluation. The average of those two scores is then used as a weight in the objective function to emphasise the training on the most reliable stations.</p> <p>The strategy is implemented for sediment modelling using the WW-HYPE model (Arheimer et al., 2019) at global scale. The score on discharge simulation performance is based on the regionalisation of the Nash-Sutcliffe Efficiency that is spatially interpolated at every sediment monitoring stations using inverse Ghosh distance weighting (de Lavenne et al., 2016). The score on the observation quality is based on the location of the station with respect to the catchment outlet and on the amount of data. A multi-objective calibration is performed to optimise parameters on two global databases, one on long terms sediment loads (730 stations) and one on sediment concentrations time series (1440 stations). The sensitivity of the model to this calibration strategy is analysed according to model performances and model outputs, such as sediment loads at global scale, in order to discuss the importance of considering this heterogeneity of the reliability of monitoring stations.</p> <p>References</p> <p>Arheimer, B., Pimentel, R., Isberg, K., Crochemore, L., Andersson, J. C. M., Hasan, A., and Pineda, L. (2019), Global catchment modelling using World-Wide HYPE (WWH), open data and stepwise parameter estimation, Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2019-111.</p> <p>de Lavenne, A., J. O. Skøien, C. Cudennec, F. Curie, and F. Moatar (2016), Transferring measured discharge time series: Large-scale comparison of Top-kriging to geomorphology-based inverse modeling, Water Resour. Res., 52, 5555–5576, doi:10.1002/2016WR018716.</p>

scholarly journals Influência da vernalização de semente na produção, crescimento e desenvolvimento de plantas de lisianthus

2018 ◽  
Vol 39 (6) ◽  
pp. 2325 ◽  
Author(s):  
Maria Yumbla-Orbes ◽  
José Geraldo Barbosa ◽  
Wagner Campos Otoni ◽  
Marcel Santos Montezano ◽  
José Antônio Saraiva Grossi ◽  
...  
Keyword(s):  
Large Scale ◽  
Limiting Factor ◽  
Scale Production ◽  
Cut Flower ◽  
Cut Flowers ◽  
Flower Production ◽  
Commercial Scale ◽  
Large Scale Production ◽  
And Control

Flowering induction and control is a limiting factor when commercially producing cut flowers of lisianthus and seed exposure to low temperatures, a physiological event called vernalization, induces the differentiation of vegetative buds to reproductive buds, contributing to a flowering that is uniform and has quality. The objective of this study was to evaluate the influence of seed vernalization in three cultivars of lisianthus (Excalibur, Echo and Mariachi) for 12, 24, 36 and 48 days at temperatures of 5, 10 and 15°C, in the production and quality of buds, making this technology feasible to large-scale production. During cultivation it was observed that the lower the temperature and higher the vernalization period, the lower the cycle and the greater the number of plants induced to flowering for all three cultivars, and those are important features in the context of flower production in a commercial scale. The seeds subjected to vernalization originated plants that produce flower stems within the standards required by the market, showing that vernalization was efficient to induce flowering without affecting the quality of the buds. To produce lisianthus as a cut flower of quality, it is recommended seed vernalization of Mariachi and Echo cultivars for 24 days at 5°C and Excalibur for 36 days at 5°C.

scholarly journals Influence of EU policy on agricultural nutrient losses and the state of receiving surface waters in Finland

2008 ◽  
Vol 16 (4) ◽  
pp. 282 ◽  
Author(s):  
P. EKHOLM ◽  
K. GRANLUND ◽  
P. KAUPPILA
Keyword(s):  
Water Quality ◽  
Large Scale ◽  
Nutrient Loading ◽  
Nutrient Losses ◽  
Agricultural Catchments ◽  
Receiving Waters ◽  
Environmental Measures ◽  
Current Loading ◽  
Regional Specialisation

In Finland, the first large-scale efforts to control nutrient loading from agriculture got under way with the introduction of the EU Agri-Environmental Program in 1995. We examined whether these efforts have decreased agricultural nutrient losses and improved the quality of receiving waters. To do so we used monitoring data on fluxes of nutrients and total suspended solids in agricultural catchments in 1990–2004 and on the water quality of agriculturally loaded rivers, lakes and estuaries in 1990–2005. No clear reduction in loading or improvement in water quality was detected. Hydrological fluctuations do not seem to have eclipsed the effects of the measures taken, since there was no systematic pattern in runoff in the period studied. The apparent inefficiency of the measures taken may be due to the large nutrient reserves of the soil, which slowed down nutrient reductions within the period studied. Simultaneous changes in agricultural production (e.g. regional specialisation) and in climate may also have counteracted the effects of agri-environmental measures. The actions to reduce agricultural loading might have been more successful had they focused specifically on the areas and actions that contribute most to the current loading.;

Assessment on the Water Quality Influenced by Large-Scale Controlled Planting of Water Hyacinth in the Dianchi Lake

2013 ◽  
Vol 726-731 ◽  
pp. 1782-1785 ◽  
Author(s):  
Xia Zhang ◽  
Zong Shou Cai ◽  
Li Hong Chen ◽  
Jian Wen Ruan
Keyword(s):  
Water Quality ◽  
Ecological Restoration ◽  
Water Hyacinth ◽  
Large Scale ◽  
Present Situation ◽  
Dianchi Lake ◽  
The Future ◽  
Before And After ◽  
Ecological Treatment

Large-scale controlled planting of water hyacinth has become one of the most important measures of Dianchi Lake’s treatment in the “12th Five-Year Plan”. This paper firstly introduced the present situation of large-scale controlled planting of water hyacinth in Dianchi Lake. The water quality of Caohai and Waihai of Dianchi Lake were compared before and after the project of planting water hyacinth. This paper concluded that the effects of large-scale controlled planting of water hyacinth on the ecological restoration of Caohai lake were outstanding. The area of controlled planting could be spread among other water areas of Dianchi lake where is suitable for the growth of water hyacinth in the future, and water hyacinth will pay a greater role in the ecological treatment of Dianchi Lake.

scholarly journals An Assessment of Drinking Water Quality in Cauvery Delta Region and Palar Region, Tamil Nadu

2017 ◽  
Vol 3 (12) ◽  
pp. 238
Author(s):  
R. Sophia Porchelvi ◽  
P. Selvavathi
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
River Basin ◽  
Tamil Nadu ◽  
Large Scale ◽  
Anthropogenic Activities ◽  
Small Scale ◽  
Drinking Purposes ◽  
Cauvery Delta

Delta regions of the Cauvery River basin are one of the significant areas of rice production in India. In spite of large-scale utilization of the river basin for irrigation and drinking purposes, the lack of appropriate water management has seemingly deteriorated the water quality due to increasing anthropogenic activities. Vellore is the second most populous district of Tamil Nadu in India where the Palar River flowing towards east for about 295 Km. Vellore is surrounded by many leather tanneries and small scale dying industries and their effluents are discharged into the Palar river causing impact on the quality of the underground water. To assess the extent of deterioration, physicochemical characteristics of surface water were analyzed select regions of Cauvery Delta River basin and Palar region, Tamil Nadu, during March 2016 to May 2016. This study aimed to examine quality of drinking groundwater. The results represented whether the water was suitable or unsuitable for drinking purposes in this area. It was also observed that some areas like Tiruvarur, Needamangalam, Kamalapuram, Arcot, Soraiyur, Ranipet had low quality drinking water. It is suggested to take some necessary measures for supplying desirable water to the people living in these areas.

The Influence of Large Scale Phosphate Mining on the Water Quality of the Huangbaihe River Basin in China: Dominant Pollutants and Spatial Distributions

2019 ◽  
Vol 38 (2) ◽  
pp. 366-377 ◽  
Author(s):  
Gebrehiwet Legese Reta ◽  
Xiaohua Dong ◽  
Bob Su ◽  
Xiaonong Hu ◽  
Huijuan Bo ◽  
...  
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Large Scale ◽  
Spatial Distributions ◽  
Phosphate Mining

ESTIMATION OF SEASONAL VARIABILITY OF WATER QUALITY IN A SURFACE SOURCE OF DRINKING WATER SUPPLY

2018 ◽  
Vol 8 (2) ◽  
pp. 20-26 ◽  
Author(s):  
Alexandra V. SELEZNEVA ◽  
Ksenia V. BESPALOVA ◽  
Vladimir A. SELEZNEV
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Seasonal Variability ◽  
Water Quality Monitoring ◽  
Limiting Factor ◽  
Surface Source ◽  
Organic Contamination ◽  
Quality Of Water ◽  
Mass Development

The results of water quality monitoring of the Saratov reservoir for the period 2000-2016 are presented. Observations were carried out monthly at a stationary station located in the lower tail of the Zhigulevskaya HPP. It is established that the quality of water in the source of water supply is characterized by signifi cant seasonal variability. During the mass development of algae the organic contamination of the reservoir increases and the concentration of nutrients decreases. Excessive content of organic substances in the summer low water complicates the technological processes of water purifi cation. It is concluded that phosphate is the limiting factor restraining the mass development of algae, the concentration of which in the peak of “fl owering” of water is reduced to almost zero.

scholarly journals The effects of industrial and agricultural activity on the water quality of the Sitnica River (Kosovo)

Geoadria ◽  
2014 ◽  
Vol 20 (1) ◽  
pp. 13
Author(s):  
Albona Shala ◽  
Fatbardh Sallaku ◽  
Agron Shala ◽  
Shkëlzim Ukaj
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Reference Station ◽  
Polluted Water ◽  
Pollution Level ◽  
Wastewater Discharge ◽  
Agricultural Lands ◽  
The Impact ◽  
Monitoring Stations

An important issue in Kosovo is water pollution. The use of polluted water has a direct impact on human health and cause long-term consequences. The longest and most polluted river in Kosovo is the Sitnica, a 90 km long river with its source located near the village of Sazli. The river flows into the Ibar River in Northern Kosovo. Agriculture is prevailing activity in the basin of Sitnica which is why agricultural as well as industrial waste are the biggest water pollutants. The purpose of this study was to evaluate water quality of the river and analyse the pollution level along the Sitnica River caused by agricultural activities and industrial discharges. In order to assess the impact of pollutants on this river, a measurements were carried out in four (five) monitoring stations: the first station represents the reference station which has not undergone or has not been affected by polluting pressures, two stations in water areas affected by the irrigation of farming land and two monitoring stations in water areas affected by industrial wastewater discharge. Some of the parameters of water quality analysed are temperature, turbidity, electrical conductivity, pH, DO, COD, BOD, P total, nitrates, sulfates, and heavy metals iron, manganese, zinc, nickel. Compared to the reference station the results obtained from the Gracka and Pestova monitoring stations prove that the dominant form of pollution is that from agricultural lands irrigation, while the Plemetin and Mitrovica stations show that the Sitnica River is affected by wastewater discharge which contains significant concentrations of heavy metals, as well as metal ions selected in this paper. It can be concluded that the irrigation of agricultural lands and discharges from mining significantly affect water quality of the Sitnica River.

scholarly journals Detection and attribution of global change effects on river nutrient dynamics in a large Mediterranean basin

2015 ◽  
Vol 12 (13) ◽  
pp. 4085-4098 ◽  
Author(s):  
R. Aguilera ◽  
R. Marcé ◽  
S. Sabater
Keyword(s):  
Water Quality ◽  
Time Series ◽  
Global Change ◽  
Large Scale ◽  
Nutrient Dynamics ◽  
Anthropogenic Impacts ◽  
Spatial Scales ◽  
Phosphate Concentration ◽  
Dynamic Factor ◽  
The Impact

Abstract. Attributing changes in river water quality to specific factors is challenging because multiple factors act at different temporal and spatial scales, and it often requires examining long-term series of continuous data. Data consistency is sometimes hindered by the lack of observations of relevant water quality variables and the low and uneven sampling frequency that characterizes many water quality monitoring schemes. Nitrate and dissolved phosphate concentration time series (1980–2011) from 50 sampling stations across a large Mediterranean river basin were analyzed to disentangle the role of hydrology, land-use practices, and global climatic phenomena on the observed nutrient patterns, with the final aim of understanding how the different aspects of global change affected nutrient dynamics in the basin. Dynamic factor analysis (DFA) provided the methodological framework to extract underlying common patterns in nutrient time series with missing observations. Using complementary methods such as frequency and trend analyses, we sought to further characterize the common patterns and identify the drivers behind their variability across time and space. Seasonal and other cyclic patterns were identified as well as trends of increase or decrease of nutrient concentration in particular areas of the basin. Overall, the impact of global change, which includes both climate change and anthropogenic impacts, on the dynamics of nitrate concentration across the study basin was found to be a multifaceted process including regional and global factors, such as climatic oscillations and agricultural irrigation practices, whereas impacts on phosphate concentration seemed to depend more on local impacts, such as urban and industrial activities, and less on large-scale factors.

scholarly journals Well water quality in rural Nicaragua using a low-cost bacterial test and microbial source tracking

2015 ◽  
Vol 14 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Patricia Weiss ◽  
Tiong Gim Aw ◽  
Gerald R. Urquhart ◽  
Miguel Ruiz Galeano ◽  
Joan B. Rose
Keyword(s):  
Water Quality ◽  
Low Cost ◽  
Global Scale ◽  
Source Tracking ◽  
Well Water ◽  
Water Wells ◽  
Compartment Bag Test ◽  
Rope Pump ◽  
Viable Method

Water-related diseases, particularly diarrhea, are major contributors to morbidity and mortality in developing countries. Monitoring water quality on a global scale is crucial to making progress in terms of population health. Traditional analytical methods are difficult to use in many regions of the world in low-resource settings that face severe water quality issues due to the inaccessibility of laboratories. This study aimed to evaluate a new low-cost method (the compartment bag test (CBT)) in rural Nicaragua. The CBT was used to quantify the presence of Escherichia coli in drinking water wells and aimed to determine the source(s) of any microbial contamination. Results indicate that the CBT is a viable method for use in remote rural regions. The overall quality of well water in Pueblo Nuevo, Nicaragua was deemed unsafe, and results led to the conclusion that animal fecal wastes may be one of the leading causes of well contamination. Elevation and depth of wells were not found to impact overall water quality. However rope-pump wells had a 64.1% reduction in contamination when compared with simple wells.

Sea Surface Temperatures along the Coast of British Columbia: Regional Evidence for a Warming Trend

1990 ◽  
Vol 47 (2) ◽  
pp. 346-350 ◽  
Author(s):  
Howard J. Freeland
Keyword(s):  
British Columbia ◽  
Time Series ◽  
Large Scale ◽  
Southern Oscillation ◽  
Warming Trend ◽  
Global Scale ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Mean Values ◽  
Surface Temperatures

Sea-surface temperature has been measured at a large number of sites around the coast of British Columbia for periods well in excess of 50 yr. These time series are long enough to give clear evidence of a large scale secular warming. For the purposes of this paper the daily SST observations are decimated to monthly mean values. The observations are of particular value because observation methods have remained invariant throughout the observation period, and many of the stations are remote from civilisation allowing trends to be estimated that have not been contaminated with urbanization effects. Eighteen out of nineteen stations that are currently being sampled show a warming trend, the one that shows a cooling trend is the shortest time series, only in its eleventh year. The sea-surface temperatures at sites exposed to the Pacific Ocean show very high coherence with global scale air temperature variations but no relationship to the El Niño/Southern Oscillation signal.

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