scholarly journals Biological and biogeochemical methods for estimating bioirrigation: a case study in the Oosterschelde estuary

2020 ◽  
Vol 17 (6) ◽  
pp. 1701-1715
Author(s):  
Emil De Borger ◽  
Justin Tiano ◽  
Ulrike Braeckman ◽  
Tom Ysebaert ◽  
Karline Soetaert
Keyword(s):  
Mechanistic Model ◽  
High Temporal Resolution ◽  
Biological Traits ◽  
Overlying Water ◽  
Pumping Rate ◽  
Sediment Biogeochemistry ◽  
Irrigation Potential ◽  
Irrigation Depth ◽  
Intertidal Habitats

Abstract. Bioirrigation, the exchange of solutes between overlying water and sediment by benthic organisms, plays an important role in sediment biogeochemistry. Bioirrigation either is quantified based on tracer data or a community (bio)irrigation potential (IPc) can be derived based on biological traits. Both these techniques were applied in a seasonal study of bioirrigation in subtidal and intertidal habitats in a temperate estuary. The combination of a tracer time series with a high temporal resolution and a mechanistic model allowed for us to simultaneously estimate the pumping rate and the sediment attenuation, a parameter that determines irrigation depth. We show that, although the total pumping rate is similar in both intertidal and subtidal areas, there is deeper bioirrigation in intertidal areas. This is explained by higher densities of bioirrigators such as Corophium sp., Heteromastus filiformis and Arenicola marina in the intertidal, as opposed to the subtidal, areas. The IPc correlated more strongly with the attenuation coefficient than the pumping rate, which highlights that the IPc index reflects more the bioirrigation depth than the rate.

scholarly journals Biological and biogeochemical methods for estimating bio-irrigation: a case study in the Oosterschelde estuary

2019 ◽  
Author(s):  
Emil De Borger ◽  
Justin Tiano ◽  
Ulrike Braeckman ◽  
Tom Ysebaert ◽  
Karline Soetaert
Keyword(s):  
High Temporal Resolution ◽  
Biological Traits ◽  
Overlying Water ◽  
Pumping Rate ◽  
Sediment Biogeochemistry ◽  
Irrigation Potential ◽  
Irrigation Depth ◽  
Intertidal Habitats ◽  
Sediment Attenuation

Abstract. Bio-irrigation, the exchange of solutes between overlying water and sediment by benthic organisms, plays an important role in sediment biogeochemistry. Quantification of bio-irrigation is done either through measurements with tracers, or more recently, using biological traits to derive the community (bio-) irrigation potential (IPc). Both these techniques were applied in a seasonal study of bio-irrigation in species communities of subtidal and intertidal habitats in a temperate estuary. A tracer time series with high-temporal resolution allowed to simultaneously estimate the pumping rate, and the sediment attenuation, a parameter that determines irrigation depth. We show that although the total pumping rate is similar in both intertidal and subtidal areas, there is deeper bio-irrigation in intertidal areas. This is explained by higher densities of bio-irrigators such as Corophium sp., Heteromastus filiformis and Arenicola marina in the intertidal, as opposed to the subtidal. The IPc correlated more strongly with the attenuation coefficient than the pumping rate, which highlights that this index reflects more the bio-irrigation depth rather than the rate.

scholarly journals A Mechanistic Model to Assess the Fate of Naphthalene and Benzo(a)pyrene in a Chilean WWTP

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1313
Author(s):  
Antonia Arroyo ◽  
Fabián Provoste ◽  
Montserrat Rodríguez ◽  
Ana L. Prieto
Keyword(s):  
Wastewater Treatment Plants ◽  
Mechanistic Model ◽  
Treated Wastewater ◽  
Urban Centers ◽  
Potable Reuse ◽  
Conventional Activated Sludge ◽  
Regulatory Standards ◽  
Polycyclic Aromatic ◽  
De Facto Reuse

Polycyclic aromatic hydrocarbons (PAHs) are a family of organic compounds of widespread presence in the environment. They are recalcitrant, ubiquitous, prone to bioaccumulation, and potentially carcinogenic. Effluent from wastewater treatment plants (WWTPs) constitutes a major source of PAHs into water bodies, and their presence should be closely monitored, especially considering the increasing applications of potable and non-potable reuse of treated wastewater worldwide. Modeling the fate and distribution of PAHs in WWTPs is a valuable tool to overcome the complexity and cost of monitoring and quantifying PAHs. A mechanistic model was built to evaluate the fate of PAHs in both water and sludge lines of a Chilean WWTP. Naphthalene and benzo(a)pyrene were used as models of low-MW and high-MW PAHs. As there were no reported experimental data available for the case study, the influent load was determined through a statistical approach based on reported values worldwide. For both naphthalene and benzo(a)pyrene, the predominant mechanism in the water line was sorption to sludge, while that in the sludge line was desorption. Compared to other studies in the literature, the model satisfactorily describes the mechanisms involved in the fate and distribution of PAHs in a conventional activated sludge WWTP. Even though there is evidence of the presence of PAHs in urban centers in Chile, local regulatory standards do not consider PAHs in the disposal of WWTP effluents. Monitoring of PAHs in both treated effluents and biosolids is imperative, especially when considering de facto reuse and soil amendment in agricultural activities are currently practiced downstream of the studied WWTP.

scholarly journals Kalman filter physical retrieval of surface emissivity and temperature from geostationary infrared radiances

2013 ◽  
Vol 6 (12) ◽  
pp. 3613-3634 ◽  
Author(s):  
G. Masiello ◽  
C. Serio ◽  
I. De Feis ◽  
M. Amoroso ◽  
S. Venafra ◽  
...  
Keyword(s):  
Kalman Filter ◽  
High Temporal Resolution ◽  
Target Area ◽  
Surface Emissivity ◽  
In Situ Data ◽  
Infrared Imager ◽  
Filter Approach ◽  
Infrared Radiances

Abstract. The high temporal resolution of data acquisition by geostationary satellites and their capability to resolve the diurnal cycle allows for the retrieval of a valuable source of information about geophysical parameters. In this paper, we implement a Kalman filter approach to apply temporal constraints on the retrieval of surface emissivity and temperature from radiance measurements made from geostationary platforms. Although we consider a case study in which we apply a strictly temporal constraint alone, the methodology will be presented in its general four-dimensional, i.e., space-time, setting. The case study we consider is the retrieval of emissivity and surface temperature from SEVIRI (Spinning Enhanced Visible and Infrared Imager) observations over a target area encompassing the Iberian Peninsula and northwestern Africa. The retrievals are then compared with in situ data and other similar satellite products. Our findings show that the Kalman filter strategy can simultaneously retrieve surface emissivity and temperature with an accuracy of ± 0.005 and ± 0.2 K, respectively.

Nitrogen mineralisation in sugarcane soils in Queensland, Australia: II. From laboratory to field-based prediction

Soil Research ◽  
2019 ◽  
Vol 57 (7) ◽  
pp. 755
Author(s):  
T. G. Orton ◽  
D. E. Allen ◽  
P. M. Bloesch
Keyword(s):  
Mechanistic Model ◽  
Predictive Ability ◽  
Statistical Modelling ◽  
Soil Conditions ◽  
Organic Carbon Content ◽  
Climate Data ◽  
Incubation Study ◽  
Moisture Conditions ◽  
Temperature Factors

Using Australian sugarcane regions as a case study, we present an approach for prediction of in-field nitrogen (N) mineralisation over a crop season. The approach builds on the statistical modelling applied in Allen et al. 2019, which demonstrated good predictive ability on data from a laboratory incubation study (an external R2 of 0.84 in a cross-validation exercise), and adjusts those mineralisation rates according to soil moisture and temperature factors. The required field soil temperature and moisture conditions were simulated using a mechanistic model for the response of soil conditions to input climate data. We investigate drivers of variability in the predicted in-season mineralised N, and compare predictions with currently implemented N fertiliser discounts, which are based on a relationship with soil organic carbon content. The main purpose of this paper is to illustrate the potential use of the results in Allen et al. (2019) for calculating predictions of in-season mineralised N that could be applicable under field conditions in the Australian sugarcane regions. A thorough test to properly validate predictions has not yet been conducted, but collecting data to do so should be the focus of further work.

Multi-scale ocean colour synergy products for coastal water quality monitoring

2020 ◽  
Author(s):  
Dimitry Van der Zande ◽  
Aida Alvera-Azcárate ◽  
Charles Troupin ◽  
João Cardoso Dos Santos ◽  
Dries Van den Eynde
Keyword(s):  
Spatial Resolution ◽  
Spectral Characteristics ◽  
Empirical Orthogonal Functions ◽  
High Temporal Resolution ◽  
Ocean Colour ◽  
Orthogonal Functions ◽  
Multi Scale ◽  
Medium Resolution ◽  
Sentinel 2

<p>High-quality satellite-based ocean colour products can provide valuable support and insights in the management and monitoring of coastal ecosystems. Today’s availability of Earth Observation (EO) data is unprecedented including medium resolution ocean colour systems (e.g. Sentinel-3/OLCI), high resolution land sensors (e.g. Sentinel-2/MSI) and geostationary satellites (e.g. MSG/SEVIRI). Each of these sensors offers specific advantages in terms of spatial, temporal or radiometric characteristics. In the Multi-Sync project, we developed advanced ocean colour products (i.e. remote sensing reflectance, turbidity, and chlorophyll a concentration) through the synergetic use of these multi-scale EO data taking advantage of spectral characteristics of traditional medium resolution sensors, the high spatial resolution of some land sensors and the high temporal resolution of geostationary sensors.</p><p>To achieve this goal a multi-scale DINEOF (Data Interpolating Empirical Orthogonal Functions) approach was developed to reconstruct missing data using empirical orthogonal functions (EOF), reduce noise and exploit spatio-temporal coherency by joining several spatial and temporal resolutions. Here we present the capacity of DINEOF to extract multi-scale information through the integration of Sentinel-3, Sentinel-2 and SEVIRI datasets.</p><p>The functionality of the advanced multi-scale products will be demonstrated in a case study for the Belgian Coastal Zone (BCZ) highly relevant to the user community: sediment transport modelling near the harbour of Zeebrugge in support of dredging operations. As stated in the OSPAR treaty (1992), Belgium is obliged to monitor and evaluate the effects of all human activities on the marine ecosystem. Dredging activities in and near Belgian harbors fall under this treaty and are performed daily to ensure accessibility of the port by ships. Optimization of these dredging activities requires monitoring data which is typically acquired through in situ observations or modelling data. In this case study we take advantage of Sentinel-3, Sentinel-2 and SEVIRI data characteristics to provide a satellite product that meets the end user requirements in terms of product quality and temporal/spatial resolution.</p><p> </p>

scholarly journals Capturing variability in pavement performance models from sufficient time-series predictors: a case study of the New Brunswick road network

2011 ◽  
Vol 38 (2) ◽  
pp. 210-220 ◽  
Author(s):  
Luis Esteban Amador-Jiménez ◽  
Donath Mrawira
Keyword(s):  
New Brunswick ◽  
Mechanistic Model ◽  
Model Parameters ◽  
Traffic Loading ◽  
Progression Model ◽  
Structural Capacity ◽  
Pavement Roughness ◽  
Data Points ◽  
Rapid Generation

This paper proposes the use of multi-level Bayesian modeling for calibrating mechanistic model parameters from historical data while capturing reliability by estimating a desired confidence interval of the predictions. The model is capable of estimating the parameters from the observed data and expert criteria even in cases of missing data points. This approach allows rapid generation of several deterioration models without the need to partition the data into pavement families. It estimates posterior distributions for model coefficients and predicts values of the response for unobserved levels of the causal factors. A case study from the New Brunswick Department of Transportation is used to calibrate a simplified mechanistic pavement roughness progression model based on 6-year international roughness index (IRI) observations. The model incorporates the effects of pavement structural capacity in terms of deflection basin parameter (AREA) in place of the modified structural number, traffic loading (ESAL) and environmental factors. The results of the model showed that, as expected, chipseal roads have higher as built roughness and deteriorate faster than asphalt roads. Sensitivity analysis of the deterministic (the mean predictions) part of the model showed that in New Brunswick where traffic is relatively low the environment is the most important factor.

scholarly journals Supplemental irrigation potential and impact on downstream flow of Karkheh River basin in Iran

2016 ◽  
Vol 20 (5) ◽  
pp. 1903-1910 ◽  
Author(s):  
Behzad Hessari ◽  
Adriana Bruggeman ◽  
Ali Mohammad Akhoond-Ali ◽  
Theib Oweis ◽  
Fariborz Abbasi
Keyword(s):  
Water Resources ◽  
River Basin ◽  
Water Productivity ◽  
Environmental Flow ◽  
Supplemental Irrigation ◽  
Irrigation Potential ◽  
Winter Crops ◽  
Downstream Flow ◽  
Karkheh River Basin

Abstract. Supplemental irrigation of rainfed winter crops improves and stabilises crop yield and water productivity. Although yield increases by supplemental irrigation are well established at the field level, its potential extent and impact on water resources at the basin level are less researched. This work presents a Geographic Information Systems (GIS)-based methodology for identifying areas that are potentially suitable for supplemental irrigation and a computer routine for allocating streamflow for supplemental irrigation in different sub-basins. A case study is presented for the 42 908 km2 upper Karkheh River basin (KRB) in Iran, which has 15 840 km2 of rainfed crop areas. Rainfed crop areas within 1 km from the streams, with slope classes 0–5, 0–8, 0–12, and 0–20 %, were assumed to be suitable for supplemental irrigation. Four streamflow conditions (normal, normal with environmental flow requirements, drought and drought with environmental flow) were considered for the allocation of water resources. Thirty-seven percent (5801 km2) of the rainfed croplands had slopes less than 5 %; 61 % (3559 km2) of this land was suitable for supplemental irrigation, but only 22 % (1278 km2) could be served with irrigation in both autumn (75 mm) and spring (100 mm), under normal flow conditions. If irrigation would be allocated to all suitable land with slopes up to 20 %, 2057 km2 could be irrigated. This would reduce the average annual outflow of the upper KRB by 9 %. If environmental flow requirements are considered, a maximum (0–20 % slopes) of 1444 km2 could receive supplemental irrigation. Under drought conditions a maximum of 1013 km2 could be irrigated, while the outflow would again be reduced by 9 %. Thus, the withdrawal of streamflow for supplemental irrigation has relatively little effect on the outflow of the upper KRB. However, if the main policy goal would be to improve rainfed areas throughout the upper KRB, options for storing surface water need to be developed.

scholarly journals Climate records in ancient Chinese diaries and their application in historical climate reconstruction – a case study of <i>Yunshan Diary</i>

2020 ◽  
Vol 16 (5) ◽  
pp. 1873-1887
Author(s):  
Siying Chen ◽  
Yun Su ◽  
Xiuqi Fang ◽  
Jia He
Keyword(s):  
Climate Change ◽  
Eastern China ◽  
Ice Age ◽  
High Temporal Resolution ◽  
Lake Basin ◽  
Extreme Climatic Events ◽  
Personal Experiences ◽  
The Yuan Dynasty ◽  
Climate Series

Abstract. Private diaries are important sources of historical data for research on climate change. Their advantages include a high veracity and reliability, accurate time and location information, a high temporal resolution, seasonal integrity, and rich content. In particular, these data are suitable for reconstructing short-term, high-resolution climate series and extreme climatic events. Through a case study of Yunshan Diary, authored by Bi Guo of the Yuan dynasty of China, this article demonstrates how to delve into climate information in diaries, including species distribution records, phenological records, daily weather descriptions and personal experiences of meteorological conditions. In addition, this article considers how to use these records, supplemented by other data, to reconstruct climate change and extreme climatic events on various timescales, from multidecadal to annual or daily. The study of Yunshan Diary finds that there was a relatively low amount of precipitation in central and southern Jiangsu Province in the summer of 1309; the winter of 1308–1309 was abnormally cold in the Taihu Lake basin. In the early 14th century at the latest, the climate in eastern China had begun to turn cold, which reflects the transition from the Medieval Warm Period to the Little Ice Age.

scholarly journals Analysing the temporal dynamics of model performance for hydrological models

2008 ◽  
Vol 5 (6) ◽  
pp. 3169-3211 ◽  
Author(s):  
D. E. Reusser ◽  
T. Blume ◽  
B. Schaefli ◽  
E. Zehe
Keyword(s):  
Time Series ◽  
Performance Assessment ◽  
Performance Measures ◽  
Hydrological Model ◽  
Temporal Dynamics ◽  
Model Performance ◽  
High Dimensional ◽  
High Temporal Resolution ◽  
Headwater Catchment

Abstract. The temporal dynamics of hydrological model performance gives insights into errors that cannot be obtained from global performance measures assigning a single number to the fit of a simulated time series to an observed reference series. These errors can include errors in data, model parameters, or model structure. Dealing with a set of performance measures evaluated at a high temporal resolution implies analyzing and interpreting a high dimensional data set. This paper presents a method for such a hydrological model performance assessment with a high temporal resolution and illustrates its application for two very different rainfall-runoff modeling case studies. The first is the Wilde Weisseritz case study, a headwater catchment in the eastern Ore Mountains, simulated with the conceptual model WaSiM-ETH. The second is the Malalcahuello case study, a headwater catchment in the Chilean Andes, simulated with the physics-based model Catflow. The proposed time-resolved performance assessment starts with the computation of a large set of classically used performance measures for a moving window. The key of the developed approach is a data-reduction method based on self-organizing maps (SOMs) and cluster analysis to classify the high-dimensional performance matrix. Synthetic peak errors are used to interpret the resulting error classes. The final outcome of the proposed method is a time series of the occurrence of dominant error types. For the two case studies analyzed here, 6 such error types have been identified. They show clear temporal patterns which can lead to the identification of model structural errors.

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