Coupled hydrological and biogeochemical model for aqueous contaminant transport

1995 ◽  
Vol 46 (1) ◽  
pp. 197 ◽  
Author(s):  
A Worman
Keyword(s):  
Contaminant Transport ◽  
Field Data ◽  
Regional Scale ◽  
Covariance Structure ◽  
Physical Modelling ◽  
Biogeochemical Model ◽  
Phosphorus Transport ◽  
Dimensionless Numbers ◽  
Average Value ◽  
Constitutive Parameters

A coupled hydrological and biogeochemical model for aqueous contaminant transport has been developed on the basis of field data on phosphorus transport in minor drainage brooks through agricultural areas in Sweden. Large scattering exists in constitutive parameters reflecting mass transfer due to solute/particle sorption and retention in bed sediments. To cope with these uncertainties, a physical/modelling framework was developed that, in a deterministic way, takes into account the most essential mechanisms controlling the transport on a regional scale and also includes randomness in process behaviour. Constitutive parameters of the governing system are conceived as stochastic, continuous fields in space and can be evaluated from field data by means of geostatistics. This modelling approach enables one to conduct analyses of uncertainty/error propagation and effects of system heterogeneity on both expected predictions and confidence intervals. Depending on the governing dimensionless numbers of the problem, changes in the covariance structure of parameter fields may cause severe deviations between statistically expected predictions associated with a stochastic parameter field and predictions based on the average value of the parameter.

scholarly journals Diversity and functional traits of lichens in ultramafic areas: a literature-based worldwide analysis integrated by field data at the regional scale

2018 ◽  
Vol 33 (3) ◽  
pp. 593-608 ◽  
Author(s):  
Sergio E. Favero-Longo ◽  
Enrica Matteucci ◽  
Paolo Giordani ◽  
Alexander G. Paukov ◽  
Nishanta Rajakaruna
Keyword(s):  
Functional Traits ◽  
Field Data ◽  
Regional Scale

Uncovering the Canning Basin: a new comprehensive SEEBASE® model

2018 ◽  
Vol 58 (2) ◽  
pp. 793
Author(s):  
Karen Connors ◽  
Cedric Jorand ◽  
Peter Haines ◽  
Yijie Zhan ◽  
Lynn Pryer
Keyword(s):  
Western Australia ◽  
Potential Field ◽  
Field Data ◽  
Regional Scale ◽  
Structural Evolution ◽  
Potential Field Data ◽  
Canning Basin ◽  
The North ◽  
Wide Range ◽  
Order Of Magnitude

A new regional scale SEEBASE® model has been produced for the intracratonic Canning Basin, located in the north of Western Australia. The 2017 Canning Basin SEEBASE model is more than an order of magnitude higher resolution than the 2005 OZ SEEBASE version — the average resolution is ~1 : 1 M scale with higher resolution in areas of shallow basement with 2D seismic coverage — such as the Broome Platform and Barbwire Terrace. Post-2005 acquisition of potential field, seismic and well data in the Canning Basin by the Geological Survey of Western Australia (GSWA), Geoscience Australia and industry provided an excellent opportunity to upgrade the SEEBASE depth-to-basement model in 2017. The SEEBASE methodology focuses on a regional understanding of basement, using potential field data to interpret basement terranes, depth-to-basement (SEEBASE), regional structural geology and basement composition. The project involved extensive potential field processing and enhancement and compilation of a wide range of datasets. Integrated interpretation of the potential field data with seismic and well analysis has proven quite powerful and illustrates the strong basement control on the extent and location of basin elements. The project has reassessed the structural evolution of the basin, identified and mapped major structures and produced fault-event maps for key tectonic events. In addition, interpretative maps of basement terranes, depth-to-Moho, basement thickness, basement composition and total sediment thickness have been used to calculate a basin-wide map of basement-derived heat flow. The 2017 Canning Basin SEEBASE is the first public update of the widely used 2005 OZ SEEBASE. All the data and interpretations are available from the GSWA as a report and integrated ArcGIS project, which together provide an excellent summary of the key features within the Canning Basin that will aid hydrocarbon and mineral explorers in the region.

Evidence that increased nitrogen efflux from wave-influenced marine sediment enhances pelagic phytoplankton production on the inner continental shelf of Western Australia

2010 ◽  
Vol 61 (5) ◽  
pp. 625 ◽  
Author(s):  
Jim Greenwood
Keyword(s):  
Continental Shelf ◽  
Surface Waves ◽  
Water Column ◽  
Chlorophyll A ◽  
Wave Height ◽  
Western Australia ◽  
Regional Scale ◽  
Reaction Rates ◽  
Phytoplankton Production ◽  
Biogeochemical Model

Increased biological and chemical reaction rates within permeable continental-shelf sediment can result from the action of passing surface waves, especially when the seabed is rippled. The effect of this on the exchange of nitrogen between the sediment and water column is the focus of the present paper. The continental shelf of Western Australia is used as an example. A time series of chlorophyll a is compared with surface-wave height revealing seasonal and sub-seasonal correlation between the two variables. At the same time, results from a coupled pelagic–benthic biogeochemical model show that temperature-controlled changes in sedimentary nitrogen efflux cannot account for the observed seasonal changes in chlorophyll a in the overlying water column. It is proposed that enhanced pore-water circulation within the sediment, caused by the action of passing surface waves, results in an increase in the efflux of nitrogen from the sediment during winter, supporting higher pelagic phytoplankton production. The parameterisation of sedimentary nitrogen mineralisation as a function of the square of wave height is suggested for the inclusion of this effect in regional-scale continental shelf models.

Physical modelling of a complex forest area in a wind tunnel—comparison with field data

2005 ◽  
Vol 129 (3-4) ◽  
pp. 121-135 ◽  
Author(s):  
Sandrine Aubrun ◽  
Ralf Koppmann ◽  
Bernd Leitl ◽  
Michael Möllmann-Coers ◽  
Andrea Schaub
Keyword(s):  
Wind Tunnel ◽  
Field Data ◽  
Physical Modelling ◽  
Forest Area

scholarly journals A new empirical equation for predicting the maximum initial amplitude of submarine landslide-generated waves

Landslides ◽  
2021 ◽  
Author(s):  
Ramtin Sabeti ◽  
Mohammad Heidarzadeh
Keyword(s):  
Field Data ◽  
Empirical Equation ◽  
Laboratory Data ◽  
Slope Angle ◽  
Physical Modelling ◽  
Empirical Equations ◽  
Submarine Landslides ◽  
Landslide Volume ◽  
Landslide Tsunami ◽  
Tsunami Amplitude

AbstractThe accurate prediction of landslide tsunami amplitudes has been a challenging task given large uncertainties associated with landslide parameters and often the lack of enough information of geological and rheological characteristics. In this context, physical modelling and empirical equations have been instrumental in developing landslide tsunami science and engineering. This study is focused on developing a new empirical equation for estimating the maximum initial landslide tsunami amplitude for solid-block submarine mass movements. We are motivated by the fact that the predictions made by existing equations were divided by a few orders of magnitude (10−1–104 m). Here, we restrict ourselves to three main landslide parameters while deriving the new predictive equation: initial submergence depth, landslide volume and slope angle. Both laboratory and field data are used to derive the new empirical equation. As existing laboratory data was not comprehensive, we conduct laboratory experiments to produce new data. By applying the genetic algorithm approach and considering non-dimensional parameters, we develop and examine 14 empirical equations for the non-dimensional form of the maximum initial tsunami amplitude. The normalized root mean square error (NRMSE) index between observations and calculations is used to choose the best equation. Our proposed empirical equation successfully reproduces both laboratory and field data. This equation can be used to provide a preliminary and rapid estimate of the potential hazards associated with submarine landslides using limited landslide parameters.

scholarly journals Nutrient cycling in the Baltic Sea – results from a 30-year physical-biogeochemical reanalysis

2016 ◽  
Author(s):  
Ye Liu ◽  
H. E. Markus Meier ◽  
Kari Eilola
Keyword(s):  
Baltic Sea ◽  
Ocean Model ◽  
Optimal Interpolation ◽  
Nutrient Concentrations ◽  
Biogeochemical Model ◽  
Phosphorus Transport ◽  
The Baltic Sea ◽  
Gulf Of Riga ◽  
Baltic Proper ◽  
The Baltic

Abstract. The long-term oxygen and nutrient cycles in the Baltic Sea are reconstructed using the Swedish Coastal and Ocean Biogeochemical model (SCOBI) coupled to the Rossby Centre Ocean model (RCO). Two simulations covering the period 1970–1999 are carried out with and without data assimilation, respectively. Here, the "weakly coupled" scheme with the Ensemble Optimal Interpolation (EnOI) method is adopted to assimilate the observed profiles in the reanalysis system. The simulation results show considerable improvements in both oxygen and nutrient concentrations in the reanalysis relative to the free run. Further, the results suggest that the assimilation of biogeochemical observations has a significant effect on the simulation of the oxygen dependent dynamics of biogeochemical cycles. From the reanalysis, nutrient transports between subbasins, between the coastal zone and the open sea, and across latitudinal and longitudinal cross sections, are calculated. Further, bottom areas of nutrient import or export are examined. Our results emphasize the important role of the Baltic proper for the entire Baltic Sea, with large net exports of nutrients into the surrounding subbasins (except the phosphorus transport into the Gulf of Riga and the nitrogen transports into the Gulf of Riga and Danish Straits). In agreement with previous studies, we found that the Bothnian Sea imports large amounts of phosphorus from the Baltic proper that are buried in this subbasin. For the calculation of subbasin budgets, it is crucial where the lateral borders of the subbasins are located, because net transports may change sign with the location of the border. Although the overall transport patterns resemble the results of previous studies, our calculated estimates differ in detail considerably.

scholarly journals Geomorphic Approaches to Estimate Short-Term Erosion Rates: An Example from Valmarecchia River System (Northern Apennines, Italy)

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2535
Author(s):  
Veronica Guerra ◽  
Maurizio Lazzari
Keyword(s):  
Drainage Basin ◽  
Regional Scale ◽  
River System ◽  
Northern Apennines ◽  
Short Term ◽  
Catchment Basin ◽  
Average Value ◽  
Erosion Rates ◽  
Fluvial Dynamics ◽  
Uplift Rates

Studying fluvial dynamics and environments, GIS-based analyses are of fundamental importance to evaluate the network geometry and possible anomalies, and can be particularly useful to estimate modifications in processes and erosion rates. The aim of this paper is to estimate short-term erosion rates attributable to fluvial processes in two sample catchment sub-basins of the Marecchia river valley, by conducting quantitative morphometric analyses in order to calculate various descriptive parameters of the hierarchisation of the river networks and the mean turbid transport of streams (Tu). Sediment yield transported by streams can in fact partially express the amount of erosional processes acting within the drainage basin. The study area includes two sub-basins of the Marecchia valley (Senatello river, 49 km2 and Mazzocco river, 47 km2), chosen because of their similar extent and of the different location in the major catchment basin. Starting from geomorphological maps of the two river basins, the Tu parameter has been calculated and converted in short-term rate (average value 0.21 mm/year). Moreover, the comparison of these short-term mean data with the uplift rates calculated on a regional scale (0.41 ± 0.26 mm/year) in the Marecchia valley confirms that the northern Apennines may represent a non-steady state system.

scholarly journals Simulating Nutrient Uptake Dynamics in Plankton Models: a Case Study for the Cilician Basin Marine Ecosystem

2020 ◽  
Vol 20 (8) ◽  
pp. 603-612
Author(s):  
Ekin Akoglu
Keyword(s):  
Nutrient Uptake ◽  
Primary Productivity ◽  
Field Data ◽  
Mathematical Formulation ◽  
Phosphorus Limitation ◽  
Uptake Kinetics ◽  
Biogeochemical Model ◽  
Monod Kinetics ◽  
Nutrient Inputs ◽  
Nutrient Uptake Kinetics

The primary productivity in the Cilician Basin is severely constrained by phosphorus limitation due to high N:P ratios in the external nutrient inputs. Therefore, special attention is required when the dynamics of plankton is modelled. Acknowledging that mathematical formulation of nutrient uptake by phytoplankton in ecosystem models is crucial as it determines the degree of realism of the representation of biogeochemical dynamics, a plankton model was developed by utilising two widely adopted approaches; i) Monod nutrient uptake kinetics, and ii) Droop nutrient uptake kinetics, to delineate the seasonality of phytoplankton in an attempt to establish a mechanistic biogeochemical model of the Cilician Basin. The model was validated against field data from Erdemli Time Series stations in the region and differences between the approaches were compared. The model successfully simulated the phosphorus limitation in the basin; however, the scenario with Droop kinetics had a better fit to the field data. Both scenarios reproduced the primary productivity in the region. Overall, the results indicated that implementation of Monod kinetics generally sufficed to represent the seasonality of phytoplankton, whereas in environments with severe temporal nutrient scarcity, i.e. the Cilician Basin, implementation of Droop kinetics is required to represent the phytoplankton dynamics more realistically.

scholarly journals Impact of climate change on the blue water footprint of agriculture on a regional scale

2018 ◽  
Vol 19 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Huiping Huang ◽  
Yuping Han ◽  
Dongdong Jia
Keyword(s):  
Climate Change ◽  
Temporal Change ◽  
Water Footprint ◽  
Regional Scale ◽  
Maximum Temperature ◽  
Agricultural Water ◽  
Climate Change Projections ◽  
Change Models ◽  
Average Value

Abstract In the case study of Tangshan city, Hebei Province, China, this paper analyzes the temporal change of the blue agricultural water footprint (WF) during 1991–2016 and discusses the applicability of different climate change models during 2017–2050. Results show effective rainfall, wind speed and maximum temperature are leading factors influencing the blue agricultural WF. Relative error analysis indicates that the HadGEM2-ES model is the most applicable for climate change projections in the period of 2017–2050. Agricultural blue WF is about 1.8 billion m3 in RCP2.6, RCP4.5 and RCP8.5 emission scenarios, which is almost equal to the average value during 1991–2016.

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