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Guide to Process Based Modeling of Lakes and Coastal Seas | Anders Omstedt | Springer
Annual Review of Ecology and Systematics. Polish Journal of Environmental Studies. S Forest Service. United States Department of Agriculture. Retrieved 2 April Limnology and Oceanography. Bibcode : LimOc.. Science of the Total Environment. Bibcode : ScTEn. TNC Report. Sandra E. Marine Biology. The Journal of Applied Ecology. Nutrient Cycling in Agroecosystems. International Environmental Technology Centre. Journal Water Pollution Control Federation. Department of Natural Resources, Maryland, U. Applied Mathematical Modelling.
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Guide to Process Based Modeling of Lakes and Coastal Seas
Geoengineering in lakes: welcome attraction or fatal distraction? Waters 4, — Phosphorus control is critical to mitigating eutrophication. Archived from the original PDF on Retrieved Guiding principles for the development and application of solid-phase phosphorus adsorbents for freshwater ecosystems. Editorial — A critical perspective on geo-engineering for eutrophication management in lakes.
Water Res. Restoration and management of lakes and reservoirs. CRC Press. Longevity and effectiveness of aluminum addition to reduce sediment phosphorus release and restore lake water quality. Controlling eutrophication by combined bloom precipitation and sediment phosphorus inactivation. Attempted management of cyanobacteria by Phoslock lanthanum-modified clay in Canadian lakes: water quality results and predictions. Lake Reserv.
Management of eutrophication in Lake De Kuil The Netherlands using combined flocculant — Lanthanum modified bentonite treatment. Nine years of phosphorus management with lanthanum modified bentonite Phoslock in a eutrophic, shallow swimming lake in Germany. Marine biology Marine chemistry Deep scattering layer Diel vertical migration Ecosystems large marine marine f -ratio Iron fertilization Marine snow Ocean nourishment Oceanic physical-biological process Ocean turbidity Photophore Thorson's rule Upwelling Whale fall More Marine pollution.
Acid rain Air quality index Atmospheric dispersion modeling Chlorofluorocarbon Indoor air quality Global dimming Global distillation Global warming Ozone depletion Atmospheric particulate matter Smog. Environmental impact of pharmaceuticals and personal care products Environmental impact of shipping Environmental monitoring Eutrophication Freshwater environmental quality parameters Groundwater pollution Hypoxia Marine debris Marine pollution Nutrient pollution Ocean acidification Oil spill Septic tank Surface runoff Thermal pollution Turbidity Urban runoff Wastewater Water quality Water stagnation Waterborne diseases.
Actinides in the environment Bioremediation of radioactive waste Environmental radioactivity Fission product Nuclear fallout Plutonium in the environment Radiation poisoning Radium in the environment Uranium in the environment. Land degradation Light pollution Pollution from nanomaterials Noise pollution Radio spectrum pollution Urban heat island Visual pollution. The inundation extent of the flood grey is given as an indicative regional modern-day analogue of the plausible extent of inundation caused by backfilling during the Holocene highstand. Palaeo-shorelines black allude to the maximum Holocene extent of Lake Alexandrina and a period of stability following retreat to the present-day shoreline II The inundation extent of the flood, the greatest flood on instrumental record, is also depicted in Fig.
This extent is not as expansive as the Malcolm soil combination within the Lower Lakes region, suggesting that water levels at the Holocene highstand were well above maximum historical records. Bank overtopping from fluvial floodwaters during the flood caused valley-wide inundation within the Murray Gorge which gives insight into the plausible response to the Holocene highstand as the LMR is backfilled. All S low scenarios correlate with the flood extent and are characterised by valley-wide inundation throughout the Murray Gorge Fig.
Inundation of these two locations is reduced in the S mid WL 0 scenarios along with isolated small dry areas, however, these models remain characterised by valley-wide inundation Fig. Conversely, even given Holocene highstand sea levels, the S up scenarios are charactered by a channel with fringing swamps upstream of Mypolonga rkm , as was evident prior to levee construction and land reclamation in the 19 th century Our results suggest that the period of sea-level fall from highstand in the late-Holocene saw a significant shift in the geomorphic character of the LMR Fig.
Overall, model results are well correlated to regional geomorphology and sedimentology, and are consistent with research into the sedimentary infill and geomorphological evolution of barrier estuaries identified on the east coast of Australia e. Holocene highstand sea levels also induce valley-wide inundation under S up morphology, with the S mid and S low morphologies resulting in a significant increase in the areal extent of the Lower Lakes Fig. These results demonstrate that sea level is the driving factor controlling the environmental character of the Lower Lakes and LMR.
Key representative maps comparing maximum salinity reached relative to sea level, bathymetric surface, discharge and barrier morphology. The hatched box highlights the common scenario between the three panels: scenario S mid WL 2 D av B mod. Salinity is measured based on the classification scheme of Tooley Comparison of 10 psu marine-brackish and backwater zone limits for all WL 0 and WL 2 paired scenarios. Given S up conditions yellow , the backwater zone is restricted to the main body of Lake Alexandrina grey shading and the Pomanda Embayment within WL 0 scenarios, with the higher sea level in WL 2 scenarios driving this limit upstream into the lower reaches of the Murray Gorge.
The influence of sea level on the backwater limit is equally apparent given S mid conditions red , where at the Holocene highstand, an enlarged low energy backwater setting was emplaced up to Walker Flat rkm We suggest that, prior to anthropogenic modifications of the flow regime, this central basin sequence was continuing to accumulate within the entirety of Lake Alexandrina; top-of-core modern dates across the regionally extensive laminated sequence support this hypothesis Variation in barrier morphology Fig.
Overall, the S low WL 2 and S mid WL 2 scenarios are well constrained by the Malcolm soil combination, and palaeo-shorelines, representing the maximum Holocene inundation extent of the Lower Lakes 31 which suggests the suitability of interpolating these results to the palaeo-environment at the Holocene highstand Fig. These results show that the Holocene highstand probably generated valley-wide inundation within the entirety of the Murray Gorge at least as far upstream as Blanchetown rkm ; Fig.
Given this single central basin depositional environment, we infer the presence of a laminated sequence within the valley-wide LMR perhaps extending as far upstream as Walker Flat rkm ; Fig. During the late-Holocene, we suggest that the bayhead delta prograded downstream to Mypolonga rkm , where there is a notable shift in the geomorphic character of the levees and fringing swamps, before anthropogenic modification inhibited further natural estuarine evolution from onwards Estuarine processes zonation and inferred resulting morphology at the Holocene highstand.
At the Holocene highstand, the tidal limit propagated beyond the study region, suggesting a minimum tidal limit of Blanchetown rkm This zonation is extrapolated into inferred resulting morphology at the Holocene highstand grey italicised text. The central basin occupied the entirety of the Lower Lakes, Lakes Alexandrina and Albert, and extended upstream within the Murray Gorge plausibly as far as Walker Flat rkm , minimum Monteith at rkm , and median Mannum at rkm Upstream, the bayhead delta occupied a low-energy backwater zone at least as far as Blanchetown rkm During the late-Holocene, the bayhead delta prograded downstream to Mypolonga rkm Our results suggest that this laminated sequence characterises the Holocene depositional fill within the Murray Gorge at least as far upstream as Monteith rkm and plausibly as far as Walker Flat rkm ; grey and blue shaded areas.
The LMR is characterised by a main channel with fringing swamps under S up scenarios, while the S mid and S low scenarios exhibit valley-wide inundation Fig. Within the Lower Lakes, the modelled inundation extent is comparable to present-day shorelines under S up scenarios, with the S mid and S low morphologies extending inundation across the Cooke Plains Embayment Fig. Despite the uncertainty in the precise location of a S mid surface, the similarity between the results from the two morphological end members S low and S up scenarios show that robust conclusions can be drawn irrespective of the validity of the S mid Holocene highstand best-estimate morphology.
Sensitivity testing for discharge reveals that the flood event has a greater influence on palaeo-salinities when compared to drought, however, only under S up WL 0 scenarios is a flood sufficient to supress Lake Alexandrina to fresher conditions Fig. The experimental hydrodynamic modelling approach adopted in this study allows for the relative importance of drivers of palaeo-environmental change to be determined.
The experimental hydrodynamic modelling approach used here subjects end-member conditions to a sensitivity analysis giving a range of plausible responses rather than an explicit replication of reality. For instance, the S low Pleistocene-Holocene boundary surface is certainly deeper than reality at the Holocene highstand, and the S up pre-regulation surface certainly shallower.
The negligible difference in results obtained through this end-member approach signifies that our models can in fact be extrapolated to represent a reasonable approximation of reality at the Holocene highstand. On a local scale, within the Lower Lakes, flood tide delta and barrier complex stratigraphic 23 , 31 , 35 , diatom 23 , 36 and midden analyses 37 support the designation of the regional palaeo-environment as estuarine at the Holocene highstand. However, our results demonstrate that the estuarine palaeo-environment was not limited solely to this region.
The low relief of this coastal plain facilitated an elongated central basin within the confines of the Murray Gorge, likely extending as far upstream as Walker Flat rkm , where the silt-clay laminated sequence that characterises the central basin deposits within Lake Alexandrina 23 , 24 are inferred to extend Fig. Adopting Zaitlin et al. We suggest that, at highstand, the fluvial inner incised valley stretched from this estuarine limit landward to Overland Corner rkm where the river enters the Murray Gorge. Here, the Coonambidgal Formation displays evidence of a declining energy gradient 39 , which is not characteristic of the sediments of a meandering river rkm upstream of its terminus.
This unusually extensive backwater zone was a consequence of the unique low relief of this coastal plain system that attenuated flow velocities and forced the limit of coarse-grained fluvial deposition well upstream. Since European settlement, the region has been subject to significant modification including extensive land reclamation and the construction of levees, locks, and barrages. Prior to this, the riverbanks between Mannum rkm and Mypolonga rkm were typically high creating natural levees that separated the channel from low-lying flats; this configuration transitioned to an unbroken series of swamps between Mypolonga rkm and Wellington rkm 78 This shift in channel fringing environment at Mypolonga rkm is inferred to be the approximate limit of bayhead delta progradation before significant European modification and regulation of the LMR disrupted the natural flow regime Fig.
A homogenous clay sequence could be expected to overlie the laminated central basin deposit, representing the downstream progradation of the bayhead delta, the precise location of which will be determined by a subsequent study. An Australian east coast analogue is present in the Hawkesbury River estuary, where the Holocene estuarine central basin and bayhead delta sediments extend well into the gorge-confined valley, with the Colo River estuarine sequence presenting similar laminations to those described in Lake Alexandrina 23 , 24 , 29 , When considering the LMR, or other gorge confined portions of coastal plain estuaries as an extension of the central basin, the definition adopted is important.
Dalrymple et al. We correlate the process-based results from S mid WL 2 scenarios with facies designation to infer the resulting morphology of the Murray estuary at the Holocene highstand Fig. Our inferred resulting morphology adopts Dalrymple et al. Here we consider the central basin as the region of lowest energy characterised by the confluence of marine and fluvial influence and the deposition of the finest sediment.
Following conventional models of estuarine facies designation, the location where the river debouches into the lagoon is the likely transitional point of the designation of fluvial to estuarine geological formations Fig. However, with low relief allowing for elongated estuarine zones at the Holocene highstand, we suggest that the location of this transition requires review across coastal plain estuaries more broadly.
How it works
In the case of the Murray estuary, the Holocene stratigraphy of Lake Alexandrina is characterised as the estuarine and coastal-marine sediments of the St Kilda Formation, whereas the LMR is characterised as the Quaternary alluvium of the Coonambidgal Formation Fig. By assigning our process-based results to inferred resulting morphology, we suggest a revision of the location of this transition is required to account for the Holocene extension of estuarine sedimentation within the gorge-confined portion of the central basin Fig.
A sedimentary analysis is currently underway to assess the upstream extent and nature of this deposit, with previous work in the region suggesting the presence of a laminated sequence may be widespread within the LMR 32 , The key to understanding responses of coastal plain estuaries to future changes in climate requires a knowledge of drivers of change, best explored by an examination of palaeo-responses to such change through representative analogues. With the pace of future sea-level rise too rapid for barriers to transgress in response, and our results demonstrating a significant change in environmental character regardless of barrier morphology, we demonstrate the utility of applying a historical analogue to understand the importance of adapting water management to future needs.
In the case of the Murray estuary, this analysis highlights the future importance of and likely need for reliance on the barrages if the current freshwater resource priorities are to be maintained. Adopting a hydrodynamic modelling approach to Holocene analogues of coastal plain estuaries allows for the significant potential impact of climate change induced sea-level rise to be realised.
We demonstrate that the estuarine limit can extend significantly further inland than expected when evaluating modern-day geomorphology in the context of conventional estuarine facies models.
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The importance of sea level in controlling the character of the Murray estuary, irrespective of fluvial discharge, bathymetry and barrier morphology, suggests the impacts of future sea-level rise due to climate change on coastal plain estuaries may be underappreciated. Our results are broadly applicable to low-gradient coastal plain estuaries with wave-dominated entrances, particularly those with large catchments and low discharges.
The extent and impact of sea-level rise as a driver of environmental change is largely a consequence of the inherently low gradient of these systems. This characteristic low gradient of coastal plain estuaries facilitates the landward extension of the estuarine zone rendering lower portions of the conventionally fluvially dominated zone particularly vulnerable to saline intrusion and potentially unable to support potable water or irrigation supplies.
The economic and social implications of our findings to the LMR and Murray estuary, and comparable coastal plain estuaries more broadly, are considerable. Using TUFLOW FV, a 2D finite volume numerical model, we simulate 72 scenarios and conduct sensitivity testing for bathymetric surface two end members and a best estimate , sea level Holocene highstand and present-day , discharge drought, pre-regulation average, and flood , and barrier morphology four scenarios, ranging from completely open to almost closed, to account for barrier evolution.
The Pleistocene-Holocene stratigraphic boundary and pre-regulation surfaces represent bathymetric end-members to constrain the entire range of plausible bathymetries at the Holocene highstand. These are denoted as S low and S up respectively. A best estimate of bathymetry at the Holocene highstand is given by the S mid surface. For each of these six categories, all possible combinations of discharge and barrier morphology were modelled.
We obtain inundation extents, water heights and depths, flow velocities and salinities for the full extent of the LMR and Murray estuary for each of the 72 modelled scenarios. This mesh was then modified to extend the model domain to encompass the entire width of the Murray Gorge, as well as the inclusion of the modern-day barrier complex and extension of the Lower Lakes based on the palaeo-maximum inundation shoreline and Holocene estuarine stratigraphy 31 , 35 , Tides were imposed based on historical data taken from Victor Harbour between 1 st January — 28 th February to remove the uncertainties associated with tidal prediction Fig.
Initial salinity was applied at each cell based on salinity data taken from 25 gauging stations throughout the region at the peak of the Millennium drought. This was deemed appropriate as the barrages are in place to curtail saline intrusion and therefore regional salinities are held fresher than would naturally occur. Due to the potential influence of stratification of the estuary a representative subset of models were run in 3D to assess the suitability of adopting computationally efficient 2D models for this study.
Refer to Supplementary methods: Comparison of 2D and 3D simulations for further information. This value is supported by sensitivity testing and calibration performed by BMT WBM on the base model provided for this study 42 , and aligns with sensible values given hypothesised Holocene regional palaeo-environmental conditions Refer to Supplementary methods: Model calibration for further information.
Details on the creation of the three bathymetric surfaces, and chain-of-islands evolution of Sir Richard and Younghusband Peninsulas used to inform the four modelled barrier morphologies are given in Supplementary methods: Morphology. Sensitivity testing for barrier evolution was based on the chain-of-islands model 13 with the location of possible palaeo-outlets interpreted from Bourman and Murray-Wallace 46 , de Mooy 31 and Luebbers Four barrier configurations were tested ranging from the complete removal of Sir Richard and Younghusband Peninsulas to the modern-day Murray Mouth Fig.
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About this book Mounting concern about the influence of humans on climate and environmental conditions has increased the need for multi-disciplinary modeling efforts, including systems such as oceans, costal seas, lakes, land surfaces, ice, rivers and atmosphere. This unique book will stimulate students and researchers to develop their modeling skills and make model codes and data transparent to other research groups.
The book uses the general equation solver PROBE to introduce process oriented numerical modeling and to build understanding of the subject step by step. PROBE is a general equation solver for one-dimensional transient, or two-dimensional steady, boundary layers. By the construction of nets of sub-basins the book illustrates how the process based modeling can be extended, complementing three-dimensional modeling.
The equation solver has been used in many applications, particularly in Sweden and Finland with their numerous lakes, archipelago seas, fjords, and coastal zones.