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On the Influence of Antecedent Morphology on Development of Equilibrium Bathymetry in Estuaries Past and Future

JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 2022年第8期127卷 e2022JF006621-e2022JF006621页

作者： Rahdarian, Amin Bryan, Karin R. Van der Wegen, Mick Univ Waikato Fac Sci & Engn Sch Sci Hamilton New Zealand IHE Delft Inst Water Educ Delft Netherlands Deltares Delft Netherlands

Although analytical and numerical models have been widely used to explore evolution and equilibrium morphology in tidal environments, less attention has been paid to examining the impact of initial bathymetry on the model outcomes. Here we use two-dimensional idealized models with contrasting initial bathymetries to study how the interactions between antecedent morphology and tidal exchange processes determine the establishment of an estuarine equilibrium bathymetry, and how these interactions mediate the morphodynamic response to rising sea levels. In all model runs with sandy beds, inter-tidal zones reach the equilibrium condition first and equilibrium profiles are similar for points close to mean seal level. However, key aspects like channel formation, residence time and energy dissipation do not evolve to the same state and are inherited from the initial bathymetry. This implies that responses to sea-level rise (SLR) are different as well. Conversely, in cases with mud and sand input at the boundaries, equilibrium occurs more quickly and the equilibrium bathymetry and channel formation are dominated by the boundary mud concentration. General implications of the study are that predictions of coastal response to changes such as SLR depend on initial bathymetric conditions.

关键词： antecedent bathymetry equilibrium condition sea-level rise tidal environment physical services process-based modeling Delft3D drainage channel network

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modeling the Morphodynamic Response of Estuarine Intertidal Shoals to Sea-Level Rise

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JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 2022年第1期127卷 e2021JF006152-e2021JF006152页

作者： Elmilady, H. van der Wegen, M. Roelvink, D. van der Spek, A. IHE Delft Dept Coastal & Urban Risk & Resilience Delft Netherlands Deltares Dept Appl Morphodynam Delft Netherlands Delft Univ Technol Fac Civil Engn & Geosci Delft Netherlands Univ Utrecht Fac Geosci Utrecht Netherlands

Intertidal shoals are key features of estuarine environments worldwide. Climate change poses questions regarding the sustainability of intertidal areas under sea-level rise (SLR). Our work investigates the SLR impact on the long-term morphological evolution of unvegetated intertidal sandy shoals in a constrained channel-shoal system. Utilizing a process-based model (Delft3D), we schematize a short tidal system in a rectangular (2.5 x 20 km) basin with a high-resolution grid. An initial, mildly sloping, bathymetry is subjected to constant semidiurnal tidal forcing, sediment supply, and small wind-generated waves modeled by SWAN. A positive morphodynamic feedback between hydrodynamics, sediment transport, and morphology causes the emergence of large-scale channel-shoal patterns. Over centuries, tide-residual sediment transport gradually decreases leading to a state of low morphological activity balanced by tides, waves, and sediment supply. Tidal currents are the main driver of the SLR morphodynamic adaptation. Wave action leads to wider and lower shoals but does not fundamentally change the long-term morphological evolution. SLR causes increased flood dominance which triggers sediment import into the system. Shoals accrete in response to SLR with a lag that increases as SLR accelerates, eventually causing intertidal shoals to drown. Seaward shoals near the open boundary sediment source have higher accretion rates compared to landward shoals. Similarly, on a shoal-scale, the highest accretion rates occur at the shoal edges bounding the sediment suppling channels. A larger sediment supply enhances the SLR adaptation. Waves help distribute sediment supplied from channels across shoals. Adding mud fractions leads to faster, more uniform, accretion and muddier shoals under SLR.

关键词： Sea-level rise Long-term morphological evolution Intertidal shoals Waves process-based modeling Delft3D

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Assessing the impacts of pre-growing-season weather conditions on soil nitrogen dynamics and corn productivity in the US Midwest

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FIELD CROPS RESEARCH 2022年 284卷

作者： Li, Ziyi Guan, Kaiyu Zhou, Wang Peng, Bin Jin, Zhenong Tang, Jinyun Grant, Robert F. Nafziger, Emerson D. Margenot, Andrew J. Gentry, Lowell E. DeLucia, Evan H. Yang, Wendy H. Cai, Yaping Qin, Ziqi Archontoulis, Sotirios, V Fernandez, Fabian G. Yu, Zhongjie Lee, DoKyoung Yang, Yufeng Univ Illinois Agroecosyst Sustainabil Ctr Inst Sustainabil Energy & Environm Urbana IL 61801 USA Univ Illinois Coll Agr Consumer & Environm Sci Urbana IL 61801 USA Univ Illinois Natl Ctr Supercomp Applicat Urbana IL 61801 USA Univ Minnesota Twin Cities Dept Bioprod & Biosyst Engn St Paul MN 55108 USA Lawrence Berkeley Natl Lab Climate & Ecosyst Sci Div Climate Sci Dept Berkeley CA 94720 USA Univ Alberta Dept Renewable Resources Edmonton AB T6G 2R3 Canada Univ Illinois Carl R Woese Inst Genom Biol Urbana IL USA Univ Illinois Dept Plant Biol Urbana IL 61801 USA Univ Illinois Ctr Adv Bioenergy & Bioprod Innovat Urbana IL USA Univ Illinois Dept Geol Urbana IL 61801 USA Iowa State Univ Dept Agron Ames IA 50011 USA Univ Minnesota Twin Cities Dept Soil Water & Climate St Paul MN 55108 USA

Improving nitrogen (N) use efficiency is urgently needed to achieve co-sustainability of agricultural productivity and environmental quality. Environmental conditions and farming management practices affect the N cycle in agroecosystems. Particularly, weather conditions during the pre-growing-season (e.g. winter and early spring for the U.S. Corn Belt) can influence the dynamics of soil inorganic N (SIN) content and have implications for the end-of-season crop yield. Here, we used an advanced agroecosystem model, ecosys, to assess the consequences of different pre-growing-season weather scenarios in terms of both SIN dynamics and crop productivity. We first benchmarked ecosys using extensive N trial data collected across the U.S. Midwest, and found that ecosys captured the N fertilizer-yield responses and field-scale N cycle dynamics. We then used ecosys to conduct multiple experiments by changing the pre-growing-season precipitation and temperature, and assessed how these changes affected soil N dynamics and crop yield. We found that: (1) wetter pre-growing-seasons reduced SIN content through increasing leaching, leading to a reduction in corn grain yield of 0.54-0.86 Mg/ha (5-14%) under no fertilizer and of 0.21-0.33 Mg/ha (1-3%) under the normal N fertilizer rate (167 kg N/ha;Illinois average N fertilizer rate in 2018);yield loss induced by higher pre-growing-season precipitation can be eliminated by applying more N fertilizer in spring;and (2) colder pre-growing-seasons can reduce SIN content through decreased N mineralization and enhanced leaching. Both factors further contribute to corn yield loss of 0.10-0.68 Mg/ha (2-8%) under no fertilizer and of 0.12-0.48 Mg/ha (1-4%) under the normal fertilizer rate;however, in this case adding more fertilizer does not necessarily eliminate the yield loss caused by the colder pre-growingseason, because the lower temperature not only causes SIN deficiency but also reduces early-growing-season active root nutrients uptake a

关键词： Corn agroecosystem nitrogen cycle process-based modeling Ecosys

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SURFWET: A biokinetic model for surface flow constructed wetlands

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SCIENCE OF THE TOTAL ENVIRONMENT 2020年 723卷 137650-137650页

作者： Aragones, David G. Sanchez-Ramos, David Calvo, Gabriel F. Univ Castilla La Mancha Sch Civil Engn Dept Math Av Camilo Jose Cela S-N Ciudad Real 13071 Spain Univ Castilla La Mancha Sch Civil Engn Res Grp Hydroecol Av Camilo Jose Cela S-N Ciudad Real 13071 Spain

Constructed wetlands are an alternative biotechnology for wastewater treatment that have several advantages over conventional systems. In this work, a biokinetic model for surface flow constructed wetlands is presented (SURFWET). SURFWET belongs to a class of models that are not only interesting from a theoretical viewpoint, as they allow to improve the understanding of the underlying processes;but also from a practical viewpoint, because they can be useful for optimal designs of constructed wetlands, complementing current empirical methods. The proposed model is centered on the intervening physical and biochemical processes involved in pollutant removal in wastewater (organic matter, nitrogen, phosphorus, suspended solids), capturing the interplay of the main agents on contaminant removal (bacteria, macrophytes and phytoplankton). Furthermore, the hydraulic model considers water volume as a variable depending on the outlet hydraulic capacity, and dissolved oxygen has also been introduced as a key driver of reaction kinetics of wetlands. Beyond putting forward a theoretical framework, SURFWET has been applied to simulate a specific case to demonstrate its robustness, in a 12-year-interval simulation. The results show the typical seasonality of this biotechnology, highlighting the importance of dissolved oxygen, which is a key limiting factor on a large number of biochemical processes. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Treatment wetlands Free-water surface process-based modeling Wastewater Pollutant removal Mathematical model

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Soil carbon and nitrous oxide dynamics in corn (Zea mays L.) production under different nitrogen, tillage and residue management practices

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FIELD CROPS RESEARCH 2022年第0期277卷 108421-108421页

作者： Jiang, Qianjing Madramootoo, Chandra A. Qi, Zhiming McGill Univ Dept Bioresource Engn Ste Anne De Bellevue PQ H9X 3V9 Canada

Reducing tillage frequency and intensity and returning crop residues to the soil are two agricultural management practices to increase soil organic carbon (SOC). Timing and rates of nitrogen fertilizer, coupled with tillage methods and residue incorporation, can also influence nitrous oxide emissions. In this study, we used measured data from a long term (23 years) tillage and residue management experiment, under intensive grain corn production, together with the DNDC (DeNitrification-DeComposition) process-based model, to ascertain the most effective fertilizer and tillage management practices to reduce nitrous oxide emissions and nitrate leaching, and increase soil carbon stocks. The field experiment consisted of no-till [NT], reduced [RT], and conventional tillage [CT], with and without corn residue return. After calibration and validation, using field observed data, the DNDC model was run with 108 management scenarios (six N application rates, spring single N fertilization, spring split N fertilization and fall fertilization, three tillage practices and two residue-return options). N application rate was predicted to be a significant driver for corn yield, SOC sequestration, N2O emissions and nitrate leaching, indicating the need to identify a critical N rate to both optimize production and achieve sustainability goals. Split (vs. single) N application did not significantly affect corn yield, nitrate leaching, N2O emissions or SOC, while fall fertilization should be avoided due to greater nitrate leaching and higher N2O emissions as well as lower crop yield. Although stimulating N2O emissions, both NT and residue return are recommended for their ability to enhance SOC stocks. Results of this study can be used for policy development regarding carbon sequestration and GHG emissions for intensive grain cropping systems in the humid regions of North America.

关键词： Carbon sequestration process-based modeling Tillage Corn residue Nitrate leaching Nitrous oxide emissions

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Bayesian mechanistic modeling characterizes Gulf of Mexico hypoxia: 1968-2016 and future scenarios

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ECOLOGICAL APPLICATIONS 2020年第2期30卷 e02032页

作者： Del Giudice, Dario Matli, V. R. R. Obenour, Daniel R. NC State Univ Dept Civil Construct & Environm Engn Raleigh NC 27695 USA NC State Univ Ctr Geospatial Analyt Raleigh NC 27695 USA

The hypoxic zone in the northern Gulf of Mexico is among the most dramatic examples of impairments to aquatic ecosystems. Despite having attracted substantial attention, management of this environmental crisis remains challenging, partially due to limited monitoring to support model development and long-term assessments. Here, we leverage new geostatistical estimates of hypoxia derived from nearly 150 monitoring cruises and a process-based model to improve characterization of controlling mechanisms, historic trends, and future responses of hypoxia while rigorously quantifying uncertainty in a Bayesian framework. We find that November-March nitrogen loads are important controls of sediment oxygen demand, which appears to be the major oxygen sink. In comparison, only 23% of oxygen in the near-bottom region appears to be consumed by net water column respiration, which is driven by spring and summer loads. Hypoxia typically exceeds 15,600 km(2) in June, peaks in July, and declines below 10,000 km(2) in September. In contrast to some previous Gulf hindcasting studies, our simulations demonstrate that hypoxia was both severe and worsening prior to 1985, and has remained relatively stable since that time. Scenario analysis shows that halving nutrient loadings will reduce hypoxia by 37% with respect to 13,900 km(2) (1985-2016 median), while a +2 degrees C change in water temperature will cause a 26% hypoxic area increase due to enhanced sediment respiration and reduced oxygen solubility. These new results highlight the challenges of achieving hypoxia reduction targets, particularly under warming conditions, and should be considered in ecosystem management.

关键词： Bayesian inference climate change dead hypoxic zones eutrophication Gulf of Mexico hindcasts and projections process-based modeling riverine nitrogen uncertainty quantification

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Morphodynamic Evolution of a Fringing Sandy Shoal: From Tidal Levees to Sea Level Rise

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JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 2020年第6期125卷 e2019JF005397-e2019JF005397页

作者： Elmilady, H. van der Wegen, M. Roelvink, D. van der Spek, A. IHE Delft Inst Water Educ Delft Netherlands Deltares Delft Netherlands Delft Univ Technol Fac Civil Engn & Geosci Delft Netherlands Univ Utrecht Fac Geosci Utrecht Netherlands

Intertidal shoals are vital components of estuaries. Tides, waves, and sediment supply shape the profile of estuarine shoals. Ensuring their sustainability requires an understanding of how such systems will react to sea level rise (SLR). In contrast to mudflats, sandy shoals have drawn limited attention in research. Inspired by a channel-shoal system in the Western Scheldt Estuary (Netherlands), this research investigates governing processes of the long-term morphodynamic evolution of intertidal estuarine sandy shoals across different timescales. We apply a high-resolution process-based numerical model (Delft3D) to generate a channel-shoal system in equilibrium and expose the equilibrium profile to variations in wave forcing and SLR. Combined tidal action and wave forcing initiate ridge formation at the seaward shoal edge, which slowly propagates landward until a linear equilibrium profile develops within 200 years. Model simulations in which forcing conditions have been varied to reproduce observations show that the bed is most dynamic near the channel-shoal interface. A decrease/increase in wave forcing causes the formation/erosion of small tidal levees at the shoal edge, which shows good resemblance to observed features. The profile recovers when regular wave forcing applies again. Sandy shoals accrete in response to SLR with a long (decades) bed-level adaptation lag eventually leading to intertidal area loss. This lag depends on the forcing conditions and is lowest near the channel and gradually increases landward. Adding mud makes the shoal more resilient to SLR. Our study suggests that processes near the channel-shoal interface are crucial to understanding the long-term morphodynamic development of sandy shoals. Plain Language Summary Intertidal area is the coastal zone that undergoes a rhythm of wet-dry cycles under the influence of tidal action. Intertidal shoals are vital components of the estuarine environment. They have high ecological value but also help

关键词： Intertidal sandy shoals Long-term estuarine morphodynamics process-based modeling Waves Tidal levees Sea-level rise

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Towards reusable process-based models of dynamical systems: A case study in the domain of aquatic ecosystems 42

Towards reusable process-based models of dynamical systems: ...

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42nd International Convention on Information and Communication Technology, Electronics and Microelectronics (MIPRO)

作者： Tolovski, Ilin Kostovska, Ana Simidjievski, Nikola Todorovski, Ljupco Dzeroski, Saso Panov, Pance Jozef Stefan Inst Dept Knowledge Technol Ljubljana Slovenia Jozef Stefan Int Postgrad Sch Ljubljana Slovenia Univ Cambridge Dept Comp Sci & Technol Cambridge England Univ Ljubljana Fac Adm Ljubljana Slovenia

ISBN: (纸本)9789532330984

Storing metadata about models of dynamical systems in a machine readable form is one of the key steps towards their accessibility and reusability. In the domain of process-based modeling of dynamical systems, the task is to construct an explanatory model of a dynamical system from domain knowledge and data. In this paper, we present a workflow for annotation, storage and querying of process-based models specifically in the domain of aquatic ecosystems. To provide the vocabulary of key terms about the process-based modeling paradigm, we use the Ontology for process-based modeling of Dynamical Systems (OntoPBM). Next, to capture the domain-specific characteristics, we extend OntoPBM with terms specific for aquatic ecosystems. The annotations for each process-based model are stored in an RDF triple store. This enables us to execute SPARQL queries on facts asserted in the annotations, as well as facts inferred from the domain knowledge encoded in the ontology. Finally, by following the proposed workflow, we generate the minimal information about a model, which takes us one step closer towards reusable research.

关键词： dynamical systems process-based modeling ontologies knowledge representation querying reusability

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Root zone soil moisture estimation with Random Forest

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JOURNAL OF HYDROLOGY 2021年 593卷 125840-125840页

作者： Carranza, Coleen Nolet, Corjan Pezij, Michiel van der Ploeg, Martine Wageningen Univ Soil Phys & Land Management Grp Wageningen Netherlands FutureWater Wageningen Netherlands Univ Twente Dept Water Engn & Management Enschede Netherlands HKV Botter 1129 NL-8232 JN Lelystad Netherlands Wageningen Univ Hydrol & Quantitat Water Management Grp Wageningen Netherlands

Accurate estimates of root zone soil moisture (RZSM) at relevant spatio-temporal scales are essential for many agricultural and hydrological applications. Applications of machine learning (ML) techniques to estimate root zone soil moisture are limited compared to commonly used process-based models based on flow and transport equations in the vadose zone. However, data-driven ML techniques present unique opportunities to develop quantitative models without having assumptions on the processes operating within the system being investigated. In this study, the Random Forest (RF) ensemble learning algorithm, is tested to demonstrate the capabilities and advantages of ML for RZSM estimation. Interpolation and extrapolation of RZSM on a daily timescale was carried out using RF over a small agricultural catchment from 2016 to 2018 using in situ measurements. Results show that RF predictions have slightly higher accuracy for interpolation and similar accuracy for extrapolation in comparison with RZSM simulated from a process-based model combined with data assimilation. RF predictions for extreme wet and dry conditions were, however, less accurate. This was inferred to be due to infrequent sampling of such conditions that led to poor learning in the trained RF model and to incomplete representation of relevant subsurface processes at the study sites in the RF covariates. Since RF does not depend on parameters required to estimate subsurface water flow, it is more advantageous than a process-based model in data-poor regions where soil hydraulic parameters are incomplete or missing, especially when the primary goal is only the estimation of soil moisture states.

关键词： Root zone soil moisture Random Forest Prediction process-based modeling

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modeling tidal sand wave recovery after dredging:effect of different types of dredging strategies

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COASTAL ENGINEERING 2021年 165卷 103862-103862页

作者： Campmans, G. H. P. Roos, P. C. Van der Sleen, N. R. Hulscher, S. J. M. H. Water Engn & Management POB 217 NL-7500 AE Enschede Netherlands Rijkswaterstaat Water Verkeer & Leefomgeving Utrecht Netherlands

Maintenance of navigation channels in shelf seas with tidal sand waves usually requires repeated dredging operations. Optimizing these interventions is a difficult task, particularly complicated by the nonlinear morphodynamics of sand wave recovery after dredging. Here we present a process-based model study, incorporating different strategies of dredging in an existing nonlinear sand wave model. We consider 'topping' (removing sand from crest) and 'swiping' (same, but now placing it in the troughs), for a range of dredging depths. Starting point is a fully developed sand wave or sand wave field, as simulated in the model. Results indicate that sand wave recovery is slowest after swiping. Also, larger dredging volumes imply longer recovery times. Next, we study the maintenance intervals and (cumulative) dredging volumes resulting from adopting a typical temporal strategy: swipe to a prescribed dredging depth, as soon as the recovering sand wave crests have reached a critical depth. Maintenance intervals are found to depend on the dredging depth and, importantly, to vary over time, as well. This last result shows that sand wave recovery depends not only on height, but also on its shape, emphasizing the limitations of existing, empirical (Landau-type of) models based on amplitude (or height) only.

关键词： Tidal sand waves Dredging strategies Morphodynamics process-based modeling

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