Jaap Nienhuis

Utrecht University | UU · Department of Physical Geography

Delta shoreline structure has long been hypothesized to encode information on the relative influence of fluvial, wave, and tidal processes on delta formation and evolution. We introduce here a novel multiscale characterization of shorelines by defining three process-informed morphological metrics. We show that this characterization yields self-emer...

Waves, rivers, and tides play a leading role in shaping delta morphology. Recent studies have enabled predictions of their relative influence for deltas globally, but methods and associated uncertainties have remained poorly described. Here we aim to address that gap and assess the quality of delta morphology predictions compared to observations fo...

Flood-protection levees have been built along rivers and coastlines globally. Current datasets, however, are generally confined to territorial boundaries (national datasets) and are not always easily accessible, posing limitations for hydrologic models and assessments of flood hazard. Here, we bridge this knowledge gap by collecting and standardizi...

Plain Language Summary River deltas are ecologically and economically important, and each delta is unique in terms of its environmental conditions and overall form. We test a 50‐year‐old hypothesis that qualitatively relates the overall form of a delta (in terms of its shoreline and channel network) to the balance between river and marine influence...

Future sea-level rise poses an existential threat for many river deltas, yet quantifying the effect of sea-level changes on these coastal landforms remains a challenge. Sea-level changes have been slow compared to other coastal processes during the instrumental record, such that our knowledge comes primarily from models, experiments, and the geolog...

Anthropogenic conversion of forests and wetlands to agricultural and urban landcovers impacts dissolved organic matter (DOM) within streams draining these catchments. Research on how landcover conversion impacts DOM molecular level composition and bioavailability, however, is lacking. In the Upper Mississippi River Basin (UMRB), water from low-orde...

Arctic continental shelves, including the Alaskan Beaufort Shelf (ABS), are experiencing declines in sea ice coverage leading to increasingly energetic sea states and coastal erosion. In this study we investigated the morphologic response of the ABS to increasing wave energy, and how shelf profile adjustments modify wave energy propagating toward t...

A new special collection invites studies on a new era of models and knowledge that provide predictions or insights into predictability in coastal geomorphology.

Summary of work on building openDELvE, the status of coverage, and developments to the database since publishing

Deltas worldwide are at risk of elevation loss and drowning due to relative sea-level rise. Management strategies to restore or enhance sedimentation on delta plains, Sedimentation-Enhancing Strategies (hereafter SES) are now being pursued in many deltas but there has been limited cross-disciplinary and cross-delta review. Here we compare 21 existi...

Arctic deltas form the critical interface between the Arctic landscape and the ocean. They filter freshwater, sediment, carbon and biochemical fluxes from approximately 14 million km² of northern permafrost terrain. This Review highlights the unique controlling factors, seasonality and morphodynamic processes affecting Arctic deltas. Arctic deltas...

Flood-protection levees have been built along rivers and coastlines globally. Current datasets, however, are generally confined to territorial boundaries (national datasets) and are not always easily accessible, posing limitations for hydrologic models and assessments of flood hazard. Here we present our work to develop a single, open-source global...

Landcover changes have altered the natural carbon cycle; however, most landcover studies focus on either forest conversion to agriculture or urban, rarely both. We present differences in dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) molecular composition within Upper Mississippi River Basin low order streams and r...

River deltas will likely experience significant land loss because of relative sea-level rise (RSLR), but predictions have not been tested against observations. Here, we use global data of RSLR and river sediment supply to build a model of delta response to RSLR for 6,402 deltas, representing 86% of global delta land. We validate this model against...

Waves and water level setup during storms can create overwashing flows across barrier islands. Overwashing flows can cause erosion, barrier breaching, and inlet formation, but their sediments can also be deposited and form washover fans. These widely different outcomes remain difficult to predict. Here we suggest that a breach develops when the sed...

p>Channel beds in estuaries and deltas often exhibit a local depth maximum close to the river mouth. There are two known mechanisms of large-scale (i.e., >10 river widths along-channel) channel bed scours: width constriction and draw-down during river discharge extremes, both creating flow acceleration. Here, we study a potential third mechanism: t...

openDELvE is a consolidated dataset of global vector and raster data regarding river levees. We present at the EGU the state of our efforts so far, including information on coverage and intent, as well as opening our dataset to feedback and suggestions. We encourage readers to visit the website www.opendelve.eu and submit admendments using the for...

Recording of presentation given at vEGU General Assembly 2021 on openDELvE

Deltas require sufficient sediment to maintain their land area and elevation in the face of relative sea-level rise. Understanding sediment budgets can help in managing and assessing delta resilience under future conditions. Here, we make a sediment budget for the distributary channel network of the Rhine–Meuse delta (RMD), the Netherlands, home to...

Prediction of the shoreline response behind offshore breakwaters is essential for coastal protection projects. Due to the complexity of the processes behind the breakwaters (e.g., wave diffraction, currents, longshore transport), detailed modelling needs high computational efforts. Therefore, simplifying the process effect in a simpler coastline mo...

It is widely recognized that waves inhibit river mouth progradation and reduce the avulsion timescale of deltaic channels. Nevertheless, those effects may not apply to downdrift‐deflected channels. In this study, we developed a coupled model to explore the effects of wave climate asymmetry and alongshore sediment bypassing on shoreline‐channel morp...

The potential for rapid coastline modification in the face of sea‐level rise or other stressors is alarming since coasts are often densely populated and support valuable infrastructure. In addition to coastal submergence, nutrient‐related water pollution is a growing concern for coastal wetlands. Previous studies found that the suspended sediment c...

River deltas will likely experience significant land loss because of relative sea-level rise (RSLR), but predictions have remained elusive. Here, we use global data of RSLR and river sediment supply to build a validated model of delta response to RSLR for all ~10,000 deltas globally. Applying this model to predict future delta change, we find that...

The natural wetlands of coastal Louisiana are experiencing rapid subsidence rates averaging 9±1 mm yr−1. Recent measurements based on GPS data and CRMS surface elevation tables (SETs) have shown that most of the subsidence is shallow and occurs in the uppermost 5 meters. Sources of subsidence and the origin of their spatial variability are strongly...

Coastal subsidence owing to compaction of Holocene strata and deeper-rooted components affects large delta plains such as the Tabasco delta in southern Mexico (Gulf coast). For this system, GNSS3-PPP ground-truthed LiDAR imagery of high-resolution dated beach-ridge series reveals considerable differential subsidence on either side of the present Us...

River deltas rank among the most economically and ecologically valuable environments on Earth. Even in the absence of sea-level rise, deltas are increasingly vulnerable to coastal hazards as declining sediment supply and climate change alter their sediment budget, affecting delta morphology and possibly leading to erosion1–3. However, the relations...

Barrier island response to sea‐level rise depends on their ability to transgress and move sediment onto and behind the barrier, either through flood‐tidal delta deposition or via overwash. Our understanding of these processes over decadal or longer timescales, however, is limited. Here we use a recently developed barrier island model (BRIE) to bett...

Barrier islands are low-lying coastal landforms vulnerable to inundation and erosion by sea level rise. Despite their socioeconomic and ecological importance, their future morphodynamic response to sea level rise or other hazards is poorly understood. To tackle this knowledge gap, we outline and describe the BarrieR Inlet Environment (BRIE) model t...

River deltas are sites of sediment accumulation along the coastline that form critical biological habitats, host megacities, and contain significant quantities of hydrocarbons. Despite their importance, we do not know which factors most significantly promote sediment accumulation and dominate delta formation. To investigate this issue, we present a...

Barrier island response to sea-level rise depends on their ability to transgress and move sediment onto and behind the barrier, either through flood-tidal delta deposition, or via overwash. Our understanding of these processes over decadal or longer timescales, however, is limited and poorly constrained. Here we use a recently developed barrier isl...

River deltas are sites of sediment accumulation along the coastline that form critical biological habitats, host megacities, and contain significant quantities of hydrocarbons. Despite their importance, we do not know which factors most significantly promote sediment accumulation and dominate delta formation. To investigate this issue, we present a...

Barrier islands are low-lying coastal landforms vulnerable to inundation and erosion by sea-level rise. Despite their socio-economic and ecological importance, their morphodynamic response to sea-level rise or other hazards is poorly understood. To tackle this knowledge gap, we outline and describe the BarrieR Inlet Environment (BRIE) model that ca...

Natural-levee breaches can not only initiate an avulsion but also, under the right circumstances, lead to crevasse splay formation and overbank sedimentation. The formative conditions for crevasse splays are not well understood, yet such river sediment diversions form an integral part of billion-dollar coastal restoration projects. Here we use Delf...

Tides tend to widen deltaic channels and shape delta morphology. Here we present a predictive approach to assess a priori the effect of fluvial discharge and tides on deltaic channels. We show that downstream channel widening can be quantified by the ratio of the tide-driven discharge and the fluvial discharge, along with a second metric representi...

p>Natural-levee breaches can not only initiate an avulsion but also, under the right circumstances, lead to crevasse splay formation and overbank sedimentation. The formative conditions for crevasse splays are not well understood, yet such river sediment diversions form an integral part of billion-dollar coastal restoration projects. Here we use De...

The distinctive plan-view shape of the Ebro Delta coast reveals a rich morphologic history. The degree to which the form and depositional history of the Ebro and other deltas represent autogenic (internal) dynamics or allogenic (external) forcing remains a prominent challenge for paleo-environmental reconstructions. Here we use simple coastal and f...

Coastal Louisiana has experienced catastrophic rates of wetland loss over the past century, equivalent in area to the state of Delaware. Land subsidence in the absence of rapid accretion is one of the key drivers of wetland loss. Accurate subsidence data should therefore form the basis for estimates of and adaptations to Louisiana’s future. Recentl...

Introduction: Sand ripples are small bedforms that are widely distributed across the sea floor and in fluvial channel beds. Ripples are formed by waves and currents , and ripple spacing is governed by flow intensity. This relationship makes ripples a useful (paleo) flow indicator of flow depth, wave period, and flow velocity on Earth as well as on...

The distinctive plan-view shape of the Ebro Delta, Spain, reveals a rich morphologic history. The degree to which the form and depositional history of the Ebro and many other deltas represent autogenic (internal) dynamics or allogenic (external) forcing remains a prominent challenge for paleo-environmental reconstructions. Here we use simple coasta...

Tidal inlets on barrier coasts can migrate alongshore hundreds of meters per year, often presenting great management and engineering challenges. Here, we perform model experiments with migrating tidal inlets in Delft3D-SWAN to investigate the mechanics and rates of inlet migration. Model experiments with obliquely approaching waves suggest that tid...

GM6.2/BG9.43/SSS9.36 Biogeomorphology: conceptualising and quantifying processes, rates and feedbacks Dear colleague, we are organizing a session on Biogeomorphology at the next EGU General Assembly Meeting in Vienna (23-28 April 2017). The session focusses on the investigation of feedbacks between Ecology and Geomorphology, and includes wetland an...

The typically single-threaded channels on wave-influenced deltas show striking differences in their orientations, with some channels oriented into the incoming waves (e.g., Ombrone, Krishna), and others oriented away from the waves (e.g., Godavari, Sao Francisco). Understanding the controls on channel orientation is important as the channel locatio...

River mouths, shoreline locations where fluvial and coastal sediments are partitioned via erosion, trapping, and redistribution, are responsible for the ultimate sedimentary architecture of deltas and, because of their dynamic nature,also pose great management and engineering challenges. To investigate the interaction between fluvial and littoral p...

Ocean waves are a powerful sediment transport mechanism in the coastal zone. This thesis investigates how waves shape deltaic landforms and how small scale river mouth processes affect large-scale delta morphology. I have developed and applied models of plan-view delta shape and their channel dynamics. Simple parameterizations and key insights from...

Myriad factors, including sea-level rise, cross-shore sediment transport, tidal inlet mechanics, geological inheritance, and, more recently, anthropogenic activities affect the shape and rates of change of the shoreline. However, the generally smooth shape of many sandy shorelines provides a rather clear demonstration that alongshore sediment trans...

We investigate the controls upon the shape of freely extending spits using a one-contour-line model of shoreline evolution. In contrast to existing frameworks that suggest that spits are oriented in the direction of alongshore sediment transport and that wave refraction around the spit end is the primary cause of recurving, our results suggest that...

River deltas, low-lying landforms that host high concentrations of human population and ecosystem services, face a new, and mostly unknown, future over the coming decades and centuries. Even as some deltas experience decreased sediment supply from damming, others will see increased sediment discharge from land-use changes. There are proposals to ac...

Wave-influenced deltas are shaped by wave-driven transport of river-borne sediments. Near the river mouth, combined jet and wave dynamics, along with morphodynamic feedbacks, control the fraction of sediment transported alongshore by littoral currents that can bypass the river channel. Here we study how different bypassing rates influence large-sca...

Sand ripples formed by waves have a uniform wavelength while at equilibrium, and develop defects while adjusting to changes in the flow. These patterns arise from the interaction of the flow with the bed topography, but the specific mechanisms have not been fully explained. We use numerical flow models and laboratory wave tank experiments to explor...

[1] River deltas and individual delta lobes frequently face reduction of sediment supply, either from the geologic process of river avulsion or, more recently, due to human activities such as river damming. Using a process-based shoreline evolution model, we investigate wave reworking of delta shorelines after fluvial input elimination. Model resul...

Distributed temperature sensing (DTS) with fiber-optic cables is a powerful tool to detect illicit connections in storm sewer systems. High-frequency temperature measurements along the in-sewer cable create a detailed representation of temperature anomalies due to illicit discharges. The detection limits of the monitoring equipment itself are well-...

Export Date: 16 January 2014, Source: Scopus

a b s t r a c t The morphology and depositional history of wave-influenced deltas reflects the interplay between the fluvial and coastal domains. Here we present initial results of the coupling of stand-alone coastal and terrestrial models within the Community Surface Dynamics Modeling System (CSDMS) Component Modeling Tool (CMT), applied to study...