About

Julia Cisneros is an Assistant Professor of Earth Surface Processes at Virginia Tech, specializing in sedimentology and geomorphology. Her research bridges the processes of bedform formation and dynamics across various environments, including ancient and inaccessible worlds. She implements robust bedform analysis techniques to reveal bedform morphology and movement, utilizing fieldwork, experimental methods, and modeling to investigate modern settings. Her work aims to understand the links between flow, sediment transport, and bedform morphodynamics, which enhances the interpretation of records of past environments, improves the characterization of conditions in Earth and planetary systems, and informs the management of contemporary environments, particularly in the context of climate change and flood risk management. Cisneros holds a PhD in Geology from the University of Illinois Urbana Champaign (2021) and a BS in Geology from Texas A&M University (2015). Her research areas include fluvial and aeolian geomorphology, sedimentology, sediment transport, and morphodynamics. She is actively involved in advancing knowledge in these fields through her research and academic contributions.

Research topics

• Geography
• Archaeology
• Computer Science
• Geology
• Business
• Geomorphology
• Data science
• Environmental science
• Paleontology
• Geotechnical engineering
• Oceanography

Selected publications

• Increased hydraulic roughness in alluvial rivers created by sand-mining sculpted bed features

  2025-02-06

  preprintOpen access

  Alluvial bedforms are a first order control on flow resistance, water levels and rate of sediment transport. Their morphologies are a direct reflection of the hydraulic and sedimentological conditions under which they are formed. Studies of natural dunes in large river systems have shown that low angled dunes are dominant, characterized by reduced flow resistance and limited recirculation of flow in their lee-slopes. However, increasingly, alluvial rivers are influenced by human activities, such as sand extraction, that directly impacts the morphologies of river beds and bedforms. Here, we present an comparison of the morphologies of natural and anthropogenically influenced bedforms observed through multibeam echo sounder surveys on the Mekong River, Cambodia. We show that anthropogenic bedforms have higher amplitudes (μ = 2.8 m, σ = 1.0 m), steeper leeside angles (μ = 20.6º, σ = 5.8º), and shorter wavelengths (μ =100.1 m, σ = 87.9 m) compared to natural dunes (amplitude : μ = 1.79 m, σ = 0.86 m, leeside angle : μ = 11.8º, σ = 5.7º, wavelength : μ = 117.0 m, σ = 89.1 m). Our data suggests that the form roughness of anthropogenic bedforms is higher (median ksf = 1.23) than natural bedforms found in the sections of the Mekong unaffected by mining (median ksf = 0.49). As a result, flow patterns subsequently force suspended load over bedforms, meaning sediment is unable to infill mining pits. Anthropogenic bedforms may represent a significant and previously under-represented control on flow and sediment transport in alluvial river systems.

  PublisherOA PDFDOI

• SWOT Satellite: A New Tool for Fluvial Geomorphology

  GSA Today · 2025-12-01

  articleOpen access

  Earth-observing satellites have revolutionized the field of fluvial geomorphology by providing large-scale and spatially contiguous observations. The recently launched Surface Water and Ocean Topography (SWOT) satellite’s novel interferometric synthetic aperture radar (inSAR) instrument delivers global measurements of several key geomorphic parameters, such as river surface water elevation, slope, and width, and thus presents the opportunity to study fluvial processes in new ways. Here we explore the utility of the SWOT satellite for advancing understanding of fluvial geomorphology across river systems in the United States, specifically focusing on water surface elevation variations in large braided rivers, temporally dynamic shear stress in bedrock rivers, and the processes associated with knickpoints and dam failures. We also discuss other relevant potential applications of SWOT satellite data related to fluvial geomorphology beyond the scope of these early explorations. By providing global multitemporal observations of several key variables in fluvial geomorphology, SWOT represents a major advance in our ability to quantify, monitor, and understand fluvial systems and their dynamics.

  PublisherDOI

• Increased Hydraulic Roughness in Alluvial Rivers Created by Sand‐Mining Sculpted Bed Features

  Journal of Geophysical Research Earth Surface · 2025-06-01 · 3 citations

  articleOpen access

  Abstract Alluvial bedforms are a first order control on flow resistance, water levels and rate of sediment transport. Their morphologies are a direct reflection of the hydraulic and sedimentological conditions under which they are formed. Studies of natural dunes in large river systems have shown that low angled dunes are dominant, characterized by reduced flow resistance and limited recirculation of flow in their lee‐slopes. However, increasingly, alluvial rivers are influenced by human activities, such as sand extraction, that directly impact the morphologies of river beds and bedforms. Here, we present a comparison of the morphologies of natural and anthropogenically influenced bedforms observed through multibeam echo sounder surveys on the Mekong River in Cambodia. We show that anthropogenic bedforms have higher amplitudes ( μ = 2.8 m, σ = 1.0 m), steeper leeside angles ( μ = 20.6°, σ = 5.8°) and shorter wavelengths ( μ = 100.1 m, σ = 87.9 m) compared to natural dunes (amplitude: μ = 1.79 m σ = 0.86 m, leeside angle: μ = 11.8° σ = 5.7°, wavelength: μ = 117.0 m, σ = 89.1 m). Our data suggests that the form roughness of anthropogenic bedforms is higher (median k sf = 1.23) than natural bedforms found in sections of the Mekong unaffected by mining (median k sf = 0.49). As a result, flow patterns subsequently force suspended load over bedforms, meaning sediment is unable to infill mining pits. Anthropogenic bedforms may represent a significant and previously under‐represented control of flow and sediment transport in alluvial river systems.

  PublisherOA PDFDOI

• Classification of underwater flow-transverse sedimentary bedforms

  2024-03-09 · 1 citations

  preprintOpen access

  Despite the recommendations given in Ashley (1990), a plethora of terms continues to be used to describe flow-scale flow-transverse sedimentary bedforms, often without clear definition or distinction between the different nomenclatures. For example, (marine) dunes and sand waves are used interchangeably in many contexts. Smaller bedforms superimposed on larger ones may be referred to as megaripples or secondary dunes. It is currently unclear if different terms are used due to intrinsic morphological or genetic differences or due to the traditions of different scientific communities. Ashley (1990) already noted that the “poor communication among scientists and engineers has perpetuated the multiplicity of terms”. Researchers from fluvial, coastal or deep-marine environments, from industry or academia, from various disciplines, such as sedimentology, oceanography, coastal and offshore engineering or geomorphology may use a specific vocabulary. Furthermore, terminology may differ depending on the country or research group in which they work. All this makes communication difficult and may cause misinterpretations, hindering progress in understanding and cross-disciplinary collaborative pursuits.The aim of the present contribution is to provide an updated classification of the different types of underwater flow-transverse sedimentary bedforms. The intent is to homogenise the nomenclature for researchers coming from different disciplines and working in varied environments, to enable the use of a common classification and terminology to improve knowledge exchange, comparison and dialogue.We propose a description table, which can be used by scientists and practitioners to describe the sedimentary bedforms with which they are working. Importantly, each bedform characteristic is described and the way to calculate the quantitative descriptive parameters is detailed. The description table aims at providing a standard and consistent way to describe the bedforms and their environmental setting prior to classifying them. The description table can be used independently of bedform type and further classification, which should overcome communication issues.Two classification schemes are then proposed. The first is based on an understanding of the genetic processes. This should be used whenever possible because it informs about the underlying processes which formed the bedform. In order to complement the process-based classification, or in situations where the genetic processes are unknown, a second, geomorphological classification is introduced. Thus, we urge the bedform community to consider deploying these descriptor and classification tools and hope our contribution leads to a much more transparent and cohesive future in bedform research.

  PublisherDOI

• Controls on the Leeside Angle of Dunes in Shallow Unidirectional Flows

  Journal of Geophysical Research Earth Surface · 2024-03-01 · 5 citations

  articleOpen access1st authorCorresponding

  Abstract Dunes are ubiquitous features in alluvial channels, serve as major agents of sediment transport and contribute significantly to flow resistance. Research in the past decade has illustrated the complexity of dune geometry and widespread occurrence of dunes that have a low leeside angle. However, there is a debate concerning the occurrence of such dunes and their formative processes. This paper seeks to further our understanding of low‐angle dunes by utilizing data from a robust set of shallow flow laboratory experiments detailing equilibrium bedform morphology across a range of sediment transport conditions. Analysis of bedform morphology demonstrates that dunes with low‐angle leesides are generated in shallow laboratory flows and are not restricted to deep rivers. Of the possible processes that have been proposed to explain the formation of low‐angle dunes, this finding unequivocally shows that liquefied leeside avalanches, which rely on deep flows for their generation, are not a controlling mechanism. In addition, dunes formed under suspension‐dominated conditions possess lower leeside angles compared with those formed under bedload‐dominated conditions. However, where bedload transport dominates and sediment suspension is likely of lesser importance, low‐angle dunes are still present, and preliminary analysis shows that bedform superimposition can result in lowering of the dune leeside angle. Low and intermediate angle dunes formed under these various conditions also have a lower potential for large‐scale, permanent, leeside flow separation compared with angle‐of‐repose dunes, confirming the need to account for these differences in predictions of flow resistance associated with dune form roughness.

  PublisherOA PDFDOI

• Automated Bedform Identification—A Meta‐Analysis of Current Methods and the Heterogeneity of Their Outputs

  Journal of Geophysical Research Earth Surface · 2024-03-01 · 7 citations

  articleOpen access

  Abstract Ongoing efforts to characterize underwater dunes have led to a considerable number of freely available tools that identify these bedforms in a (semi‐)automated way. However, these tools differ with regard to their research focus and appear to produce results that are far from unequivocal. We scrutinize this assumption by comparing the results of five recently published dune identification tools in a comprehensive meta‐analysis. Specifically, we analyze dune populations identified in three bathymetries under diverse flow conditions and compare the resulting dune characteristics in a quantitative manner. Besides the impact of underlying definitions, it is shown that the main heterogeneity arises from the consideration of a secondary dune scale, which has a significant influence on statistical distributions. Based on the quantitative results, we discuss the individual strengths and limitations of each algorithm, with the aim of outlining adequate fields of application. However, the concerted bedform analysis and subsequent combination of results have another benefit: the creation of a benchmarking data set which is inherently less biased by individual focus and therefore a valuable instrument for future validations. Nevertheless, it is apparent that the available tools are still very specific and that end‐users would profit by their merging into a universal and modular toolbox.

  PublisherOA PDFDOI

• Journal of Geophysical Research

  VTechWorks (Virginia Tech) · 2024-01-01

  article1st authorCorresponding

  Dunes are ubiquitous features in alluvial channels, serve as major agents of sediment transport and contribute significantly to flow resistance. Research in the past decade has illustrated the complexity of dune geometry and widespread occurrence of dunes that have a low leeside angle. However, debate exists concerning the occurrence of such dunes and their formative processes. This paper seeks to further our understanding of low-angle dunes by utilizing data from a robust set of shallow flow laboratory experiments detailing equilibrium bedform morphology across a range of sediment transport conditions. Analysis of bedform morphology demonstrates that dunes with low-angle leesides are generated in shallow laboratory flows, and hence are not restricted to deep rivers. Of the possible processes that have been proposed to explain the formation of low-angle dunes, this finding unequivocally shows that liquefied leeside avalanches, which rely on deep flows for their generation, are not a controlling mechanism. In addition, dunes formed under suspension-dominated conditions possess lower leeside angles compared to those formed in bedload-dominated conditions. However, where bedload transport dominates and sediment suspension is likely of lesser importance, low-angle dunes are still present, and preliminary analysis shows that bedform superimposition can result in lowering of the dune leeside angle. Low and intermediate angle dunes formed in these various conditions also have a lower potential for large-scale, permanent, leeside flow separation compared to angle-of-repose dunes, confirming the need to account for these differences in predictions of flow resistance associated with dune form roughness.

  Publisher

• Medical Device Safety Notification Process Analysis Using Queuing Theory and Simulation

  Communications in computer and information science · 2024-01-01

  book-chapter
  PublisherDOI

• Supplementary material to "The influence of dune lee side shape"

  2023-02-27

  preprintSenior author

  Mean lee side angle (°) Maximum angle (°) Max.angle position Bedform length (m) Bedform height (m) Steep portion height (m) Length flow seapration zone (m)

  PublisherDOI

• The influence of dune lee side shape

  2023-02-27

  preprintOpen accessSenior authorCorresponding

  Abstract. Underwater dunes are found in various environments with strong hydrodynamics and sandy, movable sediment such as rivers, estuaries and continental shelves. They have a diversity of morphology, ranging from low to high-angle lee sides, and sharp or rounded crests. Here, we investigate the influence of lee side morphology on flow properties (time-averaged velocities and turbulence). To do so, we carried out a large number of numerical simulations of flows over dunes with a variety of morphologies using Delft3D. Our results show that the value of the mean lee side angle, as well as the value and position of the maximum lee side angle, have an influence on the flow properties investigated. We propose a classification with 3 types of dunes: (1) low-angle dunes (mean lee side < 10°), over which there is no permanent flow separation, except if the maximum slope is steeper than 20° and situated close to the trough, and over which only little turbulence is created; (2) intermediate-angle dunes (mean lee side 10–20°) over which there is generally no permanent but likely an intermittent flow separation, situated over the trough; and (3) high-angle dunes (mean lee side > 20°) over which the flow separates at the brink point and reattaches shortly after the trough, and over which turbulence is high. We discuss the implications of this classification on the interaction between dune morphology and flow.

  PublisherDOI

Frequent coauthors

• Jim Best

  University of Illinois Urbana-Champaign

  10 shared

• Alice Lefebvre

  University of Bremen

  10 shared

• Leon Scheiber

  8 shared

• Judith Zomer

  Wageningen University & Research

  5 shared

• Renato Paes de Almeida

  Universidade de São Paulo

  5 shared

• Li Wang

  East China Normal University

  5 shared

• Aída Guhlincozzi

  5 shared

• Ronald R. Gutiérrez

  Pontifical Catholic University of Peru

  5 shared

Labs

• Department of Geosciences, Virginia TechPI