Aeolian Geomorphology Research Papers - Academia.edu (original) (raw)

2025

The Mars Global Digital Dune Database (MGD 3 ) is a GIS-based database of moderateto large-size dark dune fields on Mars. The database currently covers the area from 65°N to 65°S and will soon be expanded to include the entire planet. MGD 3 can be accessed at a variety of internet locations in a variety of formats, including a non-GIS table. The database makes it possible to look at dunes in a global context, comparing their geographic locations and attributes to other global coverages, such as the NASA/Ames General Circulation Model (GCM) [1] that is included with this database. The Viking-based Atlas of Mars 1:15,000,000 Geologic Series maps (USGS I-1802A-C) [2] and the Mars Orbiter Laser Altimeter (MOLA) elevation data set [3], two existing coverages that are not part of the database, are also included with MGD 3 for the user's convenience. Comparisons between dune field distribution and global coverages provide significant perspective on global and regional-scale aeolian processes that have shaped and continue to influence the surface of Mars. MGD 3 can also be used to locate areas of potential interest for local studies by querying the attributes provided for each dune field. These attributes include, but are not limited to: longitude, latitude, dune type, dune field area, estimated mean height of dune field, estimated dune field volume, average elevation, and slipface orientation (if measured). Also listed are the ID numbers of Thermal Emission Imaging System (THEMIS) infrared (IR), THEMIS Visible (VIS) , and Mars Orbiter Camera narrow angle (MOC NA) [5] images used to create the MGD 3 database. In addition, the following information is provided for dune fields that are located within craters: crater centroid to dune centroid azimuth, crater diameter, and crater area. Discussion: Where to find MGD 3 and how to access the database once you have found it. MGD 3 was released as United States Geological Survey (USGS) Open-File Report (OFR) 2007-1158. It can be downloaded from the following website () as a complete package, ready to use, with many layers and backgrounds. For users that do not require the entire package, its shapefiles, tables, images, and documentation are also available as separate, smaller downloads. Parts of MGD 3 can also be accessed at other internet locations. The following is a guide to finding and accessing the level of MGD 3 that suits individual user needs.

2025, Aeolian Research

Dunefields are very common in the northern coastal zone of northeast Brazil. They have the potential to yield important information about paleoclimate, paleo-winds and regional winds and their response to sea-level fluctuations during the Holocene. We reconstructed the coastal dunes geochronological evolution of northwest Ceará State -Brazil, in the last 3000 cal yrs BP, using detailed analyses of lithostratigraphy, microfossil (foraminifera), wind regime, dune monitoring and 8 radiocarbon dates. The chronology was based on 14 C dating in eolianites and monitoring transversal mobile dunes movement processes. Radiocarbon date results indicated that the dunes corresponding to eolianites revealed ages between 2760-2480 and 980-750 cal yrs BP, suggesting that the vast transversal mobile dunefields were formed after this period in similar condition to the current sea-level. We considered that the material transportation by the prevailing east winds towards the transversal dunes is estimated in the order of 11.0 m/year, thus the current aeolian system is less than 1000 yrs BP.

2025

In-stream mining is a common aggregate mining practice around the world. However, the impacts of such practice are not always taken into account when the mines are established, and the environmental cost of in-stream aggregate mining is generally not assessed. The purpose of this study was to evaluate the impacts of aggregate mining conducted in La Puerta River (Tafí valley, Northwest Argentina), a dry-pit instream mine, by considering the geomorphological, geoarchaeological, and human effects. Multitemporal analysis of the area using remote sensors (aerial photographs and satellite images 1970-2020), high-resolution drone digital elevation models and orthomosaics (2018)(2019), and an intensive survey demonstrated that the mining area grew exponentially between 2002 and 2020 under unregulated mining. As a result, this practice exerts great environmental impact, including channel section alterations and destabilization of riverbanks, soil loss, river profile changes, and the formation of lag deposits of discarded materials, thus increasing environmental hazard under unpredictable flows. Finally, this is a highly touristic area that has suffered substantial landscape degradation and irreversible archaeological damage.

2025

Departing from recent studies on Early Islamic-period agroecosystems in sand along the Mediterranean coast of Israel, we present in this editorial introduction seven papers of a Special Issue titled Connectivity of Agrotechnologies between Late Antiquity and Early Modern Times in the Mediterranean Region. The papers focus on the evolution of agricultural practices in form, space and time, the development of agricultural earthworks and systems, ancient to traditional agroecosystems' global catalysts and transfer mechanisms and impacts of agricultural practices on societal resilience to environmental and social change, mainly in marginal lands between Iran and Iberia. The results of these studies appear to be partly relevant and applicable to some modern agricultural practices and geo-heritage and preservation activities.

2025

Tsoar, H. 2000. Geomorphology and paleogeography of the sand dunes that have formed the kurkar ridges in the coastal plain of Israel. Isr. J. Earth Sci. 49: 189-196. The foredune is the only dune type that is formed parallel to coastlines and can be considered as the dune type that cemented into aeolianite (known locally as kurkar) ridges, along the coastal plain of Israel. Previous works indicate that sand-transporting wind directions during formation of the kurkar dunes were similar to those of the present; i.e., from southwest to northwest. Foredunes are formed by vegetation (principally Ammophila arenaria) that traps aeolian sand at the landward edge of the backshore. A. arenaria grows vigorously in cold and semiarid areas and can form foredunes under climatic conditions that prevailed in the coastal plain of Israel during the Late Pleistocene. Successive foredunes can form with shore progradation accompanying some oscillations of sea level. These successive foredunes trap all sand blown onshore by the wind so that the area landward of the dunes is under deflation by the wind. Only destruction of vegetation on the foredunes, resulting in blowouts, will create a gap for sand encroachment inland. Similarly, destruction of vegetation close to the backshore or prevention of foredune formation at the outlet of rivers causes sand encroachment and formation of transgressive coastal dunes such as the contemporary coastal dunes of Israel.

2025, Australian Journal of Earth Sciences

Desert dunes within the monsoon-fed Gregory Lakes basin form valuable archives for Quaternary paleoenvironments, in a region where such records are scarce. Optically stimulated luminescence (OSL) chronologies from two dunes identify the timing of eolian processes, interpreted as a complex response to aridification and increased sediment availability during lake transgressions and associated fluvial activity. The earliest eolian deposition in our record occurred ca 91.5 ka, which postdates the last 'mega-lake' phase but predates a smaller lake transgression during early MIS 3. Sand plain accretion took place around ca 47 ka during contemporaneous periodic high lake levels. This was followed by intermittent linear dune building, between ca 35 and 11.5 ka, which most likely took place during an interval of relative aridity. Close spacing of mid-Holocene ages within one dune indicates rapid sediment accumulation in a single arid event ca 5 ka. At no time in the last 50 ka have lake levels reached those of the last 'mega-lake' phase prior to ca 91.5 ka, suggesting a substantially weakened present-day monsoon.

2025

Lupinus littoralis Dougl. had a distinct pattern of distribution, in relation to the active foredune, on a recently prograded shoreline near the mouth of the Yaquina River on the Oregon coast. Personal reconnaissance revealed that L. littoralis grew at the lee base of the active foredune (as well as inland) where less sand burial took place than on top of the foredune. The objectives of this study were to determine the following: where L. littoralis occurred in the pattern of topography and soil organic matter accumulation relative to a recently prograded shoreline; what plants were found in association with L. littoralis; the gross morphology of L. littoralis; and whether the subterranean morphology of L. littoralis changed with distance from shore.

2025, Aeolian Research

The biogeomorphology of nebkha dunes, was investigated in the Fahraj Plain, which is located in southern part of the Lut Plain in southeastern Iran. Field investigations were performed to determine nature of nebkha dunes, whose genesis and growth involves the trapping of aeolian sand within the body of a plant. This study demonstrated that Tamarix, a shrub/tree in the Tamaricaceae family, has played a major role in reducing dust and sand storms in the region by trapping aeolian sediments and accumulating them in the form of nebkhas. In contrast, another tree/shrub that grows in the area, Prosopis cineraria (a variety of mesquite in the Fabaceae family), due to its structure seems not to have played an important role in aeolian sediment accumulation or in shaping any nebkha dunes in the area. Whereas previous investigations indicated that the highest nebkhas, which are located at the western margin of the Lut basin on the Takab plain, were no more than 12 m in height, our field investigations and measurements revealed that on the Fahraj plain there are nebkhas greater than 20 m in height. This would suggest that some of these nebkhas are among the largest and highest that have been reported in the world. Some were connected by rows of Tamarix and formed very long ridges more than 200 m in length. It seems that their form may be due to human activity. During our survey of nebkhas in the region we observed ongoing and increasing degradation in the nebkha field that we were examining. This seemed to be due to current climate variability and human impact. Investigation of the past climate of this region reveals that the Indian monsoon is and has been a major factor. Examination of this history also reveals the relationship between climate and sand movement in the region, and the inferred past history of nebkha dunes. Past analogue conditions from that history can provide a scenario of future nebkha evolution, and reveal if their current, ongoing degradation is a long-term trend or simply a short-term cycle.

2025

2025, Proceedings of ICAR5/GCTE …

Aeolian transport of fine to medium sized sand particles is usually occurring as saltation, the jumping movement of grains over the surface. Saltating grains receive momentum from the near-surface wind, which causes particle lift,... more

2025, Aeolian Research

Interdune areas and purported playa-type environments in Saturn's moon Titan's dune fields show substantial spatial variability in radar backscatter expression. Using examples from Death Valley, the Middle East, and northern China, this work evaluates terrestrial causes of spatial backscatter heterogeneity in similar aeolian environments. It introduces the importance of temporal change detection in interdune area backscatter expression. Using optical images, time-series radar synthetic aperture radar images, and coordinated meteorological and river discharge data (where available), backscatter variations are related to spatially changing sedimentary environments within sediment-limited areas, i.e., interdune and playas, and temporally changing surface or near-surface moisture conditions. In terrestrial environments, backscatter expression varies over seasonal and annual timescales as a function of the cumulative history of surface change, primarily driven by changes in surface and near-surface moisture from either precipitation or groundwater table rise and fall. On Titan, evidence for equatorial methane flow channels suggests that arid-climate surfaces may undergo temporal evolutions like those observed on Earth. Fluid flow and evaporite formation play crucial roles in the existence and alteration of patterns in Earth's interdunes. By analogy, these mechanisms are also expected to be at work on Titan. Despite differences between terrestrial and Titan radar observations, considering surface dynamics and evolution over time on Titan may be critical for analyzing its arid, equatorial environments.

2025

He2, Patricia McGuiggan3, Xi Zhang1, 1Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (xintingyu@ucsc.edu). 2Department of Earth and Planetary Sciences, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218. 3Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218.

2025, Journal of Paleolithic Archaeology

2025

In order to date and interpret the natural and anthropogenic forces influencing the evolution of the Early Islamic Plot-and-Berm (P&B) agroecosystem in the sandy coastal hinterlands of ancient Caesarea we integrated historical, archaeological, sedimentological, mineralogical, and meteorological findings with 165 Portable OSL (port-OSL) samples and 26 OSL ages from three structures and ten berm and plot sections, along a 650-m transect. A four-phased punctuated landscape evolution underscores the natural and anthropogenic forces shaping the P&B agroecosystem. The first phase was during the Middle Holocene as initial sandsheet incursion followed the significant reduction in the eastern Mediterranean sea-level rise rate. The second phase of incipient coastal modification, by mixing of local sand and teriatry refuse probably for agricultural practices, was OSL-dated to the Early Roman period and supported by synchronous ceramics. Surprisingly, no evidence for Byzantine activity was found. The third phase centered around 900 CE by OSL dating and ceramics, marked rapid construction of the P&B agroecosystem, characterized by emplacement of dark grey sandy refuse-sourced anthrosols in plots and anthrosediments on berms. This phase reflects late Abbasid and Fatimid influence on the region, as agrotechnological innovation, such as the P&B agroecosystem waterharvesting techniques, necessitated organized administrative management, probably responding to religious calls for land reclamation. The last phase, the abandonment of the P&B agroecosystem, was gradual with sporadic activity persisting since the late Fatimid and throughout the early Crusader periods. Aeolian and fluvial forces have been modestly infilling some of the plots with colluvium and sand, slightly eroding and deflating the berms. All four phases posess distinct port-OSL signatures and OSL age ranges demonstrating how relative and absolute luminescence datasets of humanaffected landscapes can help estimate depositional rates and refine determination of periods of natural processes and anthropogenic activities. ☆ This article is part of a special issue entitled: 'Soil Memory' published in Catena.

2025

This article discusses the archaeological, geoarchaeogical and chronological finds of our 2020-2022 fieldwork south of Caesarea, along with several archaeological and geomorphological surveys of altogether three innovative agroecosystems in the coastal sand bodies of the southeastern Mediterranean coast in Israel. The finds are hypothesised to be the first of its kind and the first major attempt to cultivate inert aeolian sand. These Early Islamic Plot-and-Berm agroecosystems perhaps heralded similar types of later traditional groundwater harvesting agrotechnologies in aeolian sand that existed along the southeastern Mediterranean coast, in Saharan Algeria, Iran and in the Atlantic coast of Iberia. The finds, combined with ongoing physical studies of the agroecosystems and their traditional analogues are anticipated to yield better understanding of the function of the agroecosystems that in turn, will provide new insights on a variety of research subjects stimulated by the database accumulated during and after our fieldwork.

2025, Quaternary Geochronology

Optically stimulated luminescence (OSL) dating of quartz extracts from postglacial aeolian dunes from central Alberta in western Canada points to a landscape that was free of ice as early as 15 ka. Data from profiles where multiple ages have been obtained indicate an increase in depositional age with depth, suggesting that older aeolian sands underlie the dated sequences. The OSL ages present plausible minimum age constraints for the retreat of the Laurentide Ice Sheet (LIS) towards the end of the Late Wisconsinan glaciation. Previous reconstructions of the LIS recession have relied on radiocarbon chronologies, despite the scarcity of contemporaneous radiocarbon-bearing material for large parts of western Canada. While the OSL chronology may be deemed concordant with ice sheet margin retreat models determined using radiocarbon data, there appears to be a systematic lag in the radiocarbon ages which may reflect that aeolian activity is initiated prior to the proliferation of organic material. The OSL chronology reported in this study does not preclude the emergence of a wide deglacial corridor between the LIS and the Cordilleran Ice Sheet by 15 ka or earlier. The possibility of such a passage would resuscitate the notion of an ice-free corridor that appeared early enough to afford the first peoples of the Americas a navigable inland migratory passage from Beringia to south of the North American ice sheets. More broadly, the corridor would also have allowed genetic exchanges between the Beringian refugium and the American middle and low latitudes.

2025, Research Article

The Great Salt Lake (Utah, USA) is reducing in size, which raises several ecological concerns, including the effect of an increasing area of dry playa exposed by the retreating lake. This study focuses solely on concerns about the toxicity of metals in the dust blowing off the playa. Although considerable efforts have been made to understand aeolian dust in urban areas along the Wasatch Front, located just east and south of the Great Salt Lake, there is still a need to consolidate existing research and to conduct a compositional analysis of the dust found in these urban areas. We investigated the dust reaching urban monitoring sites around the Great Salt Lake that are managed by the Utah Division of Air Quality. By analyzing historical data, we found that the decrease in the Great Salt Lake’s surface area has not led to a statistically significant increase in dust events in urban areas. Windrose plots align with prior research, indicating that heightened dust levels in urban areas coincide with winds originating from the south or west, passing over identified playas and deserts such as the Milford Flats, Sevier Dry Lake, Tule Dry Lake, Great Salt Lake Desert, Dugway Proving Grounds, and the West Desert of Utah. Metallic compositional analysis of urban dust was used to evaluate potential health risks associated with the dust using the hazard quotient, air regional screening levels, and cancer risk methods. This analysis revealed no significant increase in concentrations of toxic metals. However, this is not to preclude a risk of dust-related health concerns, especially due to pre-existing arsenic and lead levels.
Synopsis: This study provides insights into dust-related health risks and environmental impacts in Utah, analyzing dust exposure from shrinking Great Salt Lake.

2025

Fourteen fossil avian tracksites have been identified in Late Pleistocene aeolianite deposits on the Cape south coast of South Africa. One of these sites is unusual because of the preferential adherence of organic material (biofilm) to the natural cast tracks. This has enabled the recognition and identification of two ~6 m long, approximately parallel trackways that would otherwise not have been noticed. The trackways are visible from a distance of over 100 metres and contain 20 and 14 individual tracks, respectively. Up to 50 avian tracks are evident at this site. As the biofilm layer continues to thicken, the trackways become increasingly visible. Avian trackways of this length are globally rare. We propose that the biofilm adheres to sections with higher relief on a sedimentary surface, and that an understanding of this mode of preservation can be useful to more easily identify trackways in areas of comparable geological setting.

2025

In earlier Skeptical Inquirer articles I described how cross-bedding with maximum angles of dip greater than 30o in the Navajo Sandstone gives evidence that this sandstone was created by wind deposition that produced giant dunes in a desert environment. See: http://www.csun.edu/~vcgeo005/Nr38Reasons.pdf and http://www.csun.edu/~vcgeo005/Nr42Response.pdf. I also referred readers to the evidence reported in the book “The Grand Canyon – Monument to an Ancient Earth: Can Noah’s Flood Explain the Grand Canyon?” edited by Carol Hill, Gregg Davidson, Tim Helble, Wayne Ranney, and others, 2016, Grand Rapids, MI, Kregel Publications. In the earlier articles I gave only a limited discussion of the Coconino Sandstone (Figure 1), indicating only that it also had similar maximum dip angles greater than 30o and had raindrop prints that supported its desert origin, but I did not expand on how the Coconino Sandstone was deposited because of many complex relationships that could not be easily conden...

2024, Proceedings of ICAR5/GCTE …

2024

Barchan dunes are crescentic planform-shaped dunes that are present in many natural environments, and may occur either in isolation or in groups. This study uses high-resolution particle-image velocimetry (PIV) experiments using fixed-bed models to examine the effects of barchan dune interaction upon the flow field structure. The barchan dune models were based upon an idealized contour map, the shape and dimensions of which were based upon previous empirical studies of dune morphology. The experimental setup comprised two, co-axially aligned barchan dune models that were spaced at different distances apart. In this paper, two volumetric ratios (Vr, upstream barchan dune: downstream barchan dune) of 1.0 and 0.175 were examined. Models were placed in an Eiffel-type, open-circuit wind tunnel and flow quantification was achieved using PIV at 0.5Hz. PIV measurements of the mean and turbulent flow field were made in the streamwise-wallnormal plane, along the centerline of the barchans(s), at an average Reynolds number of 59,000. The presence of an upstream barchan dune of equal volume to the downstream barchan dune (Vr = 1) induces a 'sheltering effect' on the flow, manifested by a significantly shorter separation bubble and both reduced streamwise velocity and turbulence intensity in the downstream barchan dune leeside, as compared to an isolated barchan. The volumetric ratio Vr = 0.175 shows enhanced turbulence production over the downstream barchan dune leeside, that is proposed to be caused by interacting shear layers from the up-and downstream dunes. The influence of the upstream dune is greater for a larger volumetric ratio due to the sheltering effect of the upstream bedform. Proper orthogonal decomposition (POD) analysis shows that the distribution of turbulent kinetic energy is shifted to higher modes (i.e. smaller spatial scales) over interacting barchan dunes, which also reflects the role of the leeside free shear layer in dominating the flow field by generation, or redistribution, of TKE to higher modes.

2024, ltces.dem.ist.utl.pt

1: Department of Geology, University of Illinois, Urbana, USA, jessica.ann.palmer@gmail.com 2: Department of Mechanical Science and Engineering, University of Illinois, Urbana, USA, rmejiaa2@illinois.edu 3: Department of Mechanical... more

2024

Introduction. The predominance of aeolian (wind-driven) activity as a surface modifying agent on Mars has been recognized throughout the history of telescopic, satellite, and robotic investigation of the planet. The most obvious expressions of aeolian processes are manifested in dunes, yardangs (aerodynamic ridges in bedrock) [1,2], sand ripples [3,4], and Transverse Aeolian Ridges (TARs) [5]. TAR is a nongenetic general term proposed for linear to curvilinear aeolian features. Since their first recognition, the origin of TARs remains an area of healthy debate, are TARs small dunes or are they large ripples? The answer to this question is critical to understanding the way the wind works on the martian surface and this has implications for NASA strategic interests in area of sustained human and robotic exploration of Mars. The challenge is that to answer the questions of origin, we need to understand the details of shape, size, and spatiotemporal development of the bedforms, and the size and density of the grains that form them. Although the resolution of remotely sensed data improves rapidly, down to 25cm/pixel with HiRiSE, we are still not capable of resolving sediment-size distributions [6]. Until we can do this, our understanding of aeolian processes on Mars will remain limited to the few lander and rover sites. Thus, we still rely heavily on our understanding of similar features on Earth as analogs both in terms of form and process. Recent rover investigations of Martian TARs provide perhaps the most definitive data [7].

2024

Abstrak-Daerah penelitian seluas 9.930 hektar berada di Kecamatan Petak Malai, Kabupaten Katingan, Kalimantan Tengah. Penelitian ini bertujuan untuk mengetahui posisi singkapan batubara, jumlah lapisan batubara dan mengukur jumlah sumberdaya batubara. Penelitian ini dilakukan melalui pemetaan geologi terhadap batubara dan batuan lain. Kemudian dilakukan korelasi antar singkapan batubara dan pembuatan peta geologi. Setelah dilakukan hal-hal tersebut maka pengukuran sumberdaya terukur dan tertunjuk (indicated) dapat dilakukan.Dijumpai 10 singkapan batubara di daerah penelitian. Dari ke sepuluh singkapan ini dapat dikorelasikan menjadi tiga lapisan batubara yang memiliki ketebalan 0,13 meter hingga lebih dari 0,7 meter. Singkapan batubara dijumpai pada satuan batulempung-batupasir Formasi Dahor yang terletak di bagian tengah daerah penelitian.Perhitungan sumberdaya terukur dihasilkan 873.050 ton.Sumberdaya tertunjuk (indicated) dihasilkan 4.524.346 ton.Struktur geologi yang dijumpai di...

2024

Molds of palm fronds and vertical, cylindrical structures interpreted as molds of palm tree trunks were reported from Holocene and upper Pleistocene carbonate eolianites on several islands in the Bahamas in the early 1990s. As a result of recent discoveries described herein, palm frond and tree trunk molds are now known to be widespread in Bahamian eolianites,

2024, Geological Society of America Bulletin

Negev erg of Egypt − Particle-size fractionation of eolian sand along the Sinai Email alerting services articles cite this article to receive free e-mail alerts when new www.gsapubs.org/cgi/alerts click Subscribe America Bulletin to subscribe to Geological Society of www.gsapubs.org/subscriptions/ click Permission request to contact GSA http://www.geosociety.org/pubs/copyrt.htm#gsa click official positions of the Society. citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect presentation of diverse opinions and positions by scientists worldwide, regardless of their race, includes a reference to the article's full citation. GSA provides this and other forums for the the abstracts only of their articles on their own or their organization's Web site providing the posting to further education and science. This file may not be posted to any Web site, but authors may post works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent their employment. Individual scientists are hereby granted permission, without fees or further

2024, Territorium

O estudo da morfologia duna r no seu conjunto e a análise pormenorizada de cortes em dunas permitiram concluir sobre a ocorrência de importantes movimentações de areias no litoral centro-oeste português entre a Lagoa da Ervedeira e o limite sul da Mata Nacional de Leiria, desde há séculos. A recolha de areias em postos experimentais permitiu estabelecer ligações com os ventos predominantes e verificar que as dunas ainda se movimentam acarretando dois tipos de riscos eólicos- avanço das areias sobre áreas ocupadas pelo homem e criação de corredores de deflação que facilitam galgamentos marinhos

2024

Introduction: Dunes on Mars provide evidence of active and ancient aeolian processes and are critical for understanding the planet's stratigraphy and surface modification history. Active sand transport and ripple migration occurring on Mars has been observed using automated image feature correlation and change detection [1, 2, 3], but genetically-related Transverse Aeolian Ridges (TARs) [e.g., 1] appear to have been stationary over recent history. TARs are commonly imaged by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter (MRO), and our goal is to develop an efficient, automated mapping strategy for TARs to understand their spatial distribution, morphological characteristics, and processes of formation. Methodology: Mapping TARs and including information such as shape, crest spacing, sinuosity and surface albedo is challenging because of their small footprint in HiRISE images. TARs can be found over large areas, but are typically found in isolated patches. To obtain quantitative topographic information about TAR height and morphology, high-resolution (1 m/pixel) digital terrain models (DTMs) can be constructed from HiRISE stereo-image pairs [5] using ISIS and SOCET SET software. These stereophotogrammetry methods are based on featurematching and the algorithms often have difficulty retrieving three-dimensional (3D) information from smooth surfaces, subtle features, or contiguous ripple textures. TARs typically occupy only a small portion of any HiRISE image, which makes processing an entire DTM for these small features a time-consuming task. Likewise, the area and size of TAR bedforms are generally small and near the limit of detection with respect to the spatial resolution (~1 m/pixel) of the DTMs. Although height information is highly desirable for analysis, the pattern of ripple and TAR ridges seen from HiRISE images alone can reveal information about paleo-wind directions, which is important for understanding Martian climate. Our initial efforts to map TARs focused on manual digitization of TAR patterns and 3D profile extraction, but it became apparent that automated image processing tools would be better for mapping TARs. Various approaches have been taken to automatically map sand ripples in image data by automatic detection of ripple crest patterns [6] and dunes using supervised machine learning [7]. We initially tested techniques [6]

2024

Purpose of the study was the investigation of soil losses and runoff on microplots comparing 3 different soil types (Aridic Calcisol, Ferri Stagnic Luvisol and Chromic Calcaric Cambisol) under conventional and conservation soil management. Experimental data were obtained from a set of 12 soil erosion microplots (invested in the framework of EU project INCO-COPERNIKUS-IC15-CT98-0106). Eroding soil material from the main wheel track of Aridic Calcisol was sampled in a collectorbox. Superficial unsaturated hydraulic conductivity was investigated at all sites. Soil physical examination took place at Ferri Stagnic Luvisol and Chromic Calcaric Cambisol. Conservation tilled plots show due to vegetation effect lower soil losses compared to conventional tilled sites, in 50% higher runoff and lowest hydraulic conductivity at large. Both last-mentioned effects are caused by the platy soil surface and subsurface structure. Among conventional tilled sites lowest runoff and soil losses were measured in the Ferri Stagnic Luvisol based on high top soil sand content and thus very high hydraulic conductivity. Aridic Calcisol and Chromic Calcaric Cambisol show alternating highest soil losses, whose great silt and clay content enhances the development of hydrophobic surface structures and diminishes the hydraulic conductivity. Collectorbox soil losses in the main wheel track exceed those of the microplots for a multiple. Alike do erosion losses presented in literature exceed measured data. Both effects are due to the short slope length of microplots. In conclusion conservation soil management is effective in reducing soil erosion losses in comparison to conventional soil management. High contents of sand decrease runoff and soil losses. Platy structure develops under conservation soil management and minimizes the hydraulic conductivity resulting in high runoff. Reduced hydraulic conductivity and so high runoff in conventional tilled Aridic Calcisol and Chromic Calcaric Cambisol is caused by surface hydrophobicity due to high silt and clay content.

2024

in den bearbeiteten Böden war stark durch die Zufuhr leicht zersetzbarer organischer Substanz reguliert. Das C . je mic arg Verhältnis der Referenzböden zeigte das natürliche Gleichgewicht zwischen Zu-und Abfuhr organischer Substanz. Dieses Gleichgewicht war in den bearbeiteten Böden verändert. Der Effekt unterschiedlicher Bodennutzung aufdie Regenwurmpopulation konnte wegen besonderer Trockenheit im Untersuchungszeitraum nicht eindeutig festgestellt werden.

Roskin, J., Robins, L., Sánchez, R., Ostrowski, A., Bookman, R. and Taxel, I. 2024. Character and Evolution of Sunken Groundwater-Harvesting Agroecosystems in Aeolian Sand Since Early Islamic Times, Between Iran and Iberia. Environmental Archaeology.

2024

By reviewing traditional, sunken, groundwater-harvesting agroecosystems (SGHAS) in coastal and inland aeolian sand situated in Iran, Egypt, Gaza Strip, Algeria and Iberia, coupled with image interpretation and geospatial analysis, we study the innovation and function of recently excavated Early Islamic (EI; tenth-twelfth century), Plot-and-Berm agroecosystems along the southeastern Mediterranean coast of Israel. The SGHAS and EI agroecosystems, usually affiliated with nearby towns, possess an aeolian sand substrate enrichened with urban refuse and/or organic material. The long-term investment in SGHAS attained profitable water security in the form of temporally continuous, shallow groundwater, replenished by rainfall. The crops in SGHASs include a wide range of vegetables, watermelons, dates and grapes, implying that the EI crops were partly or fully different. The spotty, historic appearance of SGHAS since the fifteenth-sixteenth centuries temporally lags after the abandonment of the EI agroecosystems, does not support spatial and temporal connectivity of sand agriculture knowledge, but probably exemplifies the appearance of site-specific ingenuities derived from growing agro-technological knowledge, crop variety and needs for food security. This study demonstrates the importance of traditional analogues for interpreting research gaps of archaeological, agricultural landscapes and provides insight for establishing traditionally-based, sustainable agriculture in sand.

2024, arXiv (Cornell University)

Sand fences are often erected to reduce wind speed, prevent aeolian soil erosion, and induce sand deposition and dune formation in areas affected by sand encroachment and desertification. However, the search for the most efficient array of fences by means of field experiments alone poses a challenging task given that field experiments are affected by weather conditions. Here we apply Computational Fluid Dynamic simulations to investigate the three-dimensional structure of the turbulent wind field over an array of fences of different sizes, porosity and spacing. Our goal is to perform a quantitative analysis of this structure in