Rugged Topography Research Articles

Gravity terrain correction for mainland territory of Vietnam

Terrain corrections for gravity data are a critical concern in rugged topography, because the magnitude of the corrections may be largely relative to the anomalies of interest. That is also important to determine the inner and outer radii beyond which the terrain effect can be neglected. Classical methods such as Lucaptrenco, Beriozkin and Prisivanco are indeed too slow with radius correction and are not extended while methods based on the Nagy’s and Kane’s are usually too approximate for the required accuracy. In order to achieve 0.1 mGal accuracy in terrain correction for mainland territory of Vietnam and reduce the computing time, the best inner and outer radii for terrain correction computation are 2 km and 70 km respectively. The results show that in nearly a half of the Vietnam territory, the terrain correction values ≥ 10 mGal, the corrections are smaller in the plain areas (less than 2 mGal) and higher in the mountainous region, in particular the correction reaches approximately 21 mGal in some locations of northern mountainous region. The complete Bouguer gravity map of mainland territory of Vietnam is reproduced based on the full terrain correction introduced in this paper.

Quantitative Analysis of Near‐Surface Seismological Complexity Based on the Generalized Lippmann–Schwinger Matrix Equation

Near-surface complexity is characteristic of rugged topographies and strong volume heterogeneities, which significantly affects seismic data recorded at the free surface. An efficient method is presented here to quantitatively analyze the nearsurface seismological complexity. We use a boundary–volume element numerical method to discretize the generalized Lippmann–Schwinger integral equation formulated in terms of volume scattering and boundary scattering. The integral equation technique provided sufficient accuracy to model rough topographies, large-scale structures, and volume heterogeneities in a straightforward and efficient manner. Rather than solving the resultant global matrix equation at a very high computational cost, certain characteristic parameters of the scattering amplitude matrix were estimated and used as indicators to assess the near-surface seismological complexity. Applications to numerous examples validated the method’s applicability, reliability, and efficiency, whereby the resultant matrix characteristic parameters varied consistently with the near-surface complexity in geometric structures, volume heterogeneities, and computational frequencies.

Identification of new base metal mineralization in Kumaon Himalaya, India, using hyperspectral remote sensing and hydrothermal alteration

Economic mineral deposits are commonly associated with zones of intense hydrothermal alteration. Space borne hyperspectral remote sensing is one of the recent techniques that enable the identification of hydrothermally altered and weathered minerals. In this study, we identified hydrothermally altered and weathered minerals of a gossanised outcrop rich in base metal mineralization in parts of the Kumaon Himalaya, India using an EO-1 Hyperion (hyperspectral) satellite data. Spectral Angle Mapper classification method was used to map the different altered/weathered minerals within the study area. The method identified the occurrence of dolomite and dolomite with chlorite minerals from the Hyperion data. The finding was verified in the field and confirmed through laboratory analyses. Representative samples measured for spectral absorption characters, reflected and transmitted petrography, X-ray diffraction and ICP-MS analyses confirmed the occurrence of Ag, Cu, Fe, Pb, Zn, As, and Sb base metal rich elements in the Thalkedar limestone. Our study recommends the technique to the map base metals and hydrothermally altered minerals in the other parts of Thalkedar limestone of Kumaon Himalaya and similar region of the world. The study is an important case for formulating exploration strategies in terrenes with rugged topography and dense vegetation.

Effects of land use and cover type on the risks of runoff and water erosion: infiltration tests in the Ourika watershed (High Atlas, Morocco)

The upstream section of the Ourika watershed is located in the northwest slopes of the High Atlas Mountains of Morocco. It is characterized by rugged topography and sparse vegetation, and is under increasing human-induced pressures, exacerbated by climate variability and change. Its vulnerability to water erosion is high and, thus, wadi flows with significant solid loads are a constant risk. Infiltration measures through rain simulations, using a simple irrigator ramp, were carried out as part of an investigation to highlight the role of vegetation cover in mitigating soil erosion in the watershed. The methodology assessed the effect of land use and cover type on the soil surface state and properties on 1-m2 plots. Seventeen experimental sites were considered with reference to both land use and plant cover, with three test plots per site, making it a total of 51 test plots for the rainfall simulations. Soil samples were collected at different depths from each site to determine soil properties. Results obtained show that dense forests protect the soil, produce organic matter improving soil aggregation, and hence ensuring adequate infiltration. In woodlands, bare soil is susceptible to crusting, runoff, and water erosion. In overgrazed scrublands, soil compaction due to animal trampling, induces significant runoff. Croplands are poor in organic matter and are consequently very susceptible to crusting, losing infiltration capability. Infiltration was positively correlated with initial abstraction (R = 0.71), covered and non-crusted soil surfaces (R = 0.84 and R = 0.83, respectively), organic matter content (R = 0.62) and aggregate soil stability (R = 0.69). By contrast, it was negatively correlated with soil detachability (R = − 0.65), penetration resistance (R = − 0.81), and shear strength (R = − 0.64). However, a weak correlation between infiltration and either of bulk density, total porosity, or texture was observed. Findings showed that total infiltration was not correlated with the physical parameters of the soil but rather with the surface state of soils. Covered surface greatly decreased runoff and soil erosion by increasing the surface roughness and decreasing the runoff velocity in the study zone.

Interaction between active tectonics, erosion and diapirism, a case study from Habble-Rud in Southern Central Alborz (Northern Iran)

The Alborz mountain chain is a region of active deformation within the Arabia–Eurasia continental collision zone. The southern part of central Alborz Mountains, in the north of Iran, represents complex tectonics because it is located at the border of two developing continental sedimentary basins between southern central Alborz and Central Iran. An arid and semi-arid climate, a large extent of Quaternary sediments, rugged topography, salt domes and faults with historical seismicity influence the Habble-Rud River catchment. In the present research, a number of tectonic geomorphologic indices were extracted from satellite imagery and 10m DEM (digital elevation model) data in order to identify relative tectonic activity within the basin. The indices include: stream length-gradient index (Sl), drainage basin asymmetry (Af), index of mountain front sinuosity (Smf), hypsometric integral (Hi), index of drainage basin shape (Bs), ratio of valley-floor width to valley height (Vf), and fault density (Fd). Due to the presence of heterogeneous indices for all sections of the catchment causing large extension of Habble-Rud (3260km2), all of the variables such as extremely erodible formations, faults and folds and salt tectonics on the Southern part; were put into a matrix table. As a new approach, the variables were put into the SAW (simple additive model) model as one of MADM (multi-attribute decision-making models) techniques. The study area was divided into four regions according to the values of SAW. These classes include very high (%11), high (48.3%), moderate (34.7%), and low activity (3.4%). The result of the model suggests that the study area is located on a changing tectonic trend in central Alborz from NW-SE to NE-SW. The regions with high relative tectonic activity in HR catchment correspond to the active Garmsar and Sorkhe-Kalout faults and diapirs.

Novel Approach in the Use of Plasma Spray: Preparation of Bulk Titanium for Bone Augmentations.

Thermal plasma spray is a common, well-established technology used in various application fields. Nevertheless, in our work, this technology was employed in a completely new way; for the preparation of bulk titanium. The aim was to produce titanium with properties similar to human bone to be used for bone augmentations. Titanium rods sprayed on a thin substrate wire exerted a porosity of about 15%, which yielded a significant decrease of Young′s modulus to the bone range and provided rugged topography for enhanced biological fixation. For the first verification of the suitability of the selected approach, tests of the mechanical properties in terms of compression, bending, and impact were carried out, the surface was characterized, and its compatibility with bone cells was studied. While preserving a high enough compressive strength of 628 MPa, the elastic modulus reached 11.6 GPa, thus preventing a stress-shielding effect, a generally known problem of implantable metals. U-2 OS and Saos-2 cells derived from bone osteosarcoma grown on the plasma-sprayed surface showed good viability.

Development and evaluation of the Soil and Water Temperature Model (SWTM) for rural catchments

A physically-based energy balance model, the Soil and Water Temperature Model (SWTM), is developed in an effort to improve the soil temperature estimation for Korean rural watersheds or catchments, which are characterized by heterogeneous land-cover types and rugged topography and have many paddy fields retaining surface water during the growing season. The developed model is applied to a small rural catchment in South Korea where soil temperature is measured for two months, July to August 2008, at eight monitoring sites including forest, paddy field, dry field, and natural vegetation area. The degree of agreement between the simulated and observed soil temperature is quite good for the soil surface (RMSE 1.11–3.16°C, R2 0.80–0.88), except for forests. Although some estimation errors resulting from data deficiency and model structure are observed, SWTM reasonably well simulates the spatial and temporal distribution of soil temperature at the catchment scale by considering the effects of topography, vegetation cover, and hydrological characteristics, especially the existence of surface water. SWTM is well suited for rural watersheds or catchments and expected to contribute to enhancing our understanding of watershed biogeochemical processes and managing the watershed environment.

Applying joint traveltime and waveform inversion to image the Sichuan Basin, China

ABSTRACTWe apply a joint first‐arrival traveltime and early‐arrival waveform inversion method to image complex near‐surface structures in the Sichuan Basin, China. The area includes rugged topography and large near‐surface velocity variations. Due to the near‐surface effects, it is difficult to produce high‐quality reflection images of the deep subsurface. First‐arrival traveltime tomography is often applied for near‐surface imaging, but the results may not be sufficiently accurate because of ray assumptions and the limited traveltime information. Waveform inversion should allow complex structures to be resolved; however, it may fall into local minima because of cycle skipping issues and may also produce artefacts in very shallow areas that are associated with rugged topography. Therefore, we combine the advantages of the two methods and mitigate their problems by performing joint inversion of the two types of data. We demonstrate the effectiveness of the joint inversion method using synthetic and real data from Sichuan, China. In the real data example, we compare the velocity models resolved from waveform inversion alone with those resolved from the joint inversion. We calculate long‐wavelength static corrections and apply them to the data processing. The common midpoint stacking results show that the joint inversion method produces a more effective statics solution.

Mapping thermal comfort in Iran based on geostatistical methods and bioclimatic indices

The cognition of thermal comfort plays a pivotal role in human life and activities. Recognizing thermal comfort based on climatic parameters is substantially significant. The main objective of the present study is to map thermal comfort using statistics from 43 meteorological stations, from 1970 to 2013. Initially, according to temperature and relative humidity, annual and seasonal thermal comfort conditions were mapped, and later bioclimatic human thermal comfort conditions in line with spatial factors were zoned based on bioclimatic indexes of Temperature Humidity Index (THI), effective temperature (ET) and Relative Strain Index (RSI). Among geostatistical methods, empirical Bayesian kriging (EBK) method with less RSME is more efficient. The annual distribution of temperature changes according to spatial factors of rugged topography and elevation, and latitude affects relative humidity. Thermal comfort in the northern and western half of Iran is higher than the southern and eastern areas of the country. Spatial factors of latitude and altitude reduce bioclimatic uniformity and create small areas with or without thermal comfort conditions. Bioclimatic indicators based on air temperature and relative humidity range of bioclimatic zones show. The results of ET and THI divide the whole country into six zones, from lack of thermal comfort to having thermal comfort conditions. Areas of southern strip as well as central and southeastern parts of the country do not have any human thermal comfort conditions in most of the year.

Processes and Status of Land Degradation in a Plateau Fringe Region of Tropical Environment

The concept of land degradation means a temporary or permanent long-term decline in an ecosystem function and its productive capacity. Land degradation is the result of numerous factors or a combination thereof, including physical (climate change, soil degradation) as well as anthropogenic activities such as unsustainable land management practices. The present study primarily concerns the processes and status of land degradation in a part of the eastern Chotanagpur Plateau, India. The basin falls under the transitional zone, is undulating in nature and situated between the Chotanagpur Plateau area in the west and the greater Ganga plain area in the east. Largely, the basin falls under the Ganga River system. The major part of the population (>70%) of the area is dependent on agriculture which is largely affected by land degradation as well as soil erosion processes. The status of land degradation is estimated from different physical factors (geology, soil, geomorphology, slope, relief, groundwater, drainage density, rainfall intensity, green biomass cover) as well as anthropogenic factors (land use land cover change, population pressure on agricultural land, deforestation, irrigation intensity etc.). All these factors have been weighted with considerable importance to show the resultant varying intensities of land degradation. The different factor weighted raster has been multiplied in the GIS environment. The different vulnerable land degradation areas have been identified on the basis of the final weighted value. It has been shown that the upper reaches of the basin is considerably more prone to degradation due to its rugged topography, poor soil development and high drainage density. In the lower reaches of the Silabati River, the left bank is characterized by a high degreee of slope whereas the right bank shows intensive agricultural density, which couple up, to cause medium to high degree of land degradation vulnerability.

Integrating petrogenesis and weathering to understand regolith chemistry: examples from the Palaeoproterozoic Carson Volcanics, north Kimberley, Western Australia

The rugged topography of the Kimberley area of northern Western Australia preserves examples of the complete weathering cycle to produce regolith. With increasing weathering intensity, Palaeoproterozoic mafic volcanic rocks of the Carson Volcanics are progressively depleted in low field strength element (LFSE) and rare earth elements (REE), and enriched in high-field strength elements (HFSE), Th, Cr and chalcophile elements. This reflects the breakdown of the main rock-forming minerals, the concentration of resistate phases such as zircon, chromite, monazite and rutile, and the development of secondary clay minerals, oxides and oxyhydroxides. Some regolith samples at the base of the volcanic succession have high Cr, As and detectable Au and Pd. This regolith chemistry reflects not only the intensity of weathering, but also the less fractionated and weakly mineralized nature of flow units erupted early in the volcanic cycle. Elsewhere in the Carson Volcanics, two regolith samples with unusually high concentrations of Ba, REE and Zn are located close to regional structures, which acted as conduits along which hydrothermal fluids migrated resulting in surface alteration, probably after regolith formation. Both examples show that regolith chemistry should be interpreted in the context of both weathering and petrogenetic processes that affect bedrock composition.

La red social del abasto urbano: aguadores y fiadores en Zacatecas, México (siglo XIX)

Este artículo tiene el objetivo de estudiar a un grupo de individuos (en su mayoría hombres) que, desde el periodo fundacional del espacio minero zacatecano, se dedicaron a llevar agua a las viviendas de los habitantes que tenían solvencia económica para pagar el costo por el acarreo del líquido. Esta acción no era sencilla, la accidentada topografía del enclave minero y la distancia de los pozos, manantiales y arroyos que rodeaban el poblado dificultaban la labor. Aunque no se cuenta con un registro de aguadores que date de 1546 (fundación del Real de Minas de Nuestra Señora de Zacatecas), se tienen datos que reflejan su prolongada existencia desde finales del XVIII hasta terminar el siglo XIX. En este periodo, los denominados aguadores tuvieron que realizar vínculos políticos y económicos no solo con la institución que los registraba, regulaba y organizaba: el Ayuntamiento; también se relacionaron con un grupo denominado fi adores que otorgaban avales para que pudieran desempeñar su oficio. En este sentido, se pretende establecer una red social entre ambos actores sociales.

Plasma-enhanced synthesis of carbon nanocone arrays by magnetic and electric fields coupling HFCVD

In this paper, magnetic and electric fields coupling hot filament chemical vapor deposition (HFCVD) was used to fabricate a series of carbon films varying from nanocrystalline diamonds (NCD) to carbon nanocone arrays. The surface morphology and composition of the film were examined by scanning electron microscopy and Raman spectroscopy. After adding magnetic field, the morphology of the as-grown NCD film was a serried form instead of a rugged topography obtained under the absence of magnetic field. As electric field intensity increased, the etching degree of NCD films enhanced and the structural transformation of NCD to microcrystalline graphite occurred. We proposed that magnetic and electric fields can effectively introduce plasma into HFCVD system to optimize the film deposition process and studied the impact of magnetic and electric fields. The presence of electric field promoted ionization of reactive gas, and magnetic field made these ionic gases bound to a certain area around the sample, increasing the regional density of plasma. Specially, unique carbon nanocone arrays were obtained by synergistic effect of magnetic and electric fields, which exhibited optimal electron field emission properties, showing the lowest turn-on field of 5.65V/μm.

Seismic migration in generalized coordinates

Reverse time migration (RTM) is a technique widely used nowadays to obtain images of the earth’s sub-surface, using artificially produced seismic waves. This technique has been developed for zones with flat surface and when applied to zones with rugged topography some corrections must be introduced in order to adapt it. This can produce defects in the final image called artifacts. We introduce a simple mathematical map that transforms a scenario with rugged topography into a flat one. The three steps of the RTM can be applied in a way similar to the conventional ones just by changing the Laplacian in the acoustic wave equation for a generalized one. We present a test of this technique using the Canadian foothills SEG velocity model.

Joint traveltime, waveform, and waveform envelope inversion for near-surface imaging

The first-arrival traveltimes without large offsets constrain very shallow velocities, the waveform envelope presents low-frequency data, and the high-frequency waveform itself includes information regarding structural details. We have developed a joint traveltime, waveform, and waveform envelope (JTWE) inversion method for inverting near-surface velocity structures. By inverting three types of data, we are able to recover the low- and high-wavenumber structures and mitigate the cycle-skipping problem in waveform inversion. The calculation of traveltimes and raypaths is fast. Most of the computation effort is focused on dealing with the waveform and waveform envelope. JTWE backward propagates the waveform residual and envelope residual simultaneously to calculate the model updating gradients. This simultaneous backward-propagation strategy ensures that the computational cost of JTWE is similar to the cost of inverting waveform alone. In a synthetic experiment, we determine that JTWE mitigates the cycle-skipping problem and recovers the near-surface structures without the need for additional low-frequency data. The final results of JTWE indicate that it delivers improved results with low-velocity inclusions compared with full-waveform inversion. For field data from the Middle East, JTWE helps resolve a complex near-surface model with rugged topography and fit all three types of data.

Prestack time migration of nonplanar data: Improving topography prestack time migration with dip-angle domain stationary-phase filtering and effective velocity inversion

We have developed a modified prestack time migration (PSTM) approach that can directly image nonplanar data by using two effective velocity parameters above and below a datum. The proposed extension improves the so-called topography PSTM by introducing a dip-angle domain stationary-phase migration (or filtering) and combining effective velocity inversion with the residual static corrections. The stationary-phase migration to constrain the imaging aperture within Fresnel zones significantly improves the signal-to-noise ratio (S/N) of the image gathers, especially in the presence of steeply dipping structures. This helps to extract an accurate residual moveout from the common shot and receiver image gathers, and the surface-consistent residual statics hidden in these image gathers can be simultaneously obtained from an inversion process. As a result, the final migrated images show higher S/N and are better focused than the conventional topography PSTM. The proposed technique can handle rugged topography, especially in the presence of high near-surface velocities, without the need for prior elevation static corrections. The SEG foothills overthrust model and a real data set acquired on a piedmont zone are used to validate the modified topography PSTM. Synthetic and field data examples are obtained with good results.

Tectonic constraints on a deep-seated rock slide in weathered crystalline rocks

Deep-seated rock slides (DSRSs), recognised as one of the most important mass wasting processes worldwide, involve large areas and cause several consequences in terms of environmental and economic damage; they result from a complex of controlling features and processes. DSRSs are common in Calabria (southern Italy) where the complex geo-structural setting plays a key role in controlling the geometry of the failure surface and its development. This paper describes an integrated multi-disciplinary approach to investigate a DSRS in Palaeozoic high-grade metamorphic rocks of the Sila Massif; it focuses on the definition of the internal structure and the predisposing factors of the Serra di Buda landslide near the town of Acri, which is a paradigm for numerous landslides in this area. An integrated interdisciplinary study based on geological, structural, and geomorphological investigations—including field observations of weathering grade of rocks, minero-petrographic characterisations, geotechnical investigations and, in particular, fifteen years of displacement monitoring—is presented. Stereoscopic analysis of aerial photographs and field observations indicate that the Serra di Buda landslide consists of two distinct compounded bodies: (i) an older and dormant body (~7ha) and (ii) a more recent and active body (~13ha) that overlies the previous one. The active landslide shows movement linked to a deep-seated translational rock slide (block slide); the velocity scale ranges from slow (1.6m/year during paroxysmal stages) to extremely slow (<16mm/year during stable creep stages). The geological structures and rock weathering have played a key role in the landslide's initiation and further development. Steep slope angles, rugged topography, river deepening and erosion at the toe of the slope are also responsible for the formation of this landslide. In particular, the landslide shows a strongly tectonic constraint: the flanks are bounded by high-angle faults, and the main basal failure surface developed inside an E–W southward-dipping thrust fault zone. The entire active rock mass (total volume of approximately 6Mm3) slid at one time on a failure surface that dipped<27°, and the maximum depth, as determined by inclinometer measurements, was approximately 58m. Petrographic and mineralogical analyses suggest that the rocks in the thrust zones, where the failure surfaces develop, are highly affected by weathering processes that significantly reduce the rock strength and facilitate the extensive failure of the Serra di Buda landslide. Finally, the landslide's internal structure, according to geotechnical investigations and displacement monitoring, is proposed. The proposed approach and the obtained results can be generalised to typify other deep landslides in similar geological settings.

Downward shortwave radiation estimation and spatial assessment on sites over complex terrain applying integrative approach of MTCLIM-XL, interpolation, RS and GIS

Downward shortwave radiation (DSR) is a highly variable solar source on spatiotemporal basis and essential for energy and agriculture systems, while its calculations are helpful in the environment-related studies, climatology, and monitoring fire risk. Statistical methods developed to extrapolate values of climatic variables and radiation could fail to generate reliable findings of DSR over a complex terrain without considering local topographic factors. In the present study, we proposed an integrative approach of MTCLIM-XL extrapolation with remote sensing (RS) and geographic information system (GIS) to estimate real-time DSR and its spatial potential over surfaces of contrasting elevated sites on a mountainous terrain of Quetta (Pakistan).Based on methodological approach, remote sensing data product of high-resolution DEM (SRTM 30m) was processed to extract topographic data, and meteorological data were obtained from a base site, Subsequently, MTCLIM-XL executed the simulation to calculate the daily-based DSR (W/m2).Spatial distribution of DSR was generated by applying deterministic interpolation with complementing quantification of Hillshade analysis for spatially obstructive surfaces, and resultant spatial hotspot-based potential was assessed on basis of specified threshold level (above 250 W/m2 = 2 kW h/m2) over the specified area. We observed usable potential of DSR at target sites and its spatial distribution during the study period of 2015 to April 2016. Using EUMETSAT CMSAF data as a standard, the validation demonstrates agreeable results of low RMSE and high correlation coefficient values for selected sites, except some sites with relatively high elevations and irregular gradients. Analysis of solar zenith angle to evaluate its inverse relation with increment in DSR values shows agreeable high inverse relation, while the negative trend for only some sites features relatively high rugged topography. In conclusion, MTCLIM-XL with RS and GIS integration manifests as a reliable approach for estimation and spatial potential assessment-based exploration of DSR over complex terrain having no ground data, while prospectively it will complement to the environment-related studies on local to mesoscale.

Landscape-level habitat use and movement patterns of black bears in northeastern Arizona

Abstract Little is known about black bear (Ursus americanus) populations in northeastern Arizona, an area characterized by rugged canyon topography and varied habitat composition. We placed global positioning system collars on four bears in this area to characterize second-order, landscape-level habitat use and examine habitat use and movement patterns of bears across this landscape. Data from four global positioning system collars revealed that bears use areas with higher tree canopy cover and terrain ruggedness, indicating that forest and escape cover are important factors driving black bear habitat use at the landscape level. Movement patterns revealed long, linear mean daily movements that follow the structure of the canyon topography. These long, linear movements also allow bears to take advantage of the mosaic of habitats and food resources available in this unique landscape.

Sedimentary environment of vermicular red clay in South China

Increasing interest in recent years has focused on vermicular red clay (VRC) in southern China due to its controversial sedimentary environment and provenance. Grain size is a useful way to determine sedimentary environment and provenance. Fisher Linear Discriminant Analysis (LDA) is a common and widely used method for multivariate statistical analysis. Based on a proper training sample set, the LDA can be used to discuss the sediment provenance. In this study, grain size data for 77 Malan loess samples and 41 floodplain deposit samples were used as a training sample set to deduce a Fisher linear discriminant function. Then, 299 VRC samples from 6 Quaternary red clay profiles were analyzed using the discriminant function. Grain size parameters and microscopic images of quartz grains separated from the VRC were evaluated in detail to determine the VRC sedimentary environment in south China. The results show that VRC profiles can be classified into two regions: the Chiang-nan Hilly Region and Wuyi Mountains Region. The VRC samples in the Chiang-nan Hilly Region originated from eolian dust deposits. This VRC is characterized by a higher content of fine particles (<20 μm) and lower average transport kinetic energy than loess in a C-M plot. The quartz grain sizes and microscope images of this VRC suggest that it could be a polyphyletic mixture of far-sourced and near-sourced eolian deposits. The far-sourced eolian deposits share similar provenance with Xiashu loess and were transported by the East Asian winter monsoon. The near-sourced eolian deposits were dust emitted from the adjacent floodplain. In the Wuyi Mountains Region, the rugged topography weakened the dustfall and strengthened the reconstructive effect of hydrodynamic forces during the Quaternary glacial periods. The VRC in this region was reworked strongly by water and retained typical hydraulic characteristics no matter the source.