Gentle Slope Research Articles

Depositional process and sediment dispersal pattern of mass transport complex on a slope with numerous elliptical depressions, northwestern South China Sea

A Quaternary mass transport complex (MTC), formed by debris flows on a slope with numerous elliptical depressions in the Qiongdongnan Basin, is identified using three-dimensional seismic data. 25 % (5.7 km3) of the total volume of the MTC was deposited on the Upper and Middle slopes, mainly owing to the elliptical depressions capturing the bypassed debris flows. The megascour with slot-like geometry on the base of the MTC trends north–north-east on the Upper and Middle slopes, implying debris flows flowed downslope toward the north–north–east. The steep slope is responsible for the bypassing of the main body of debris flows. Moreover, the steep slope probably accelerated the debris flows, and thus the debris flow plowed, eroded and incorporated the substrate sediments to form the megascour. As a result, 75 % (17.3 km3) of the total volume of the MTC occurs on the Lower slope, mainly consisting of the lobe-like accumulation zones 1 and 2. Trends of the pressure ridges in the lobe-like accumulation zone 1 suggest debris flows spread in an unconfined manner due to the relatively gentle Lower slope, until it reached the topographic barrier to the north. As a result of the blocking of the topographic high, only a portion of the debris flows continues to flow northeastward evidenced by the small-scale megascour with slot-like geometry on the base of the MTC resulting from the relatively steeper slope. It is clear that the topography of the pre-existing slope plays a significant role in the depositional process and dispersal of the MTC. Topography of the pre-existing slope mainly resulted from tectonic movements and sedimentary infilling processes. It was also complicated by the elliptical depressions that were formed by the normal-drag along the arcuate normal-faults, which are attributed to sediment load that favors the downward slip on the walls of the erosional troughs within the substrate of the MTC. The steep slope and high sedimentation rates probably are important triggers for the occurrence of the MTC. This study is helping to improve current knowledge of the interaction between debris flows and the topography of the pre-existing slope.

Effects of small-scale topography on organic sulfur mineralization of subtropical soils

Organic sulfur (S) mineralization is an important source of sulfate in soils, compared to atmospheric and weathering inputs. Previous studies on the effects of topography on the decomposition of organic matter have focused exclusively on mountainous regions with steep slopes, without considering low hilly regions with gentle slopes. It therefore remains unclear whether and how hilly regions create distinct environmental conditions that could affect organic S mineralization. We determined S sources, speciation and decomposition index in soil profiles and corresponding plant samples along a catena in a subtropical monsoon climate using a combination of S isotope ratios and S K-edge X-ray absorption near edge structure (XANES) spectroscopy. Sulfur in surface soils is mainly derived from decomposing litter. The decomposition of organic S is the primary process influencing the proportions of water-soluble and adsorbed SO42− in soil profiles. Pedogenic Fe and Al minerals contribute significantly to S stabilization in soils. The most oxidized S species are abundant in plants (10–56%) and may have the potential to stimulate biochemical mineralization through the hydrolysis of ester-S, thereby enhancing S-supplying capacity of soils. Water availability, influenced by small-scale topography, plays a key role in the S biological mineralization. The slower S decomposition rates at the lower elevation can be attributed to the high water content that inhibits microbial activities. Our results suggest that incorporating local-scale topography into the modeling frameworks may improve predictions of ecosystem S status and its responses to climate change.

Pore Structures and Evolution Model of Reservoirs in Different Secondary Structural Zones in the Eocene Shahejie Formation, Chezhen Sag, Bohai Bay Basin.

Although abundant unconventional oil resources have been discovered in conglomerate and sandstone reservoirs in rift basins, the mechanism of differential pore evolution in conglomerates and sandstone reservoirs within different secondary structural zones of rift basins is not yet clear. The pore structures of conglomerate and sandstone reservoirs in the distinct secondary structural zones in the Chezhen Sag were quantified in three dimensions using high-resolution microcomputed tomography (micro-CT). Thin section and scanning electron microscopy observations were used to investigate the differential evolution mechanisms of conglomerate and sandstone reservoirs. Micro-CT analysis of the pore structures of conglomerate and sandstone reservoirs revealed that sandstone reservoirs are superior to conglomerate reservoirs with regard to the pore number and pore connectivity and that sandstone reservoirs are more heterogeneous than conglomerate reservoirs. Triangles dominate the pore and pore throat geometries of sandstone and conglomerate reservoirs, while the sandstone reservoir pores are more regular than conglomerate reservoir pores. The depositional environment, mineral composition, and diagenetic intensity jointly control the quality of the reservoirs. Because of the lengthy transportation distance of their parent rocks, the compositional maturity and sorting behavior of sandstone reservoirs in depression and gentle slope zones are better than those of conglomerate reservoirs in steep slope zones, and thus sandstone reservoirs have a higher initial porosity than conglomerate reservoirs. The rapid compaction experienced by the conglomerate reservoirs in steep slope zones in their early stages creates a closed diagenetic environment, making it difficult to effectively improve reservoir porosity through dissolution. However, the widely developed microfractures in the reservoirs provide channels for fluid migration, promote the development of dissolution pores, and form a tight reservoir dominated by secondary pores. With weak compaction and an open diagenetic environment, the primary pores in sandstone reservoirs in the gentle slope zone are preserved in large quantities. Meanwhile, dissolution expands the secondary pores of the reservoir, resulting in a high-quality reservoir having both primary and secondary pores. In addition, an approach based on primary, secondary, and total porosity was proposed in the study to efficiently evaluate reservoir quality and identify reservoir evolution mechanisms.

Wildfire susceptibility mapping by incorporating damage proxy maps, differenced normalized burn Ratio, and deep learning algorithms based on sentinel-1/2 data: a case study on Maui Island, Hawaii

ABSTRACT Climate change has contributed to the recent increase in wildfire occurrences, vegetation failures, human health risks, physical damage, and economic losses. Wildfire susceptibility mapping is an essential technique for assessing areas prone to wildfires. In this study, we proposed the combination of the damage proxy map (DPM) and differenced normalized burn ratio (dNBR) method to generate a precise wildfire inventory map and used it to predict areas susceptible to wildfire. The wildfire susceptibility maps were produced using frequency ratio (FR), convolutional neural network (CNN), and long short-term memory (LSTM)-based deep learning and their performances were compared. We implemented the proposed method on Maui Island, Hawaii, where wildfires frequently occur. We started the process by generating a wildfire inventory map from 2019 to 2023 based on the DPM method applied to Sentinel-1 synthetic aperture radar (SAR) data combined with a dNBR map retrieved from Sentinel-2 data. The wildfire inventory was randomly divided into a training dataset (70%) and a testing dataset (30%). Fifteen wildfire-related factors, including topographical, meteorological, land use, environmental, and anthropological factors, were selected to predict wildfires. The wildfire-related factors were selected by conducting study literature and considering spatial correlation analysis based on the FR method, information gain ratio analysis (IGR), and multicollinearity assessment using tolerance (TOL) and variance inflation factor (VIF) metrics. The level of susceptibility of an area to wildfire is divided into five, namely very high, high, moderate, low, and very low. The FR, CNN, and LSTM produced wildfire susceptibility maps with similar patterns, significantly influenced by land use and rainfall factors. The highly susceptible areas are located on gentle slopes covered by agricultural land and unhealthy vegetation, and these areas have low rainfall intensity but receive high levels of solar radiation. Meanwhile, areas with relatively low susceptibility occur in forests with high levels of wet canopy evaporation. The prediction results were evaluated using the area under the receiver operating characteristic (ROC) curve (AUC), and the CNN performed slightly better than the FR and LSTM, with AUC values of 0.879, 0.877, and 0.870, respectively. Hence, the use of the CNN algorithm in the proposed method is appropriate, specifically for the study area. In addition, the susceptibility map provides information on susceptible areas on Maui Island, Hawaii, to increase public awareness.

Comprehensive Analysis of Landform and Land Use/ Land Cover Mapping of Waghora Watershed Using Sentinal-2B and SRTM-DEM Data

This paper aims to integrate the use of high spectral resolution a remote sensing data of Sentinel-2B imagery along with the Digital Elevation Model (DEM) derived from the SRTM stereo data to delineate the landforms and analyze the land use and land cover in Waghora watershed, Sausar tehsil, Chhindwara district, situated on basaltic terrain in northern Deccan plateau. A 30 m resolution DEM of the study area was generated, capturing terrain parameters like elevation, slope, aspect, hillshade, and drainage. Sentinel-2B (10 m) images from two seasons were collected FCC (false colour composite) and were prepared by ARCGIS software. combination of Sentinel-2B imagery, SRTM-DEM data, and ground truth verifications to delineate eight major landforms in the studied area. Slope information, extracted from high-resolution DEMs, reveals 4 distinct slope classes. The landforms, including Plateau, Escarpment, Foot Slope, Upper Pediment, Lower Pediment, Valley, Interfluve, and Mound, are characterized based on visual interpretation and geological context. Each landform exhibits unique features, elevation ranges, and dominant land use/cover types, such as single crop cultivation, forest, or degraded land. This detailed terrain analysis aids in land-use planning and environmental management initiatives. The land use/land cover analysis utilizes Sentinel-2B data to identify five classes: degraded forest, double crop, single crop, orchard, and land with and without scrubs. Dense forest dominates 24.2% of the watershed, while double crop and single crop lands cover 36.7% and 24.2% respectively. Orchards occupy a minimal 0.8% of the area, and wastelands account for 5.7%. The relationship between landforms, slope, and land use/cover reveals dominant forestation on steep escarpments, while valleys and interfluves support double cropping due to gentle slopes and depositional processesThe study elucidated connections to examine diverse biophysical phenomena. It highlights the effectiveness of employing SRTM-DEM and Sentinel-2B imagery for analyzing geomorphic characteristics and mapping land use/land cover, offering significant perspectives for land management and planning approaches.

Dynamic modeling of minimum mass of pore-gas for triggering landslide in stable gentle soil slope

This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes. A stable gentle soil slope model is constructed with a dry cement powder core, a saturated clay middle layer, and a dry sand upper layer. The test injects H2O2 solution into the cement core to produce new pore-gas. The model test includes three identical H2O2 injections. The small mass of generated oxygen gas (0.07% of slope soil mass and landslide body) from the first injection can build sufficient pore-gas pressure to cause soil upheaval and slide. Meanwhile, despite the first injection causing leak paths in the clay layer, the generated small mass of gas from the second and third injections can further trigger the landslide. A dynamic theoretical analysis of the slope failure is carried out and the required minimum pore-gas pressure for the landslide is calculated. The mass and pressure of generated gas in the model test are also estimated based on the calibration test for oxygen generation from H2O2 solution in cement powder. The results indicate that the minimum mass of the generated gas for triggering the landslide is 2 ppm to 0.07% of the landslide body. Furthermore, the small mass of gas can provide sufficient pressure to cause soil upheaval and soil sliding in dynamic analysis.

Particle crushing and critical state of volcanic pumice – 2018 Hokkaido Eastern Iburi Earthquake

Volcanic pumice, with special characteristics such as crushable particles and high water retention, is distributed throughout Japan and serves as the source layer for slope hazards characterised by post-failure gentle slope flows and long-distance flows. The aim of this study is to determine the relationship between the crushing characteristics and the mechanical properties of porous pumice, which often contributes to such disasters. As the porous pumice material, Ta-d pumice, which caused numerous slope disasters during the 2018 Hokkaido Eastern Iburi Earthquake in Japan, was collected and subjected to a series of triaxial compression tests. The grain size distribution of the pumice before all the tests was adjusted to be uniform, and the amount of crushing was quantified by measuring the grain size distribution after the tests. The results suggest that the critical state and isotropic consolidation of porous pumice can be systematically expressed in a three-dimensional space with the axes of the void ratio, mean effective stress, and degree of particle crushing. Furthermore, a gentle slope disaster with an inclination of less than 21°, that had occurred at the site from which the Ta-d pumice was collected, was discussed in terms of its flow potential, showing that the flow distance can be adequately explained.

Latent Heat Loss Through Fabrics During an Alternate Simulated Work–Rest Sequence

Humans produce different rates of sweating depending on the intensity level of a given activity. The clothing worn during the activity has a significant effect on the latent heat loss that can occur before, during, and after the activity. The water adsorption and spreading properties of a material yield differences in the amount of heat exchange that can occur between the person and the environment. Current test methods evaluate this using a value known as evaporative resistance, which is used to determine the heat exchange potential of a material. However, this value is only taken once the material has reached “steady state” and does not consider the sweating period before steady state is reached, or the drying period after steady state is reached. Therefore, an area under the curve (AUC) value was derived during these periods to compare the heat exchange properties of different materials. A sweating guarded hot plate was used to simulate different sweat rates, and therefore activity levels, to compare materials constructed of cotton, viscose, polyester, and wool. The overall latent heat loss of the hydrophobic wool was much less compared to the other samples with a gentler slope and lower AUC values than the other samples. It was found that the segment of time analyzed has a significant impact on the conclusion drawn about the latent heat loss of a material, p < 0.0001. Sweat rate also has a significant impact on the heat loss value, p < 0.0001, but is perhaps less useful when comparing samples to each other. It was found that comparing the different periods of the test could yield different conclusions when comparing materials for latent heat loss. Several current test methods do not consider phases outside of the steady state period and therefore miss valuable information pertinent to user comfort during these phases, especially in the post-exercise phase.

Analysis of the Spatial Distribution Characteristics and Influencing Factors of Traditional Mosque Architecture in the Hehuang Area (China)

Clarifying the spatiotemporal distribution and influencing factors of mosque architecture in China’s Hehuang region has significant positive implications for the overall protection and development of the region’s architectural cultural heritage. This study utilizes field surveys and acquires POI data of traditional mosques built before 1993 in the region to analyze the distribution characteristics of mosques, aiming to explore future development trends of these religious structures. It also investigates the influencing factors, with the goal of emphasizing the primary and secondary factors affecting mosque distribution. The study finds the following: (1) Mosques are generally centered around the Huangshui Valley, displaying a “central clustering, peripheral dispersal” distribution pattern, forming a spatial structure of “two cores, one belt, multiple points”, with distinct differentiation and overall uneven distribution. (2) Mosques are primarily situated at elevations between 2147 and 2764 m; on slopes less than 15°, in sunny and gentle slopes; within 20 km from rivers; within 14 km from roads; in areas receiving 400–500 mm annual rainfall; and within temperature ranges of 5.54–10.22 °C. (3) The study also finds that the spatial distribution of mosques is profoundly influenced by both natural geographical factors and human environmental factors. The better the natural location, the larger and denser the population, the richer the cultural resources, the higher the level of economic development, and the greater the concentration of Hui people, the more numerous and concentrated the mosques. (4) Population factors are the dominant factors for the clustered distribution of traditional mosques in the Hehuang area. Since the construction of mosques in the region is closely related to the number of Hui people and the proportion of Muslim adherents, areas with a high concentration of mosques also have relatively larger populations of Hui people. Temperature, precipitation, altitude, rivers, and roads are foundational factors for traditional mosques in the Hehuang area, influencing mosque distribution as external factors.

Hydrological responses of pine needle litter to rainfall erosional processes on Chinese karst hillslopes

Native vegetation restoration, such as pines, is an effective measure for mitigating soil erosion. However, the impact of pine needle litter on runoff, soil erosion, and hydrological responses on karst hillslopes remains unclear. This study investigated these factors during the rainy season from June to August 2021 under six distinct treatments (flat, gentle, and steep slopes with and without pine needle coverings). The results showed that pine needle litter significantly increased the soil water content, particularly on steeper slopes, by improving the water-holding capacity. It also substantially reduced runoff (by 23.8%) and soil erosion (by 92.5%). The critical rainfall threshold for generating runoff did not occur in the pine needle covering treatment, whereas it was 19.3 ± 8.8 mm in the bare soil treatment under wet conditions. These findings highlight the efficacy of pine needle cover in mitigating runoff and soil erosion in karst areas, suggesting it as a sustainable alternative against erosion, and underscoring the importance of pine plantations in degraded soil restoration efforts.

Prospectivity of Pliocene-Miocene deposits of the Khasilat field of the Absheron oil and gas bearing region according to surface and well seismic data

Prospectivity of Pliocene-Miocene deposits of the Khasilat field of the Absheron oil and gas bearing region according to surface and well seismic data

Biophysical characteristics of coastal habitat at Geleang island Karimunjawa National Park as a nesting area hawksbill turtle (Eretmochelys imbricata, Linnaeus 1766)

The hawksbill turtle (E. imbricata) are internationally Critically Endangered as determined by the IUCN. For this reason, action is needed to preserve the sea turtle in the future. The purpose of this study was to determine the bio-physical characteristics of the beach (beach width and slope; pH, temperature, grain size and sand moisture; nest size; nest distance from high tide; beach vegetation and predators) where hawksbill turtles (E. imbricata) lay their eggs on Geleang Island, Karimunjawa National Park. Concerning conservation, the number, condition, egg removal techniques and egg maintenance found on Geleang Island from January to February 2022 were also described. The research was conducted from January to April 2022 using the observation method which includes field observation and primary data collection. The results showed that Geleang Island has a narrow beach width with a gentle slope. The pH of the sand ranges from 6.5 - 7, the average sand temperature variable is around 28˚C. Sand humidity has a value range of 82% - 90%. Sand grain analysis on Geleang Island, the results of the most retained sediment were found to be on test sieves with a diameter of 250 µm so that it was classified as a type of medium sand. The dominant vegetations are sea pine (Casuarina equisetifolia) and gabusan (Scaevola taccada). No predators of hatchlings were found on Geleang Island. The amount of hawksbill turtle eggs found on Geleang Island from January to February 2022 amounted to 1.981 eggs.Keywords: Characteristic of coastal habitat; hawksbill hatchlings

Generation Of Highly Nonlinear Waves In A Short Wave Flume

The typical approach for generating nonlinear waves in physical models involves employing first- or second-order wave theory, requiring a large water depth at the wavemaker. When the prototype bathymetry shows a gentle slope, a large facility is required. However, practical constraints often make this unfeasible, leading to the use of steep transition slopes to obtain sufficient water depth at the generator. Incorporating a transition slope may generate unwanted free waves beyond the transition point, significantly impacting the wave parameters. The presence of these free waves causes the response of the tested structure to deviate from that found in the prototype. This paper offers guidelines for using transition slopes effectively while avoiding the generation of undesired free waves after the transition point.

Geotechnical Characterisation of Flysch-Derived Colluvial Soils from a Pre-Alpine Slope Affected by Recurrent Landslides

Heterogeneous rock masses that include rhythmic alternations of marl, shale, marly limestone, sandstone, siltstone, and argillite, such as Flysch, are particularly prone to generating colluvial deposits on gentle slopes, which are often subject to failures triggered by heavy rainfall. Flysch-derived colluvial soils are made up of highly heterogeneous sediments ranging from clayey loam to rock fragments, and they have been studied more rarely than homogeneous soils. In this work, we present a geotechnical and hydraulic characterisation performed both in situ and in the laboratory on flysch-derived colluvial soils that were involved in a channelised landslide in the pre-alpine area of the Friuli Venezia Giulia region (NE Italy). The investigated soils were characterised by the average values of the grain size composition of about 25% gravel, 20% sand, 30% silt, and 25% clay. The loamy matrix presented low-to-medium values of the liquid and plastic limits, as well as of the plasticity index (LL = 40%, PL = 23%, and PI = 17%, respectively). The values of the peak friction angle for natural intact samples were 33° < ϕ’p < 38°, whereas the residual friction angle fell to 23–24° at great depths and high vertical stresses, for a prevailing silty–clayey matrix. Variable head permeability tests were performed both in situ and in the laboratory, showing that the values of the vertical and horizontal permeability were very close and in the range 1 × 10−4–1 × 10−6 m/s. The soil permeability measured in the field was generally higher than the hydraulic conductivity calculated on laboratory samples. The proposed geotechnical and hydrological characterisation of flysch-derived colluvial soils can be of fundamental importance before the use of more thorough analyses/models aimed at forecasting the possible occurrence of slope failures and evaluating the related landslide hazard. The reported geotechnical and hydraulic parameters of flysch-derived colluvial materials can represent a useful reference for rainfall infiltration modelling and slope stability analyses of colluvial covers that are subject to intense and/or prolonged precipitation. However, when facing engineering problems involving colluvial soils, particularly those coming from flysch rock masses, the intrinsic variability in their grain size composition, consistency, and plasticity characteristics is a key feature and attention should be paid to the proper assumption of the corresponding geotechnical and hydraulic parameters.

Topographical gradient of the structure and diversity of a woody plant community in a seasonally dry tropical forest in northwestern Madagascar

AbstractFew studies have evaluated the structure and dynamics of forests in Madagascar with high levels of endemism. Ankarafantsika National Park holds the largest of the remaining primary dry forests in northwestern Madagascar, where most of the forests have been lost or degraded by fire and other human activities. In this primary forest, we established a 15‐ha forest dynamics monitoring plot and mapped and identified all woody stems with a diameter at breast height (DBH) ≥5 cm. The forest stand was characterized by small‐sized individuals (75% of stems with DBH <10 cm, with 99% of trees with height <15 m), encompassing 35,758 tree and 513 liana individuals belonging to 160 species in 53 families (including 20 species of lianas accounting for 1.4% of the stems). Most species‐rich families were Rubiaceae, Fabaceae, Lamiaceae, and Malvaceae, which together encompassed 43 tree species and 23% of all tree individuals. The plot was located on a hill consisting of white sand at elevations from 150 to 200 m, with a gentle slope down from southwest to northeast. Over this elevation gradient, stem density and species diversity increased with elevation, while tree height and diameter decreased. The most abundant two species, Drypetes perrieri (Putranjivaceae) and Noronhia alleizettei (Oleaceae) are evergreen, suggesting the importance of a nutrient conservation strategy. These results provide the foundational knowledge necessary for the conservation and restoration of natural semi‐deciduous dry forests that used to cover large areas in northwestern Madagascar until recently.

Evaluating Sea Level Rise Impacts on the Southeastern Türkiye Coastline: a Coastal Vulnerability Perspective

Coastal areas are inherently sensitive and dynamic, susceptible to natural forces like waves, winds, currents, and tides. Human activities further accelerate coastal changes, while climate change and global sea level rise add to the challenges. Recognizing and safeguarding these coasts, vital for both socioeconomic and environmental reasons, becomes imperative. The objective of this study is to categorize the coasts of the Mersin and İskenderun bays along the southeastern coast of Türkiye based on their vulnerability to natural forces and human-induced factors using the coastal vulnerability index (CVI) method. The study area encompasses approximately 520 km of coastline. The coastal vulnerability analysis reveals that the coastal zone comprises various levels of vulnerability along the total coastline: 24.7% (128 km) is categorized as very high vulnerability, 27.4% (142 km) as high vulnerability, 23.7% (123 km) as moderate vulnerability, and 24.3% (126 km) as low vulnerability. Key parameters influencing vulnerability include coastal slope, land use, and population density. High and very high vulnerability are particularly prominent in coastal plains characterized by gentle slopes, weak geological and geomorphological features, and significant socioeconomic value.

Study on the geographic distribution and influencing factors of Dai settlements in Yunnan based on geodetector

The Dai people are primarily found in Yunnan Province, China, and have a long heritage there. The latest national census reports that Yunnan is home to 1,259,000 individuals of the Dai ethnic group. This study focuses on 3504 Dai settlements in Yunnan, identified through county records. Using the ArcGIS spatial analysis platform, we first evaluated their settlements’ spatial distribution patterns using metrics like the nearest neighbor index and geographic concentration index. Then, we applied geodetector to investigate the underlying mechanisms of their distribution. The results reveal that: (1) Dai settlements in Yunnan Province generally have a cohesive spatial distribution; at the provincial level, however, there is an uneven distribution pattern, with many densely populated areas and a pattern of “two cores, one belt, one area, and two points”; (2) The Dai settlements predominantly occupy the third gradient of the vertical zonation, with Dai gathering settlements primarily found in the Lancang, Ayeyarwaddy, and Red River basins. Conversely, Dai mixed settlements are mainly situated in the Lancang, Red, and Nu River basins; (3) Analysis via geodetector indicates that ethnocultural factors are the most significant in determining the spatial distribution of the Dai settlements, followed by socio-economic and natural factors; (4) The distribution of settlements is significantly influenced by the proportion of the Dai population within these settlements. Dai gathering settlements are typically located on flat slopes with elevations ranging from 500 to 1000 m and slopes of 0°–5°. Meanwhile, Dai mixed settlements are found on gentle slopes with elevations of 1000–2000 m and slopes of 5°–15°. The study reveals that the location of Dai settlements is strongly influenced by environmental considerations and has a significant explanation from similar origins.

Analyzing the Spatiotemporal Dynamics and Driving Forces of Ecological Environment Quality in the Qinling Mountains, China

The Qinling Mountains serve as a vital ecological barrier for China, needing regular monitoring for sustainable progress. The present study analyzed the Qinling Mountains (sections in Shaanxi province) via the Google Earth Engine (GEE) and Landsat images, constructing a Remote Sensing Ecological Index (RSEI) for quantitatively analyzing the spatiotemporal evolution of the ecological environment quality from 1990 to 2020. Additionally, this study integrated geodetector and multiscale geographically weighted regression (MGWR) to discern the driving factors influencing ecological quality. The results indicated the following: (1) over the 30 years, the RSEI in the study area initially declined (1990–2005) and then began to improve (2005–2020), demonstrating an overall upward trend; (2) RSEI varied with topography: lower values corresponded to lower elevations (<1200 m) and gentle slopes (<10°), whereas higher values were linked to higher elevations (>1600 m) and steeper slopes (>20°); and (3) NDVI, DEM, land use, and the presence of protected areas emerged as the main driving forces of ecological quality. The interaction between ecological conservation policies and socioeconomic factors enhanced the explanatory strength for the differentiation in ecological environment quality. In conclusion, factors like increased vegetation cover and the establishment of protected areas have significantly promoted the improvement of ecological environment quality in the Qinling region, making this study a scientific reference for providing ecological environment protection and promoting high-quality development.

Stability evaluation of gentle slopes in spatially variable soils using discretized limit analysis method: a probabilistic study

Stability evaluation of gentle slopes in spatially variable soils using discretized limit analysis method: a probabilistic study

Reconstruction of Single-Bay Buddhist Architecture Based on Stylistic Comparisons in Northeast Fujian, the Core Hinterland of the Changxi River Basin—Using Gonghoulong Temple as an Example

In the Changxi River Basin in eastern Fujian, a few stone elements remain and Buddhist buildings with one bay in width and three bays in depth have been preserved dating from the timespan of the Tang to the Song dynasty. These features are characterized by a regional form of early Buddhist architecture seldom seen in Chinese history. The article focuses on the reconstruction of a Song dynasty Buddhist building at the Gonghoulou Temple site in Huotong Town, Jiaocheng District, Ningde City, and aims to analyze the potential characteristics and rules of single-bay Buddhist architecture. From the styles of the remaining stone columns, the direction of the lotus carving at the column base, and the mortises of the plinth stone, a spatial arrangement is indicated that includes an open front corridor and a closed rear section. A “reconstruction” of the ruler used in the original building reveals the possibility that a local Fujian ruler was used, shorter than the standard measurement device employed elsewhere. The analysis of the frame construction indicates that this hip-gable roof-covered Buddhist hall utilizes the horizontally layered logic of multi-storied palatial-style halls. Key elements include its gentle roof slope, restraint from the practice of shortening the roof ridge, use of the traditional chuji method, and the interior columns use of internal longitudinal architraves secured to beam supporting brackets. This research brings to light a unique architectural type that has disappeared in the course of history and was previously unknown to the academic community. It holds significant importance and value for deepening the understanding of the history of timber frame architecture technology in Fujian.