Slope Grade Research Articles

Increased medial tibial slope is a possible risk factor for patellar cartilage lesions.

Axial malalignment in the coronal plane has been identified as a significant risk factor for knee cartilage damage, leading to osteoarthritis progression. However, the impact of sagittal axial deviation on cartilage damage remains underexplored. Biomechanical studies have suggested that an increased tibial slope leads to altered pressure distribution in the articular cartilage, potentially contributing to cartilage damage. Despite these biomechanical insights, clinical evidence linking increased tibial slope to cartilage damage is lacking. This retrospective study focuses on patients who underwent surgical cartilage transplantation between January 2016 and July 2023. A total of 108 patients were divided into two groups based on the presence or absence of other pathologies contributing to cartilage damage. Clinical data, including tibial slope measurements from lateral radiographs, were collected. A further subgroup-matched pair analysis was conducted comparing cases with patellar lesions and healthy knees. Statistical analysis compared tibial slope values between groups and assessed correlations between tibial slope and cartilage lesion grade. Patients without other identifiable pathologies exhibited a significantly higher medial tibial slope compared to those with known causative factors for cartilage damage (p < 0.05). Cartilage damage, particularly in the patellar region, was more prevalent in patients with an increased tibial slope. Patients with patellar lesions had a significant increased slope than healthy controls (p < 0.05). However, there was no significant correlation between cartilage lesion grade and tibial slope. The study identified increased medial tibial slope as a possible independent risk factor for cartilage damage in the knee, especially in the patellar region. Level IV.

Can minimally invasive transforaminal lumbar interbody fusion achieve a better clinical and radiological outcome than traditional open technique in isthmic spondylolisthesis?

BackgroundSpondylolisthesis is a prevalent condition in the lumbar spine that can cause low back pain, leg pain, neurogenic claudication, and impact health-related quality of life in symptomatic individuals.Aimto assess the results of minimally invasive TLIF (MIS-TLIF) versus open-TLIF and the impact of correcting spino-pelvic parameters on the Health-Related Quality of Life (HRQoL) in patients with low-grade isthmic spondylolisthesis. The primary objective was to compare the effectiveness of both methods in correcting spinopelvic parameters. The secondary objectives involved comparing clinical improvement, operating time, blood loss, complications, and postoperative hospital stays between the two procedures.Patients and methodsSeventy-two patients with low-grade isthmic spondylolisthesis were enrolled in this retrospective cohort-control study, with a minimum follow-up period of 18 months. Disability was assessed using the Oswestry Disability Index (ODI), while back and leg discomfort were rated using the Visual Analogue Scale (VAS) for each patient. The measurements comprised the sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and Meyerding slip grades. We measured lumbar lordosis (LL), and segmental lordosis.ResultsThe seventy-two patients were 60 female and 12 males. There was no statistically significant difference in the duration of operation between the two groups. In the MIS group, there was a notable reduction in blood loss, higher radiation exposure, and a shorter hospital stay (P < 0.001). The back VAS showed more favorable outcomes in the MIS-TLIF, while the leg VAS showed better results in the Open-TLIF in the early outcome. Both procedures significantly reduced leg and back pain VAS scores and ODI, with no notable difference between the two groups at the final follow-up. Post-surgery, the pelvic incidence (PI) and lumbar lordosis (LL) matched properly in all patients, showing a rise in LL and sacral slope along with a decrease in pelvic tilt.ConclusionBoth open-TLIF and MIS-TLIF are effective methods for correcting spino-pelvic parameters and improving HRQoL in patients with low-grade isthmic spondylolisthesis. The rapid improvement in back pain experienced by these patients favored the use of MIS-TLIF. However, the cost-effectiveness of this approach must be carefully evaluated.

ИССЛЕДОВАНИЕ СЫПУЧЕСТИ ЗЕРНА И РАЗРАБОТКА УНИВЕРСАЛЬНОГО АЭРАТОРА КОЛОНКОВОГО ТИПА

The article studies physical property of grain flowability at free or natural grain flow when pouring through a small hole onto a flat horizontal plane, as well as when grain is in cramped conditions. The study classifies grains into 5 classes according to their flowability depending on their natural slope of repose. It also determines limiting values of slope of repose of basic grains at humidity of 14–16 % and with free flow on the designed device. The research detects penetration of grain into the partition space when grain was cramped into the designed device. It figures out that with increasing distance between the partitions, depth of grain penetration increases regardless of the partition grade of slope. Optimal values of partition grade of slope are within 20º, at which the penetration of grain between partitions is minimal. So, to solve various problems of grain aeration, it is possible to select the optimal values of partitions grade of slope and distances between them, at which grain does not flow into partitions internal cavity, connected to air supply channel. Based on the results of this experiment, the Department of Technological Systems of the Agro-Industrial Complex (Federal State Budgetary Educational Institution of Higher Education Arctic State Technical University) developed a technical solution for universal core type aerator, which was recognized as an invention (Patent N 2777902). Preliminary tests of the aerator showed its versatility and cost-effectiveness.

A pathogen's spatial range is not constrained by geographical features in the flax rust pathosystem.

Climate change and shifting environmental conditions can allow pathogens to spread into previously unburdened areas. For plant pathogens, this dynamic has the potential to disrupt natural ecosystem equilibria and human agriculture, making predicting plant pathogen range shifts increasingly important. Although such predictions will hinge on an accurate understanding of the determinants of pathogen range-namely the environmental, geographical, and host range characteristics that modulate local pathogen habitation-few studies to date have probed these in natural plant populations. Here, we characterize range determinants for the model system of Lewis flax (Linum lewisii) and its pathogen, flax rust (Melampsora lini), in the Rocky Mountains. Transect surveys were performed to assess three relationships: (i) the effect of geographical features-elevation, slope aspect, slope grade, and land cover-on flax presence and density, (ii) the effect of geographical features on flax rust presence and prevalence, and (iii) the effects of flax's local population density and metapopulation structure on flax rust presence and prevalence. We found that flax population density, but not host metapopulation structure, influences the distribution of flax rust. Additionally, we showed that, while the distribution of flax was broadly constrained to a relatively narrow range of geographical and resulting environmental features, flax rust was evenly distributed across the full range of settings measured. These results indicate that a warming environment, which is expected to modulate such features, may restrict the optimal range of the plant more than that of its pathogen. Importantly, our results also suggest that even if flax shifts its spatial range to escape increasing climatic pressures, flax rust will not face any significant barriers to track this movement.

A deep learning approach for optimize dynamic and required power in electric assisted bicycle under a structure and operating parameters

The purpose of this research is to study how the operating and structure parameter affect the dynamic, require power and electric consumption of electric assisted bicycle (EAB). The paper applied a combined an artificial neural network (ANN) with genetic algorithm (GA) method to predict the required power, electric consumption of EAB and find an effective performance area. The MATLAB-Simulink simulation model is established to create 1000 data point, that is applied in an ANN for training, testing and verifying. The ANN-GA method is applied to identify the optimized required power and electric consumption under four typical slope grades in the area of (0–0.65%), four typical wheel radius in the area of (0.3–0.0.39 m), four typical frontal areas in the range of (0.423–1.323 m2), four typical speed levels from speed level 1 to speed level 4. After the ANN is trained, it is applied into the genetic algorithm to identify the effective performance. The prediction results reflect the major physical mechanism that governs ES performance and are validated against the MATLAB-Simulink simulation model. Additionally, the electric assisted bicycle can reach an effective performance area at 27.16 km/h with the optimized required power of 545.5 W at slope grade of 0%, wheel radius of 0.39 m, speed level 4, frontal area of 0.423 m2. The results show that the ANN-GA method is suitable to identifying structure and operating parameters including various slope grades, frontal areas, wheel radius, speed level for optimizing effective performance of EAB, which contributes a helpful method for EAB design and control. Beside that, the experimental test was conducted on real road test at Taehwa river to verify the simulated results. The experiment results and simulation results have the same trend at the same conditions. (The short version of the paper was presented at ICAE2022,Bochum, Germany,Aug 8–11, 2022. This paper is a substantial extension of the short version of the conference paper.)

Effects of the Structure and Operating Parameters on the Performance of an Electric Scooter

The research objective is to approach the dynamic and consumed electrical energy of an electric scooter by varying the key input parameters, including rider mass, electric scooter mass, wind speed, wheel radius, and slope grade. A simulation model of an electric scooter was applied in a MATLAB-Simulink environment to investigate the scooter velocity, required power, battery voltage, and propulsion torque of the e-scooter. It was established by employing mathematical equations during the of electric scooters. The study found that the scooter velocity and electricity consumption were optimized by 3.9% and 0.08%, respectively, when the scooter weight decreased from 26 to 10 kg. The scooter velocity, electricity consumption, and required power decreased by 23.2%, 0.55%, and 8.56%, respectively, when the slope grade decreased from 1.15% to 0%. Following a wind speed reduction from 4 to 0 m/s, the consumed electricity and required power were optimized by 0.2% and 5.5%, respectively. The consumed electricity increased by 0.2% and the scooter velocity and required power significantly increased by 36.5% and 34.3% when the wheel radius increased from 0.105 to 0.185 m. Furthermore, the e-scooter could achieve an effective performance with a weight of 10 kg, wheel radius of 0.185 m, wind speed of 0 km/h, slope grade of 0%, and minimal rider weight. The simulation results showed that the scooter’s effective performance range and consumed electrical energy could be optimized by suitably adjusting the key structures and operating parameters. To support this research, a concurrent experiment investigated the dynamic characteristics and electricity consumption of the electric scooter during operation. The experimental and simulated results had the same patterns in similar initial conditions.

Characterizing Heterogeneous Traffic Flow at a Slope Bottleneck via Cellular Automaton Model

This paper considers the unique attributes of autonomous vehicles, the characteristics of expressways&#x2019; minor actual slope grade, and the speed update integer requirements of discrete cellular automata (CA). The continuous deceleration efficiency of the uphill is discretized by introducing variable parameters connected to the vehicle position and gradient, and the hybrid traffic flow CA model suitable for slope bottlenecks based on the principle of the safety distance is further improved. The simulation results show that the improved model can simulate the unique traffic flow phenomenon caused by the change in slope conditions. There is a critical mutation in the traffic flow phase on the slope road section. Secondly, according to the different main factors influencing traffic flow, free flow, terrain jams, and homogeneous congested flow coexist on the slope section. The traffic flow in the crowded terrain area is significantly negatively correlated with the length and longitudinal gradient of the slope, and increasing the longitudinal angle of the hill will extend the congested terrain area. In addition, the influence of the change in slope conditions on mixed traffic flow has a critical longitudinal gradient of 3% and a fixed critical slope length. In non-free flow areas, autonomous vehicles can significantly alleviate traffic congestion on upslopes.

Suitability evaluation of land reclamation as arable land in coal mining area based on catastrophe theory

Niumasi Coal Mine (located in Shaodong City, Hunan Province, China) was an important producing area of high-quality coking coal in Hunan Province. After large-scale mining of underground coal seams in the area, there has been a large area of surface subsidence and serious land damage. The damaged land urgently needs to be reclaimed. In this paper, the suitability of land reclamation as arable land in Niumasi coal mining area was comprehensively evaluated, and a catastrophe progression model (CPM) for the suitability evaluation of land reclamation as arable land in coal mining area was put forward with the help of the catastrophe theory. The suitability classification was divided into four grades: suitable, moderately suitable, less suitable, and unsuitable. Eleven parameters including terrain slope grade, effective thickness of soil layer, soil parent materials, soil contamination, organic content, alkali hydrolyzable nitrogen (N), available phosphorus (P), available potassium (K), ground collapse, land destruction extent, and conditions of irrigation and drainage were selected as evaluation indicators, and the classification standards of each evaluation indicator was determined. Using MATLAB software to generate a total of 1200 samples (300 samples per level) between the arrays corresponding to each level of standards according to the normal distribution principle, of which 800 samples were used as training samples to establish the catastrophe progression criteria, and 400 samples as test samples to verify the reliability of the proposed criteria. According to CPM, the suitability status of the four land samples in Shuijingtou working area of Niumasi Coal Mine were identified. The evaluation results show that the suitability level of three lands are all ‘Moderately suitable’, and one sample is ‘Unsuitable’. Mining coal has the greatest damage to paddy fields, followed by the dry farming lands and vegetable lands, and the least impact to the forest lands. CPM can not only evaluate the suitability of land reclamation, and comprehensively compare the suitability degrees, but also can assess the damage degree of coal mining to different types of lands. This paper aims to provide a new idea for the study of quantitative evaluation methods of land reclamation suitability. The results have reference and guiding significance for the comprehensive evaluation of the suitability of land reclamation as arable land in coal mining areas.Article highlightsThe catastrophe theory can be used to evaluate the suitability of land reclamation as arable land in coal mining area. A catastrophe progression model for the suitability evaluation of land reclamation as arable land in coal mining area was put forward.Using MATLAB software to establish the catastrophe progression criteria according to the normal distribution principle.The results have reference and guiding significance for the comprehensive evaluation of the suitability of land reclamation as arable land in coal mining areas.

Optimal Time Phase Identification for Apple Orchard Land Recognition and Spatial Analysis Using Multitemporal Sentinel-2 Images and Random Forest Classification

The significance of identifying apple orchard land and monitoring its spatial distribution patterns is increasing for precise yield prediction and agricultural sustainable development. This study strived to identify the optimal time phase to efficiently extract apple orchard land and monitor its spatial characteristics based on the random forest (RF) classification method and multitemporal Sentinel-2 images. Firstly, the Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), Ratio Vegetation Index (RVI), and Difference Vegetation Index (DVI) between apple orchard land and other green vegetation (other orchards, forest and grassland) during the growing stage were calculated and compared to identify the optimal time phase for apple orchard land extraction; the RF classifier was then constructed using multifeature variables on Google Earth Engine to efficiently identify apple orchard land, and the support vector machine (SVM) classification results were used as a comparison; GIS spatial analysis, a slope calculation model, and Moran’s I and Getis-Ord GI* analysis were employed to further analyze the spatial patterns of the apple orchard land. The results found the following: (1) April, May, and October were the optimal time phases for apple orchard identification. (2) The RF-based method combining coefficients of indexes, the grayscale co-occurrence matrix, and 70% of the ground reference data can precisely classify apple orchards with an overall accuracy of 90% and a Kappa coefficient of 0.88, increasing by 9.2% and 11.4% compared to those using the SVM. (3) The total area of apple orchard land in the study area was 485.8 km2, which is 0.6% less than the government’s statistical results. More than half (55.7%) of the apple orchard land was distributed on the gentle slope (Grade II, 6–15°) and the flat slope (Grade I, 0–5°); SiKou, Songshan, and Shewopo contained more than 50% of the total orchard land area. (4) The distribution of apple orchard land has a positive spatial autocorrelation (0.309, p = 0.000). High–High cluster types occurred mainly in Sikou (60%), High–Low clusters in Songshan (40%), Low–High clusters in Sikou (47.5%), and Low–Low clusters in Taocun and Tingkou (37.4%). The distribution patterns of cold and hot spots converged with those of the Local Moran Index computation results. The findings of this study can provide theoretical and methodological references for orchard land identification and spatial analysis.

Slope Scaling Effect and Slope-Conversion-Atlas for Typical Water Erosion Regions in China

Slope has obvious scale-dependent characteristics and it changes with the change in DEM resolution, which brings uncertainty to the evaluation process of regional resource and environment. In this paper, one typical county in each of the six water erosion regions in China was selected as the sample area, respectively. Based on DEM data of ALOS DEM, ASTER GDEM and SRTM DEM with different spatial resolutions, slope characteristics, such as gradient, eigenvalue, frequency and cumulative frequency curves, were calculated by using the third-order inverse distance square weighted difference algorithm, to explore the ability of depicting terrain by these three DEM data. Based on the idea of geo-information map, the “surface-slope conversion atlas” under different resolutions was constructed to achieve the grading correction of slope extraction under low resolution. The results showed that: (1) with the resolution of DEM decreases, the slope information of each area tends to be more generalized and gradually concentrated. The slope frequency curve gradually changed from “tall and thin” to “short and fat”, and the peak of the cumulative frequency curve moved to the low-slope area. Six sample areas showed different degrees of slope reduction. (2) In the process of slope grading correction, except for Maoxian, the proportion of low-resolution results converted to medium and low slope grades (0°–25°) is large. (3) The slope spectrum conversion method has a good correction effect on the errors generated by the slope extraction results of DEM90 and DEM30, and the correction rates reached 80% and 90%, respectively. A slope conversion atlas can effectively improve the expression ability of low-resolution DEM data on topography, which can provide a basis for regional resource and environment evaluation, and territorial space optimization.

Experimental Study on Gully Erosion Characteristics of Mountain Torrent Debris Flow in a Strong Earthquake Area

In recent years, as the frequency of debris flow outbreak in strong earthquake areas has increased and the scale has been expanding, in order to explore the erosion characteristics of debris flow, a lateral erosion flume model experimental device has been designed, and 18 groups of incomplete orthogonal experiments have been carried out, with a unit weight of debris flow of 1.6~2.0 g/cm3, a content of fine particles in the accumulation of 0~28.82%, and a longitudinal slope gradient of the gully of 8°~20° as variables. The results show that the erosion width, erosion depth, and erosion volume decrease with the increase in fluid bulk density and increase with the increase in gully slope. When the longitudinal slope of the gully was 16°, the sediment with 11.40% fine particles had the strongest erosion effect, indicating that more or less fine particles are not conducive to the occurrence of lateral erosion of the gully. Finally, through multi-factor variance analysis, it was found that the order of the three factors on the gully lateral erosion degree from strong to weak is: debris flow unit weight, gully slope, and accumulation grading. The analysis results further showed that the unit weight of debris flow has the greatest impact on the erosion degree of the side slope, which is consistent with the experimental results. The research results have important reference significance for revealing the mechanism of lateral erosion and improving the level of debris flow disaster prevention in strong earthquake areas.

Architectural design methods for mountainous environments

ABSTRACT As an important part of urban space, mountains play an extremely important role in the overall landscape and ecology of cities. However, with the continuous development of urbanization and building construction, mountains have been occupied and destroyed in unreasonable ways. Therefore, with the aim of reducing the damage to mountains from construction, this paper explores the design methods to deal with the relationship between buildings and mountainous environments. The historic district of Signal Hill in Qingdao is taken as the research area, since buildings here coexist with the mountainous environment harmoniously. Through the combination of modeling and field research, the slope of the mountain can be divided into three grades: “0–5.8°”, “5.8–11.7°” and “11.7–17.3°”. Therefore, the design characteristics and distribution patterns of 20 design methods that dealt with the mountainous environment in different slope grades can be obtained. Furthermore, by analyzing the design characteristics and distribution patterns, the relationship between the design methods and the slope of mountains can be found, providing more suitable design strategies for buildings located on different slopes of mountains. For other mountain cities worldwide, these rational strategies can provide some helpful design suggestions to better use terrain. It can also reduce the amount of construction volume and damage to the mountainous environment, and further better achieve sustainable development goals.

Spatiotemporal variations of water conservation function based on EOF analysis at multi time scales under different ecosystems of Heihe River Basin

Water conservation function is a critical terrestrial ecosystem service in providing water supply and achieving water security, which has raised concerns under the pressure of climate change. However, the knowledge of variance on multi-time scale, spatiotemporal dynamic, and ecosystem variance of water conservation is insufficient. In this paper, the annual, monthly, and daily scales of water conservation and the spatiotemporal pattern of monthly water conservation were estimated based on the SWAT model from 2010 to 2020 in the Heihe River Basin (HRB). Additionally, EOF (Empirical orthogonal function) analysis was conducted to decompose the time series of water conservation function distribution into temporal coefficients and spatial patterns. The HRB was categorized into six representative ecosystems with three slope grades to illustrate the variance of water conservation function. The annual water conservation depth (WC) slightly decreased (−10.36 mm/10a) from 2010 to 2020, the monthly WC was dominated by the effects of seasonal variation, and the daily WC was highly nonlinear. The high variability and importance region is mainly located in the upstream and the central area of midstream, which deserves more attention for ecological management and priority protection. Moreover, the forest ecosystem is of the highest resilience and great ecological significance, which increased risk of reduced water conservation under the lack of precipitation. Even in a forest-dominated basin, water conservation can be impacted by other ecosystems with the strong influence of human activities. Our results provide scientific evidence for the improvement of water conservation capacity and making the adapted land use policy in Yellow River basins.

Site Quality Classification Models of Cunninghamia Lanceolata Plantations Using Rough Set and Random Forest West of Zhejiang Province, China

The site quality evaluation of plantations has consistently been the focus in matching tree species with sites. This paper studied the site quality of Chinese fir (Cunninghamia lanceolata) plantations in Lin’an District, Zhejiang Province, China. The site quality model was constructed using the algebraic difference approach (ADA) to classify the site quality grades. The rough set algorithm was used to screen out the key site factors affecting the site rank of Chinese fir plantations. Site quality classification models based on random forest were established, and the importance of key site factors was evaluated. The results are as follows. The random forest model based on the rough set algorithm had small scale and low complexity, and the training and testing accuracies of the model were 92.47% and 78.46%, respectively, which were better than the model without attribute reduction. The most important factors affecting Chinese fir growth in the study area were the slope aspect, slope grade, and canopy closure. The least important factors were the humus layer thickness, soil layer thickness, naturalness, and stand origin. The attribute reduction method proposed in this study overcame the subjectivity of traditional site factor selection, and the site quality classification model constructed improved the model accuracy and reduced the complexity of the algorithm. The methods used in this study can be extended to other tree species to provide a basis for matching tree species with sites and to improve the level of forest management in the future.

Incorporating the effect of approach slab to the dynamic response of simply supported bridges under moving vehicle

Reinforced concrete approach slabs serve as a transitional component between the roadway pavement and the bridge deck. Due to the settlement of the embankment soil, the slab is bent, and its slope grade will be suddenly changed resulting in bumps at both ends of the deck; this may increase the dynamic response of bridges induced by the interaction with moving vehicles. In addition, the presence of such bumps not only causes an uncomfortable ride but also exhibits a potentially hazardous condition to the traffic. Since most of the studies have considered either the interaction model between the slab and soil or between the bridge and moving load; in this study, a novel finite element model is established for the bridge under traffic loads, considering the presence of the approach slab that is simulated as a beam rested on a dynamic soil model. The separated models of the approach slab and bridge deck are validated by previous studies and demonstrate their accuracy in predicting the dynamic response of the bridge-vehicle system. A comprehensive parametric study is then performed considering the effect of the soil stiffness, the stiffness of the shear layer of the foundation, and the approach slab length. The results of the study are useful criteria for the practice design of the approach slab in different embankment conditions.

Fruit Zone Shading to Control Grape Berry Temperature: A Modeling Study

Recent increases in average air temperatures and heat wave intensity can present challenges in maintaining grape productivity and quality. As a result, growers are exploring approaches to protect berries from excessive temperatures, however, they can be costly and time-consuming to experimentally evaluate, and results may not be generalizable. In this work, we developed and evaluated a new 3-D model that can predict metrics related to berry temperature and light interception in response to varying vineyard architecture, topography, and shade cloth density. The resulting modeling tool was applied to better understand and evaluate a range of potential vineyard design and management practices for mitigation of elevated berry temperatures in vertically trained grapevines. Model validation showed close agreement between predicted and measured temperature dynamics, which responded appropriately to the application of shade cloth. In a simulation experiment, row spacing, row orientation, slope grade and aspect, and shade cloth density were varied to evaluate their effect on berry and canopy light interception, berry temperature spikes, and integrated berry heat accumulation. On flat terrain, a northeast-southwest row orientation provided the best compromise of berry light and temperature balance between opposing vine faces while avoiding excessive berry temperatures, while north-south rows provided good daily symmetry but had risk of high afternoon berry temperatures. The efficacy of shade cloth in mitigating excessive temperatures depended strongly on all variables considered. Slopes with southern or western exposure increased the imbalance in and risk of high berry temperatures, which in some cases could not be well-managed by shade cloth. Overall, the modeling tool appears capable of providing quantitative guidance for vineyard design and management where excessive berry temperatures are of concern.

Analysis of deformation characteristics of reverse slope under the influence of reservoir water based on community detection

To study the deformation characteristics of reverse slope, this paper took the slope of Xiaodongcao as the research object, applied the Louvain community detection algorithm, considered the influence of reservoir water level change, and partitioned the slope deformation characteristics. The deformation characteristic zoning result was superimposed with the slope displacement cloud map and three types of geological geometric characteristic factor zoning map obtained by ArcGIS. The results show that: community detection can quickly identify the closely connected part of slope network, and the specific location of this part is affected by reservoir water. After the community detection result is superimposed with the displacement cloud map, the areas with large deformation and close connection in the slope can be identified. It is found that the community with severe deformation has at least 5% more displacement and up to 21% more displacement than that with slow deformation. In addition, the location of leader nodes can be identified, and the number of leader nodes does not exceed 20% of the total nodes in the community, and its average displacement is at least 10% more than that of ordinary nodes, up to 36%. After the community detection result is superimposed with the zoning map of slope grade, it can be concluded that the slope grade within the community with severe deformation is greater than 60°, indicating that the larger slope grade is more sensitive to the bank slope deformation.

Evaluation methods of regional bank slope stability based on geographic information systems and integrated information model

Through the combination of the geographic information systems (GIS) and the integrated information model, the stability of regional bank slope was comprehensively evaluated. First, a regional bank slope stability evaluation index system was established through studying seven selected factors (slope grade, slope direction, mountain shadow, elevation, stratigraphic lithology, geological structure and river action) that have an impact on the stability of the slope. Then, each factor was rasterized by GIS. According to the integrated information model, the evaluation index distribution map based on rasterized factors was obtained to evaluate the stability of the regional bank slope. Through the analysis of an actual project, it was concluded that the geological structure and stratigraphic lithology have a significant impact on the evaluation results. Most of the research areas were in the relatively low stable areas. The low and the relatively low stable areas accounted for 15.2% and 51.5% of the total study area respectively. The accuracy of slope evaluation results in the study area reached 95.41%.

Retrieval of Tidal Flat Elevation Based on Remotely Sensed Moisture Approach

Due to challenging conditions of field survey techniques, it is difficult to measure the topography of tidal flats, an important parameter to understanding the evolution and dynamics of the constantly changing zone. This study used remotely sensed sediment moisture estimates to retrieve tidal flat elevation. The method is based on the observation that the intertidal zone is gradually exposed from land to sea at low tide, meaning that higher elevations contain less moisture. Here, we investigate the nature of the relationship between reflectance and moisture content from Landsat Enhanced Thematic Mapper Plus images and the study areas as a proxy for mapping the elevation of an exposed tidal flat surface. Statistical analysis confirmed a negative correlation between moisture and elevation; however, the correlation coefficient was relatively weak, and the slope of the intersecting tidal creek was found to be a crucial factor affecting this relationship. After segmenting the slope to correspond to areas of tidal flat and nontidal flat surfaces, the correlation coefficient of the moisture and elevation increased significantly. A retrieval model was then developed to generate the tidal flat elevations of different slope grades. After verification, the retrieval accuracy of the model was up to 17.3 cm. This research study demonstrated that the remotely sensed moisture method is suitable for monitoring the surface elevation of tidal flats.

Lateral force–displacement response of buried pipes in slopes

A series of full-scale experiments was conducted to estimate lateral soil constraints on pipes buried in dense sandy slopes at different burial depths. The experimental data indicated that the soil force on the pipe increases with increase in the slope grade and burial depth ratio. The lateral soil force against relative pipe displacement response observed from the experiments is presented and compared to those arising from level ground conditions. The study was extended to larger burial depth ratios by simulating pipes under sloping ground conditions using a numerical (finite-element) model that was initially calibrated using the results from physical modelling. The findings from the study in terms of the variation of peak lateral soil restraint as a function of the slope grade and burial depth ratio are presented for consideration in pipeline design.