Geospatial susceptibility mapping of earthquake-induced landslides in Nuweiba area, Gulf of Aqaba, Egypt

Earthquake induced landslides are one of the most severe geo-environmental hazards that cause enormous damage to infrastructure, property, and loss of life in Nuweiba area. This study developed a model for mapping the earthquake-induced landslide susceptibility in Nuweiba area in Egypt with considerations of geological, geomorphological, topographical, and seismological factors. An integrated approach of remote sensing and GIS technologies were applied for that target. Several data sources including Terra SAR-X and SPOT 5 satellite imagery, topographic maps, field data, and other geospatial resources were used to model landslide susceptibility. These data were used specifically to produce important thematic layers contributing to landslide occurrences in the region. A rating scheme was developed to assign ranks for the thematic layers and weights for their classes based on their contribution in landslide susceptibility. The ranks and weights were defined based on the knowledge from field survey and authors experiences related to the study area. The landslide susceptibility map delineates the hazard zones to three relative classes of susceptibility: high, moderate, and low. Therefore, the current approach provides a way to assess landslide hazards and serves for geo-hazard planning and prediction in Nuweiba area.

Association of ratios of visceral fat area/subcutaneous fat area and muscle area/standard body weight at T12 CT level with the prognosis of acute respiratory distress syndrome

Background:It is well-known that body composition metrics can influence the prognosis of various diseases.This study investigated how body composition metrics predict acute respiratory distress syndrome(ARDS)prognosis,focusing on the ratio of visceral fat area(VFA)to subcutaneous fat area(SFA),SFA to standard body weight(SBW),VFA to SBW,and muscle area(MA)to SBW.These metrics were assessed at the level of the twelfth thoracic vertebra(T12 computed tomography[CT]level)to determine their correlation with the outcomes of ARDS.The goal was to utilize these findings to refine and personalize treatment strategies for ARDS.Methods:Patients with ARDS admitted to the intensive care units(ICUs)of three hospitals from January 2016 to July 2023 were enrolled in this study.Within 24 hours of ARDS onset,we obtained chest CT scans to mea-sure subcutaneous fat,visceral fat,and muscle area at the T12 level.We then compared these ratios between survivors and non-survivors.Logistic regression was employed to identify prognostic risk factors.Receiver oper-ating characteristic(ROC)curve analysis was utilized to determine the optimal cutofffor predictors of in-hospital mortality.Based on this cutoff,patients with ARDS were stratified.To reduce confounding factors,1:1 propensity score matching(PSM)was applied.We conducted analyses of clinical feature and prognostic differences pre-and post-PSM between the stratified groups.Additionally,Kaplan-Meier survival curves were generated to compare the survival outcomes of these groups.Results:Of 258 patients with ARDS,150 survived and 108 did not.Non-survivors had a higher VFA/SFA ra-tio(P<0.001)and lower SFA/SBW and MA/SBW ratios(both P<0.001).Key risk factors were high VFA/SFA ratio(OR=2.081;P=0.008),age,acute physiology and chronic health evaluation(APACHE)II score,and lac-tate levels,while MA/SBW and albumin were protective.Patients with a VFA/SFA ratio≥0.73 were associated with increased mortality,while those with an MA/SBW ratio>1.55 cm^(2)/kg had lower mortality,both pre-and post-PSM(P=0.001 and P<0.001,respectively).Among 170 patients with pulmonary-origin ARDS,87 survived and 83 did not.The non-survivor group showed a higher VFA/SFA ratio(P<0.001)and lower SFA/SBW and MA/SBW(P=0.003,P<0.001,respectively).Similar risk and protective factors were observed in this cohort.For VFA/SFA,a value above the cutoffof 1.01 predicted higher mortality,while an MA/SBW value below the cutoffof 1.48 cm2/kg was associated with increased mortality(both P<0.001 pre-/post-PSM).Conclusions:Among all patients with ARDS,the VFA to SFA ratio,MA to SBW ratio at the T12 level,age,APACHE II score,and lactate levels emerged as independent risk factors for mortality.

Two-dimensional physical habitat modeling of effects of habitat structures on urban stream restoration

River corridors, even if highly modified or degraded, still provide important habitats for numerous biological species, and carry high aesthetic and economic values. One of the keys to urban stream restoration is recovery and maintenance of ecological flows sufficient to sustain aquatic ecosystems. In this study, the Hongje Stream in the Seoul metropolitan area of Korea was selected for evaluating a physically-based habitat with and without habitat structures. The potential value of the aquatic habitat was evaluated by a weighted usable area （WUA） using River2D, a two-dimensional hydraulic model. The habitat suitability for Zacco platypus in the Hongje Stream was simulated with and without habitat structures. The computed WUA values for the boulder, spur dike, and riffle increased by about 2%, 7%, and 131%, respectively, after their construction. Also, the three habitat structures, especially the riffle, can contribute to increasing hydraulic heterogeneity and enhancing habitat diversity.

An Analysis of Water Environment Factors and an Evaluation of Water Quantity of Liangzi Lake

The experiments of single factor evaluation method, principal component analysis and voronoi area weighting factor method on the sample data of Liangzi Lake in October 2012 combined with the national surface water environment quality standards can get the map of comprehensive water quality distribution by Kriging interpolation. The analysis shows, the grades of comprehensive water quality gained by three methods are all only class III or class IV, and the quality of water is different from east and west that the water quality of east is better. However, the percent of IV class water is higher in the result of single factor evaluation method means class IV is the main grade of water quality. The result of principal component analysis shows the percent of class Ⅲ water is higher than other classes. The result of voronoi area weighting factor method shows the percent of IV class is higher than other classes. CODMn is the main factor that influences the method of singal factor evaluation and reduces the grade of water quality overall. The effect of single factor is reduced by principal component analysis, and the analysis on water quality is more accurate. The voronoi area weighing factor method reduces the effect of single factor and extends the content, can make a comprehensive evaluation on water quality.

An Intelligent Early Warning Method of Press-Assembly Quality Based on Outlier Data Detection and Linear Regression

Focusing on controlling the press-assembly quality of high-precision servo mechanism,an intelligent early warning method based on outlier data detection and linear regression is proposed.Linear regression is used to deal with the relationship between assembly quality and press-assembly process,then the mathematical model of displacement-force in press-assembly process is established and a qualified press-assembly force range is defined for assembly quality control.To preprocess the raw dataset of displacement-force in the press-assembly process,an improved local outlier factor based on area density and P weight(LAOPW)is designed to eliminate the outliers which will result in inaccuracy of the mathematical model.A weighted distance based on information entropy is used to measure distance,and the reachable distance is replaced with P weight.Experiments show that the detection efficiency of the algorithm is improved by 5.6 ms compared with the traditional local outlier factor(LOF)algorithm,and the detection accuracy is improved by about 2%compared with the local outlier factor based on area density(LAOF)algorithm.The application of LAOPW algorithm and the linear regression model shows that it can effectively carry out intelligent early warning of press-assembly quality of high precision servo mechanism.

Examples of compactλ-hypersurfaces in Euclidean spaces

In this paper,we first construct compact embeddedλ-hypersurfaces with the topology of torus which are calledλ-torus in Euclidean spacesℝn^+1.Then,we give many compact immersedλ-hypersurfaces in Euclidean spacesℝn^+1.

A cell-centered lagrangian scheme in two-dimensional cylindrical geometry

A new Lagrangian cell-centered scheme for two-dimensional compressible flows in planar geometry is proposed by Maire et al.The main new feature of the algorithm is that the vertex velocities and the numerical fluxes through the cell interfaces are all evaluated in a coherent manner contrary to standard approaches.In this paper the method introduced by Maire et al.is extended for the equations of Lagrangian gas dynamics in cylindrical symmetry.Two different schemes are proposed,whose difference is that one uses volume weighting and the other area weighting in the discretization of the momentum equation.In the both schemes the conservation of total energy is ensured,and the nodal solver is adopted which has the same formulation as that in Cartesian coordinates.The volume weighting scheme preserves the momentum conservation and the area-weighting scheme preserves spherical symmetry.The numerical examples demonstrate our theoretical considerations and the robustness of the new method.

A high-precision hydrodynamic model coupled with the hydrological habitat suitability model to reveal estuarine vegetation distribution

In this paper,based on the finite volume method,a high-precision hydrodynamic model coupled with the habitat suitability model is established,and the computational efficiency of the coupled model is improved by a graphics processing unit(GPU)-accelerated technology.The coupled model is used to solve the problem of the non-conservation of mass that may be caused by the nearshore hydrodynamic model in the processing of wetting and drying,while avoiding the unphysical high velocities at the wetting and drying boundaries.The coupled model is applied to simulate the high-precision hydrodynamic process of the Liao River estuary(LRE)and the hydrological habitat suitability of the estuarine vegetation(Suaeda heteroptera)growing in the LRE.The simulated values of the hydrological variables(the water level,the water depth,the current velocity and direction)are highly consistent with the measured values.The root mean square errors(RMSE)of the hydrological variables are 0.10m,0.12m/s and 17.24°,respectively.Furthermore,the simulated combined suitability index(CSI)distribution of Suaeda heteroptera(S.heteroptera)matches with the distribution of S.heteroptera obtained from the high-resolution remote sensing satellite images during the same time period.The ratio of the simulated weighted usable area(WUA)of S.heteroptera to the area obtained from the remote sensing satellite images during the same period is 81.9%.This study reveals the phenomenon that the distribution of S.heteroptera in the LRE is highly correlated with the high-precision hydrodynamic processes,and provides a scientific basis and a valuable reference for the conservation and the restoration of the estuarine vegetation.