Trend Surface Analysis Method Research Articles

Development of a GIS-Based Predicted-VS30 Map of Türkiye Using Geological and Topographical Parameters: Case Study for the Region Affected by the 6 February 2023 Kahramanmaraş Earthquakes

Abstract The time-averaged shear-wave velocity in the upper 30 m of a site (VS30) is virtually essential in characterizing local soil conditions for multiple purposes, including estimation of site effects, anticipated ground-motion levels, seismic hazards, and the shape of design spectra. Considering the significance of this proxy and that a number of the Disaster and Emergency Management Presidency of Türkiye (AFAD) strong ground-motion stations across Türkiye lack assigned VS30 values, a comprehensive study was performed herein to develop empirical equations for estimating VS30 values in Türkiye based on relationships between 432 VS30 measurements at the AFAD stations, geologic units, and topographic data. Initially, units in the geological digital maps were reclassified into four geological periods. Statistical relationships between geological period classes and VS30 samples were interpreted to determine the VS30 boundaries for each period class. Second, VS30 estimations with topographic parameters by utilizing a 2D trend surface analysis method were performed. The resultant two-parameter polynomial coefficients were associated with VS30 according to the least squares principle, leading to the development of topographic functions for VS30 estimation under each geological period class (R2=0.601). Thereby, digital VS30 estimation maps were produced in grid (90 m) format that may be queried in a Geographic Information Systems environment. Moreover, the quantile regression method was also utilized to determine the coefficients of the envelope curve corresponding to a given exceedance probability (p) for the worst case scenario. Finally, to evaluate the accuracy of the proposed equations, the verifications performed with the VS30 data at the selected AFAD stations in the region affected by the 6 February 2003 earthquakes have also presented successful outcomes. Considering the availability of VS30 maps derived from digital elevation data in the literature, this study offers novel equations that take into account geological units and provide crucial background data for the regional seismic hazard-based risk assessments in Türkiye, especially for site effect studies using VS30 as a regional site classification parameter.

Research on the Spatial Differences and Influencing Factors of Energy Development in Guangdong Province

Studying the spatial differences and influencing factors of regional energy development can promote regional sustainable development. This study uses the per capita electricity consumption of 21 cities in Guangdong Province in 2021 as an indicator to measure regional energy development and uses ArcGIS's natural discontinuity method, spatial trend surface analysis method, and spatial autocorrelation to study the spatial differences and spatial agglomeration of energy development in 21 cities in Guangdong Province, Finally, the geographically weighted regression model is applied to explore the various factors affecting the energy development of 21 cities in Guangdong Province. It is concluded that the energy development of 21 cities in Guangdong Province in 2021 has significant spatial differences and positive agglomeration, The energy development in the north-south and east-west wings is relatively weak, while the energy development in the north-south direction and the east-west transition zone is relatively strong. The coefficient of the level of industrial structure influencing factor is higher than that of the development of the digital economy, the level of scientific and technological development, the level of opening-up, the level of economic development, and other influencing factors.

Unraveling the uncertainty of geological interfaces through data-knowledge-driven trend surface analysis

Modeling complex geological interfaces is a common task in geosciences. Many data sources are available for geological interface modeling, including borehole data and geophysical surveys. Geological knowledge, such as the delineation from geologists, is difficult to quantify but likely adds value to geological interface modeling. To integrate all information, we present a data-knowledge-driven trend surface analysis method to construct stochastic geological interfaces. We design a Metropolis–Hastings sampling framework to sample stochastic trend interfaces and quantify the uncertainty of geological interfaces given all information sources. This method is suitable for both explicit and implicit representations of geological interfaces. We demonstrate our method in three different test cases: modeling stochastic interfaces of Greenland subglacial topography, magmatic intrusion, and buried river valleys in Australia.

Identifying geochemical anomalies using a new method of Yang Chizhong-spatial scan statistic

Identifying anomalies from geochemical data by modeling of the background and statistical evaluation of anomalies is a major concern in geochemical exploration. This study developed a novel method (namely YangScan) for extracting geochemical anomalies by using Yang Chizhong filtering and a spatial scan statistic. The Yang Chizhong filtering, a progressive filtering method on the principle of weighted moving mean of binomial coefficient, was used to construct the background whose concavity and convexity are consistent with the original data. After removing the background from the original data, a spatial scan statistic based on multidirectional optimization was developed to identify arbitrary shaped and statistically significant anomalies from the residuals. YangScan was tested on both simulated datasets and a stream sediment geochemical dataset collected in the Northwestern Jiaodong Peninsula, Eastern China. The experimental results evaluated by geology consistency, recall, and weights of evidence contrast show that YangScan outperforms the two comparision methods (i.e., the trend surface analysis method and k-nearest neighbor anomaly detector) in identifying weak and irregularly-shaped geochemical anomalies. The distribution of geochemical anomalies linked to Au mineralization identified by YangScan is highly correlated with the trending of known Au deposits and ore-controlling structures. Therefore, YangScan is a powerful tool for identifying geochemical anomalies and can provide a useful reference for mineral exploration.

Studying The Boundaries of The Tectonic Zones South of Latitude 32◦ of Iraq Using Trend Surface Analysis method

A geophysical study investigation was conducted in the southern part of Iraq bounded by coordinates; longitudes (39◦ - 48◦) East and latitude (29◦ - 32◦) North. This study includes analysis and interpretation of the potential data (gravity and magnetic) derived from the Bouguer anomaly map and Aeromagnetic total field intensity map of Iraq both of them is within the scale of (1: 1,000,000) and do comparison with the information available from geological maps, which include Tectonic, Hydrological and Geological information. Gravity and Magnetic maps of the study area were digitized at a grid interval of (1×1) cm which is equivalent to (10×10) km on the land. The trend surface technique was applied on the Bouguer anomaly map of the area. Through these analyses there are three tectonic boundaries have been proposed (A, B, and C). Results were compared with potential analyses of available geological information which match some faults proposed through data analysis with other geological information.

The distribution of Van Genuchten model parameters on soil-water characteristic curves in Chinese Loess Plateau and new predicting method on unsaturated permeability coefficient of loess.

The unsaturated permeability coefficients are often used to solve geotechnical problems associated with unsaturated soils. But it is very difficult to measure. However, the unsaturated permeability coefficients can be predicted by the Soil-water Characteristic Curves (SWCCs). The Van Genuchten Model (VG model) is very rife as it's smooth and good fitting, thus, it has the most research data. Therefore, the research data on VG model parameters (α, n, θs and θr) of Malan loess in Chinese Loess Plateau are collected in the past two decades to obtain the spatial distribution characteristics of parameters. The trend surface analysis method is employed to clarify the regional scale distribution and the variation regular pattern on ArcGIS. Then the linear regression method is utilized to fit the relationship between suction and water content in three different regions of Chinese Loess Plateau, which is divided according to the properties and particle gradation. By using this relationship and the trend surface analysis contour map, the unsaturated permeability coefficient of the sample can be predicted after measuring the saturated permeability coefficient. The example verification shows that the difference between the prediction results and the experimental results is very small when the sample has the lower saturation, and the deviation is slightly larger if it has the higher saturation, but they are all within the acceptable range. This method not only saves the test cost, but also considers the physical properties of the loess in the three different regions of the Loess Plateau. With the improvement of data and the gradual improvement of sampling density, the prediction accuracy will gradually improve. It can provide convenience for solving the engineering problems of loess and water and other engineering applications.

Application of trend surface analysis to reservoir distribution in Wayaopu Oilfield

In order to determine the distribution of oil reservoirs, the trend value and residual value of the top structure and layer thickness of Chang-6 in Wayaopu Oilfield were analyzed by using the method of trend surface analysis, and the relationship between oil well distribution, production, structural location and residual value was comprehensively analyzed by combining the existing geological data. This study uses the method of mathematical modeling to deepen the study of reservoir distribution law through existing data. The results show that the existing oil wells have obvious combination characteristics on the structural residual trend and thickness residual trend. Most oil wells in the structural positive residual area and the thickness negative residual area have high productivity, and the structure has become the main factor to control the oil well productivity. Through the significance test, it is proved that the mathematical model conforms to the actual geological conditions and has guiding significance for the distribution of oil reservoirs in the study area.

Indoor Positioning With Adaptive Wavelet Denoise Enhancement and Trend Surface Analysis Based Multipath Map

The channel multipath and non-line-of-sight (NLOS) reflections introduce a bias on the time difference of arrival (TDOA) observations, which reduce the accuracy of the ultra-wideband (UWB) positioning performance in an indoor environment. In previous research, the multipath map (MPM) method is based on spatial domain modeling principle in the reverse positioning framework and is used to mitigate the multipath effect. Utilizing the mean value of the multipath residuals as the calibration value will inevitably lead to insufficient or excessive multipath modification in the grid. By combining the trend surface analysis method, this paper proposes an advanced multipath mitigation method named trend surface analysis based multipath map (TMPM). Meanwhile, this paper propose an adaptive wavelet denoise (AWD) method in order to eliminate the noise of data set in advance. We mainly demonstrate the effect of TMPM in reverse positioning scenarios, analyze the multipath correction effect of TMPM. The experimental results show that the accuracy of the tag positioning is 16.0 cm with TMPM, which is improved by 22.7% compared to that of MPM. In dynamic positioning case, results with TMPM also show benefit over MPM.

Multipath mitigation based on trend surface analysis applied to dual-antenna receiver with common clock

Multipath mitigation methods based on the intrinsic spatiotemporal repeatability of multipath effect are commonly applied in high-precision Global Navigation Satellite System positioning. Among which multipath hemispherical map (MHM) has the advantages of simplicity of calculation and real-time multipath reduction of static environment or some dynamic environment. However, utilizing the average of residuals as the calibration values will inevitably lead to insufficient or excessive modification of multipath in the lattice. We proposed an advanced multipath elimination method named trend surface analysis-based multipath hemispherical map (T-MHM), which extends the primary MHM by combining the trend surface analysis method to investigate the multipath spatial distribution and trend in each lattice. A short baseline experiment was carried out using a dual-antenna receiver with common clock in campus of East China Normal University. Single-difference carrier residuals were used for relative multipath modeling. The multipath elimination results indicate that, compared with the original approach, the T-MHM improves the dispersion and accuracy of the baseline solution and increases the phase observation residuals reduction rate. It also enhances the modeling of multipath information in both low- and high-frequency bands. Meanwhile, T-MHM is less sensitive to lattice size. In practical applications, larger lattice size can be adopted to improve the computational efficiency and spatial coverage with little loss of accuracy.

An Inproved Up-scaling Algorithm Combined TSA and PSF

Taking the Guanzhong Plain of Shanxi Province as the research area, the combine method of trend surface analysis method (TSA) and point spread function (PSF) (TSA+PSF) were used to up-scale the vegetation temperature condition index (VTCI) retrieved from Landsat 8 images (Landsat-VTCI) from a finer resolution to a coarser resolution. The up-scaled results were compared with VTCI images retrieved from Aqua MODIS (MODIS-VTCI) to provide technical support for the comprehensive application of drought monitoring results on two spatial scales. Meanwhile, a range of indicators, such as the semivariogram function (SVF), the structural similarity (SSIM), the correlation coefficients (r), root mean square errors (RMSE) were used to systematically compared the up-scaled methods. The results show that TSA+PSF performed better than TSA in terms of SSIM, the correlation and RMSE, the up-scaling model TSA+PSF has the higher accuracy, and it is more effective and robust than TSA. The model that uses PSF to analyze trend surface constructed by TSA is an improvement for up-scaling Landsat- VTCI images from a finer resolutions to a coarser resolutions.

Application of trend surface analysis in early warning model of coal mine gas explosion

Aiming at the catastrophic problem of common coal mine gas explosion, this paper combines the trend surface analysis method to establish a gas explosion warning model, and validates the model through actual data, and the model has good robustness. Through the data fusion of the comprehensive information of gas explosion, the gas and oxygen concentration are selected as the key indicators of the early warning model, and the trend surface analysis of the finite discrete data is established. The trend surface warning model of gas and oxygen concentration is established, and the distribution of key indicators is obtained. Features that enable predictions and warnings of potential gas hazards.

Privacy-preserving trend surface analysis on partitioned data

Spatial interpolation methods which are one of most commonly applied functions of Geographic information systems (GIS) provide prediction values for unmeasured coordinates. Reliability and robustness of all spatial interpolation methods depend on the total amount of data collected in the interested region. Obtaining such valuable spatial data may require a vast of amount time and budget. In some situations, institutions even competing ones may collect data from the same region. If data collected by such organizations can be integrated, they will have more accurate prediction models. However, they may not to share such valuable information with other institutions or companies due to privacy concern. Additionally, in some countries there are laws against sharing private data especially health and financial records. Therefore, a privacy-preserving solution which offers confidentiality of both parties’ data may induce them to collaborate. Furthermore, our solution protects the client’s privacy who requests predictions from such institutions. In this study, we propose a privacy-preserving Trend surface analysis method that provides privacy of both clients and data holders. In addition to this, our solution will produce more accurate and reliable predictions on combined data of two data holders without violating their privacy. We analyses our solution in terms of performance, privacy and accuracy. Although privacy-preserving solution may bring extra storage, computation and communication costs, we will present that they do not affect overall performance of the interpolation process.

An Up-Scaled Vegetation Temperature Condition Index Retrieved From Landsat Data with Trend Surface Analysis

Drought causes great losses in regional agricultural production and decreases socioeconomic growth. The vegetation temperature condition index (VTCI) has a distinct advantage in monitoring the onset, duration, and intensity of droughts. With the development of modern remote sensing technologies, remotely sensed data with variable spatial and temporal resolution are used to generate multiscale maps of droughts. Therefore, understanding the scale effect and developing appropriate up-scaling methods to retrieve spatiotemporal drought variables across different scales is valuable. As an alternative to the commonly used window averaging (WA) method, we develop the trend surface analysis (TSA) method based on multiple regression analysis to up-scale Landsat-derived VTCI (Landsat-VTCI) images from a finer to a coarser resolution. The two methods are systematically evaluated in a case study according to various statistical indicators, including the spatial and frequency distributions of features, and the correlation coefficients and root mean square errors between up-scaled Landsat-VTCI images and moderate-resolution Imaging Spectroradiometer (MODIS)-derived VTCI (MODIS-VTCI) images. The results show that TSA is reliable and more suitable than WA for non-normally distributed Landsat-derived VTCIs, whereas the WA results are similar to the TSA results for normal distributions. The TSA method is flexible for any type of distribution of Landsat-VTCIs within a study area and can be programmed to up-scale spatial drought variables from a finer to a coarser spatial resolution because of its efficiency and flexibility compared to the WA method.

Trend Surface Analysis Method Applied in Coal Seam Structure in ZhuJiaHe

Due to the impact of multi-period structure in Zhujiahe coal,Mine structure complicated and Has caused a certain impact on coal mine safety production. article Randomly selected 30 from 170 borehole date in coal mine.This paper analyzes 1, 2, 3 times of trend surface on No. 5-2 coal seam floor elevation.exploring the trend surface analysis method research in mine geological structure regular.

An integrative geothermal resource assessment study for the siliciclastic Granite Wash Unit, northwestern Alberta (Canada)

This study explores the siliciclastic Granite Wash Unit in northwestern Alberta as a potential geothermal reservoir. The approach covers regional 3D structural geological modelling of a 90 km × 70 km area based on well log and legacy 2D seismic data. The fault strike was interpreted from lineaments, which were identified with the refined trend surface analysis method. The stress state of the Granite Wash reservoirs was determined by an integrated approach of 3D fault modelling, stress ratio definition based on frictional constraints, and slip tendency analysis. The results show that the best site for a geothermal application is located in the southwestern study area, where the highest temperatures (above 70 °C) coincide with the largest thickness (above 20 m) and zones of elevated porosity and permeability. The integrated stress analysis indicates an in situ stress regime from normal to strike-slip faulting maintaining a non-critically stressed reservoir or faults therein, assuming a friction coefficient of 0.7. The granite wash reservoirs could be used for heating of greenhouses, domestic warm water provision and district heating.

Reconstruction and Optimization of Tritium Time Series in Precipitation of Beijing, China

Tritium time series for precipitation in Beijing have been reconstructed for the period 1953–2002 using various methods: Guanbingjun method; trend surface analysis method; double reference curve method; triangulation method; and correlation method. By comparing the reconstructed results with the measured data of Beijing as well as data of other regions available in the IAEA GNIP database, the corresponding tritium time series have been developed for Beijing for the period 1953–2002, and the optimal time series was selected. The reconstructed result can be used for groundwater dating and related studies in Beijing as well as the surrounding areas.

Reconstruction and Optimization of Tritium Time Series in Precipitation of Beijing, China

Tritium time series for precipitation in Beijing have been reconstructed for the period 1953–2002 using various methods: Guanbingjun method; trend surface analysis method; double reference curve method; triangulation method; and correlation method. By comparing the reconstructed results with the measured data of Beijing as well as data of other regions available in the IAEA GNIP database, the corresponding tritium time series have been developed for Beijing for the period 1953–2002, and the optimal time series was selected. The reconstructed result can be used for groundwater dating and related studies in Beijing as well as the surrounding areas.

Geostatistical mapping of geomorphic variables in the presence of trend

AbstractMapping geomorphic variables geostatistically, specifically by kriging, runs into difficulties when there is trend. The reason is that the variogram required for the kriging must be of residuals from any trend, which in turn cannot be estimated optimally by the usual method of trend surface analysis because the residuals are correlated. The difficulties can be overcome by the use of residual maximum likelihood (REML) to estimate both the trend and the variogram of the residuals simultaneously.We summarize the theory of REML as it applies to kriging in the presence of trend. We present the equations to show how estimates of the trend are combined with kriging of residuals to give empirical best linear unbiased predictions (E‐BLUPs). We then apply the method to estimate the height of the sub‐Upper‐Chalk surface beneath the Chiltern Hills of southeast England from 238 borehole data. The variogram of the REML residuals is substantially different from that computed by ordinary least squares (OLS) analysis. The map of the predicted surface is similar to that made from kriging with the OLS variogram. The variances, however, are substantially larger because (a) they derive from a variogram with a much larger sill and (b) they include the uncertainty of the estimate of the trend. Copyright © 2006 John Wiley & Sons, Ltd.

Distribution of Landscape Elements Along Environmental Gradients in Over-Cut Forests

The method of trend surface analysis was used to analyze the distribution of landscape elements along environmental gradients in Jingouling forest farm, northeast China’s Jilin Province. Results showed that topographic characteristics and disturbance pattern have much more impacts on the distribution of landscape elements than do horizontal geographical position in the study area. The elevation, slope aspect, and slope degree were found to be dominant features controlling landscape pattern. At different altitudinal ranges, the effects of slope aspect and slope degree on the distribution of landscape elements vary markedly in orientation and intensity. These differences were analyzed and discussed, and some basic rules of spatial distribution of landscape elements were proposed.

Strategic environment assessment on land-use planning

The study centers on the necessity, the workflow and the synthetically integrated methods (Principal Component Analysis (PCA), Andytical Hierarchy Process (AHP) and Fuzzy Comprerhensive Evaluation(FCE) of strategic environment assessment (SEA) on land-use planning. The whole article includes three main parts: firstly, some attribute database, graphic-base and the spatial transform matrix, which reflect the change of regional land-use pattern, can be obtained by GIS technique; secondly, adopting fitting method of trend-surface analysis will convert environment monitoring data from scattered spots to regular control spots, based on which we can perform regional environment impact assessment; finally, Changchun Economic and Technological Developmen Zone is chosen as a case study on land-use planning. Through those efforts the results may be obtained as follows: 1) according to transform matrix, the possibility of transformation from one land-use to another can be obtained after the planning is carried out; 2) environment quality would change as a result of the change of land-use pattern; 3) the SEA on land-use plan is an effective tool to make land-use pattern more reasonable.