A comparative study of trend surface analysis and spectrum–area multifractal model to identify geochemical anomalies

Wang, Haicheng; Zuo, Renguang

doi:10.1016/j.gexplo.2015.04.013

Cited by 56 publications

(14 citation statements)

References 52 publications

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“…In this study, the results of the moving weighted trend surface analysis showed that the ESV losses pattern of the agro-pastoral ecotone was similar to an “inclined surface”, i.e., the northeastern section of the ecotone lost more ESV than the other sections. This virtual “surface” is an expression of ecological vulnerability on a macro scale that is more sensitive to external disturbances [51,52]. The surface, which is a visible manifestation of strained human-land relations, was mainly formed by the long-term improper use of land resources and it provides a quantitative description of ESV losses.…”

Section: Discussionmentioning

confidence: 99%

Spatiotemporal Variation Characteristics of Ecosystem Service Losses in the Agro-Pastoral Ecotone of Northern China

Yang

Wang

Liu

et al. 2019

IJERPH

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Being subject to climate change and human intervention, the land-use pattern in the agro-pastoral ecotone of Northern China has undergone complex changes over the past few decades, which may jeopardize the provision of ecosystem services. Thus, for sustainable land management, ecosystem services should be evaluated and monitored. In this study, based on Landsat TM/ETM data, we quantitatively evaluated the losses of ecosystem service values (ESV) in three sections of the agro-pastoral ecotone from 1980–2015. The results were as follows: (1) the main characteristic of the land conversions was that a large area of grassland was converted into cultivated land in the agro-pastoral ecotone; (2) on the spatial scale, the ESV losses of the agro-pastoral ecotone can be called an “inclined surface” in the direction of the northeast to southwest, and the northeastern section of the agro-pastoral ecotone lost more ESV than the middle and northwest sections (p < 0.05), on the temporal scale, the order of losses was 1990–2000 > 1980–1990 > 2000–2015; (3) the agro-pastoral ecotone lost more ESV, which was mainly due to four kinds of land conversion, which were grassland that was transformed into cultivated land, grassland transformed into unused land, grassland transformed into built-up areas, and cultivated land transformed into built-up areas; (4) although these land conversions were curbed after the implementation of protection policies at the end of the 1990s, due to reduced precipitation and increasing temperatures, the agro-pastoral ecotone will face a more severe situation in the future; and, (5) during the period of 1990–2015, the overall dynamic processes of increasing population gradually expanded to the sparsely populated pastoral area. Therefore, we believe that human interventions are the main cause of ecological deterioration in the agro-pastoral ecotone. This study provides references for fully understanding the regional differences in the ecological and environmental effects of land use change and it helps to objectively evaluate ecological civilization construction in the agro-pastoral ecotone of Northern China.

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Section: Discussionmentioning

confidence: 99%

Spatiotemporal Variation Characteristics of Ecosystem Service Losses in the Agro-Pastoral Ecotone of Northern China

Yang

Wang

Liu

et al. 2019

IJERPH

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“…The TSA method is a multivariate statistical analysis method that fits the spatial distribution and variability 0.4 ~ 1.6 τ ¼ 0:974290 À 0:08007ω 1.6 ~ 3.0 τ ¼ 1:031412 À 0:11536ω Low air (winter) 0.4 ~ 1.6 τ ¼ 0:982007 À 0:09611ω 1.6 ~ 3.0 τ ¼ 1:053710 À 0:14142ω of geographic drought variables and provides additional information by constructing surfaces that are usually decomposed into trend surfaces and residual surfaces (Eppler & Full, 1992;Wang & Zuo, 2015). Based on a previous study (Bai et al, 2017), we select the quadratic polynomial trend surface to produce the trend surface.…”

Section: Trend Surface Analysis Methodsmentioning

confidence: 99%

Effectiveness of upscaling the vegetation temperature condition index retrieved from Landsat data using an algorithm combining the trend surface analysis and the spatial variation weight method

Bai

Kang

Wang

et al. 2020

European Journal of Remote Sensing

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“…In spectrum method, the input data are transformed to frequency field using Fourier transforms. This means that the variations of the standard for all the positions of the input map (raw data) are converted to the frequency domain [21]. To execute, input data is prepared using an interpolation method in the form of a co-concentration line map.…”

Section: Spectrum-area Methodsmentioning

confidence: 99%

Application of Finite Difference Method in Multifractal Techniques to Identify Pb–Zn Anomalies: a Case Study from Khomein, Iran

Khavari

Ghadimi

Mojeddifar

2020

Mining, Metallurgy & Exploration

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Separation of geochemical anomalies from background is an important and essential issue in the exploration of mineral deposits. Statistical methods are used to separation of anomaly from background. Fractal/multifractal and singularity methods are very suitable for the separation of weak anomalies. For interpolation, various methods could be used such as most distance-weighting methods, kriging, spline interpolation, interpolating polynomials, and finite difference methods. This paper addressed application of multifractal techniques together with finite difference procedure to detect the anomalous regions. Fractal models such as concentration-area, spectrum-area, and singularity index model were selected to identify Pb-Zn anomalies. In this research, 170 samples from 33 boreholes were taken in the Haft-Savaran area and analyzed for determination of Pb-Zn anomaly. Singularity method was a suitable method for separating Pb and Zn anomalies. Also, the results showed that the geochemical anomaly has occurred along NE-SW trend and is consistent with the sulfide mineralization process and the faults of the region.

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A comparative study of trend surface analysis and spectrum–area multifractal model to identify geochemical anomalies

Cited by 56 publications

References 52 publications

Spatiotemporal Variation Characteristics of Ecosystem Service Losses in the Agro-Pastoral Ecotone of Northern China

Spatiotemporal Variation Characteristics of Ecosystem Service Losses in the Agro-Pastoral Ecotone of Northern China

Effectiveness of upscaling the vegetation temperature condition index retrieved from Landsat data using an algorithm combining the trend surface analysis and the spatial variation weight method

Application of Finite Difference Method in Multifractal Techniques to Identify Pb–Zn Anomalies: a Case Study from Khomein, Iran

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