scholarly journals Spatiotemporal Distribution of Nonseismic Landslides during the Last 22 Years in Shaanxi Province, China

2019 ◽  
Vol 8 (11) ◽  
pp. 505
Author(s):  
Haijun Qiu ◽  
Yifei Cui ◽  
Dongdong Yang ◽  
Yanqian Pei ◽  
Sheng Hu ◽  
...  
Keyword(s):  
Power Law ◽  
Spatiotemporal Distribution ◽  
Shaanxi Province ◽  
Annual Rainfall ◽  
Landslide Risk ◽  
Time Interval ◽  
Valuable Insight ◽  
Cumulative Frequency ◽  
Stream Channels ◽  
Large Spatial Scale

The spatiotemporal distribution of landslides provides valuable insight for the understanding of disastrous processes and landslide risk assessment. In this work, we compiled a catalog of landslides from 1996 to 2017 based on existing records, yearbooks, archives, and fieldwork in Shaanxi Province, China. The statistical analyses demonstrated that the cumulative frequency distribution of the annual landslide number was empirically described by a power-law regression. Most landslides occurred from July to October. The relationship between landslide time interval and their cumulative frequency could be fitted using an exponential regression. The cumulative frequency of the landslide number could be approximated using the power-law function. Moreover, many landslides caused fatalities, and the number of fatalities was related to the number of landslides each month. Moreover, the cumulative frequency was significantly correlated with the number of fatalities and exhibited a power-law relationship. Furthermore, obvious differences were observed in the type and density of landslides between the Loess Plateau and the Qinba Mountains. Most landslides were close to stream channels and faults, and were concentrated in cropland at elevations from 600–900 m and on slope gradients from 30–40°. In addition, the landslide frequency increased as the annual rainfall levels increased over a large spatial scale, and the monthly distribution of landslides presented a significant association with the precipitation level. This study provides a powerful method for understanding the spatiotemporal distribution of landslides via a rare landslide catalog, which is important for engineering design and planning and risk management.

Elaeagnus umbellata (autumn olive).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Nick Pasiecznik
Keyword(s):  
Sand Dunes ◽  
Pinus Thunbergii ◽  
Shaanxi Province ◽  
Annual Rainfall ◽  
Coastal Sand Dunes ◽  
Elaeagnus Umbellata ◽  
Autumn Olive ◽  
Pioneer Tree ◽  
Coastal Sand ◽  
Deciduous Shrub

Abstract E. umbellata is an important deciduous shrub which reaches up to 5 m high and 10 cm in d.b.h. It is found in thickets and sparse woods of Japan, Korea and China. E. umbellata is a shade intolerant pioneer tree and is also commonly found along riversides and seashores in Japan. This species is growing in humid areas with 1000-4000 mm of annual rainfall in Japan. In China it is reported to grow even in semi-arid areas of Nei Menggu, Gansu and Shaanxi province, where annual rainfall is around 400 mm (Niu, 1990). E. umbellata can fix nitrogen and it is tolerant to salt winds, this species is therefore used for fixation of coastal sand dunes in Japan, and is frequently planted mixed with Pinus thunbergii as a soil improving tree. E. umbellata is also planted in eroded areas of mountainous zones to re-establish and develop vegetation. In China, E. umbellata is occasionally cultivated in gardens (Zhang, 1997).

scholarly journals Generalized Memory: Fractional Calculus Approach

2018 ◽  
Vol 2 (4) ◽  
pp. 23 ◽  
Author(s):  
Vasily E. Tarasov
Keyword(s):  
Differential Equations ◽  
Fractional Calculus ◽  
Power Law ◽  
Memory Function ◽  
Time Interval ◽  
Infinite Time ◽  
Suggested Approach ◽  
Infinite Time Interval ◽  
History Of ◽  
With Memory

The memory means an existence of output (response, endogenous variable) at the present time that depends on the history of the change of the input (impact, exogenous variable) on a finite (or infinite) time interval. The memory can be described by the function that is called the memory function, which is a kernel of the integro-differential operator. The main purpose of the paper is to answer the question of the possibility of using the fractional calculus, when the memory function does not have a power-law form. Using the generalized Taylor series in the Trujillo-Rivero-Bonilla (TRB) form for the memory function, we represent the integro-differential equations with memory functions by fractional integral and differential equations with derivatives and integrals of non-integer orders. This allows us to describe general economic dynamics with memory by the methods of fractional calculus. We prove that equation of the generalized accelerator with the TRB memory function can be represented by as a composition of actions of the accelerator with simplest power-law memory and the multi-parametric power-law multiplier. As an example of application of the suggested approach, we consider a generalization of the Harrod-Domar growth model with continuous time.

scholarly journals Towards a real-time susceptibility assessment of rainfall-induced shallow landslides on a regional scale

2011 ◽  
Vol 11 (7) ◽  
pp. 1927-1947 ◽  
Author(s):  
L. Montrasio ◽  
R. Valentino ◽  
G. L. Losi
Keyword(s):  
Real Time ◽  
Regional Scale ◽  
Back Analysis ◽  
Early Warning Systems ◽  
Shallow Landslides ◽  
Landslide Risk ◽  
Time Interval ◽  
Slip Model ◽  
Temporal Prediction ◽  
Physically Based

Abstract. In the framework of landslide risk management, it appears relevant to assess, both in space and in time, the triggering of rainfall-induced shallow landslides, in order to prevent damages due to these kind of disasters. In this context, the use of real-time landslide early warning systems has been attracting more and more attention from the scientific community. This paper deals with the application, on a regional scale, of two physically-based stability models: SLIP (Shallow Landslides Instability Prediction) and TRIGRS (Transient Rainfall Infiltration and Grid-based Regional Slope-stability analysis). A back analysis of some recent case-histories of soil slips which occurred in the territory of the central Emilian Apennine, Emilia Romagna Region (Northern Italy) is carried out and the main results are shown. The study area is described from geological and climatic viewpoints. The acquisition of geospatial information regarding the topography, the soil properties and the local landslide inventory is also explained. The paper outlines the main features of the SLIP model and the basic assumptions of TRIGRS. Particular attention is devoted to the discussion of the input data, which have been stored and managed through a Geographic Information System (GIS) platform. Results of the SLIP model on a regional scale, over a one year time interval, are finally presented. The results predicted by the SLIP model are analysed both in terms of safety factor (Fs) maps, corresponding to particular rainfall events, and in terms of time-varying percentage of unstable areas over the considered time interval. The paper compares observed landslide localizations with those predicted by the SLIP model. A further quantitative comparison between SLIP and TRIGRS, both applied to the most important event occurred during the analysed period, is presented. The limits of the SLIP model, mainly due to some restrictions of simplifying the physically based relationships, are analysed in detail. Although an improvement, in terms of spatial accuracy, is needed, thanks to the fast calculation and the satisfactory temporal prediction of landslides, the SLIP model applied on the study area shows certain potential as a landslides forecasting tool on a regional scale.

scholarly journals Nanocracks upon Fracture of Oligoclase

2021 ◽  
Vol 57 (6) ◽  
pp. 894-899
Author(s):  
V. I. Vettegren ◽  
A. V. Ponomarev ◽  
R. I. Mamalimov ◽  
I. P. Shcherbakov
Keyword(s):  
Free Radicals ◽  
Power Law ◽  
Time Interval ◽  
Electron Traps ◽  
Surface Areas ◽  
Electronically Excited ◽  
Order Of Magnitude ◽  
20 Nm

Abstract—The spectrum of fractoluminescence (FL) upon fracture of the surface of oligoclase is obtained. The analysis of the spectrum has shown that fracture of crystals leads to the formation of electronically excited free radicals ≡Si−O• and Fe3• ions as well as electron traps. FL consisted of a set of the signals with the intensities varying by an order of magnitude. The duration of the signals was ~50 ns and the time interval between them varied from ~0.1 to 1 μs. Each signal contained four maxima associated with the destruction of barriers preventing the motion of dislocations along the sliding planes. These breakthroughs cause the formation of the smallest (“primary”) cracks. All other, larger cracks are formed by the coalescence of the “primary” cracks. The sizes of “primary” cracks range from ~10 to 20 nm and the time of their formation is 16 ns. The distribution of cracks by size (surface areas of crack walls) is power law with the exponent –1.9.

scholarly journals Accelerator and Multiplier for Macroeconomic Processes with Memory

2017 ◽  
Vol 9 (3) ◽  
pp. 86 ◽  
Author(s):  
Valentina V. Tarasova ◽  
Vasily E. Tarasov
Keyword(s):  
Power Law ◽  
Finite Time ◽  
Time Interval ◽  
Fading Memory ◽  
Finite Time Interval ◽  
Exogenous Variables ◽  
Macroeconomic Models ◽  
Economic Agents ◽  
Special Cases ◽  
With Memory

The paper proposes an approach to the description of macroeconomic phenomena, which takes into account the effects of fading memory. The standard notions of the accelerator and the multiplier are very limited, since the memory of economic agents is neglected. We consider the methods to describe the economic processes with memory, which is characterized by the fading of a power-law type. Using the mathematical tools of derivatives and integrals of non-integer orders, we suggest a generalization of the concept of the accelerator and multiplier. We derive the equations of the accelerator with memory and the multiplier with memory, which take into account the changes of endogenous and exogenous variables on a finite time interval. We prove the duality of the concepts of the multiplier with memory and the accelerator with memory. The proposed generalization includes the standard concepts of the accelerator and the multiplier as special cases. In addition these generalizations provide a range of intermediate characteristics to take into account the memory effects in macroeconomic models.

Twelve-Year Landslide Risk Assessment in Villa de Independencia, Bolivia, with Sentinel-1 and ALOS-1/2 InSAR Observations

2020 ◽  
Author(s):  
Chuang Song ◽  
Zhenhong Li ◽  
Stefano Utili ◽  
Chen Yu
Keyword(s):  
Time Series ◽  
Eigenvalue Decomposition ◽  
Landslide Risk ◽  
Time Interval ◽  
Deformation Pattern ◽  
Radar Images ◽  
Satellite Radar ◽  
North Edge ◽  
The Village ◽  
Landslide Movement

<p>Monitoring of slow landslide movement on a local scale with Interferometric Synthetic Aperture Radar (InSAR) observations can provide long-term deformation information and assist in identifying failure triggers. We combined three different tracks of satellite radar images spanning 12 years from ALOS-1 PALSAR-1, ALOS-2 PALSAR-2, and Sentinel-1 to assess the evolution of a landslide in Bolivia where the village of Independencia lies at the slope foot. For ALOS-1 PALSAR, SAR data was acquired on 15 dates during the period from 28 February 2007 to 11 March 2011 in ascending mode. For ALOS-2 PALSAR-2, eight acquisitions between 07 October 2015 and 29 November 2017 were available in ascending mode. The low temporal resolution of ALOS images makes the detection of deforming signal difficult though the L-band data captures more coherent pixels on vegetation areas than C-band. Sentinel-1 data with a minimum time interval of six days from 16 October 2014 to 08 September 2019 (144 images) is collected and processed to recover the dynamic behaviour of the landslide movement.</p><p>To explore the sensitivity of different InSAR time series analysis methods on revealing the deformation pattern of the landslide, we respectively used Persistent Scatterer Interferometry (PSI), Small Baseline Subset (SBAS) algorithm and Distributed Scatterer Interferometry (DSI) based on phase eigenvalue-decomposition to process the mentioned multiple satellite radar observations. Overlapping valid pixels from these three methods share similar temporal evolution while SBAS and DSI trace more measurement points than PSI in spatial distribution. Preliminary results show that the village central exhibits extremely slow movements (<= 10 mm/yr) with seasonal oscillation. The north edge of the village in the middle of the landslide body retains stable until 2018. Deformation time series after early 2018 perform an acceleration from about 5 mm/yr to 15 mm/yr. Such acceleration may result from artificial irrigation activities, precipitation or internal landslide reactivation, and we expect to collect more ground evidence to interpret the acceleration. To conclude, the failure risk of this landslide is relatively higher since 2018 and is more noteworthy than before.</p>

scholarly journals Impact of Bursty Human Activity Patterns on the Popularity of Online Content

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Qiang Yan ◽  
Lianren Wu
Keyword(s):  
Power Law ◽  
Activity Patterns ◽  
Temporal Analysis ◽  
Time Interval ◽  
Online Content ◽  
Power Law Decay ◽  
Content Popularity ◽  
Human Activity Patterns ◽  
The Impact ◽  
Statistical Results

The dynamics of online content popularity has attracted more and more researches in recent years. In this paper, we provide a quantitative, temporal analysis about the dynamics of online content popularity in a massive system: Sina Microblog. We use time-stamped data to investigate the impact of bursty human comment patterns on the popularity of online microblog news. Statistical results indicate that the number of news and comments exhibits an exponential growth. The strength of forwarding and comment is characterized by bursts, displaying fat-tailed distribution. In order to characterize the dynamics of popularity, we explore the distribution of the time intervalΔtbetween consecutive comment bursts and find that it also follows a power-law. Bursty patterns of human comment are responsible for the power-law decay of popularity. These results are well supported by both the theoretical analysis and empirical data.

scholarly journals APPLICATION OF BED THICKNESS DISTRIBUTIONS IN TURBIDITE DEPOSITS OF LEMNOS ISLAND, NE GREECE

2018 ◽  
Vol 40 (1) ◽  
pp. 154
Author(s):  
A. Maravelis ◽  
P. Konstantopoulos ◽  
G. Pantopoulos ◽  
A. Zelilidis
Keyword(s):  
Frequency Distribution ◽  
Power Law ◽  
Thickness Distribution ◽  
Late Eocene ◽  
Cumulative Frequency ◽  
Cumulative Frequency Distribution ◽  
Submarine Fan ◽  
Early Oligocene ◽  
Power Law Exponent ◽  
Bed Thickness

The submarine fan deposits in Lemnos Island, of the NE Greece provide a perfect opportunity to investigate the influence of processes such as erosion and bed amalgamation in the alternation of the shape of a power-law cumulative frequency distribution. The bed thickness distribution in two outcrops of late Eocene to early Oligocene turbidite deposits that correspond to different sub-environment, has been assessed statistically. Sediments of the outcrop 1 at the SE parts of the Lemnos Island interpreted as outer fan deposits and sediments of the outcrop 2 located at the NE parts of the island as inner fan deposits show both a good fit to the power-law, amplifying the hypothesis that departures from power-law statistics might be used as evidence of erosion and bed amalgamation. The main difference between these two outcrops is that the power law exponent decreases abruptly from outcrop 1 to outcrop 2, confirming with the aspect that the power law exponent can be considered as a good indicator for the available sedimentary space.

Impact of organizational mistreatment on employee performance in the hotel industry

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Aisha Sarwar ◽  
Lakhi Muhammad
Keyword(s):  
Employee Performance ◽  
Hotel Industry ◽  
Time Interval ◽  
Valuable Insight ◽  
Content Type ◽  
Mediating Role ◽  
Effective Strategies ◽  
Hotel Managers ◽  
Moderating Role

Purpose The purpose of this paper is to investigate the factors that can hinder employee performance. Thereof, this study also investigates the mediating role of perceived incivility and the moderating role of psychological capital (PsyCap) to address “why” and “when” employee performance is undermined. Design/methodology/approach Data from 485 employees of hotel industry were gathered in two-time intervals (T1 and T2) by conducting a survey. The time interval gap between Time 1 and Time 2 was 15 days. The data of the respondents were analyzed by using Smart PLS3. Findings The results revealed that injustice perceptions led to perceived incivility, while organizational dehumanization and perceived incivility decreased employee performance. Perceived incivility mediated the relationship between interactional injustice and employee performance. Moreover, PsyCap played the moderating role in curbing the effect of stressor. Practical implications This study offers hotel managers a valuable insight to formulate effective strategies that can enhance performance and PsyCap amongst their employees, aside from minimizing stressors within the context of hotel industry. Originality/value This research contributes to literature by focusing on factors that can undermine employee performance. The study outcomes have essential implications for students, researchers and practitioners. The valuable insights facilitate researchers to focus on factors that lead to deterioration of employee performance, instead of investigating the often-sought employee performance increment factors. This study aids fresh research endeavor by establishing a new avenue for investigation. Hotel managers may find this study insightful to minimize adverse stressors that could deteriorate employee performance.

scholarly journals Measurement of the X-ray proper motion in the south-east rim of RX J1713.7−3946

2017 ◽  
Vol 597 ◽  
pp. A106 ◽  
Author(s):  
Fabio Acero ◽  
Satoru Katsuda ◽  
Jean Ballet ◽  
Robert Petre
Keyword(s):  
Power Law ◽  
Proper Motion ◽  
Ambient Medium ◽  
Time Interval ◽  
X Rays ◽  
The South ◽  
X Ray ◽  
North West ◽  
East Region ◽  
Power Law Index

We report on the first proper motion measurement in the supernova remnant RX J1713.7−3946 using the XMM-Newton X-ray telescope on a 13 yr time interval. This expansion measurement is carried out in the south-east region of the remnant, where two sharp filament structures are observed. For the outermost filament, the proper motion is 0.75+0.05-0.06 ± 0.069syst arcsec yr-1 which is equivalent to a shock speed of ~3500 km s-1 at a distance of 1 kpc. In contrast with the bright north-west region, where the shock is interacting with the border of the cavity, the shock in the south-east region is probably expanding in the original ambient medium carved by the progenitor and can be used to derive the current density at the shock and the age of the remnant. In the case where the shock is evolving in a wind profile (ρ ∝ r− s, s = 2) or in a uniform medium (s = 0), we estimate an age of ~2300 yr and ~1800 yr respectively for an ejecta power-law index of n = 9. The specific case of an ejecta power-law index of n = 7, and s = 0, yields an age of ~1500 yr, which would reconcile RX J1713.7−3946 with the historical records of SN 393. In all scenarios, we derive similar upstream densities of the order of 0.01 cm-3, compatible with the lack of thermal X-rays from the shocked ambient medium.

Sign in / Sign up

Export Citation Format

Share Document