Research on the Spatio-Temporal Evolution and Driving Forces of Green Spaces in the Central Urban Area of Zunyi City

Green space,as a medium for carrying out urban functions and guiding urban development,is becoming a scarce resource along with the urbanization process and the intensification of environmental problems.In the face of the spatial mismatch between high demand and low supply,it is of great significance to clarify the evolution mechanism of green space to undertake national spatial planning,protect the natural strategic resources in the urban fringe area,and promote the sustainable development of the“three living spaces.”The study focuses on the Zunyi City Center,selecting the 20 years of rapid development following its establishment as a city as the study period.It explores the dynamic evolution of green space and the main driving forces during different periods using remote-sensing image data.The study shows that from 2003 to 2023,the total scale of green space has an obvious decreasing trend along with the expansion of the urban built-up area.A large amount of arable land is being converted to construction land,resulting in a sudden decrease in arable land area.In the past 10 years,the comprehensive land use dynamics have accelerated.Still,the spatial difference has gradually narrowed,indicating that the overall development intensity of Zunyi City’s central urban area has increased.There is a gradual spread of the trend to the hilly areas.The limiting effect of the mountainous natural environment on the city’s development has gradually diminished under the superposition of external factors,such as economic development,industrial technological upgrading,and policy orientation so the importance of the effective protection and rational utilization of urban green space has become more prominent.

In situ infrared, Raman and X-ray spectroscopy for the mechanistic understanding of hydrogen evolution reaction

Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy future.Computational methods have been widely used to study the reaction mechanism of the hydrogen evolution reaction(HER),but the calculation results need to be supported by experimental results and direct evidence to confirm the mechanistic insights.In this review,we discuss the fundamental principles of the in situ spectroscopic strategy and a theoretical model for a mechanistic understanding of the HER.In addition,we investigate recent studies by in situ Fourier transform infrared(FTIR),Raman spectroscopy,and X-ray absorption spectroscopy(XAS) and cover new findings that occur at the catalyst-electrolyte interface during HER.These spectroscopic strategies provide practical ways to elucidate catalyst phase,reaction intermediate,catalyst-electrolyte interface,intermediate binding energy,metal valency state,and coordination environment during HER.

Spatio-temporal Evolution of Marine Fishery Industry Ecosystem Vulnerability in the Bohai Rim Region

The building of the ocean power strategy and the implementation of the blue agriculture plan urgently need to strengthen the sustainable development of marine fishery.Taking vulnerability as the starting point, this paper constructs the vulnerability index system of marine fishery industry ecosystem from the aspects of sensitivity and response capacity, and combines the entropy method with the Topsis to comprehensively analyze the spatio-temporal evolution characteristics of vulnerability of marine fishery industry ecosystem in the Bohai Rim Region from 2001 to 2015.The results show that: 1) In the time dimension, from 2001 to 2015, the vulnerability of the marine fishery industry ecosystem in the Bohai Rim Region shows a fluctuant and degressive trend;2) In the spatial dimension, the spatial distribution of the marine fishery industry ecosystem vulnerability in the Bohai Rim Region presents the gradient characteristics which shows high vulnerability in the east and low vulnerability in the west.According to the evolution track of the system’s vulnerability level, the vulnerability of the marine fishery industry ecosystem is divided into ‘declining’ and ‘stable’ types of evolutionary structures;3) The development of marine fishery in the Bohai Rim Region needs to be derived from the marine fishery’s ecological environment and the industrial development mode and structure, which can improve the marine environment remediation efforts, optimize the marine fishery industry structure, vigorously focus on pelagic fishery, and enhance the introduction of marine fishery’s science and technology talents, etc.Then, the marine fishery’s development in the Bohai Rim Region will be moving in the green, circular and sustainable direction.

Spatio-temporal evolution of ecologically-sustainable land use in China's Loess Plateau and detection of its influencing factors

Ecological land(Eco-land) is a basic resource for human beings to survive, and eco-land use is a strategy, a way to manage the land resource. So, ecologically-sustainable land use is essential for human beings to survive. This paper investigates the spatiotemporal characteristics and mechanisms of urban-rural eco-land using a new and innovative integration way based on eco-land change data in China's Loess Plateau(LP) prefecture level cities and explores factors of eco-land change. The spatial difference characteristic of eco-land among different level cities in the LP is that: small cities > big cities > middle cities. From 2009 to 2016, the eco-land in the LP from the perspective of urban-rural areas has changed significantly. Significant differences of urban-rural eco-land were identified among various urban growth types, and all the cities in the LP were further classified into four types based on eco-land change trend, with type A and B cities identified as the vital zone and major zone. Taking the eco-fragile region Loess Plateau(LP) as an example, our results demonstrated that the migrants to cities in LP could relieve ecological pressures and promote restoration of ecological vegetation. We have demonstrated that urbanization and the influence of government policy can be discerned through the quantification of the spatial-temporal change of eco-land and suggest that combining both urban and rural eco-land can support more effective land use decisions and provide theoretical basis for the practical application of urban planning, policy-making and sustainable development. What's more, governments should strive to population mobility and restore vegetation to sustain this fragile ecological environment.

Spatio-temporal Evolution and Driving Factors of the High-quality Development of Provincial Tourism in China

Accelerating the promotion of high-quality development of tourism(HQDT) is of great significance to the sustainable development of tourism. This paper defined the concept of HQDT, and then built an evaluation system for HQDT measurement to analyze the spatio-temporal evolution characteristics of China’s HQDT based on provincial panel data from 2010 to 2019, using Geodetector to explore the similarities and differences between driving factors of HQDT and tourism development scale(TDS). The results show that:1) Taking the development concepts of innovation, coordination, green, openness and sharing as the guidance, and considering the organic unity of quantity and quality, the evaluation index system of the HQDT consists of six dimensions of economic stability, innovation driving, coordination and linkage, green and sustainability, openness and cooperation, and sharing and harmony, which respectively represent the basis, momentum, means, orientation, direction and purpose of the HQDT;2) The level of China’s HQDT shows an upward trend, presenting the characteristics of eastern region > central region > western region > northeastern region in 2019. The regional differences in China’s HQDT show a downward trend, and the intra-regional differences have replaced the inter-regional differences as the main source of regional differences;3) China’s HQDT shows the characteristics of higher in the east and lower in the west along the Hu line, while the improvement speed of HQDT shows the characteristics of faster in the west and slower in the east, making the decline of east-west differentiation of China’s HQDT and the movement of the gravity center towards southwest;4) Both HQDT and TDS are obviously driven by tourism capital investment and regional consumption. In terms of differences, the HQDT is more driven by government guidance, innovation driving force, and opening up, while the main driving factors of TDS are more biased toward capital elements and hardware facilities, including informatization, tourism resource, traffic, and eco-environment.

Spatio-temporal Evolution Characteristics and Driving Mechanism of the New Infrastructure Construction Development Potential in China

With the advent of the era of big data and artificial intelligence, new infrastructure construction(NIC) has attracted the attention of many countries. The development of NIC provides an opportunity to bridge the digital divide and narrow the regional gap,providing continuous impetus to further promote economic development. Here, we considered 31 provincial-level administrative units in China(not including Hong Kong, Macao, and Taiwan of China due to data unavailable) and established comprehensive evaluation indicators for the development potential of NIC. Afterward, we used the entropy-weight TOPSIS model to determine the development potential of NIC and analyze its spatio-temporal evolution characteristics. Furthermore, the GeoDetector model was applied to explore the driving mechanism of the NIC development potential. The conclusions were as follows: (1) The Chinese NIC development potential is generally low. The eastern China was the region with the highest development potential year by year, while the development potential in the central China was found to be in an accelerating phase. (2) The evolution of the Chinese NIC development potential’s spatial pattern has been characterized by an inland extension and coastal agglomeration. Moreover, we identified a superior development zone, a rising development zone, an inferior development zone, and a declining development zone. (3) The scope of Chinese NIC development potential agglomeration areas has gradually expanded and its degree has gradually deepened. The range of high-value agglomeration in eastern area gradually expanded and its degree gradually deepened. (4) Investment in innovative talents appears as the core factor affecting the Chinese NIC development potential. Whether acting alone or synergistically with other factors, its promoting effect on Chinese NIC development potential is the strongest.

Study of spatial and temporal evolution of Ar and F atoms in SF6/Ar microsecond pulsed discharge by optical emission spectroscopy

The study of sulfur hexafluoride(SF6) discharge is vital for its application in gas-insulated equipment. Direct current partial discharge(PD) may cause SF6 decomposition, and the decomposed products of SF6, such as F atoms, play a dominant role in the breakdown of insulation systems. In this study, the PD caused by metal protrusion defects is simulated by a needle-plate electrode using pulsed high voltage in SF6/Ar mixtures. The spatial and temporal characteristics of SF6/Ar plasma are analyzed by measuring the emission spectra of F and Ar atoms, which are important for understanding the characteristics of PD. The spatial resolved results show that both F and Ar atom spectral intensities increase first from the plate anode to the needle and then decrease under the conditions of a background pressure of400 Pa, peak voltage of-1000 V, frequency of 2 kHz, pulse width of 60 μs, and electrode gap of 5-9 mm. However, the distribution characteristics of F and Ar are significantly different. The temporal distribution results show that the spectral intensity of Ar decreasesfirst and then increases slowly, while the spectral intensity of F increases slowly for the duration of the pulsed discharge at the electrode gap of 5 mm and the pulse width of40-80 μs.

Electrocatalysis induced reconstruction of RuNiPO for highly efficient hydrogen evolution reaction

Reconstruction during the catalytic process has been considered to play a key role for the performance.Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction(HER),which can benefit from a long-term reconstruction during HER for 10 h to continuously increase the performance.The final catalyst(e-RuNiPO)shows a huge morphology change from bulk sphere to highly exposed layered structure in the electrocatalysis process,and exhibits an interesting electronic structure modification with the electron transfer from Ru to Ni for better interfacial interaction and quick charge transfer.Due to the favorable morphology with more exposed active sites and the optimized electronic structure,the final catalyst can achieve an outstanding performance with only an overpotential of 15 mV at 10 mA cm^(-2)(with a good stability more than 100 h),even outperforming the performance of benchmark 20 wt%Pt/C catalyst(18 mV at 10 mA cm^(-2))by using a much lower Ru content.

Surface reconstruction of Se-doped NiS_(2) enables high-efficiency oxygen evolution reaction

Surface reconstruction of electrocatalysts has been widely witnessed during the electrochemical processes.Here,NiS_(2),NiSe_(2), and Se doped NiS_(2)(Se-NiS_(2)) are fabricated for oxygen evolution reaction(OER) through a mild sulfuration and/or selenylation process of Ni(OH)_(2) supported on carbon cloth(CC).Through careful in-situ Raman spectroscopy and ex-situ X-ray photoelectron spectroscopy,surface reconstruction of NiS_(2),NiSe_(2),and Se-NiS_(2) during the OER process has been revealed.A potentialdependent study shows that Se-NiS_(2) undergoes surface evolution at lower potentials and requires the lowest potential for conversion to NiOOH as a highly OER-active species,accompanied by the leaching of SO_(4)^(2-) and SeO_(4)^(2-) that can again be adsorbed on the catalyst surface to enhance the catalytic activity.Density functional theory(DFT) calculations confirm that Se-NiS_(2) is more susceptible to surface oxidation through the OER process.Therefore,Se-NiS_(2) exhibits outstanding OER activity and stability in alkaline conditions,requiring an overpotential of 343 mV at a current density of 50 mA cm^(-2).A novel insight is provided by our work in understanding the surface reconstruction and electrocatalytic mechanism of Ni-based chalcogenides.

Temporal and spatial evolution measurement of laser-induced breakdown spectroscopy on hydrogen retention in tantalum

Fuel retention measurement on plasma-facing components is an active field of study in magnetic confinement nuclear fusion devices.The laser-induced breakdown spectroscopy(LIBS)diagnostic method has been well demonstrated to detect the elemental distribution in PFCs.In this work,an upgraded co-axis LIBS system based on a linear fiber bundle collection system has been developed to measure the hydrogen(H) retention on a tantalum(Ta) sample under a vacuum condition.The spatial resolution measurement of the different positions of the LIBS plasma can be achieved simultaneously with varying delay times.The temporal and spatial evolution results of LIBS plasma emission show that the H plasma observably expands from the delay times of 0-200 ns.The diameter of Ta plasma is about 6 mm which is much less than the size of H plasma after 200 ns.The difference in the temporal and spatial evolution behaviors between H plasma and Ta plasma is due to the great difference in the atomic mass of H and Ta.The depth profile result shows that H retention mainly exists on the surface of the sample.The temporal and spatial evolution behaviors of the electron excited temperature are consistent with that of the Ta emission.The result will further improve the understanding of the evolution of the dynamics of LIBS plasma and optimize the current collection system of in situ LIBS in fusion devices.

Temperature Evolution of Energy Gap and Band Structure in the Superconducting and Pseudogap States of Bi_2Sr_2CaCu_2O_(8＋δ) Superconductor Revealed by Laser-Based Angle-Resolved Photoemission Spectroscopy

We carry out detailed momentum-dependent and temperature-dependent measurements on Bi_2Sr_2CaCu_2O_（8＋δ）（Bi2212） superconductor in the superconducting and pseudogap states by super-high resolution laser-based angleresolved photoemission spectroscopy. The precise determination of the superconducting gap for the nearly optimally doped Bi2212（T_c= 91 K） at low temperature indicates that the momentum-dependence of the superconducting gap deviates from the standard d-wave form（cos（2Φ））. It can be alternatively fitted by including a high-order term（cos（6Φ）） in which the next nearest-neighbor interaction is considered. We find that the band structure near the antinodal region smoothly evolves across the pseudogap temperature without a signature of band reorganization which is distinct from that found in Bi_2Sr_2CuO_（6＋δ） superconductors. This indicates that the band reorganization across the pseudogap temperature is not a universal behavior in cuprate superconductors.These results provide new insights in understanding the nature of the superconducting gap and pseudogap in high-temperature cuprate superconductors.

Temporal and Spatial Evolution of Laser-Induced Plasma from a Slag Sample

Laser-Induced Breakdown Spectroscopy （LIBS） has been demonstrated to be an effective method for slag analysis. In order to better clarify the nature of the plasma generated from a slag sample, an Nd：YAG pulse laser at 1064 nm wavelength was used to ablate the slag sample in air. The temporal and spatial evolutions of plasma parameters, including emission intensity, electronic density and plasma temperature, have been studied. It is shown that the electron density and plasma temperature drop off rapidly with the delay time as a result of plasma expansion and cooling. It has been found that the electron density of the whole plasma is close to that of the center regions in the plasma. The results of the spatial distributions on the two-dimensional plane have shown that there is a big region with lower electron density values caused by the recombination process in the center of the plasma. The maximum of the plasma temperature takes place at the regions close to the target, and the border of the plasma front-head has higher plasma temperatures than that of the center part.

Promoting surface reconstruction of NiFe layered double hydroxides via intercalating[Cr(C_(2)O_(4))_(3)]^(3-)for enhanced oxygen evolution

Rationally manipulating surface reconstruction of catalysts for water oxidation,inducing formation and dynamic accumulation of catalytically active centers still face numerous challenges.Herein,the introduction of[Cr(C_(2)O_(4))_(3)]^(3-)into NiFe LDHs by intercalation engineering to promote surface reconstruction achieves an advanced oxygen evolution reaction(OER)activity.In view of the weak electronegativity of Cr^(3+) in[Cr(C_(2)O_(4))_(3)]^(3-),the intercalation of[Cr(C_(2)O_(4))_(3)]^(3-)is expected to result in an electron-rich structure of Fe sites in NiFe LDHs,and higher valence state of Ni can be formed with the charge transfer between Fe and Ni.The optimized electronic structure of NiFe-[Cr(C_(2)O_(4))_(3)]^(3-)-LDHs with more active Ni^(3+) species and the expedited dynamic generation of Ni^(3+) (Fe)OOH phase during the OER process contributed to its excellent catalytic property,revealed by in situ X-ray absorption spectroscopy,Raman spectroscopy,and quasi-in situ X-ray photoelectron spectroscopy.With the modulated electronic structure of metal sites,NiFe-[Cr(C_(2)O_(4))_(3)]^(3-)-LDHs exhibited promoted OER property with a lower overpotential of 236 mV at the current density of 10 mA cm^(-2).This work illustrates the intercalation of conjugated anion to dynamically construct desired Ni^(3+) sites with the optimal electronic environment for improved OER electrocatalysis.

Hydrogen evolution kinetics on Ni cathodes modified by spontaneous deposition of Ag or Cu

Nickel modification by spontaneous deposition of transition metals such as Ag and Cu is shown as an economic and simple alternative for the activation of hydrogen evolution reaction（HER） on cathodes in alkaline media. The kinetics of HER is studied on Ni/Ag and Ni/Cu catalysts by cyclic voltammetry and electrochemical impedance spectroscopy（EIS） using a rotating disk electrode（RDE）. Freshly synthesized catalysts, as well as catalysts subjected to a short chronoamperometric ageing procedure, are analyzed and the kinetic and thermodynamic parameters of the HER are obtained. The nickel surface modified with transition metals with an outer shell electronic configuration [xd;（x+1）s;], such as Cu(3d;4s;)and Ag(4d;5s;), shows an improved activity for the HER compared to bare nickel. Furthermore, the Ni/Cu catalyst presents a decreased onset potential. The hydrogen evolution rate, measured as current density at –1.5 V（vs. SCE）, is similar on Ni/Cu and Ni/Ag electrodes.

Insights into spatio-temporal slow slip events offshore the Boso Peninsula in central Japan during 2011-2019 using GPS data

Using Global Positioning System(GPS)coordinate time series,we detect three transient slow slip events(SSEs)offshore the Boso Peninsula in central Japan during 2011-2019.To extract the tiny SSE signals obscured by the significant post-seismic deformation after the 2011 MW9.0 Tohoku earthquake,we develop a new GPS coordinate time series processing software to obtain these SSE-induced deformations from highnoise GPS data.In addition,we apply the principal component analysis-based inversion method(PCAIM)to get the spatio-temporal slip distribution of the three SSEs.The spatio-temporal evolutions of these slips reveal that the nucleation styles are different.Compared to the 2011 and 2018 SSEs,the 2013-2014 SSE displays faster slip spatio-temporal variation,deeper slip,shorter slip duration,minor seismic moment,and lower maximum slip rate.The 2018 SSE exhibits the most significant seismic moment,the maximum slip,and the maximum slip rate of these three SSEs.The spatio-temporal variations of the 2011 SSE are the most complex,containing two acceleration and deceleration phases.The slip zone expanded along the eastern side of the Boso Peninsula in the acceleration phase and shrank back in the deceleration phase.Furthermore,the recurrence interval of SSEs spans from 2.2 to 4 years during 2011-2019,suggesting that the recurrence interval might become shorter and non-periodic due to the enormous earthquake.After the 2013-2014 SSE,the recurrence interval of the SSE gradually returns to normal.Thus,we can infer that the SSE may occur every 4-7 years after the 2018 SSE if there is no large earthquake.

Path of Rural Sustainable Development Based on the Evolution and Interaction of Rural Functions:A Case Study of Chongqing Municipality,China

In order to investigate the evolutionary characteristics of rural functions and their interaction,37 districts and counties in Chongqing,China are used as research objects to measure the level of rural functions and analyze the interaction between rural functions using entropy value method and spatial autocorrelation method.The results show that from 2009 to 2019,the three main functions of production,living and ecology in Chongqing’s villages have been greatly enhanced,especially the production function.On the whole,the production and living functions are stronger in the western part,while the ecological functions are significant in the eastern and southern parts of Chongqing,with some differences in local spatial characteristics.This finding is consistent with the regional economic and social development of Chongqing.In addition,the interaction between rural functions is also evident.In general,production and living functions are mainly expressed in synergistic relationships.Ecological and production functions,including ecological and subsistence functions,mainly present a trade-off relationship.The interactions between rural functions also show clear spatial and temporal differences.In addition,different regions have different comparative advantage functions,and in this study,the counties of Chongqing are classified into four types.Policy makers are advised to adopt different measures according to the different types to promote sustainable rural development by coordinating the’production-living-ecological’functions of rural areas.This study reveals the spatio-temporal evolution of rural functions and the interaction between rural functions,which can provide theoretical support and practical reference for rural revitalisation and sustainable development.

Temporal and Spatial Evolution of Precursory Anomalies of the Wenchuan MS8.0 Earthquake and Their Mechanical Analysis

In order to study the spatiotemporal evolution of the precursory anomalies 10 years before the Wenchuan M_S8. 0 earthquake in 2008, the epicentral distance of the precursory anomalies is calculated by using the geometric center of the rupture region and the elliptical centerline of the aftershock region. The result shows, precursor anomalies gradually increased about 2 years before the Wenchuan earthquake. The ratio of abnormal items is greater than 25% in the near source area (about twice the source scale) and 17%-24% in the remote area (about 3-5 times the source scale). There are three different stages of spatiotemporal evolution of precursory anomalies. During the α stage (including α_1 and α_2,between 700 to 3000 days before the main earthquake),the anomalies are mainly distributed in the southwest and northwest area of the Wenchuan aftershocks area. It is shown that the precursors of the far source region and the near source area have the characteristics of outward expansion. During the β stage (between 300 to 700 days before the main earthquake), the anomalies are distributed in the southwest and northern region of the aftershock region, showing a large range of anomalies. During the γ stage (including γ_1 and γ_2, 300 days before the main earthquake),the range of anomaly distribution is wide,and the anomalies are distributed in the southwest and northeast of the aftershock area. The anomalies converged to epicenter (γ_1) in the far source region and expand outwards (γ_2) in the near source region. Results of the experimental study and mechanical analysis of earthquake preparation process indicate that the three-stage characteristics of precursory anomalies in the process of earthquake preparation may be controlled by the seismogenic body,which is a form of expression in the process of earthquake preparation and a universal featureduring the earthquake preparation process,which has a certain guiding role in earthquake prediction.

粗糙金属电极的原位电化学拉曼光谱法在固-液界面分析中的进展

原位电化学拉曼光谱利用入射光诱导物质分子的散射现象,通过测定拉曼光谱信号与电极电位或电流强度的变化关系,来表征电极表面(界面)的分子微观结构。该技术能够获取电化学界面上的分子振动信息以及与化学反应相关的结构信息,并进行实时监测,因此在物质界面表征领域得到了广泛应用。本文从原位电化学拉曼光谱的原理出发,综合叙述了基于粗糙金属电极的原位电化学拉曼光谱在固-液界面分析的进展,包括分子吸附、析氧反应、析氢反应和氧还原反应;同时,探讨了界面结构、反应过程以及催化中间体与拉曼信号强度的关系,介绍了催化过程反应机理和催化物质的催化机理,最后,对下一阶段原位电化学拉曼光谱法在固-液界面分析中存在的科学问题进行展望。

高温^(107)Ag^(5+)离子辐照后核石墨的截面微区拉曼表征与缺陷演化规律研究

在第四代反应堆中,核石墨作为慢化体和反射体材料服役于高温和高通量的快中子辐照环境中。快中子辐照会在核石墨中产生大量的弗伦克尔缺陷对。这些缺陷经过湮灭、扩散、最终形成更大的缺陷团簇,从而改变核石墨的微观结构,进而改变核石墨的宏观性能。因此,研究核石墨在高温辐照条件下的缺陷演化行为和机理对提高反应堆安全性具有重要意义。本研究采用30 MeV的^(107)Ag^(5+)离子在420℃下辐照IG-110核石墨来模拟核石墨在快中子辐照过程中的缺陷演化行为。通过微区拉曼光谱对IG-110核石墨截面结构进行表征,并对比不同深度处的拉曼光谱特征参数和辐照损伤剂量之间的关系,研究IG-110核石墨微观结构随辐照损伤剂量(Displacements Per Atom,DPA)的演化行为。研究结果表明,随着注量的增加,核石墨拉曼光谱的特征参数D峰高度与G峰高度比值(I_(D)/I_(G))、G峰半高宽(Full Width at Half Maximum of the G peak,FWHM(G))以及G峰的偏移量都显著增加。与^(58)Ni^(5+)辐照样品相比,相同辐照损伤剂量下,^(107)Ag^(5+)辐照的石墨拉曼光谱的I_(D)/I_(G)和FWHM(G)更大。相同的FWHM(G)下,^(107)Ag^(5+)辐照的石墨拉曼光谱的I_(D)/I_(G)比^(58)Ni^(5+)辐照样品大。这些结果说明更重的重离子辐照会在核石墨中引起更高速率的缺陷积累,从而更快地导致石墨晶粒尺寸变小,并促进纳米晶化进程。

South China Sea Typhoon Hagibis enhanced Xinfengjiang Reservoir seismicity

There was an evident increase in the number of earthquakes in the Xinfengjiang Reservoir from June to July 2014 after the landing of Typhoon Hagibis.To understand the spatial and temporal evolution of this microseismicity,we built a high-precision earthquake catalog for 2014 and relocated 2275 events using recently developed methods for event picking and catalog construction.Seismicity occurred in the southeastern part of the reservoir,with the preferred fault plane orientation aligned along the Heyuan Fault.The total seismic energy peaked when the typhoon passed through the reservoir,and seismicity correlated with typhoon energy.In contrast,a limited seismic response was observed during the later Typhoon Rammasun.Combining data regarding the water level in the Xinfengjiang Reservoir and seismicity frequency changes in the Taiwan region during these two typhoon events,we suggest that typhoon activity may increase microseism energy by impacting fault stability around the Xinfengjiang Reservoir.Whether a fault can be activated also depends on how close the stress accumulation is to its failure point.