The interpretation of regional gravity and magnetic data, especially the extracted information about concealed targets and structures, provide important evidence for geological structure research, oil-gas resource ass...The interpretation of regional gravity and magnetic data, especially the extracted information about concealed targets and structures, provide important evidence for geological structure research, oil-gas resource assessment, mineral potential forecast and prospective area delineation. Several interpretation methods have been proposed to determine structural boundary, including vertical derivative, horizontal first-order derivative, total horizontal derivative, total gradient modulus, tilt derivative, and theta graph, and each have their advantages and disadvantages. This study used the tilt derivate method to obtain bouguer gravity anomalies in the Beya area, as shown in Fig. 1a.展开更多
Acoustic emission(AE)localization plays an important role in the prediction and control of potential hazardous sources in complex structures.However,existing location methods have less discussion on the presence of un...Acoustic emission(AE)localization plays an important role in the prediction and control of potential hazardous sources in complex structures.However,existing location methods have less discussion on the presence of unknown empty areas.This paper proposes an AE source location method for structures containing unknown empty areas(SUEA).Firstly,this method identifies the shape,size,and location of empty areas in the unknown region by exciting the active AE sources and using the collected AE arrivals.Then,the unknown AE source can be located considering the identified empty areas.The lead break experiments were performed to verify the effectiveness and accuracy of the proposed method.Five specimens were selected containing empty areas with different positions,shapes,and sizes.Results show the average location accuracy of the SUEA increased by 78%compared to the results of the existing method.It can provide a more accurate solution for locating AE sources in complex structures containing unknown empty areas such as tunnels,bridges,railroads,and caves in practical engineering.展开更多
Ecosystem services can be enhanced through ecological restoration,industrial structure adjustment,land-use optimization,and agricultural and forestry ecosystem transformation.The ecosystem services in hilly and mounta...Ecosystem services can be enhanced through ecological restoration,industrial structure adjustment,land-use optimization,and agricultural and forestry ecosystem transformation.The ecosystem services in hilly and mountainous areas of southern China are crucially needed to be enhanced since these regions are important ecological functional zones in China.However,due to its large area,it is not possible to simultaneously upgrade the ecosystem services for all areas,and therefore,priority areas need to be selected to individually upgrade the ecosystem service function.In this study,via an approach of combining remote sensing,geographic information system,and spatial statistics,we identify the priority areas that need to be upgraded based on the analysis of ecological sensitivity,importance of ecosystem service function,and decreased degree in ecosystem services.For five counties in hilly and mountainous areas of southern China,only less than 2% of the total area was identified as the first priority area;its land-use compositions were analyzed and recommendations on how to enhance ecosystem service were suggested.This approach overcomes the conflict and contradiction issues associated with identifying priority areas in previous studies and solves the problems of high cost or difficult implementation of priority areas.展开更多
Promoting sustainable livelihoods for villagers is an essential strategy for rural revitalization in areas enriched with heritage sites.Northwest Yunnan,despite being one of China’s poorest regions,is globally renown...Promoting sustainable livelihoods for villagers is an essential strategy for rural revitalization in areas enriched with heritage sites.Northwest Yunnan,despite being one of China’s poorest regions,is globally renowned for the Three Parallel Rivers and its premier hiking destinations,so exploring sustainable income-increasing opportunities for its villagers is important for its rural revitalization.By using density analysis,logical matrix construction and cluster analysis with GPS data,this study explored the spatial distribution characteristics of hiking tourism in Northwest Yunnan and identified the hiking popular areas.A revenue generation framework,informed by Sustainable Livelihood Approach(SLA)and customized to the unique hiking characteristics of such popular areas,was constructed to analyze income opportunities for villagers in these areas,so as to offer theoretical support for the hiking tourism development and rural revitalization in this region.The results showed that:(1)The distribution of hiking points of interest(POIs)in Northwest Yunnan was relatively centralized with three agglomeration areas from north to south,namely,the Deqin Agglomeration Area,the Lijiang-Shangri-La Agglomeration Area,and the Dali-Yangbi Agglomeration Area.(2)Northwest Yunnan mainly had three popular hiking areas and eight hiking sub-areas correspondingly.(3)The income-generating opportunities for villagers mainly included unique accommodation and food service,guide and gear transportation services,equipment supply,tourism product sales,and logistics support for hiking races.It indicated that due to the differing temporal-spatial characteristics,and themes of activities in each hiking sub-area,the approaches to revenue generation are uniquely distinctive for each sub-area.The diverse tourism-related livelihoods of villagers enrich tourists’experiences while the nature of tourist activities guides the villagers’livelihood choices.Hiking tourism serves as a vital avenue for economic growth in areas like Northwestern Yunnan,where villagers can significantly boost their income by offering a variety of tourism services.展开更多
The abrupt occurrence of the Zhongbao landslide is totally unexpected,resulting in the destruction of local infrastructure and river blockage.To review the deformation history of the Zhongbao landslide and prevent the...The abrupt occurrence of the Zhongbao landslide is totally unexpected,resulting in the destruction of local infrastructure and river blockage.To review the deformation history of the Zhongbao landslide and prevent the threat of secondary disasters,the small baseline subsets(SBAS)technology is applied to process 59 synthetic aperture radar(SAR)images captured from Sentinel-1A satellite.Firstly,the time series deformation of the Zhongbao landslide along the radar line of sight(LOS)direction is calculated by SBAS technology.Then,the projection transformation is conducted to determine the slope displacement.Furthermore,the Hurst exponent of the surface deformation along the two directions is calculated to quantify the hidden deformation development trend and identify the unstable deformation areas.Given the suddenness of the Zhongbao landslide failure,the multi-temporal interferometric synthetic aperture radar(InSAR)technology is the ideal tool to obtain the surface deformation history without any monitoring equipment.The obtained deformation process indicates that the Zhongbao landslide is generally stable with slow creep deformation before failure.Moreover,the Hurst exponent distribution on the landslide surface in different time stages reveals more deformation evolution information of the Zhongbao landslide,with partially unstable areas detected before the failure.Two potential unstable areas after the Zhongbao landslide disaster are revealed by the Hurst exponent distribution and verified by the GNSS monitoring results and deformation mechanism discussion.The method combining SBASInSAR and Hurst exponent proposed in this study could help prevent and control secondary landslide disasters.展开更多
Asphalt pavement repair areas affect pavement performance and service levels.It is neces-sary to distinguish the repair areas from normal sections.Based on vehicle vibration sig-nals,this study identified ten pavement...Asphalt pavement repair areas affect pavement performance and service levels.It is neces-sary to distinguish the repair areas from normal sections.Based on vehicle vibration sig-nals,this study identified ten pavement repair areas and divided them into four cases by factors including length and form in conjunction with the driving approach.Additionally,time domain analysis,frequency analysis,and probability distribution analysis were used to form the characteristics of the repair cases as well as the normal sections.It was found that the maximum value,extreme deviation,standard deviation in the time domain,max-imum amplitude in the frequency domain,and peak of the probability density curve would serve as judgment indexes.A framework for identifying the repair areas was also estab-lished based on the five indexes.By validation,the overall accuracy can reach 95.0%,demonstrating a strong generalization capability.展开更多
文摘The interpretation of regional gravity and magnetic data, especially the extracted information about concealed targets and structures, provide important evidence for geological structure research, oil-gas resource assessment, mineral potential forecast and prospective area delineation. Several interpretation methods have been proposed to determine structural boundary, including vertical derivative, horizontal first-order derivative, total horizontal derivative, total gradient modulus, tilt derivative, and theta graph, and each have their advantages and disadvantages. This study used the tilt derivate method to obtain bouguer gravity anomalies in the Beya area, as shown in Fig. 1a.
基金We are grateful for the financial support from the National Science Foundation for Excellent Young Scholars of China(51822407)the Natural Science Foundation of China(51774327)+1 种基金the Special Fund for Basic Scientific Research Operations in Universities(2282020cxqd055)the Fundamental Research Funds for the Central Universities of Central South University(2021zzts0875).
文摘Acoustic emission(AE)localization plays an important role in the prediction and control of potential hazardous sources in complex structures.However,existing location methods have less discussion on the presence of unknown empty areas.This paper proposes an AE source location method for structures containing unknown empty areas(SUEA).Firstly,this method identifies the shape,size,and location of empty areas in the unknown region by exciting the active AE sources and using the collected AE arrivals.Then,the unknown AE source can be located considering the identified empty areas.The lead break experiments were performed to verify the effectiveness and accuracy of the proposed method.Five specimens were selected containing empty areas with different positions,shapes,and sizes.Results show the average location accuracy of the SUEA increased by 78%compared to the results of the existing method.It can provide a more accurate solution for locating AE sources in complex structures containing unknown empty areas such as tunnels,bridges,railroads,and caves in practical engineering.
基金financially supported by the National Key Research and Development Program of China(2017YFC0505606)the Top Discipline and First-class University Construction Project(ydzxxk201618)of Minzu University of China。
文摘Ecosystem services can be enhanced through ecological restoration,industrial structure adjustment,land-use optimization,and agricultural and forestry ecosystem transformation.The ecosystem services in hilly and mountainous areas of southern China are crucially needed to be enhanced since these regions are important ecological functional zones in China.However,due to its large area,it is not possible to simultaneously upgrade the ecosystem services for all areas,and therefore,priority areas need to be selected to individually upgrade the ecosystem service function.In this study,via an approach of combining remote sensing,geographic information system,and spatial statistics,we identify the priority areas that need to be upgraded based on the analysis of ecological sensitivity,importance of ecosystem service function,and decreased degree in ecosystem services.For five counties in hilly and mountainous areas of southern China,only less than 2% of the total area was identified as the first priority area;its land-use compositions were analyzed and recommendations on how to enhance ecosystem service were suggested.This approach overcomes the conflict and contradiction issues associated with identifying priority areas in previous studies and solves the problems of high cost or difficult implementation of priority areas.
基金The Yunnan Provincial Department of Culture and Tourism Project(01300206020618018)。
文摘Promoting sustainable livelihoods for villagers is an essential strategy for rural revitalization in areas enriched with heritage sites.Northwest Yunnan,despite being one of China’s poorest regions,is globally renowned for the Three Parallel Rivers and its premier hiking destinations,so exploring sustainable income-increasing opportunities for its villagers is important for its rural revitalization.By using density analysis,logical matrix construction and cluster analysis with GPS data,this study explored the spatial distribution characteristics of hiking tourism in Northwest Yunnan and identified the hiking popular areas.A revenue generation framework,informed by Sustainable Livelihood Approach(SLA)and customized to the unique hiking characteristics of such popular areas,was constructed to analyze income opportunities for villagers in these areas,so as to offer theoretical support for the hiking tourism development and rural revitalization in this region.The results showed that:(1)The distribution of hiking points of interest(POIs)in Northwest Yunnan was relatively centralized with three agglomeration areas from north to south,namely,the Deqin Agglomeration Area,the Lijiang-Shangri-La Agglomeration Area,and the Dali-Yangbi Agglomeration Area.(2)Northwest Yunnan mainly had three popular hiking areas and eight hiking sub-areas correspondingly.(3)The income-generating opportunities for villagers mainly included unique accommodation and food service,guide and gear transportation services,equipment supply,tourism product sales,and logistics support for hiking races.It indicated that due to the differing temporal-spatial characteristics,and themes of activities in each hiking sub-area,the approaches to revenue generation are uniquely distinctive for each sub-area.The diverse tourism-related livelihoods of villagers enrich tourists’experiences while the nature of tourist activities guides the villagers’livelihood choices.Hiking tourism serves as a vital avenue for economic growth in areas like Northwestern Yunnan,where villagers can significantly boost their income by offering a variety of tourism services.
基金support from the National Key R&D Program of China(Grant No.2021YFB3901403)Project supported by graduate research and innovation foundation of Chongqing,China(Grant No.CYS23115)Special project for performance incentive and guidance of scientific research institutions in Chongqing(Grant No.cstc2021jxjl120011)are greatly appreciated。
文摘The abrupt occurrence of the Zhongbao landslide is totally unexpected,resulting in the destruction of local infrastructure and river blockage.To review the deformation history of the Zhongbao landslide and prevent the threat of secondary disasters,the small baseline subsets(SBAS)technology is applied to process 59 synthetic aperture radar(SAR)images captured from Sentinel-1A satellite.Firstly,the time series deformation of the Zhongbao landslide along the radar line of sight(LOS)direction is calculated by SBAS technology.Then,the projection transformation is conducted to determine the slope displacement.Furthermore,the Hurst exponent of the surface deformation along the two directions is calculated to quantify the hidden deformation development trend and identify the unstable deformation areas.Given the suddenness of the Zhongbao landslide failure,the multi-temporal interferometric synthetic aperture radar(InSAR)technology is the ideal tool to obtain the surface deformation history without any monitoring equipment.The obtained deformation process indicates that the Zhongbao landslide is generally stable with slow creep deformation before failure.Moreover,the Hurst exponent distribution on the landslide surface in different time stages reveals more deformation evolution information of the Zhongbao landslide,with partially unstable areas detected before the failure.Two potential unstable areas after the Zhongbao landslide disaster are revealed by the Hurst exponent distribution and verified by the GNSS monitoring results and deformation mechanism discussion.The method combining SBASInSAR and Hurst exponent proposed in this study could help prevent and control secondary landslide disasters.
基金supported by the National Natural Science Foundation of China under Grant(No.51778482).
文摘Asphalt pavement repair areas affect pavement performance and service levels.It is neces-sary to distinguish the repair areas from normal sections.Based on vehicle vibration sig-nals,this study identified ten pavement repair areas and divided them into four cases by factors including length and form in conjunction with the driving approach.Additionally,time domain analysis,frequency analysis,and probability distribution analysis were used to form the characteristics of the repair cases as well as the normal sections.It was found that the maximum value,extreme deviation,standard deviation in the time domain,max-imum amplitude in the frequency domain,and peak of the probability density curve would serve as judgment indexes.A framework for identifying the repair areas was also estab-lished based on the five indexes.By validation,the overall accuracy can reach 95.0%,demonstrating a strong generalization capability.
