The Karakoram Highway(KKH),a part of the China–Pakistan Economic Corridor(CPEC),is a major highway connecting northern Pakistan to China.The inventorying and analysis of landslides along KKH are challenging because o...The Karakoram Highway(KKH),a part of the China–Pakistan Economic Corridor(CPEC),is a major highway connecting northern Pakistan to China.The inventorying and analysis of landslides along KKH are challenging because of poor accessibility,vast study area,limited availability of ground-based datasets,and the complexity of landslide processes in the region.In order to preserve life,property,and infrastructure,and to enable the uninterrupted and efficient operation of the KKH,it is essential to strengthen measures for the prevention and control of geological disasters.In the present study,SBASInSAR(Small Baseline Subsets-Interferometric Synthetic Aperture Radar)was used to process 150 scenes of Sentinel 1-A images in the year 2017 along the Karakoram Highway.A total of 762 landslides,including 57 complex landslides,126 rock falls,167 debris slides,and 412 unstable slopes,ranging in size between 0.0017 and 10.63 km2 were identified.Moreover,this study also gains an inventory of 40 active glacier movements in this region.Landslide categorization,displacements characteristics,spatial distribution,and their relationship with various contributing factors have been successfully investigated along the entire KKH using image interpretation and frequency-area statistics.The criteria adopted for landslides categorization is presented in the study.The results showed that the 2-D ground deformation derived in Hunza valley echoes well with the general regional landslides characteristics.The spatial distribution analysis revealed that there are clumped distributions of landslides in the Gaizi,Tashkurgan,and Khunjerab in China,as well as in Hunza valley,and north of Chilas city in Pakistan.Statistical results indicated that these landslides mainly occur on south-facing slopes with a slope angle of 20°–45°and elevation relief of 550–2,100 m.Landslide development is also related to low vegetation cover and weathering effects in mountain gullies.Overall,our study provides scientific data support and theoretical references for prevention,control,and mitigation of geological disasters in the Karakoram region.展开更多
On 18 January 2016,the Zhangjiazhuang high-speed railway tunnel in Ledu,Qinghai Province,China,underwent serious deformation and structural damage.A crack formed at the top of the tunnel and the concrete on the crown ...On 18 January 2016,the Zhangjiazhuang high-speed railway tunnel in Ledu,Qinghai Province,China,underwent serious deformation and structural damage.A crack formed at the top of the tunnel and the concrete on the crown peeled off.As a result,the tunnel could not be operated for three months.In order to determine the types and spatial distribution of the landslides in the region and the surface deformation characteristics associated with the tunnel deformation,we used field geological and geomorphological surveys,unmanned aerial vehicle image interpretation and differential interferometric synthetic aperture radar(D-In SAR) surface deformation monitoring.Nine ancient and old landslides were identified and analysed in the study area.Surface deformation monitoring and investigation of buildings in several villages on the slope front showed that the tunnel deformation was not related to deep-seated gravitational slope deformation.However,surface deformation monitoring revealed an active NEE–SWW fault in the area intersecting the tunnel at the location of the tunnel rupture.This constitutes a plausible mechanism for the deformation of the tunnel.Our study highlights the need for detailed engineering geomorphological investigations to better predict the occurrence of tunnel deformation events in the future.展开更多
武器-目标分配(weapon target assignment,WTA)问题是根据武器对来袭目标毁伤概率的不同,合理确定待打击目标的武器分配方案,以达到用尽可能少的武器对来袭目标毁伤程度最大化的目的,是作战指挥决策领域的重要研究内容。在构建WTA问题...武器-目标分配(weapon target assignment,WTA)问题是根据武器对来袭目标毁伤概率的不同,合理确定待打击目标的武器分配方案,以达到用尽可能少的武器对来袭目标毁伤程度最大化的目的,是作战指挥决策领域的重要研究内容。在构建WTA问题模型的基础上,针对传统灰狼优化(grey wolf optimization,GWO)算法局部开发能力不足等问题,采取了一种精英保留及免疫变异局部搜索策略。改进灰狼优化算法(improved grey wolf optimization,IGWO)首先在灰狼种群中选择部分优质精英个体,然后通过随机点变异和受体编辑两种免疫局部搜索策略对精英个体进一步寻优,从而改善传统GWO算法过早收敛和易陷入局部最优的缺点。针对3种不同规模的武器-目标分配问题,将IGWO与交叉熵算法、传统GWO算法进行了对比,计算结果显示IGWO算法所求适应度值的分位数均明显高于对比算法,进而验证了IGWO算法的有效性。展开更多
基金supported by National Key Research and Development Program of China(Grant No.2017YFC1501005)National Natural Science Foundation of China(Grant Nos.41661144046,42007232)+3 种基金the Science and Technology Major Project of Gansu Province(Grant No.19ZD2FA002)the Science and Technology Planning Project of Gansu Province(Grant No.18YF1WA114)the Fundamental Research Funds for the Central Universities(Grant Nos.lzujbky-2021-ey05)Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0902)。
文摘The Karakoram Highway(KKH),a part of the China–Pakistan Economic Corridor(CPEC),is a major highway connecting northern Pakistan to China.The inventorying and analysis of landslides along KKH are challenging because of poor accessibility,vast study area,limited availability of ground-based datasets,and the complexity of landslide processes in the region.In order to preserve life,property,and infrastructure,and to enable the uninterrupted and efficient operation of the KKH,it is essential to strengthen measures for the prevention and control of geological disasters.In the present study,SBASInSAR(Small Baseline Subsets-Interferometric Synthetic Aperture Radar)was used to process 150 scenes of Sentinel 1-A images in the year 2017 along the Karakoram Highway.A total of 762 landslides,including 57 complex landslides,126 rock falls,167 debris slides,and 412 unstable slopes,ranging in size between 0.0017 and 10.63 km2 were identified.Moreover,this study also gains an inventory of 40 active glacier movements in this region.Landslide categorization,displacements characteristics,spatial distribution,and their relationship with various contributing factors have been successfully investigated along the entire KKH using image interpretation and frequency-area statistics.The criteria adopted for landslides categorization is presented in the study.The results showed that the 2-D ground deformation derived in Hunza valley echoes well with the general regional landslides characteristics.The spatial distribution analysis revealed that there are clumped distributions of landslides in the Gaizi,Tashkurgan,and Khunjerab in China,as well as in Hunza valley,and north of Chilas city in Pakistan.Statistical results indicated that these landslides mainly occur on south-facing slopes with a slope angle of 20°–45°and elevation relief of 550–2,100 m.Landslide development is also related to low vegetation cover and weathering effects in mountain gullies.Overall,our study provides scientific data support and theoretical references for prevention,control,and mitigation of geological disasters in the Karakoram region.
基金funded by the National Key Research and Development Program of China (Grant No.2018YFC1504704)the National Natural Science Foundation of China (Grant No.41661144046)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No.lzujbky-2018-k14)the Key Research and Development Program of Gansu Province (Grant No.18YF1WA114)。
文摘On 18 January 2016,the Zhangjiazhuang high-speed railway tunnel in Ledu,Qinghai Province,China,underwent serious deformation and structural damage.A crack formed at the top of the tunnel and the concrete on the crown peeled off.As a result,the tunnel could not be operated for three months.In order to determine the types and spatial distribution of the landslides in the region and the surface deformation characteristics associated with the tunnel deformation,we used field geological and geomorphological surveys,unmanned aerial vehicle image interpretation and differential interferometric synthetic aperture radar(D-In SAR) surface deformation monitoring.Nine ancient and old landslides were identified and analysed in the study area.Surface deformation monitoring and investigation of buildings in several villages on the slope front showed that the tunnel deformation was not related to deep-seated gravitational slope deformation.However,surface deformation monitoring revealed an active NEE–SWW fault in the area intersecting the tunnel at the location of the tunnel rupture.This constitutes a plausible mechanism for the deformation of the tunnel.Our study highlights the need for detailed engineering geomorphological investigations to better predict the occurrence of tunnel deformation events in the future.
文摘武器-目标分配(weapon target assignment,WTA)问题是根据武器对来袭目标毁伤概率的不同,合理确定待打击目标的武器分配方案,以达到用尽可能少的武器对来袭目标毁伤程度最大化的目的,是作战指挥决策领域的重要研究内容。在构建WTA问题模型的基础上,针对传统灰狼优化(grey wolf optimization,GWO)算法局部开发能力不足等问题,采取了一种精英保留及免疫变异局部搜索策略。改进灰狼优化算法(improved grey wolf optimization,IGWO)首先在灰狼种群中选择部分优质精英个体,然后通过随机点变异和受体编辑两种免疫局部搜索策略对精英个体进一步寻优,从而改善传统GWO算法过早收敛和易陷入局部最优的缺点。针对3种不同规模的武器-目标分配问题,将IGWO与交叉熵算法、传统GWO算法进行了对比,计算结果显示IGWO算法所求适应度值的分位数均明显高于对比算法,进而验证了IGWO算法的有效性。
