EN中文

过刊目录

  • 2023年, 20卷, 第12期
    刊出日期：2024-06-19
      
  • 全选
    |
  • Mapping cultural ecosystem services in mountain forests using mobile phone data
    CIESIELSKI Mariusz, KAMI?SKA Agnieszka
    2023, 20(12): 3437-3449.
      可视化   收藏
    The aim of the work was to determine the spatial distribution of activity in the forest on the area of the Forest Promotional Complex “Sudety Zachodnie” using mobile phone data. The study identified the sites with the highest(hot spot) and lowest(cold spot) use. Habitat, stand, demographic, topographic and spatial factors affecting the distribution of activity were also analyzed. Two approaches were applied in our research: global and local Moran's coefficients, and a machine learning technique, Boosted Regression Trees. The results show that 11,503,320 visits to forest areas were recorded in the “Sudety Zachodnie” in 2019. The most popular season for activities was winter, and the least popular was spring. Using global and local Moran's I coefficients, three small hot clusters of activity and one large cold cluster were identified. Locations with high values with similar neighbours(hot-spots) were most often visited forest areas, averaging almost 200,000 visits over 2019. Significantly fewer visits were recorded in cold-spots, the average number of visits to these areas was about 4,500. The value of global Moran's I was equal to 0.54 and proved significant positive spatial autocorrelation. Results of Boosted Regression Trees modeling of visits in forest, using tree stand habitat and spatial factors accurately explained 76% of randomly selected input data. The variables that had the greatest effect on the distribution of activities were the density of hiking and biking trails and diversity of topography. The methodology presented in this article allows delineation of Cultural Ecosystem Services hot spots in forest areas based on mobile phone data. It also allows the identification of factors that may influence the distribution of visits in forests. Such data are important for managing forest areas and adapting forest management to the needs of society while maintaining ecosystem stability.
  • A long way to go: impacts of urbanization on migrants' livelihoods and rural ecology in less industrialized regions
    ZHANG Zhi-qi, LI Ming-jing, LI Wen-jun, WEI Yi-ran, SHI Yi-lu
    2023, 20(12): 3450-3463.
      可视化   收藏
    Urbanization, often coupled with industrialization, is generally considered as a boost for improving livelihood as well as alleviating ecological pressures of the rural areas. However, this experience needs to be tested in less industrialized areas, particularly where the urbanization is driven by non-economic factors such as urban public services and relevant government policies rather than employment opportunities. Taking two villages on the Qinghai-Tibet Plateau as examples, through the field investigation by using semi-structured questionnaires and in-depth interviews, and statistical data analysis, we explored the impacts of urbanization on migrants' livelihoods and the ecological conditions of their original village rangeland. We found that the disposable income and savings of emigrant households were less than the stay households, which might be correlated to the limited employment due to the lagged industrialization in the local township, and the mismatch between their traditional labor skills and the demands of urban services. Their home-village rangeland overuse was not alleviated since the increasing grazing pressure caused by the stay households, though the emigrant households intended to decrease the number of livestock on their home pasture. We concluded that the urbanization misaligned with local industrialization may fail to improve migrant livelihoods and local ecological conditions in less industrialized areas. Our research supplements the previous urbanization theory by highlighting the non-industrialization driven urbanization, and is particularly pertinent for the transitional countries worldwide.
  • Understanding human-leopard conflict in the ‘Mid-hill' region of western Nepal
    LAMICHHANE Saroj, THAPA Arjun, THAPA Mahendra Singh, PANTHI Saroj, GIORDANO Anthony J
    2023, 20(12): 3464-3475.
      可视化   收藏
    Livestock rearing and agriculture are the main sources of community-based livelihoods in western Nepal. Across the rural mid-hills region of Gandaki Province, leopards are the top predator and frequently depredate livestock and attack humans. Spatiotemporal patterns of human-leopard conflicts(HLC) in Nepal are poorly known at the provincial and national scales, which are essential to formulating effective conflict mitigation strategies and implementing them in the field. This study aims to analyze the spatiotemporal pattern of HLC by applying Maxent modeling to covariates relating to known and registered conflict cases(n=842) collected from Nepalese government offices. We found that cases of HLC have been increasing significantly over the past five years. We also concluded that mid-elevation, south-facing slopes were more susceptible to HLC, but that mean annual temperature was by far the most important predictor of HLC; overall livestock density and proximity to roads were also important, but secondarily so. Although we found the increase in human fatalities to 2.16/year was significant(p<0.05), overall human injuries were down slightly, though not significantly(5.16/year; p>0.05). However, we also found an increasing trend in livestock depredation rates for this same five-year period(p<0.05), which averaged 159.6 head/year among incidents reported. We also found that winter was the main season when depredations occurred, and that goats were the most depredated of all livestock. A total US $86,892.25($17,378.45/year) of economic losses were incurred by communities during this time, with 78.57% of the total value reimbursed as compensatory relief through the government's relief fund. We recommend that the use of predator-proof livestock corrals, greater awareness in local communities about wildlife behavior, better animal husbandry and security practices, and a more efficient compensation program, can improve coexistence between leopard populations and human communities in western Nepal.
  • Assessment of precipitation type discrimination methods on glacier of Qilian Mountains
    CHEN Ji-zu, DU Wen-tao, KANG Shi-chang, QIN Xiang, SUN Wei-jun, JIANG You-yan, SUN Wen-xuan
    2023, 20(12): 3476-3487.
      可视化   收藏
    Solid precipitation is not only the main supply for glacier mass, but also exerts an important influence on surface albedo and intensifies glacier melting. However, precipitation type observation is very scarce in the high alpine glaciers, which limits the precise simulation of glacier mass balance. This study assessed three discrimination methods of precipitation types including Ding method, Dai method and Froidurot method based on surface albedo observation data on the Laohugou Glacier No. 12(LHG Glacier) in western Qilian Mountains. The results showed that Ding method had a best applicability on the LHG Glacier, the other two need to calibrate parameters when they are used in the high elevation glacier region. Then we fitted the relationship between snowfall probability and fresh snow albedo, and put forward a revised formula to simulate fresh snow albedo based on Ding method, which is expected to reduce the uncertainty in glacier mass and energy balance model. Finally, we found a best air temperature threshold of 4℃ for discriminating monthly precipitation types. In order to accurately simulate the glacier melt, it is necessary to obtain the threshold temperature appropriately in different glacier region with different elevation and humidity.
  • Variations of extreme temperature in the Mount Qomolangma region in China during 1971-2020
    WANG Shun-jiu
    2023, 20(12): 3488-3499.
      可视化   收藏
    According to observational daily temperature data from the meteorological stations during 1971-2020, the variations of the extreme temperature event in the Mount Qomolangma(also known as Mount Everest) region in China have been analyzed using statistical methods. The extreme temperature indices recommended by the World Meteorological Organization are selected to describe the extreme temperature event. The RClimDEX 1.0 software is used to calculate the extreme temperature indices. There are no tropical nights, and just three summer days at the last 50 years. The frost days are the main extreme temperature events all year round. The temperature in the north slope is more extreme than that in the south slope of the Mount Qomolangma. There is remarkable decadal variation for the extreme temperature indices except diurnal temperature range. There are the warm extremes increasing, however, the cold extremes decreasing with the decadal lapse, which is more remarkable into the 21~(th) century. The tendencies for the extreme temperature indices in the north slope are consistent with those in the south slope. There are statistically significant trends for most extreme temperature indices during the study period. It shows that the warm extremes would be more prominent in the future with the global continued warming. The abrupt changes of the extreme temperature index have occurred mainly in the 20~(th) century especially from the mid to late 1980s and 1990s. The periodic changes in the south slope do not synchronize those in the north slope for the most extreme temperature indices. It is different for most extreme temperature indices between the south and north slope, which has demonstrated that the regional or local changes are not neglectable for extreme temperature research. The results of this study are also the consistent response of extreme temperature event to the global warming.
  • Effect of tectonic-climatic controllers on the transition of Endorheic to Exorheic Basins in the Zagros mountain range
    Gholam HASSAN JAFARI, Peyman MOHAMMADI-AHMADMAHMOUDI, Mohsen EHTESHAMI-MOINABADI
    2023, 20(12): 3500-3524.
      可视化   收藏
    Endorheic basins(ENBs) are inland drainage basins allowing no outflow to oceans. These basins in the active mountain chains of the convergence zones are under the influence of compressional tectonic activity and climate condition. The Zagros Mountains of Iran is one of the youngest convergence zones in which continental-continental collision has occurred. In this paper we hypothesize the formation of ENBs among the Zagros range after the epeirogenic stage in the Late Paleogene-Early Neogene. Due to tectonic activity and Quaternary climatic conditions, the ENBs pass the transition stage to exorheic, and still, some tectonic depressions are not linked to the evolutionary process of exorheic drainage of Zagros. The geometry of the drainage network of Kul and Mond basins in Fars arch shows that 67% of their water gaps are located along the thrusts and transverse basement faults in the east and west of the Fars arch. Geometrically, the Kul and Mond basins form triangles with their sides matching with the edges of the Arabian Plate where the major inherited faults of Arabian plate controls the shape of the Zagros basin and a low strain zone along the Razak fault with lower salt tectonic activity, where the wind gaps are created. The ENBs are located in the rainshadow slopes, but the Kul and Mond basins are located in the upwind slopes of rain waves. This factor and the heavy rains of the basin lead to increase of the erosion potential, destruction of depressions, and floods and consequently, the funnel-shaped gaps have a significant impact on the flood flow.
  • Relationship between gravitational flap structures in the backlimb of anticlinal breakthrough Fault-Propagation Folds: case study of the Southern-Central Tunisian Atlas
    Soulef AMAMRIA, Hassen BENSALEM, Hassan TAIB, Mohamed Sadok BENSALEM, Riheb HADJI, Younes HAMED
    2023, 20(12): 3525-3541.
      可视化   收藏
    The development of orogenic belts structures in the Southern-Central Tunisian Atlas is influenced by the evolution of tectonic activities during different phases, which are also closely linked to the formation of gravitational collapse structure. The typical example is that of the northern flank of the Jebel Orbata particularly the Ben Zannouch fold. It is an asymmetrical anticline interpreted by the model of “Fault Propagation Folds”. The development of the Ben Zannouch structures is resulted from landslides, scree falls and inverted layers plunging to the south. The direction of resulted gravitational structure is parallel to the main thrust direction of the Bou Omrane anticline. The thrust activity of Bou Omrane fault is associated to the important paleo-slope facing south and plastic lithology(incompetent marl layers) of outcropped series, facilitates the development of the Ben Zannouch Flap structure. The definition of gravitational collapse structures for the first time in Tunisia particularly in the northern flank of the Jebel Orbata is controlled by many principal structural conditions: fragmentation of the landslide surfaces, rheology and topography. Other regional factors can be distinguished in the Southern-Central Tunisian Atlas as the seismic activity of the pre-existing Gafsa fault reactivated during compressive phases and the weather conditions during the postglacial period.
  • A decline in snow cover area of Passu and Ghulkin valleys between 1995 and 2022
    Imran HUSSAIN, Mumtaz ALI, Sher MUHAMMAD, Wajid HASSAN, Salar ALI, Zakir HUSSAIN, Syed Hammad ALI, Shaukat ALI, Muhammad Younis KHAN
    2023, 20(12): 3542-3551.
      可视化   收藏
    The global cryosphere is experiencing accelerated melting due to climate change. Currently, the Karakoram anomaly is under discussion with a debate about the possibility that the anomaly may have recently ended. This study aims to evaluate the up-to-date changes in snow cover in the western Karakoram region. We observed the snow cover changes in Passu and Ghulkin valleys in the Hunza River basin(HRB) of the Karakoram through multitemporal Landsat satellite data between 1995 and 2022. We found a significant reduction in snow cover in these valleys, with an average reduction rate of 0.42 km~2/yr, resulting in a total reduction of ～11.46 km~2 between 1995 and 2022. This reduction in snow cover is consistent with the mass loss of glaciers in the Karakoram region in recent years. The decline in snow cover in these valleys is also consistent with the meteorological data. The temperature in summer(June) has significantly increased whereas the precipitation in the accumulation season(March) has decreased. These rapid changes suggest that it is crucially important to monitor the snow cover on a regular basis to support downstream management of snowmelt runoff. In addition, there is a need of planning for mitigation and adaptation strategies for snow-related hazards.
  • Influence law of modified glutinous rice-based materials on gravel soil reinforcement and water erosion process
    ZHANG Weng-xiang, PEI Xiang-jun, ZHANG Xiao-chao, WU Xue-min, XIAO Wei-yang, QIN Liang, ZHU Jin-yu
    2023, 20(12): 3552-3567.
      可视化   收藏
    A large number of loose piles formed by mountain hazards are highly susceptible to hydraulic erosion under rainfall conditions. The use of ecological substrate materials for erosion control and ecological restoration of gravel soil slopes has become a current research hotspot and the study difficulty. The post-earthquake slump accumulation gravel soil in Jiuzhaigou was selected as the research object, and the self-developed modified glutinous rice-based material was used to reinforce the gravel soil. The variable slope flume erosion test and rainfall simulation test were carried out to study the water erosion resistance of the material reconstructed soil under the influence of runoff erosion and raindrop splash erosion. The results show that: As the material content reached 12.5%, the reconstructed soil did not disintegrate after 24 hours of immersion, the internal friction angle was increased by 42.26%, and the cohesion was increased by 235.5%, which played a significant reinforcement effect. In the process of slope erosion, the soil rill erodibility parameter Kr was only 3‰ of the gravel soil control group, the critical shear force τ increased by 272%, and the soil erosion resistance was significantly improved. In the process of rainfall and rainfall on the slope, the runoff intensity of the reconstructed soil was stable, and the ability to resist runoff erosion and raindrop splash erosion was enhanced. The maximum value of soil loss rate on different slope slopes is 0.02-0.10 g·m~(-2)s~(-1), which is significantly lower than that of the control group and has better erosion reduction effect.
  • Phylogenetic conservatism in threatened species responses to climate change differs between functional types in the Gongga Mountains of China
    ZU Kui-ling, Nawal SHRESTHA, JIANG Yong, JIA Guo-qing, PENG Shi-jia, ZHU Xiang-yun, WANG Zhi-heng
    2023, 20(12): 3568-3581.
      可视化   收藏
    Climate change has become one of the most critical threats to global biodiversity. However, whether phylogenetically related species respond to climate change in similar ways remains controversial. The answer to this question is crucial for understanding the impacts of climate change and the conservation on the tree of life. By integrating species distribution models with a molecular phylogeny of 50 threatened plant species from one of the global biodiversity hotspots, Gongga Mountains(Mt. Gongga) in southwest China, we evaluated the responses of threatened plant species to future climate change, and estimated whether species responses are phylogenetically conserved. Phylogenetic reconstruction was used to calculate the phylogenetic distance and null model to verify the reliability of the results. We found that correlations between responses of different species to future climate change decreased with the increase in their phylogenetic distance in the monocotyledonous or herbaceous species, but not in the dicotyledonous and woody species. Our results suggested that the responses of herbaceous and monocotyledonous threatened species in Mt. Gongga to future climate change tend to be phylogenetically conserved, while the responses of woody and dicotyledonous threatened species are not. Our study provides evidence for the existence of phylogenetically non-random extinction in the monocotyledonous herbs in Mt. Gongga and highlights the importance of integrating phylogenetic information and evolutionary history into conservation planning. We also provide theoretical basis and technical support for designing effective conservation schemes for the protection of biodiversity under anthropogenic climate change.
  • Effects of heavy metals on soil microbial community of different land use types
    ZHU Di, ZHANG Zhao-hui, WANG Zhi-hui
    2023, 20(12): 3582-3595.
      可视化   收藏
    To evaluate soil environmental quality of introduced new crops and other traditional crops, and to understand the importance of response of soil microbial community to heavy metal stress, rhizosphere soil samples of different land use types(Sphagnum farming, rice field, grassland and bare land) in Dading Village, Duyun City, Guizhou Province of China were selected as research objects. The differences of soil chemical properties, heavy metal concentration and microbial community among different land use types were compared. The abundance and structural diversity of microbial communities in soil samples were analyzed by 16S rDNA sequencing, the relationship between soil pollution characteristics and microbial community in farmland was studied. The results showed that the different land use types planting different agricultural products under the same growing environment were subject to different heavy metal pollution. Soil chemical properties and heavy metals had significant effects on the soil microbial community. Proteobacteria, Actinobacteriota and Acidobacteriota were the most dominant groups of bacteria. The soil microorganisms responded more actively to the variability of pH, SOM and AK contents, although the variability was not high. With the increase of pH value, the abundance of the dominant species Proteobacteria also increased. Verrucomicrobiota had a better tolerance to the heavy metal Hg. Verrucomicrobiota and Firmicutes had strong resistance to the heavy metal Cd. These results deepen our understanding of the changes and aggregation of microorganisms under different land use patterns in heavy-metal contaminated farmland soils.
  • Development characteristics and failure modes of reactivated ancient landslides in the Sichuan–Tibet transportation corridor, China
    WU Rui-an, ZHANG Yong-shuang, GUO Chang-bao, REN San-shao, YAO Xin, LIU Xiao-yi, YANG Zhi-hua, DU Guo-liang
    2023, 20(12): 3596-3613.
      可视化   收藏
    The risk of reactivated ancient landslides in the Sichuan–Tibet transportation corridor in China is significantly increasing, primarily driven by the intensification of engineering activities and the increased frequency of extreme weather events. This escalation has resulted in a considerable number of fatalities and extensive damage to critical engineering infrastructure. However, the factors contributing to the reactivation and modes of destruction of ancient landslides remain unknown. Therefore, it is imperative to systematically analyze the developmental characteristics and failure modes of reactivated ancient landslides to effectively mitigate disaster risks. Based on a combination of data collection, remote sensing interpretation, and field investigations, we delineated the developmental attributes of typical ancient landslides within the study area. These attributes encompass morphological and topographic aspects, material composition, and spatial structure of ancient landslides. Subsequently, we identified the key triggers for the reactivation of ancient landslides, including water infiltration, reservoir hydrodynamics, slope erosion, and excavation, by analyzing representative cases in the study area. Reactivation of ancient landslides is sometimes the result of the cumulative effects of multiple predisposing factors. Furthermore, our investigations revealed that the reactivation of these ancient landslides primarily led to local failures. However, over extended periods of dynamic action, the entire zone may experience gradual creep. We categorized the reactivation modes of ancient landslides into three distinct types based on the reactivation sequences: progressive retreat, backward thrusting, and forward pulling–backward thrusting. This study is of great significance for us to identify ancient landslides, deepen our understanding of the failure modes and risks of reactivated ancient landslides on the eastern margin of the Tibetan Plateau, and formulate effective disaster prevention and mitigation measures.
  • Deformation characteristics and mechanism of an impoundment-induced toppling landslide in Baihetan Reservoir based on multi-source remote sensing
    ZHOU Zhen-kai, YAO Xin, LI Ren-jiang, JIANG Shu, ZHAO Xiao-ming, REN Kai-yu, ZHU Yi-fei
    2023, 20(12): 3614-3630.
      可视化   收藏
    Impoundment and water level fluctuations in reservoirs can induce landslides, especially during initial filling and drawdown. Since the initial impoundment in April 2021, multiple landslides have occurred within the Baihetan(BHT) reservoir, which is located at the boundary of Sichuan and Yunnan province in southeast China. However, due to the complex terrain conditions of reservoir banks, traditional landslide research methods, such as surveys, deformation monitoring, and geotechnical experiments, cannot be effectively conducted in a timely manner. In recent years, the development of remote sensing technology has addressed the shortcomings of traditional landslide research methods that may not be promptly carried out. In particular, interferometric synthetic aperture radar(InSAR) technology, capable of measuring subtle deformations, and portable small unmanned aerial vehicles(UAVs) have played a significant role. This study integrates multiple remote sensing data sources, including InSAR results, optical remote sensing images, digital elevation model(DEM), and UAV imagery, to investigate and elucidate the deformation characteristics and mechanisms of the Xiaomidi(XMD) landslide developed on the left bank of Jinsha River,about 100 km from the BHT hydropower dam site. The spatial deformation distribution of the landslide before and after impoundment and the deformation time series during filling were examined. Monitoring water level variation and analysing the deformation process of the landslide were achieved by employing continuous synthetic aperture radar(SAR) intensity images and DEM. UAV photography was utilized to assist in the verification of ground deformation. The findings suggest that the weak strength of the reversed bedding strata structure and the steep slope eroded by the Jinsha River are inherent factors that contribute to the development of the landslide. The rise in the water level leads to softening of the rock mass at the slope toe, thereby directly facilitating the acceleration of landslide deformation. The toppling deformation of the lower rock mass initiates the formation of surface cracks and localized uneven subsidence in the overlying colluvial deposits.
  • Flood risk assessment of check dams in the Wangmaogou watershed on the Loess Plateau of China
    GAO Ze-chao, SHI Peng, LI Zhan-bin, LI Peng, BAI Lu-lu, JIA Yi-li, CUI Lin-zhou
    2023, 20(12): 3631-3647.
      可视化   收藏
    Check dams have been widely used in China's Loess Plateau region due to their effectiveness in erosion and flood control. However, the safety and stability of the check dam decrease with the operation process, which increases the probability of dam failure during flood events and threatens local residents' life and property. Thus, this study simulated flood process of the check dam failure in the Wangmaogou watershed in Yulin City, Shaanxi Province, China, calculated different types of inundation losses based on the flood inundation area within the watershed, and determined the number of key flood protection check dams by classifying the flood risk levels of the check dams. The results showed that 5 dams in the watershed were subject to overtopping during different rainfall return periods, which was related to their flood discharge capacity. Dam failure flood process showed a rapid growth trend followed by slow decrease, and the time of flood peak advanced with increase in the return period. After harmonization of evaluation scales, the magnitude of flood inundation losses can be ranked as: economic losses(212.409 million yuan) > life losses(10.368 million yuan) > ecological losses(6.433 million yuan). The risk value for both individual dams and the whole dam system decreases as the return period increases. The number of key flood protection check dams in the Wangmaogou watershed was 2, 3, 3, 3, 4, and 5 for floods with return periods of 10, 20, 30, 50, 100, and 200 years, respectively. The results provided a theoretical basis for the safe operation and risk evaluation of check dams in the Loess Plateau Hills watershed.
  • Unloading damage patterns of rock slopes in open pit mines and analyses of their mechanisms
    WANG Jian-ming, ZHOU Zi-han, DOU Wei, CHEN Zhong-hui
    2023, 20(12): 3648-3664.
      可视化   收藏
    The stability of slopes is essential for ensuring safe production in open-pit mines. Analyzing and managing the deformation and failure of the slope rock mass becomes more challenging as the slope height increases. To investigate the damage patterns of slopes with varying heights, three slope models were developed based on a rock slope in Dagushan, China. The deformation failure processes of slopes under the influence of excavation and unloading were analyzed using the base friction test method in combination with digital image technology contrasting. The results supported the following findings:(1) Unloading tensile stress caused lateral partitioning in the slope. Both the foot and top of the slope underwent initial tensile cracks.(2) The destabilization mechanism of unloading deformation in slopes of different heights involved a combination of traction at the foot of the slope or pushing at the top of the slope, followed by accelerated deformation, deceleration creep, and overall destabilization.(3) The unloading damage patterns of slopes at different heights were summarized as follows: compression tension cracking, traction, and slip damage for medium and low slopes; compression tension cracking, traction, and slip failure for the upper part of high slopes; and relaxation tension cracking, pushing, traction, and slip failure for the lower part. Moreover, the upper part of ultra-high slopes exhibited compression tension cracking, traction, and slip failure, while the middle and lower parts displayed relaxation tension cracking, pushing, traction, and slip patterns. Finally, numerical simulations were conducted to verify the results of the test analyses, which demonstrated good consistency. These research results were of great engineering value for proposing effective safety management measures for high slopes.
  • GIS-based flash flooding susceptibility analysis and water management in arid mountain ranges: Safaga Region, Red Sea Mountains, Egypt
    Ahmed E. EL-RAYES, Mohamed O. ARNOUS, Ahmed M. HELMY
    2023, 20(12): 3665-3686.
      可视化   收藏
    The Safaga Region(SR) is part of the Red Sea mountain range in Egypt. Catastrophic flash flooding is now an inescapable event, wreaking havoc and causing massive loss of life and property. The majority of the floodwater, however, has been wasted as runoff to the Red Sea, which, if used wisely, could meet a fraction of the water demands for a variety of applications in this area. The current work aims to use GIS techniques to integrate remote sensing data for evaluating, mitigating, and managing flash floods in SR. The data set comprised Tropical Rainfall Measuring Mission(TRMM) thematic rainfall data, 1:50,000 scale topographical map sheets, geological maps, the ASTER Digital Elevation Model(ASTER GDEM), Landsat 7 Enhanced Thematic Mapper"(ETM7+), and Landsat 8 Operational Land Imager. The flash flood risk model of SR is developed using ArcGIS-10.3 geoprocessing tools integrating all the causal factors thematic maps. The final flood risk model for the SR suggests that 57% of the total basins in the SR are at high risk of flooding. Almost 38% of all basins are at moderate flood risk. The remaining 5% of basins are less prone to flooding. Flood-prone zones were identified, suitable dam-building sites were located, and extremely probable areas for water recharge were recognized. On the basis of reliable scientific data, structural and non-structural mitigation strategies that might reduce the damage susceptibility, alleviate the sensitivity of the flash flood, and best utilize its water supply were recommended.
  • Impact of glacier changes and permafrost distribution on debris flows in Badswat and Shishkat catchments, Northern Pakistan
    HASSAN Wajid, SU Feng-huan, LIU Wei-ming, HASSAN Javed, HASSAN Muzammil, BAZAI Nazir Ahmed, WANG Hao, YANG Ze-wen, ALI Muzaffar, CASTELLANOS Daniel Garcia
    2023, 20(12): 3687-3702.
      可视化   收藏
    Knowledge of glacier changes and associated hazards is of great importance for the safety consideration of the population and infrastructure in the mountainous regions of Upper Indus Basin(UIB).In this study, we assessed the variations in glacier velocity, glacier surface elevation change, meteorological conditions, and permafrost distribution in Badswat and Shishkat catchments located in UIB to access the potential impact on the occurrence of debris flow in both catchments. We find that the glacier surface velocity increased during the debris flow event in the Badswat catchment and the mean daily temperature was 3.7℃ to 3.9℃ higher in most of the locations. The enhanced glacier surface elevation lowering period coincide with the rise in temperature during spring and autumn months between 2015 to 2019 in Badswat catchment. The source region of debris flow falls within the lower boundary of permafrost occurrence zone and lies below the 0℃ isotherm during late spring and summer months. In Shishkat catchment the 0℃ isotherm reaches above the debris flow source area during August and the glacier do not show any significant variations in velocity and surface elevation change. The debris flow source area is adjacent to the slow-moving rock glacier in Shishkat catchment while in Badswat catchment the debris flow initiated from the former glacier moraine. Both catchments are largely glacierized and thus sensitive to changes in climatic conditions and changes in the cryosphere response possess significant threats to the population downstream. Continuous monitoring of cryosphere-climate change in the region can contribute toward the improvement of disaster risk reduction and mitigation policies.
  • Behavior of traditional concrete dams and three-dimensional printed concrete dams under the debris flow impact
    MEREE Hani, YAN Shuai-xing, WANG Dong-po, BI Yu-zhang
    2023, 20(12): 3703-3717.
      可视化   收藏
    This study investigated the resilience of traditional concrete dams compared to 3D printed concrete dams(3DPC) when subjected to debris flow. Three types of dams, namely check dams, arch dams, and curve dams, were numerically analyzed using a three-dimensional Coupled Eulerian-Lagrangian(CEL) methodology. The research focused on critical factors such as impact force and viscous energy dissipation to compare dam performance. Additionally, the study examined the printing and service phases of 3DPC models, determining potential failure modes and analyzing printing parameters. The results demonstrated that 3DPC dams outperformed traditional concrete dams, with filament deposition orientation, perpendicular to the debris flow direction, identified as a pivotal factor. Infill percentage and pattern were also found to influence the behavior of 3DPC models. Notably, curved dams exhibited superior performance based on dam geometry. These findings have significant potential for advancing the development of resilient dam structures capable of withstanding debris flow impacts.
  • A method to predict the peak shear strength of rock joints based on machine learning
    BAN Li-ren, ZHU Chun, HOU Yu-hang, DU Wei-sheng, QI Cheng-zhi, LU Chun-sheng
    2023, 20(12): 3718-3731.
      可视化   收藏
    In geotechnical and tunneling engineering, accurately determining the mechanical properties of jointed rock holds great significance for project safety assessments. Peak shear strength(PSS), being the paramount mechanical property of joints, has been a focal point in the research field. There are limitations in the current peak shear strength(PSS) prediction models for jointed rock:(i) the models do not comprehensively consider various influencing factors, and a PSS prediction model covering seven factors has not been established, including the sampling interval of the joints, the surface roughness of the joints, the normal stress, the basic friction angle, the uniaxial tensile strength, the uniaxial compressive strength, and the joint size for coupled joints;(ii) the datasets used to train the models are relatively limited; and(iii) there is a controversy regarding whether compressive or tensile strength should be used as the strength term among the influencing factors. To overcome these limitations, we developed four machine learning models covering these seven influencing factors, three relying on Support Vector Regression(SVR) with different kernel functions(linear, polynomial, and Radial Basis Function(RBF)) and one using deep learning(DL). Based on these seven influencing factors, we compiled a dataset comprising the outcomes of 493 published direct shear tests for the training and validation of these four models. We compared the prediction performance of these four machine learning models with Tang's and Tatone's models. The prediction errors of Tang's and Tatone's models are 21.8% and 17.7%, respectively, while SVR＿linear is at 16.6%, SVR＿poly is at 14.0%, and SVR＿RBF is at 12.1%.DL outperforms the two existing models with only an 8.5% error. Additionally, we performed shear tests on granite joints to validate the predictive capability of the DL-based model. With the DL approach, the results suggest that uniaxial tensile strength is recommended as the material strength term in the PSS model for more reliable outcomes.
  • Performance comparison of training algorithms for the estimation of B?hme abrasion resistance using neural networks
    Ali Can OZDEMIR, Esma KAHRAMAN
    2023, 20(12): 3732-3742.
      可视化   收藏
    Natural stones used as floor and wall coverings are exposed to many different abrasive forces, so it is essential to choose suitable materials for wear resistance in terms of the life of the structure. The abrasion resistance of natural stones can be determined in the laboratory by applying the B?hme abrasion resistance(BAR) test. However, the direct analysis of BAR in the laboratory has disadvantages such as wasting time and energy, experimental errors, and health impacts. To eliminate these disadvantages, the estimation of BAR using artificial neural networks(ANN) was proposed. Different natural stone samples were collected from Türkiye, and uniaxial compressive strength(UCS), flexural strength(FS), water absorption rate(WA), unit volume weight(UW), effective porosity(n), and BAR tests were carried out. The outputs of these tests were gathered and a data set, consisting of a total of 105 data, was randomly divided into two groups: testing and training. In the current study, the success of three different training algorithms of Levenberg-Marquardt(LM), Bayesian regularization(BR), and scaled conjugate gradient(SCG) were compared for BAR prediction of natural stones. Statistical criteria such as coefficient of determination(R~2), mean square error(MSE), mean square error(RMSE), and mean absolute percentage error(MAPE), which are widely used and adopted in the literature, were used to determine predictive validity. The findings of the study indicated that ANN is a valid method for estimating the BAR value. Also, the LM algorithm(R~2 = 0.9999, MSE= 0.0001, RMSE= 0.0110, and MAPE= 0.0487) in training and the BR algorithm(R~2 = 0.9896, MSE= 0.0589, RMSE= 0.2427, and MAPE= 1.2327) in testing showed the best prediction performance. It has been observed that the proposed method is quite practical to implement. Using the artificial neural networks method will provide an advantage in similar laborintensive experimental studies.