Scientific and precise evaluations of the megafaunal and landform characteristics of seamounts are important guides for their protection and study.A series of manned and unmanned submersibles have provided invaluable ...Scientific and precise evaluations of the megafaunal and landform characteristics of seamounts are important guides for their protection and study.A series of manned and unmanned submersibles have provided invaluable observational imaging data for the ecological study of seamounts.However,traditional methods of artificial observation of seamount imaging data cannot accurately and efficiently determine the characteristics of megafauna and landforms.This research harnesses data-driven technology to systematically investigate the distributional traits and morphological features of megafaunal organisms,as well as the topographical characteristics,in the Caiwei Guyot region of the western Pacific’s Magellan Seamounts.To construct the landform and megafauna dataset of the Caiwei Guyot region,we used a data preprocessing technology based on image enhancement to provide high-quality imaging data for data-driven technologies.A megafaunal identification and counting algorithm based on YOLOv5(You Only Look Once Version 5)was developed to efficiently assess the abundance,variety,and dominant species of megafauna.Simultaneously,a landform three-dimensional(3D)reconstruction algorithm based on PatchmatchNet was developed to reconstruct the 3D form of the terrain accurately.This study pioneers the application of data-driven technology to deep-sea imaging within the Caiwei Guyot region,offering an innovative approach to accurately and efficiently characterize the region’s unique megafauna and landforms.展开更多
Loess landforms in the Loess Plateau are typical landforms in arid and semiarid areas and have a significant impact on the environment and soil erosion.Quantitative analyses on loess landform have been employed from v...Loess landforms in the Loess Plateau are typical landforms in arid and semiarid areas and have a significant impact on the environment and soil erosion.Quantitative analyses on loess landform have been employed from various perspectives.Peak intervisibility can provide the potential topographic information implied in the visual connectivity of peaks,however,its application in loess landform analysis remains unexplored.In this study,the interwoven sightlines among peaks,representing peak intervisibility,were extracted from the digital elevation model and simulated into a peak intervisibility network(PIN).Nine indices were proposed to quantify the PIN.Through a case study in Northern Shaanxi,China,three tasks were conducted,including,landform interpretation,spatial pattern mining,and landform classification.The main findings are as follows:(1)PIN responds to terrain morphology and is beneficial for loess landform interpretation.(2)The spatial patterns of PIN indices are heterogeneous and strongly coupled with the terrain morphologies,showing anisotropy and autocorrelation in spatial variations.(3)Using the light gradient boost machine classifier,the PIN index-based classification reaches a mean accuracy of 86.09%,an overall accuracy of 86%and a kappa coefficient of 0.84.These findings shed light on the applicability of PIN in loess landform analysis.Peak intervisibility not only enriches the theories and methodologies of relation-based digital terrain analysis,but also enhances our comprehension of loess landform genesis,morphology,distribution,and evolution.展开更多
Jeju Island,Korea,was formed through volcanic activity from approximately 1.8 million to 1,000 years ago.The island was designated a Global Geopark in 2010 in recognition of its diverse geoheritage.As part of a specia...Jeju Island,Korea,was formed through volcanic activity from approximately 1.8 million to 1,000 years ago.The island was designated a Global Geopark in 2010 in recognition of its diverse geoheritage.As part of a special edition for the International Geological Congress 2024,this article shares the latest scholarship on Jeju’s volcanic geoheritage sites to enhance public understanding of the island’s geoheritage as earlier misconceptions continue to spread through books,websites,and information boards,etc.Despite long being interpreted as a typical shield volcano,for example,Mt.Hallasan has been recategorized as a polygenetic and composite volcano that formed through Strombolian eruptions,lava effusions,and magma intrusions from 200,000 to 17,000 years ago.Moreover,although once interpreted as a single scoria cone that formed a thousand years ago,Biyangdo Island(Biyangbong)formed through subaerial volcanic eruptions 26,000 years ago that produced both a scoria cone and a spatter cone.This research is presented with the latest research on other volcano-related Jeju Island Global Geopark geosites,including Suwolbong Tuff Cone and Seongsan Ilchulbong Tuff Ring.Alongside regular research and monitoring,public awareness is essential to ensure sustainable protection due to increasing rockfalls caused by rising sea levels at coastal geosites and climate changeexacerbated freeze-thaw weathering at inland sites on Mt.Hallasan.展开更多
Based on diverse landforms, the correlation between soil organic matter content and multi-spectral band of remote sensing image was analyzed in this pa- per. In addition, the inversion models were built for the soil o...Based on diverse landforms, the correlation between soil organic matter content and multi-spectral band of remote sensing image was analyzed in this pa- per. In addition, the inversion models were built for the soil organic matter content in different landforms. The results showed that the spectral reflectance was nega- tively related to soil organic matter content; linear regression analysis of remove was performed throughout the bands using SPSS. When the inversion models were built based on all the bands, better fitting effect was obtained. The precision of in- version models built based on different landforms was higher than those built re- gardless landforms. Compared with the actual value, the identification level of soil organic matter content was 91 65% under the allowable error was 7%. It indicated that the extraction of soil organic matter with inversion model that was built based on different landforrrs was feasible with higher precision.展开更多
Granites of the Mesozoic Era are widespread in South China,and many of them have been shaped into spectacular landscapes with high tourism development values.However,the controlling factors and evolution stages of the...Granites of the Mesozoic Era are widespread in South China,and many of them have been shaped into spectacular landscapes with high tourism development values.However,the controlling factors and evolution stages of these granite landscapes were poorly understood.In this study,the Hypsometric Integral curves(HIc),and Hypsometric Integral(HI)values of the Mount Wugong were extracted from digital elevation model data in a geographic information system environment.The relationships between the HIc,HI values,and factors including the tectonism,lithology and climate of the study area were analyzed to determine the evolution of granite landscapes evolution in the main scenic areas of the Mount Wugongshan.The HI values on the northwestern and southeastern slopes of the Mount Wugongshan range from 0.223 to 0.415 and 0.385 to 0.465,respectively;the HIc are mainly concave on the northwestern slopes and irregularly‘Sshaped’on the southeastern slopes.The main ridge of the granite geomorphic scenic area of the Mount Wugongshan,where the alpine meadow geomorphic landscape is located,is in the youthful stage of geomorphic evolution,the Mt.Jinding-Mt.Wanlong and Mt.Mingyue-Wentang scenic areas are in the old stage,and the Yangshimu scenic area is in the mature stage.Differences in watershed scale may be the main reason for the variabilities in geomorphic evolution in the area,while the regular development of tectonic phenomena is a key factor shaping the spatial variability in the watersheds on both sides of the main ridge.展开更多
Dunhuang Yardang National Geo-park, situated in the Gansu Province of northwestern China （40°25′36″N-40°33′10″N, 93°00′00″E-93°13′30″E）, was chosen as a research locality of aesthetics ev...Dunhuang Yardang National Geo-park, situated in the Gansu Province of northwestern China （40°25′36″N-40°33′10″N, 93°00′00″E-93°13′30″E）, was chosen as a research locality of aesthetics evaluation of yardang landforms landscape. The yardang landforms landscape is a composite structural system of patch-corridor-matrix, with four landscape unit elements as dense group, sparse group, single body and remnant. The study of the landscape aesthetics spatial pattern of Dunhuang Yardang National Geo-park shows that yardang dense group, sparse group and single body provide the greatest contribution to the aesthetic value of yardang landforms landscape. Yardang bodies are scarce, unique, irreplaceable, and priceless resources in yardang landforms areas. However, they are easily destroyed under the influence of the natural and artificial factors. Therefore, when the tourism potential of yardang landforms landscape is exploited, the protection should be fully improved.展开更多
The west block of the middle belt of TanLu fault belt is one of the areas where volcanic landforms are mainly distributed. This paper divides the volcanic landforms into four grades according to formation, morphology,...The west block of the middle belt of TanLu fault belt is one of the areas where volcanic landforms are mainly distributed. This paper divides the volcanic landforms into four grades according to formation, morphology, and ingredient of matter. Lava cones are divided into two types based on the force of top-support and the fluid form of magma: the arc-projecting type and spring-spilling type. Furthermore, the courses of development of volcanic landforms are divided into three stages according to the form and strength of volcanic activities.展开更多
A Danxia landform is a red-bed landform characterized by steep cliffs. It was initially discovered and named by Chinese scholars. Although there are red-bed landforms in many parts of the world, China, with a special ...A Danxia landform is a red-bed landform characterized by steep cliffs. It was initially discovered and named by Chinese scholars. Although there are red-bed landforms in many parts of the world, China, with a special fondness for the color red, boasts the most widely distributed Danxia possessing unique characteristics. This is a mesmerizing natural formation and a special gift that nature has bestowed upon this country.展开更多
Sedimentary environments in the Hangzhou Bay are introduced by a three-subregional landform pattern and a sedimentation map with six major sedimentation types. The geographic setting, sediment transportation and sedim...Sedimentary environments in the Hangzhou Bay are introduced by a three-subregional landform pattern and a sedimentation map with six major sedimentation types. The geographic setting, sediment transportation and sedimentation in different subregions are discussed with sediment grain parameters. Sedimentary basin suffering from effect of plume front can be identified by the fine sediments with median ( Mdφ ) 7φ-8φ, clay content 30% - 40% and silt 60% - 70%. Sediment transportation along the plume front seems not to be a direct effect on sedimentary formation of the shoals fringing the south coast of the Hangzhou Bay.展开更多
Wadi Qudaid is located in the west central part of Saudi Arabia. It about 135<span style="font-size:10pt;font-family:""> <span style="font-size:10pt;font-family:""><span st...Wadi Qudaid is located in the west central part of Saudi Arabia. It about 135<span style="font-size:10pt;font-family:""> <span style="font-size:10pt;font-family:""><span style="font-family:Verdana;font-size:12px;">km to the northeast of Jeddah city along Al Haramein highway and it represents the upstream of the very large alluvial plain along the Red Sea coast. It runs in NE direction parallel to many wadis of the west central part of Saudi Arabia <span style="font-family:Verdana;font-size:12px;">i.e.<span style="font-family:Verdana;font-size:12px;"> Wadi Fatima, wadi Sitarah. The wadi floor is filled by Quaternary deposits which represent good groundwater aquifer. Geologically, the present-day residual landforms of Wadi Qudaid are composed mainly of Precambrian Arabia shield rocks overlained by Tertiary sedimentary rocks and finally harrat (Tertiary volcanic). The Precambrian rocks are represented by 1) a lower layered basic and intermediate volcanic and the intercalated volcaniclastics. This unit is correlatable with Samran Group, 2) an upper layered acidic volcanic and the intercalated acidic volcaniclastics. The Arabian shield rocks are intensively folded and dragged along the major NE faults. They are directly overlain by Tertiary basic volcanic (harrat) and the related volcanoclastic red beds). The main geomorphologic elements of the <span style="font-family:Verdana;font-size:12px;">study area include plateau, scarps, and the wadi floor. The plateau is represented <span style="font-family:Verdana;font-size:12px;">by the black basaltic sheet that contains some semi-rounded depressions filled with Quaternary eolian sands. The scarps of the main wadi and its tributaries are nearly steep and contain many asphaltic roads with some isolated cone hills detached from the scarps. Geomorphological, Wadi Qudaid<span style="font-family:Verdana;font-size:12px;"> represents the incomplete erosion cycle that begins with the formation of deep galleries and very steep and narrow wadies formed along the major NE faults and related fractures and folds. The progress of the erosion processes led to the formation of narrow interfluves as a result of pedimentation and sculpturing of the wadies sides by scarp retreat. The peniplanation stages of the erosion cycles are reached in the southwestern and the central part of the wadi where fast peniplained areas were formed. The results of this study revealed the role of the different geological processes (lithology, structural elements and climatic conditions) in the distribution of present-day human populations in urban extensions. Qudaid, Dhubaya-Jumah, Dabyah, Al Khamrah, Almansa and Al<span style="font-size:10pt;font-family:""> <span style="font-family:Verdana;">Massamah are the main villages of Wadi Qudaid area.展开更多
The automatic recognition of landforms is regarded as one of the most important procedures to classify landforms and deepen the understanding on the morphology of the earth. However, landform types are rather complex ...The automatic recognition of landforms is regarded as one of the most important procedures to classify landforms and deepen the understanding on the morphology of the earth. However, landform types are rather complex and gradual changes often occur in these landforms, thus increasing the difficulty in automatically recognizing and classifying landforms. In this study, small-scale watersheds, which are regarded as natural geomorphological elements, were extracted and selected as basic analysis and recognition units based on the data of SRTM DEM. In addition, datasets integrated with terrain derivatives(e.g., average slope gradient, and elevation range) and texture derivatives(e.g., slope gradient contrast and elevation variance) were constructed to quantify the topographical characteristics of watersheds. Finally, Random Forest(RF) method was employed to automatically select features and classify landforms based on their topographical characteristics. The proposed method was applied and validated in seven case areas in the Northern Shaanxi Loess Plateau for its complex andgradual changed landforms. Experimental results show that the highest recognition accuracy based on the selected derivations is 92.06%. During the recognition procedure, the contributions of terrain derivations were higher than that of texture derivations within selected derivative datasets. Loess terrace and loess mid-mountain obtained the highest accuracy among the seven typical loess landforms. However, the recognition precision of loess hill, loess hill–ridge, and loess sloping ridge is relatively low. The experiment also shows that watershed-based strategy could achieve better results than object-based strategy, and the method of RF could effectively extract and recognize the feature of landforms.展开更多
A field investigation on Quaternary glacial landforms in Laoshan Motmtain has discovered many glacial potholes, scouring grooves on top of granite ridges, and large boulders. These erosional landforms were formed by t...A field investigation on Quaternary glacial landforms in Laoshan Motmtain has discovered many glacial potholes, scouring grooves on top of granite ridges, and large boulders. These erosional landforms were formed by the meltwater from the overlying ice cap, suggesting that there was at least an ice cap covering Laoshan Mountain and the surrounding areas or even a continental ice sheet over the vast area of Shandong Province in the Late Pleistocene. The ice sheet was obstructed by the Laoshan Mountain, Dazhu Mountain and Xiaozhu Mountain in the coastal areas as it moved toward the Yellow Sea. The ice flows eroded the bedrock and carved the weak intersection of the fault systems in the NE and NW directions into a deep channel, which gradually formed a fjord in the area of the Jiaozhou Bay basin by 20.00 ka BE The seawater gradually invaded the fjord from the beginning of the Holocene （11.00 ka BP） and Jiaozhou Bay was eventually formed. Similar fjords are easily found along the east of China and they share a similar origin because of the Quaternary glaciation in the region.展开更多
Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical m...Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical movement of earth surface, while published research results on Chinese granite landforms are very rare, especially in international journals. Based on the process analysis of chemical weathering and physical disintegration, four granite landform regions in China are classified according to the present climate regime. On the Tibetan Plateau, the cold and freezing climate induced periglacial landscapes; the northeast region is characterized by physical disintegration and low round mounds are widespread; in the northwest region controlled by arid climate, wind-carved minor landscapes are extremely prominent. The most spectacular granite landscapes in China are presented in southeast as a result of Iongtime chemical weathering under humid and warm conditions, as well as the differential uplift after Neogene. Correlating the weathering crust in southern China, Tibetan Plateau and India, a possible unified planation surface in Neogene is proposed. With corestones as indicators of original weathering front, the differential uplift extent of dissected planation surfaces can be estimated. At least three landforms implying uplift can be identified in southeastern China, with elevations of 300-400 m, 2000 m and 3600 m above the sea level respectively.展开更多
Danxia geomorphology originates fi＇om China. This paper studies the spatial distribution and differences in characteristics of Danxia landforms. Based on relevant research and investigations, three congregated areas ...Danxia geomorphology originates fi＇om China. This paper studies the spatial distribution and differences in characteristics of Danxia landforms. Based on relevant research and investigations, three congregated areas of Danxia landform in China are discussed in this paper. They are the southeast area （including Jiangxi, Fujian, Zhejiang, Hunan and Guangxi provinces）, the southwest area （the transitional zone of Yunnan-Guizhou Plateau and Sichuan Basin） and the northwest area （including Longshan mountain and along the banks of the Huanghe River and its anabranches）. Not only the conditions of geology and geography of the three areas but also the differences of Danxia landforms of the three areas are analyzed. The Danxia landscape, characterized by upright-shaped peaks, Danxia mesa, stone wall, cave and vertical cave, ＂Danxia natural bridge＂, ＂a narrow strip of sky＂ and so on, often presents in the southeast area. The landscape of southwest area is characterized by Danxia escarpment faces and waterfalls. In the northwest area, the Danxia landscape has the traits of arid areas simultaneously, for example, mud-coating type, columniation type, board type, moreover, it is greatly different between these environmental factors such as the microclimate, water, wind, and the loess cover. Finally it explores the causes which lead differences in landform and also explains the landform formation process and its mechanism with reference to the rates of crustal uplift, the tectonic red-basin, and the external processes including working of running water, weathering, biogenic, gravity in each area of Danxia Landforms in China.展开更多
Threshold is a limit and marginal point when a qualitative change takes place. Since threshold principle was firstly used in landform research by S.A.Schumm in the 1970s, the quantitative research on watershed landfor...Threshold is a limit and marginal point when a qualitative change takes place. Since threshold principle was firstly used in landform research by S.A.Schumm in the 1970s, the quantitative research on watershed landform development stage has come true. Davis proposed a three-stage model on landform evolution: young, mature and old stages. Thereafter Strahler quantified this model by hypsometric analysis method. The authors thought that the material movement stage cannot be expressed by hypsometric method in watershed landform at development stage, because of the uncertainty on stage delimitation. To meet this shortcoming, this paper presents an integral erosion value method. A clear delimitation on landform development stage in the Loess Plateau region has been tested by this method. The result shows that gullied loessial hilly area is at the mature stage, and gullied loessial tableland area is at the young stage. It is estimated that from the point of erosion related sediment yield, natural erosion accounts for 70% of the total erosion amount, and artificial accelerating erosion is 30%. Therefore soil and water conservation is very crucial for the Loess Plateau.展开更多
The history of dune landform changes and dust activity at mid-latitudes is a good archive for exploring environmental changes and related landscape response.In this study,the dynamic changes,material sources,dust acti...The history of dune landform changes and dust activity at mid-latitudes is a good archive for exploring environmental changes and related landscape response.In this study,the dynamic changes,material sources,dust activity history and the influencing factors of typical sand dunes in the Hexi Corridor were comprehensively analyzed from the aspects of aeolian geomorphology,grain-size sedimentology,geochemistry and climatology.The results show that in the past half century,the typical crescent-shaped dunes and chains of crescent-shaped dunes in the study area have moved or swayed greatly,with an average speed ranging from 0.8 m/a(Dunhuang)to 6.2 m/a(Minqin).The dynamic changes of sand dunes are mainly affected by annual precipitation,annual average wind speed and annual gale days,which indicates that climate is the primary influencing factor of dune landform changes.The three-stage grain-size curve model of dune sands is obviously different from that of gobi sediments(two-stage),revealing the“immaturity”of the latter in sedimentology,while the former has experienced efficiently aeolian differentiation and non-local origin.The comprehensive evidences of paleogeography,sedimentology and geochemistry reveal that the source materials of sand dunes are mainly alluvial/proluvial and palaeo-fluvial sediments,including clastic sediments in the denudation/erosion zones of the north and south piedmonts.Indicators such as the proportion of surface fine particles,the coverage of surface salt crusts,and the content of erodible sandy materials indicate that the western gobi areas are not the main source areas of wind-blown dust in the central and eastern parts of the Hexi Corridor.The spatial distribution of the movement direction of sand dunes is similar to that of the regional dominant wind direction,which indicates that the difference in the dynamic evolution of dune landforms between the east and west of the Hexi Corridor should be controlled by the regional-scale wind system,that is,controlled by the dynamic mechanism rather than the difference in material sources.The warming and humidification of the Hexi climate is a synchronous response to the global warming and the strengthening of the Asian Summer Monsoon.It is also the main reason for the reduction of dust storms in the study area,which means that a potential inverse desertification process exists in the Hexi Corridor during the same period and it is also controlled by climate change.However,the process of desertification in the oasis areas during the period is caused by groundwater fluctuation affected by human activities.展开更多
Mt.Ma'an (4288 m) is the highest mountain in the southwest edge of Sichuan Basin. It is situated to the south of the Dadu River. The geographic coordinates are: 28°58′N, 102°55′E. There are six peaks ...Mt.Ma'an (4288 m) is the highest mountain in the southwest edge of Sichuan Basin. It is situated to the south of the Dadu River. The geographic coordinates are: 28°58′N, 102°55′E. There are six peaks over 4000 m in elevation. Many quaternary glacial landforms in this mountain have been discovered. It's a typical example of fossil glacial landform in the east China. Its glacial stages are the last glaciation (Q 3 3) and the neoglaciation (Q 3 4). Mt. Ma'an and Mt. Luoji (4359 m) are similar in the fossil glacial landforms, but there are still some differences between them. For example, the ratio between the direct difference and the minus difference is different.展开更多
The science of geomorphology works on natural 3D landforms.Research includes the change of landforms as well as the processes causing these changes.Material transport processes lead to a composition of a geomorphic sy...The science of geomorphology works on natural 3D landforms.Research includes the change of landforms as well as the processes causing these changes.Material transport processes lead to a composition of a geomorphic system that follows a certain spatial hierarchy.The analysis of 3D topological relations of landforms can help to investigate geomorphic systems in two ways.First,chronological order of geomorphic genesis can be derived and,second,indications of material source can be found.However,at least some 3D geometric information is needed if topology is supposed to be derived and examined.Landforms cannot simply be reconstructed by surface measurements.Data capture is a major problem when buried features are under investigation.Subsurface information is gathered by drillings or geophysical methods that reveal point or line information.Unfortunately,the ISO 19107 Spatial Schema does not offer a valid representation of 3D geometry from sparse data,either by aggregating a surface and one or few points or by aggregating a surface and a line.Here,we discuss the possibilities for the analysis of chronological order of landform genesis and material dependencies that arise from applying 3D topological relationships to geomorphic system analysis.We show five relationships that are able to be observed in nature.Further,we introduce a new class for the representation of 3D objects with under-specified geometry.A_UG_Solid mediates between the Spatial Schema’s geometric primitives with a dimension less than three on the one side and a GM_Solid on the other side.Constraints to aggregate such a_UG_Solid are defined.The introduction of a_UG_Solid facilitates the application of 3D topological concepts to geometric objects that are known to be volumetric but have to be modeled from sparse data.展开更多
The research selected five indices to measure fragmentation degrees of three landforms with GIS and analyzed the relationship with production profits of arable lands. The results showed that fragmentation degree of ar...The research selected five indices to measure fragmentation degrees of three landforms with GIS and analyzed the relationship with production profits of arable lands. The results showed that fragmentation degree of arable lands tends to be volatile upon landforms, For example, the fragmentation degree of mountainous area reached 0.985, followed by hills of 0.705 and the fragmentation degree of plains was the least at 0.068. Production profits of arable lands were negatively correlated with arable landscape fragmentation. Hence, it is necessary to take measures to reduce landscape fragmentation as per specific local circumstances to imorove production Drofits.展开更多
Check dams have been used worldwide for a variety of purposes.With increasing age,check dams gradually lose their sediment trapping function via the continuous deposition of material carried by debris flows and flash ...Check dams have been used worldwide for a variety of purposes.With increasing age,check dams gradually lose their sediment trapping function via the continuous deposition of material carried by debris flows and flash floods,and eventually,check dams become unable to perform the designed mitigation function.In this paper,the sediment deposit evolution in a dam with multiple debris flow surges and its influence on the sediment trapping effect were investigated.The results showed that the debris flow deposition process can be divided into three phases:the backwater-controlled deposition phase,landform-controlled deposition phase,and quasi-equilibrium phase.The sediment trapping ratio of the check dam gradually decreased as the deposit volume increased and was linearly negatively correlated with the sediment deposition rate.Moreover,a mathematical model describing the negative feedback between deposit volume and sediment trapping ratio was established,and the physical meanings of the coefficients in the model and their empirical values were clarified.Furthermore,the deposit distribution,which satisfied the Weibull distribution in the longitudinal direction,was revealed.In the cross-sectional direction,the distribution of deposition gradually became uneven with increasing sediment filling rate.展开更多
基金The Key Research and Development Program of Shandong Province of China under contract No.2020JMRH0101the National Key Research and Development Project of China under contract No.2021YFC2802100the Qingdao Natural Science Foundation under contract No.24-4-4-zrij-127-jch.
文摘Scientific and precise evaluations of the megafaunal and landform characteristics of seamounts are important guides for their protection and study.A series of manned and unmanned submersibles have provided invaluable observational imaging data for the ecological study of seamounts.However,traditional methods of artificial observation of seamount imaging data cannot accurately and efficiently determine the characteristics of megafauna and landforms.This research harnesses data-driven technology to systematically investigate the distributional traits and morphological features of megafaunal organisms,as well as the topographical characteristics,in the Caiwei Guyot region of the western Pacific’s Magellan Seamounts.To construct the landform and megafauna dataset of the Caiwei Guyot region,we used a data preprocessing technology based on image enhancement to provide high-quality imaging data for data-driven technologies.A megafaunal identification and counting algorithm based on YOLOv5(You Only Look Once Version 5)was developed to efficiently assess the abundance,variety,and dominant species of megafauna.Simultaneously,a landform three-dimensional(3D)reconstruction algorithm based on PatchmatchNet was developed to reconstruct the 3D form of the terrain accurately.This study pioneers the application of data-driven technology to deep-sea imaging within the Caiwei Guyot region,offering an innovative approach to accurately and efficiently characterize the region’s unique megafauna and landforms.
基金supported by the National Natural Science Foundation of China(Grant No.41771423)the Natural Science Foundation of Fujian Province(Grant No.2023J01421).
文摘Loess landforms in the Loess Plateau are typical landforms in arid and semiarid areas and have a significant impact on the environment and soil erosion.Quantitative analyses on loess landform have been employed from various perspectives.Peak intervisibility can provide the potential topographic information implied in the visual connectivity of peaks,however,its application in loess landform analysis remains unexplored.In this study,the interwoven sightlines among peaks,representing peak intervisibility,were extracted from the digital elevation model and simulated into a peak intervisibility network(PIN).Nine indices were proposed to quantify the PIN.Through a case study in Northern Shaanxi,China,three tasks were conducted,including,landform interpretation,spatial pattern mining,and landform classification.The main findings are as follows:(1)PIN responds to terrain morphology and is beneficial for loess landform interpretation.(2)The spatial patterns of PIN indices are heterogeneous and strongly coupled with the terrain morphologies,showing anisotropy and autocorrelation in spatial variations.(3)Using the light gradient boost machine classifier,the PIN index-based classification reaches a mean accuracy of 86.09%,an overall accuracy of 86%and a kappa coefficient of 0.84.These findings shed light on the applicability of PIN in loess landform analysis.Peak intervisibility not only enriches the theories and methodologies of relation-based digital terrain analysis,but also enhances our comprehension of loess landform genesis,morphology,distribution,and evolution.
基金supported by the Jeju World Heritage Office of Jeju Special Self-Governing Province.
文摘Jeju Island,Korea,was formed through volcanic activity from approximately 1.8 million to 1,000 years ago.The island was designated a Global Geopark in 2010 in recognition of its diverse geoheritage.As part of a special edition for the International Geological Congress 2024,this article shares the latest scholarship on Jeju’s volcanic geoheritage sites to enhance public understanding of the island’s geoheritage as earlier misconceptions continue to spread through books,websites,and information boards,etc.Despite long being interpreted as a typical shield volcano,for example,Mt.Hallasan has been recategorized as a polygenetic and composite volcano that formed through Strombolian eruptions,lava effusions,and magma intrusions from 200,000 to 17,000 years ago.Moreover,although once interpreted as a single scoria cone that formed a thousand years ago,Biyangdo Island(Biyangbong)formed through subaerial volcanic eruptions 26,000 years ago that produced both a scoria cone and a spatter cone.This research is presented with the latest research on other volcano-related Jeju Island Global Geopark geosites,including Suwolbong Tuff Cone and Seongsan Ilchulbong Tuff Ring.Alongside regular research and monitoring,public awareness is essential to ensure sustainable protection due to increasing rockfalls caused by rising sea levels at coastal geosites and climate changeexacerbated freeze-thaw weathering at inland sites on Mt.Hallasan.
文摘Based on diverse landforms, the correlation between soil organic matter content and multi-spectral band of remote sensing image was analyzed in this pa- per. In addition, the inversion models were built for the soil organic matter content in different landforms. The results showed that the spectral reflectance was nega- tively related to soil organic matter content; linear regression analysis of remove was performed throughout the bands using SPSS. When the inversion models were built based on all the bands, better fitting effect was obtained. The precision of in- version models built based on different landforms was higher than those built re- gardless landforms. Compared with the actual value, the identification level of soil organic matter content was 91 65% under the allowable error was 7%. It indicated that the extraction of soil organic matter with inversion model that was built based on different landforrrs was feasible with higher precision.
基金supported by the Doctoral Scientific Research Foundation of East China University of Technology(Grant No.DHBK2019005)the Postdoctoral Research Foundation of the Geological Survey of Jiangxi Province(Grant No.202020)。
文摘Granites of the Mesozoic Era are widespread in South China,and many of them have been shaped into spectacular landscapes with high tourism development values.However,the controlling factors and evolution stages of these granite landscapes were poorly understood.In this study,the Hypsometric Integral curves(HIc),and Hypsometric Integral(HI)values of the Mount Wugong were extracted from digital elevation model data in a geographic information system environment.The relationships between the HIc,HI values,and factors including the tectonism,lithology and climate of the study area were analyzed to determine the evolution of granite landscapes evolution in the main scenic areas of the Mount Wugongshan.The HI values on the northwestern and southeastern slopes of the Mount Wugongshan range from 0.223 to 0.415 and 0.385 to 0.465,respectively;the HIc are mainly concave on the northwestern slopes and irregularly‘Sshaped’on the southeastern slopes.The main ridge of the granite geomorphic scenic area of the Mount Wugongshan,where the alpine meadow geomorphic landscape is located,is in the youthful stage of geomorphic evolution,the Mt.Jinding-Mt.Wanlong and Mt.Mingyue-Wentang scenic areas are in the old stage,and the Yangshimu scenic area is in the mature stage.Differences in watershed scale may be the main reason for the variabilities in geomorphic evolution in the area,while the regular development of tectonic phenomena is a key factor shaping the spatial variability in the watersheds on both sides of the main ridge.
基金supported by fund project from professor for "Yangtze River Scholar" of the Ministry of Education(No.801813)
文摘Dunhuang Yardang National Geo-park, situated in the Gansu Province of northwestern China （40°25′36″N-40°33′10″N, 93°00′00″E-93°13′30″E）, was chosen as a research locality of aesthetics evaluation of yardang landforms landscape. The yardang landforms landscape is a composite structural system of patch-corridor-matrix, with four landscape unit elements as dense group, sparse group, single body and remnant. The study of the landscape aesthetics spatial pattern of Dunhuang Yardang National Geo-park shows that yardang dense group, sparse group and single body provide the greatest contribution to the aesthetic value of yardang landforms landscape. Yardang bodies are scarce, unique, irreplaceable, and priceless resources in yardang landforms areas. However, they are easily destroyed under the influence of the natural and artificial factors. Therefore, when the tourism potential of yardang landforms landscape is exploited, the protection should be fully improved.
文摘The west block of the middle belt of TanLu fault belt is one of the areas where volcanic landforms are mainly distributed. This paper divides the volcanic landforms into four grades according to formation, morphology, and ingredient of matter. Lava cones are divided into two types based on the force of top-support and the fluid form of magma: the arc-projecting type and spring-spilling type. Furthermore, the courses of development of volcanic landforms are divided into three stages according to the form and strength of volcanic activities.
文摘A Danxia landform is a red-bed landform characterized by steep cliffs. It was initially discovered and named by Chinese scholars. Although there are red-bed landforms in many parts of the world, China, with a special fondness for the color red, boasts the most widely distributed Danxia possessing unique characteristics. This is a mesmerizing natural formation and a special gift that nature has bestowed upon this country.
基金This work is supported by both Grant-4860244 from the National Natural Science Foundation of China and Grant-188011 from the Zhejiang Provincial Natural Science Foundation
文摘Sedimentary environments in the Hangzhou Bay are introduced by a three-subregional landform pattern and a sedimentation map with six major sedimentation types. The geographic setting, sediment transportation and sedimentation in different subregions are discussed with sediment grain parameters. Sedimentary basin suffering from effect of plume front can be identified by the fine sediments with median ( Mdφ ) 7φ-8φ, clay content 30% - 40% and silt 60% - 70%. Sediment transportation along the plume front seems not to be a direct effect on sedimentary formation of the shoals fringing the south coast of the Hangzhou Bay.
文摘Wadi Qudaid is located in the west central part of Saudi Arabia. It about 135<span style="font-size:10pt;font-family:""> <span style="font-size:10pt;font-family:""><span style="font-family:Verdana;font-size:12px;">km to the northeast of Jeddah city along Al Haramein highway and it represents the upstream of the very large alluvial plain along the Red Sea coast. It runs in NE direction parallel to many wadis of the west central part of Saudi Arabia <span style="font-family:Verdana;font-size:12px;">i.e.<span style="font-family:Verdana;font-size:12px;"> Wadi Fatima, wadi Sitarah. The wadi floor is filled by Quaternary deposits which represent good groundwater aquifer. Geologically, the present-day residual landforms of Wadi Qudaid are composed mainly of Precambrian Arabia shield rocks overlained by Tertiary sedimentary rocks and finally harrat (Tertiary volcanic). The Precambrian rocks are represented by 1) a lower layered basic and intermediate volcanic and the intercalated volcaniclastics. This unit is correlatable with Samran Group, 2) an upper layered acidic volcanic and the intercalated acidic volcaniclastics. The Arabian shield rocks are intensively folded and dragged along the major NE faults. They are directly overlain by Tertiary basic volcanic (harrat) and the related volcanoclastic red beds). The main geomorphologic elements of the <span style="font-family:Verdana;font-size:12px;">study area include plateau, scarps, and the wadi floor. The plateau is represented <span style="font-family:Verdana;font-size:12px;">by the black basaltic sheet that contains some semi-rounded depressions filled with Quaternary eolian sands. The scarps of the main wadi and its tributaries are nearly steep and contain many asphaltic roads with some isolated cone hills detached from the scarps. Geomorphological, Wadi Qudaid<span style="font-family:Verdana;font-size:12px;"> represents the incomplete erosion cycle that begins with the formation of deep galleries and very steep and narrow wadies formed along the major NE faults and related fractures and folds. The progress of the erosion processes led to the formation of narrow interfluves as a result of pedimentation and sculpturing of the wadies sides by scarp retreat. The peniplanation stages of the erosion cycles are reached in the southwestern and the central part of the wadi where fast peniplained areas were formed. The results of this study revealed the role of the different geological processes (lithology, structural elements and climatic conditions) in the distribution of present-day human populations in urban extensions. Qudaid, Dhubaya-Jumah, Dabyah, Al Khamrah, Almansa and Al<span style="font-size:10pt;font-family:""> <span style="font-family:Verdana;">Massamah are the main villages of Wadi Qudaid area.
基金supported by the National Natural Science Foundation of China (Grant NOs. 41601411, 41571398, 41671389)the Priority Academic Program Development of Jiangsu Higher Education Institutions-PAPD (Grant No.164320H101)
文摘The automatic recognition of landforms is regarded as one of the most important procedures to classify landforms and deepen the understanding on the morphology of the earth. However, landform types are rather complex and gradual changes often occur in these landforms, thus increasing the difficulty in automatically recognizing and classifying landforms. In this study, small-scale watersheds, which are regarded as natural geomorphological elements, were extracted and selected as basic analysis and recognition units based on the data of SRTM DEM. In addition, datasets integrated with terrain derivatives(e.g., average slope gradient, and elevation range) and texture derivatives(e.g., slope gradient contrast and elevation variance) were constructed to quantify the topographical characteristics of watersheds. Finally, Random Forest(RF) method was employed to automatically select features and classify landforms based on their topographical characteristics. The proposed method was applied and validated in seven case areas in the Northern Shaanxi Loess Plateau for its complex andgradual changed landforms. Experimental results show that the highest recognition accuracy based on the selected derivations is 92.06%. During the recognition procedure, the contributions of terrain derivations were higher than that of texture derivations within selected derivative datasets. Loess terrace and loess mid-mountain obtained the highest accuracy among the seven typical loess landforms. However, the recognition precision of loess hill, loess hill–ridge, and loess sloping ridge is relatively low. The experiment also shows that watershed-based strategy could achieve better results than object-based strategy, and the method of RF could effectively extract and recognize the feature of landforms.
基金Doctorate Research Program of China University of Petroleum (No. Y020109)
文摘A field investigation on Quaternary glacial landforms in Laoshan Motmtain has discovered many glacial potholes, scouring grooves on top of granite ridges, and large boulders. These erosional landforms were formed by the meltwater from the overlying ice cap, suggesting that there was at least an ice cap covering Laoshan Mountain and the surrounding areas or even a continental ice sheet over the vast area of Shandong Province in the Late Pleistocene. The ice sheet was obstructed by the Laoshan Mountain, Dazhu Mountain and Xiaozhu Mountain in the coastal areas as it moved toward the Yellow Sea. The ice flows eroded the bedrock and carved the weak intersection of the fault systems in the NE and NW directions into a deep channel, which gradually formed a fjord in the area of the Jiaozhou Bay basin by 20.00 ka BE The seawater gradually invaded the fjord from the beginning of the Holocene （11.00 ka BP） and Jiaozhou Bay was eventually formed. Similar fjords are easily found along the east of China and they share a similar origin because of the Quaternary glaciation in the region.
基金National Natural Science Foundation of China, No.40701017
文摘Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical movement of earth surface, while published research results on Chinese granite landforms are very rare, especially in international journals. Based on the process analysis of chemical weathering and physical disintegration, four granite landform regions in China are classified according to the present climate regime. On the Tibetan Plateau, the cold and freezing climate induced periglacial landscapes; the northeast region is characterized by physical disintegration and low round mounds are widespread; in the northwest region controlled by arid climate, wind-carved minor landscapes are extremely prominent. The most spectacular granite landscapes in China are presented in southeast as a result of Iongtime chemical weathering under humid and warm conditions, as well as the differential uplift after Neogene. Correlating the weathering crust in southern China, Tibetan Plateau and India, a possible unified planation surface in Neogene is proposed. With corestones as indicators of original weathering front, the differential uplift extent of dissected planation surfaces can be estimated. At least three landforms implying uplift can be identified in southeastern China, with elevations of 300-400 m, 2000 m and 3600 m above the sea level respectively.
基金N ationalN aturalScience Foundation ofChina,N o.48970006
文摘Danxia geomorphology originates fi＇om China. This paper studies the spatial distribution and differences in characteristics of Danxia landforms. Based on relevant research and investigations, three congregated areas of Danxia landform in China are discussed in this paper. They are the southeast area （including Jiangxi, Fujian, Zhejiang, Hunan and Guangxi provinces）, the southwest area （the transitional zone of Yunnan-Guizhou Plateau and Sichuan Basin） and the northwest area （including Longshan mountain and along the banks of the Huanghe River and its anabranches）. Not only the conditions of geology and geography of the three areas but also the differences of Danxia landforms of the three areas are analyzed. The Danxia landscape, characterized by upright-shaped peaks, Danxia mesa, stone wall, cave and vertical cave, ＂Danxia natural bridge＂, ＂a narrow strip of sky＂ and so on, often presents in the southeast area. The landscape of southwest area is characterized by Danxia escarpment faces and waterfalls. In the northwest area, the Danxia landscape has the traits of arid areas simultaneously, for example, mud-coating type, columniation type, board type, moreover, it is greatly different between these environmental factors such as the microclimate, water, wind, and the loess cover. Finally it explores the causes which lead differences in landform and also explains the landform formation process and its mechanism with reference to the rates of crustal uplift, the tectonic red-basin, and the external processes including working of running water, weathering, biogenic, gravity in each area of Danxia Landforms in China.
文摘Threshold is a limit and marginal point when a qualitative change takes place. Since threshold principle was firstly used in landform research by S.A.Schumm in the 1970s, the quantitative research on watershed landform development stage has come true. Davis proposed a three-stage model on landform evolution: young, mature and old stages. Thereafter Strahler quantified this model by hypsometric analysis method. The authors thought that the material movement stage cannot be expressed by hypsometric method in watershed landform at development stage, because of the uncertainty on stage delimitation. To meet this shortcoming, this paper presents an integral erosion value method. A clear delimitation on landform development stage in the Loess Plateau region has been tested by this method. The result shows that gullied loessial hilly area is at the mature stage, and gullied loessial tableland area is at the young stage. It is estimated that from the point of erosion related sediment yield, natural erosion accounts for 70% of the total erosion amount, and artificial accelerating erosion is 30%. Therefore soil and water conservation is very crucial for the Loess Plateau.
基金National Natural Science Foundation of China,No.41930640,No.41771014The Second Tibetan Plateau Scientific Expedition and Research,No.2019QZKK1003。
文摘The history of dune landform changes and dust activity at mid-latitudes is a good archive for exploring environmental changes and related landscape response.In this study,the dynamic changes,material sources,dust activity history and the influencing factors of typical sand dunes in the Hexi Corridor were comprehensively analyzed from the aspects of aeolian geomorphology,grain-size sedimentology,geochemistry and climatology.The results show that in the past half century,the typical crescent-shaped dunes and chains of crescent-shaped dunes in the study area have moved or swayed greatly,with an average speed ranging from 0.8 m/a(Dunhuang)to 6.2 m/a(Minqin).The dynamic changes of sand dunes are mainly affected by annual precipitation,annual average wind speed and annual gale days,which indicates that climate is the primary influencing factor of dune landform changes.The three-stage grain-size curve model of dune sands is obviously different from that of gobi sediments(two-stage),revealing the“immaturity”of the latter in sedimentology,while the former has experienced efficiently aeolian differentiation and non-local origin.The comprehensive evidences of paleogeography,sedimentology and geochemistry reveal that the source materials of sand dunes are mainly alluvial/proluvial and palaeo-fluvial sediments,including clastic sediments in the denudation/erosion zones of the north and south piedmonts.Indicators such as the proportion of surface fine particles,the coverage of surface salt crusts,and the content of erodible sandy materials indicate that the western gobi areas are not the main source areas of wind-blown dust in the central and eastern parts of the Hexi Corridor.The spatial distribution of the movement direction of sand dunes is similar to that of the regional dominant wind direction,which indicates that the difference in the dynamic evolution of dune landforms between the east and west of the Hexi Corridor should be controlled by the regional-scale wind system,that is,controlled by the dynamic mechanism rather than the difference in material sources.The warming and humidification of the Hexi climate is a synchronous response to the global warming and the strengthening of the Asian Summer Monsoon.It is also the main reason for the reduction of dust storms in the study area,which means that a potential inverse desertification process exists in the Hexi Corridor during the same period and it is also controlled by climate change.However,the process of desertification in the oasis areas during the period is caused by groundwater fluctuation affected by human activities.
文摘Mt.Ma'an (4288 m) is the highest mountain in the southwest edge of Sichuan Basin. It is situated to the south of the Dadu River. The geographic coordinates are: 28°58′N, 102°55′E. There are six peaks over 4000 m in elevation. Many quaternary glacial landforms in this mountain have been discovered. It's a typical example of fossil glacial landform in the east China. Its glacial stages are the last glaciation (Q 3 3) and the neoglaciation (Q 3 4). Mt. Ma'an and Mt. Luoji (4359 m) are similar in the fossil glacial landforms, but there are still some differences between them. For example, the ratio between the direct difference and the minus difference is different.
文摘The science of geomorphology works on natural 3D landforms.Research includes the change of landforms as well as the processes causing these changes.Material transport processes lead to a composition of a geomorphic system that follows a certain spatial hierarchy.The analysis of 3D topological relations of landforms can help to investigate geomorphic systems in two ways.First,chronological order of geomorphic genesis can be derived and,second,indications of material source can be found.However,at least some 3D geometric information is needed if topology is supposed to be derived and examined.Landforms cannot simply be reconstructed by surface measurements.Data capture is a major problem when buried features are under investigation.Subsurface information is gathered by drillings or geophysical methods that reveal point or line information.Unfortunately,the ISO 19107 Spatial Schema does not offer a valid representation of 3D geometry from sparse data,either by aggregating a surface and one or few points or by aggregating a surface and a line.Here,we discuss the possibilities for the analysis of chronological order of landform genesis and material dependencies that arise from applying 3D topological relationships to geomorphic system analysis.We show five relationships that are able to be observed in nature.Further,we introduce a new class for the representation of 3D objects with under-specified geometry.A_UG_Solid mediates between the Spatial Schema’s geometric primitives with a dimension less than three on the one side and a GM_Solid on the other side.Constraints to aggregate such a_UG_Solid are defined.The introduction of a_UG_Solid facilitates the application of 3D topological concepts to geometric objects that are known to be volumetric but have to be modeled from sparse data.
文摘The research selected five indices to measure fragmentation degrees of three landforms with GIS and analyzed the relationship with production profits of arable lands. The results showed that fragmentation degree of arable lands tends to be volatile upon landforms, For example, the fragmentation degree of mountainous area reached 0.985, followed by hills of 0.705 and the fragmentation degree of plains was the least at 0.068. Production profits of arable lands were negatively correlated with arable landscape fragmentation. Hence, it is necessary to take measures to reduce landscape fragmentation as per specific local circumstances to imorove production Drofits.
基金supported by the National Natural Science Foundation of China(No.41925030)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0904)+1 种基金the Chinese Academy of Sciences“Light of West China”ProgramSupport from the Dongchuan Debris Flow Observation and Research Station(DDFORS),Chinese Academy of Sciences,is acknowledged.
文摘Check dams have been used worldwide for a variety of purposes.With increasing age,check dams gradually lose their sediment trapping function via the continuous deposition of material carried by debris flows and flash floods,and eventually,check dams become unable to perform the designed mitigation function.In this paper,the sediment deposit evolution in a dam with multiple debris flow surges and its influence on the sediment trapping effect were investigated.The results showed that the debris flow deposition process can be divided into three phases:the backwater-controlled deposition phase,landform-controlled deposition phase,and quasi-equilibrium phase.The sediment trapping ratio of the check dam gradually decreased as the deposit volume increased and was linearly negatively correlated with the sediment deposition rate.Moreover,a mathematical model describing the negative feedback between deposit volume and sediment trapping ratio was established,and the physical meanings of the coefficients in the model and their empirical values were clarified.Furthermore,the deposit distribution,which satisfied the Weibull distribution in the longitudinal direction,was revealed.In the cross-sectional direction,the distribution of deposition gradually became uneven with increasing sediment filling rate.
