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Factors affecting land dissection density in geomorphological regions of China

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Journal of Mountain Science 2024年第4期21卷 1372-1387页

作者： SUN Xiaolin ZHAO Yinjun PENG Peihao cheng weiming WEI Yongping YANG Ronghao LI Jiaxu College of Earth Sciences Chengdu University of TechnologyChengdu 610059China School of Civil Engineering Guangxi Polytechnic of ConstructionNanning 530001China Key Laboratory of Environment Change and Resources Use in Beibu Gulf Ministry of EducationNanning Normal UniversityNanning 530001China Key Laboratory of Earth Surface Process and Intelligent Simulation(Guangxi) Nanning Normal UniversityNanning 530001China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China School of Earth and Environmental Sciences The University of QueenslandBrisbane 4702Australia School of Geography and Planning Nanning Normal UniversityNanning 530001China

Land dissection density(LDD)provides morphological evidence regarding prior intense soil erosion and quantifies the distribution of land dissections.A comprehensive understanding of the potential factors influencing the spatial pattern and value of the LDD is vital in geological disasters,soil erosion,and other related *** dissection phenomena in China affects large areas with different morphological,pedological,and climatic *** studies have focused on the potential factors influencing the LDD at a watershed ***,these results are insufficient to reflect the status quo of dissection development and its primary influencing factors on a national ***’s spatial patterns and the dominant factors at a regional scale in millions of square kilometers remain to be *** study used the geomorphon-based method and the geographical detector model to quantify the spatial pattern of LDD over China and identify the dominant factors affecting this pattern in China’s six first-order geomorphological regions(GR1~GR6).The results yield the following findings:(1)LDD in China ranges from 0~4.55 km/km^(2),which is larger in central and eastern regions than in other regions of China;(2)dominant factors and their dominant risk subcategories vary with each geomorphological region’s primary internal and external forces;(3)the influence of natural factors is more significant on the large regional scale in millions of square kilometers compared to anthropogenic factors;relief degree of land surface(RDLS)is dominant in GR1,GR2,and GR5;the slope is dominant in GR6,soil type is dominant in GR3 and GR4,and lithology plays a critical role in the dominant interactions of GR3,GR4,and GR6;(4)the interactions between factors on LDD’s spatial pattern have a more significant effect than individual factors.

关键词： Land dissection density Influencing factors Regional scale Spatial pattern Geographical detector model Geomorphon-based method China

Revealing the Landform Types and Morphologic Features of Lunar Surface

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Acta Geologica Sinica(English Edition) 2017年第4期91卷 1517-1518页

作者： cheng weiming State Key Laboratory of Resources and Environmental Information System Institute of Geographic Science and Natural Resources Research CAS Beijing 100101 China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023 Jiangsu China

A lunar geologic map at a scale of 1：5000000 was finished in the 1970s by the National Aeronautics and Space Administration, U.S U.S. Geological Survey. Department of the Interior, Till now, the landform classification system and lunar morphologic mapping have not been clarified. The work aims to put forward a new landform classification system and to obtain index and map in the Sheet H010. Some key morphologic features of lunar surface were compared with those of the Earth. This research is very important for whole lunar morphologic mapping and unraveling evolutionary progress.

关键词： than Revealing the Landform Types and Morphologic Features of Lunar Surface

Streamflow trends and hydrological response to climatic change in Tarim headwater basin

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Journal of Geographical Sciences 2007年第1期17卷 51-61页

作者： JIANG Yan ZHOU chenghu cheng weiming Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China

This paper has studied the change of streamflow and the impact of climatic variability conditions on regional hydrological cycle in the headwater of the Tarim River Basin. This study investigates possible causes of observed trends in streamflow in an environment which is highly variable in terms of atmospheric conditions, and where snow and ice melt play an important role in the natural hydrological regime. The discharge trends of three head streams have a significant increase trend from 1957 to 2002 with the Mann-Kendall test. Complex time-frequency distributions in the streamflow regime are demonstrated especially by Morlet wavelet analysis over 40 years. The purpose is to ascertain the nature of climatic factors spatial and temporal distribution, involved the use of EOF （Empirical Orthogonal Function） to compare the dominant temperature, precipitation and evaporation patterns from normally climatic records over the Tarim＇s headwater basin. It shows that the first principal component was dominated since the 1990s for temperature and precipitation, which identifies the significant ascending trend of spatial and temporal pattern characteristics under the condition of the global warming. An exponential correlation is highlighted between surface air temperature and mean river discharge monthly, so the regional runoff increases by 10%-16% when surface air temperature rises by 1 ℃. Results suggest that headwater basins are the most vulnerable environments from the point of view of climate change, because their watershed properties promote runoff feeding by glacier and snow melt water and their fundamental vulnerability to temperature changes affects rainfall, snowfall, and glacier and ice melt.

关键词： climatic change EOF Mann-Kendall test runoff streamfiow Tarim Basin wavelet

Variations of bank shift rates along the Yinchuan Plain reach of the Yellow River and their influencing factors

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Journal of Geographical Sciences 2014年第4期24卷 703-716页

作者： WANG Suiji LI Ling cheng weiming Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China

It is important to examine the lateral shift rate variation of river banks in different periods. One of the challenges in this regard is how to obtain the shift rate of river banks, as gauging stations are deficient for the study of river reaches. The present study selected the Yinchuan Plain reach of the Yellow River with a length of 196 km as a case study, and searched each point of intersection of 153 cross-sections （interval between two adjacent cross-sections was 1.3 km） and river banks in 1975, 1990, 2010 and 2011, which were plotted according to remote sensing images in those years. Then the shift rates for the points of intersection during 1975-1990, 1990-2010 and 2010-2011 were calculated, as well as the average shift rates for different sections and different periods. The results show that the left bank of the river reach shifts mostly to the right, with the average shift rates being 36.5 m/a, 27.8 m/a and 61.5 m/a in the three periods, respectively. Contemporarily, the right bank shifts mostly to the right in the first period, while it shifts to the left in the second and third periods, with the average shift rates being 31.7 m/a, 23.1 m/a and 50.8 m/a in the three periods, respectively. The average shift rates for the left and right banks during the period 1975-2011 are 22.3 m/a and 14.8 m/a, respectively. The bank shift rates for sections A, B and C are different. The shift rate ratio of the left bank in the three sections is 1：7.6：4.6 for shift to the left and 1：1.7：3.8 for shift to the right, while that of the right bank is 1：1.8：1.2 for shift to the left and 1：5.6：17.7 for shift to the right during the period 1975-2011. Obviously, the average shift rate is the least in section A, while it is maximum in section B for shift to the left and in section C for shift to the right. The temporal variation of the shift rate is influenced by human activities while the spatial variation is controlled by the local difference in bank materials.

关键词： river bank shift rate discharge sediment structure Yellow River

The effect of multilayer structure on magnetic properties of FePt thin films

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Acta Metallurgica Sinica(English Letters) 2009年第1期22卷 22-26页

作者： Kaifeng DONG Xiaofei YANG Junbing YAN weiming cheng Xiaomin cheng Department of Electronic Science ＆： Technology Huazhong University of Science ＆ TechnologyWuhan 430074 China

The Fe/Pt multilayer films with different structures were deposited by RF magnetron sputtering on glass substrates, and the L10-FePt films were obtained after the asdeposited samples were subjected to vacuum annealing at various temperatures. Results show that the Fe/Pt multilayer structure can effectively reduce the ordering temperature of FePt film, and the in-plane coercivity of [Fe （5.2 nm）/Pt （5.2 nm）]7 multilayers can reach 161.2 kA/m after annealed at 350℃ for 30 min. When Fe and Pt layer thickness is equal, the coercivity of the film is the largest. On the other hand, the different Fe-Pt crystalline phases such as Fe3Pt and FePt3 phases are formed after annealing when the thickness ratio of Fe/Pt deviates from 1 after annealing. When Fe and Pt have the same thickness, the thinner single layer gets the lower ordering temperature and the larger coercivity.

关键词： L10-FePt thin films Multilayer structure Coercivity Ordering temperature

Sustainable land-use patterns for arid lands: A case study in the northern slope areas of the Tianshan Mountains

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Journal of Geographical Sciences 2010年第4期20卷 510-524页

作者： LUO Geping FENG Yixing ZHANG Baiping cheng weiming Xinjiang Institute of Ecology and Geography CAS Urumqi 830011 China Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Sustainable land use patterns are ecological and economic prerequisites of regional sustainable development. This is especially true for arid lands, where the environment is wholly fragile thanks to extremely limited precipitation, and where human activities have greatly transformed natural desert system by clearing natural vegetation, expanding oases and even building dams on inland rivers. However, the current studies on land use patterns are still characterized by field investigations and case studies, with almost no solid scientific basis. This paper holds that land types and their combination patterns are the principal basis for designing sustainable land use patterns, and that GIS and RS-based large-scale land type mapping and the study of their spatial combination structures should be coordinated with the demand of social development. The existing environmental problems induced by irrational land use mostly result from their deviation from the natural properties of land types. Taking the northern slope of the Tianshan Mountains （NSTM） as an example and considering land type patterns as the basis of land use patterns, this paper improves the vertical oa- sis-and-mid-mountain two-belts development model and the sustainable mountain land use model for arid lands put forward in recent years; and in terms of oases patterns, it outlines oasis development models, including intensive land use pattern in alluvial-diluvial fans, moderate agricultural development pattern in alluvial plains, and ecological land use pattern in river-end oases.

关键词： northern slope of the Tianshan Mountains land type land-use pattern oases

Effect of Ni doping on the microstructure and magnetic properties of FePt films

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Rare Metals 2009年第3期28卷 257-260页

作者： DONG Kaifeng cheng Xiaomin YAN Junbing cheng weiming LI Peng YANG Xiaofei Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

FePtNi films with different Ni contents were deposited on glass substrates by RF magnetron sputtering, and the L10-FePtNi films were obtained after the asdeposited samples were subjected to vacuum annealing. The magnetic properties, structures, and orientations of the L10-FePt films with Ni doping were studied. The results show that with increasing Ni content, the （001） peak position of the FePtNi films shifts to a higher angle in comparison with FePt, which suggests that there is partial Ni substitution in the L10 lattice. The perpendicular coercivity decreases from 661 to 142 kA/m and magnetization decreases from 512 to 433 kA/m with increasing Ni content. In comparison with FePt films, the FePtNi films can effectively reduce the Curie temperature, which makes FePtNi films promising media candidates in thermally assisted recording （TAR）.

关键词： FePtNi films Curie temperature magnetization coercivity

Automatic mapping of lunar landforms using DEM-derived geomorphometric parameters

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Journal of Geographical Sciences 2017年第11期27卷 1413-1427页

作者： WANG Jiao cheng weiming ZHOU chenghu ZHENG Xinqi School of Information Engineering China University of Geosciences Beijing 100083 China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China

Developing approaches to automate the analysis of the massive amounts of data sent back from the Moon will generate significant benefits for the field of lunar geomorphology. In this paper, we outline an automated method for mapping lunar landforms that is based on digital terrain analysis. An iterative self-organizing （ISO） cluster unsupervised classification enables the automatic mapping of landforms via a series of input raster bands that utilize six geomorphometric parameters. These parameters divide landforms into a number of spatially extended, topographically homogeneous segments that exhibit similar terrain attributes and neighborhood properties. To illustrate the applicability of our approach, we apply it to three representative test sites on the Moon, automatically presenting our results as a thematic landform map. We also quantitatively evaluated this approach using a series of confusion matrices, achieving overall accuracies as high as 83.34% and Kappa coefficients （K） as high as 0.77. An immediate version of our algorithm can also be applied for automatically mapping large-scale lunar landforms and for the quantitative comparison of lunar surface morphologies.

关键词： automatic classification geomorphometric parameters ISO cluster lunar iandforms DEM

面向自然场景土地覆被分类的遥感物候模式分区

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地理学报 2024年第9期79卷 2206-2229页

作者：刘晓亮王志华杨晓梅程维明张俊瑶刘岳明刘彬孟丹曾晓伟中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室北京100101 中国科学院大学北京100049

选取适当地理边界对研究区或影像进行分区,降低区域内土地覆被复杂程度及其在影像中的特征变异性,能够有效提升土地覆被遥感分类的精度和效率。现有土地覆被制图中开展分区分类策略所借助的生态分区等区划数据缺乏目标针对性,其对遥感... 详细信息

选取适当地理边界对研究区或影像进行分区,降低区域内土地覆被复杂程度及其在影像中的特征变异性,能够有效提升土地覆被遥感分类的精度和效率。现有土地覆被制图中开展分区分类策略所借助的生态分区等区划数据缺乏目标针对性,其对遥感分类的适用性范围及精度提升效果仍存在限制。植被物候变化是造成自然场景土地覆被类内光谱异质的主要原因,本文利用遥感观测的反映地表植被绿度状态的植被指数和反映地表植被生长发育节律的关键物候期构建分区指标体系,以反映微地貌形态、坡面属性及地表物质组成的地貌小区为分区单元,采用数据驱动的空间约束层次聚类算法,提出了面向自然场景土地覆被分类的遥感物候模式分区。基于统计检验和多源土地覆被产品的分区评价结果表明,本文的遥感物候模式分区可有效降低区域内土地覆被复杂程度和植被物候变化引起的类内特征异质,在土地覆被代表性样本库构建以及分区分类策略实施等方面具有较高应用潜力。

关键词：物候分区/区划土地覆被分类遥感中国