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1.
月球地貌是月球表面发生的地质和地貌过程的结果,月球地貌单元的划分和等级分类体系的构建是月球地貌学研究的基础,也是月球地貌图制图的基础和关键科学问题。地貌学是研究形态和成因的科学,高程和起伏度是最基本的地貌指标。本文基于LOLA(Lunar Orbiter Laser Altimeter) DEM数据以及LOLA和SELENE TC(Terrain Camera)融合的DEM数据(SLDEM2015,文中简称SLDEM),利用均值变点法确定月表起伏度计算的最佳窗口,并以起伏度100 m、200 m、300 m、700 m、1500 m及2500 m为阈值将月球表面分为微起伏平原(< 100 m)、微起伏台地[100 m, 200 m)、微小起伏丘陵[200 m, 300 m)、小起伏山地[300 m, 700 m)、中起伏山地[700 m, 1500 m)、大起伏山地[1500 m, 2500 m)及极大起伏山地(≥ 2500 m)地貌7个类型。划分结果显示:微起伏平原主要分布在月海平原区域、部分有玄武岩充填的撞击盆地的盆底区域以及撞击坑坑底区域;微起伏台地主要分布在月海和月陆区域的交界区域;微小起伏丘陵主要分布在月溪和皱脊等构造单元区域;小起伏山地主要分布在撞击坑中央峰及坑底断裂区域;中起伏山地主要分布在撞击坑坑底和坑壁过渡区域、撞击坑坑壁和坑缘过渡区域、撞击盆地盆底与盆壁过渡区域以及盆壁与盆缘过渡区域;大起伏和极大起伏山地主要分布在撞击坑坑壁区域及撞击盆地盆壁区域。本文确定的月表起伏度分级标准可以对月表数字地貌分类体系的构建和月球地貌图集的编研提供定量标准和重要参考。  相似文献   

2.
月球是地球的唯一天然卫星,也是现阶段深空探测的主要天体。月表形貌研究有助于了解月球的状态、结构和组成,能够为探究月球起源和演化等科学问题提供直接、可靠的证据。与地貌分类相比,月貌研究起步较晚,发展较为缓慢。尽管月貌研究已取得了一定进展,但月球形貌分类过程中仍旧缺乏对于形貌指标,如高程等的应用,对于形貌特征的描述仍存在部分缺失。本文通过分析月球表面高程的整体特征以及月海、撞击坑、南极艾肯盆地等典型地质构造单元的高程特征,认为-2500 m等高线能够较好的区分月海内部区域;-1500 m等高线能够较好的区分月海区域与月陆区域;1000 m等高线与南极艾肯盆地边界拟合程度较好;3000 m等高线能够较好地突出月陆地区撞击坑的边界。在此基础上,提出以-2500 m、-1500 m、1000 m、3000 m 4个高程值作为月球形貌分类体系中的高程分类标准,将月球表面划分为极低海拔、低海拔、中海拔、高海拔和极高海拔5个形貌类型。  相似文献   

3.
月表形貌特征研究进展及趋势分析   总被引:4,自引:0,他引:4  
程维明  王娇  周成虎 《地理研究》2014,33(6):1003-1014
在月球探测及科学研究过程中,对月表形貌特征的认识和分析是月球探测计划的关键任务之一,有助于理解和揭示月球的形态特征及空间分异规律,对于分析月球岩石构造、估算月表年龄、反演月壤厚度、恢复月球的起源和演化历史等都具有重要意义。从月表形貌特征的塑造及表达、宏观特征的分析与定量刻画、月表撞击坑的识别与分类及空间分异特征等几方面进行了归纳和分析,提出了未来月表形貌的研究方向,包括全月球形貌特征的多级分区划分、撞击坑类型的划分、全月球撞击坑空间分异特征及规律的研究、基于撞击坑空间分布探讨月球演化、基于形貌特征的比较行星学研究等。  相似文献   

4.
全月球撞击坑识别、分类及空间分布   总被引:2,自引:1,他引:2  
撞击坑是月球表面分布广泛的地貌单元,是研究月球的最直接窗口。本文以嫦娥一号卫星获取的遥感影像和DEM,以及国际天文学联合会(IAU)公布的撞击坑名录为基础数据源,以全月球表面撞击坑为研究对象,采用遥感图像处理与专家知识融合的目视解译法确定撞击坑的边界,识别出全月球表面直径大于500 m的撞击坑共计106030个,采用累积频率和与IAU公布撞击坑对比两种方法对目视解译的撞击坑进行精度评价,其识别的总体误差率为10.97%;按照形态特征指标,将全月球撞击坑分为六大类,对比分析了不同类的撞击坑影像及形貌差异性;对全月球撞击坑分类进行统计分析,得出了不同类型撞击坑在月球表面的数量与密度特征及空间分布情况。  相似文献   

5.
南昌厚田沙地沉积物的粒度特征及其影响因素   总被引:1,自引:1,他引:1  
厚田沙地是亚热带湿润地区的典型风沙化土地,分析不同地貌部位沉积物的粒度特征,有助于探讨其分布规律与影响因素.结果表明:厚田沙地沉积物主要由中沙和粗沙组成,平均粒径为1.28 Φ,分选性较差,呈正偏和窄峰态分布,整体表现为距赣江越远,细颗粒含量增多,粗颗粒含量减少,平均粒径逐渐变细.不同地貌部位沉积物的粒度特征存在较大差...  相似文献   

6.
Shape characterisation is important in many fields dealing with spatial data. For this purpose, numerous shape analysis and recognition methods with different degrees of complexity have so far been developed. Among them, relatively simple indices are widely used in spatial applications, but their performance has not been investigated sufficiently, particularly for building footprints (BFs). Therefore, this article focuses on BF shape characterisation with shape indices and classification schemes in a GIS environment. This study consists of four phases. In the first phase, the criteria for BF shape complexity were identified, and accordingly, benchmark data was constructed by human experts in three shape complexity categories. In the second phase, 18 shape indices were selected from the literature and automatically computed in GIS. The performance of these indices was then statistically assessed with histograms, correlation matrix and boxplots, and consequently four indices were found to be appropriate for further investigation. In the third phase, two new indices (Equivalent Rectangular index and Roughness index) were proposed with the objective to measure some BF shape characteristics more efficiently. The proposed indices also were found to be appropriate with the same statistical assessment procedures. In the final phase, BF shape complexity categories were created with the pairs of six appropriate indices and four choropleth mapping classification schemes (equal intervals, natural break, standard deviation, and custom) in GIS. The performance of the index–scheme pairs was assessed against the benchmark data. The findings demonstrated that both new indices and two of the selected indices (Convexity and Rectangularity) delivered higher performance. The custom classification scheme was found more ideal to reveal absolute shape complexity with the index value ranges derived from the boxplots while the other classification schemes were more appropriate to reveal relative shape complexity.  相似文献   

7.
Reviewing some important German scientists who have developed climatic regionalization schemes either on a global or Chinese scale, their various definitions of the tropical climate characteristics in China are discussed and compared with Huang Bingwei's climate classification scheme and the identification of the tropical climate therein. It can be seen that, due to different methodological approaches of the climatic regionalization schemes, the definitions of the tropics vary and hence also their spatial distribution in China. However, it is found that the tropical climate type occupies only a peripheral part of southern China, though it firmly represents a distinctive type of climate that is supsequently associated with a great economic importance for China. As such, the tropical climate type was mostly identified with its agro-climatological significance, that is by giving favourable growing conditions all-year round for perennial crops with a great heat demand. Tropical climate is, hence, conventionally regarded to be governed by all-year round summer conditions "where winter never comes".  相似文献   

8.
王林  曾坚 《地理研究》2021,40(8):2235-2251
村镇聚落空间格局系统认知与分类研究是乡村地域国土空间有效治理和差异化管控的基础,对乡村振兴和新型城镇化战略实施具有支撑作用,鲁西南地区相关研究时代和现实价值凸显。基于菏泽市2018年遥感影像解译数据,综合统计分析和探索性空间数据分析方法,多尺度多维度系统探测村镇聚落空间分异特征,并通过多维特征耦合划分村镇聚落类型。结论如下:① 菏泽市村镇聚落总体表现为点位密度较高、规模普遍偏小、形状普遍规整,国土空间集约整治潜力巨大。② 村镇聚落“三维”(点位、规模、形态)空间格局特征存在尺度差异性。市域尺度“三维”分布特征均存在一定空间异质性,但分异程度不明显;县域尺度“三维”特征空间分异规律多元复杂,表现出以乡镇为单元的局域多样性;乡镇尺度“三维”特征均趋向统一均衡,呈现单中心结构和“同质性”特征。③ 以乡镇为划分单元,基于“三维”特征耦合形成八种村镇聚落类型,并尝试分类提出空间优化和治理建议。  相似文献   

9.
Reviewing some important German scientists who have developed climatic regionalization schemes either on a global or Chinese scale, their various definitions of the tropical climate characteristics in China are discussed and compared with Huang Bingwei‘s climate classification scheme and the identification of the tropical climate therein. It can be seen that, due to different methodological approaches of the climatic regionalization schemes, the definitions of the tropics vary and hence also their spatial distribution in China. However, it is found that the tropical climate type occupies only a peripheral part of southern China, though it firmly represents a distinctive type of climate that is subsequently associated with a great economic importance for China. As such, the tropical climate type was mostly identified with its agro-climatological significance, that is by giving favourable growing conditions all-year round for perennial crops with a great heat demand. Tropical climate is, hence, conventionally regarded to be governed by all-year round summer conditions “where winter never comes“.  相似文献   

10.
Reviewing some important German scientists who have developed climatic regionalizationschemes either on a global or Chinese scale, their various definitions of the tropical climatecharacteristics in China are discussed and compared with Huang Bingwei's climate classificationscheme and the identification of the tropical climate therein. It can be seen that, due to differentmethodological approaches of the climatic regionalization schemes, the definitions of the tropics varyand hence also their spatial distribution in China. However, it is found that the tropical climate typeoccupies only a peripheral part of southern China, though it firmly represents a distinctive type ofclimate that is subsequently associated with a great economic importance for China. As such, thetropical climate type was mostly identified with its agro-climatological significance, that is by givingfavourable growing conditions all-year round for perennial crops with a great heat demand. Tropicalclimate is, hence, conventionally regarded to be govemed by all-year round summer conditions "wherewinter never comes".  相似文献   

11.
中国资源型城市的职能分类与演化特征   总被引:6,自引:1,他引:6  
刘云刚 《地理研究》2009,28(1):153-160
资源型城市是中国式"问题城市"的代表,但它本质上不属于同一职能类型.随发展阶段的不同,资源型城市表现出不同的职能特点.本文利用全国城市职能分类的成果,按照优势职能、突出职能、职能强度和职能规模四要素对中国资源型城市的职能特征进行了整理.按照优势职能将资源型城市划分为典型期资源型城市和变异期资源型城市,按照突出职能划分为采掘业城市、制造业城市和商业城市,按照职能强度和职能多样化程度划分为职能专业化和职能多样化的资源型城市.中国资源型城市的职能具有多样化的趋向,但多数城市仍囿于采掘业城市和制造业城市的范畴,并且职能演化缓慢反复.这说明,资源型城市的转型仍将是一个长期的政策命题.  相似文献   

12.
张耀光  刘锴  郭建科  马慧强 《地理研究》2013,32(6):1095-1102
我国海岛众多,具有丰富港口资源,其中一些港口深水岸线逼近岛岸,适宜发展大型深水集装箱港。目前海岛港口资源开发程度较低,在海岛上已开发的大型港口仅有上海洋山港,多数海岛县为规模不大的地方小港。对中国海岛县的港口吞吐量、港口用地等应用洛伦兹曲线(基尼系数)分析集聚状况,并用回归分析方法,分析港口发展与经济增长的关系。根据海岛港口规模、区位、腹地、港口“代际”以及海岛与大陆连通等指标,对中国海岛港口进行类型划分,并对划分的洋山港、舟山港以及地方小港等三种不同类型的港口特征进行了分析。进而结合当前国际海运业的要求与建造大船舶以适应大型深水港的发展趋势,提出了今后发展海岛深水港的方向。  相似文献   

13.
Zhang  Jingjing  Zhu  Wenbo  Zhu  Lianqi  Cui  Yaoping  He  Shasha  Ren  Han 《地理学报(英文版)》2019,29(4):598-612
Topographical relief is a key factor that limits population distribution and economic development in mountainous areas. The limitation is especially apparent in the mountain-plain transition zone. Taking the transition zone between the Qinling Mountains and the North China Plain (i.e. the mountainous area in western Henan Province) as an example and based on the 200-m resolution DEM data, we used the mean change-point analysis to determine the optimal statistical unit for topographical relief, and thereafter extracted the relief degree. Taking the 1:100,000 land use data, township population and county-level industrial data, population and economic spatial models were constructed, and 200-m resolution grid population and economic density maps were generated. Afterwards, statistical analysis was carried out to quantitatively reveal the impact of topographical relief on population and economy. In addition, the impacts of other topographical factors were discussed. The results showed the following. (1) The relief degree in western Henan is generally low, where 58.6% of the regional topography does not exceed half the height of a reference mountain (relative elevation ≤250 m). Spatially, the relief degree is high in the west while low in the east, and high in the middle while low in the north and south. There is a positive correlation between relief degree and elevation, and a much stronger correlation between relief degree and slope. (2) The linear fitting degree between the population and economic validation data and the corresponding simulation data are 0.943 and 0.909, respectively, indicating that the spatialized results can reflect the actual population and economic distribution. (3) The impact of topographical relief on population and economy was stronger than that of other topographical factors. The relief degree showed a good logarithmic fit relationship with population density (0.911) and economic density (0.874). Specifically, 88.65% of the population lives in areas where the topographical relief is ≤0.5 and 88.03% of the gross regional product was from areas where the relief is ≤0.3. Compared with the population distribution, the economic development showed an obvious agglomeration trend towards low relief areas.  相似文献   

14.
青藏高原地形起伏度及其地理意义   总被引:3,自引:1,他引:3  
封志明  李文君  李鹏  肖池伟 《地理学报》2020,75(7):1359-1372
地形起伏度是区域人居环境适宜性与资源环境承载力的关键评价指标之一。当前有关其最佳评价窗口、及其与海拔—相对高差的相互关系仍缺乏深入研究,进而影响该指标对区域地形起伏的有效表征。客观认识青藏高原地形起伏度有助于促进其国家生态安全屏障建设与区域绿色发展。以先进星载热发射和反射辐射仪全球数字高程模型(ASTER GDEM, 30 m)地形数据(V2)为基础,本文利用均值变点分析法确定了青藏高原地形起伏度评价的最佳分析窗口,基于地形起伏度模型(RDLS)研制了青藏高原首套30 m地形起伏度专题图,据此分析了地形起伏度与海拔、相对高差的相互关系,并界定了地形起伏度对区域地形起伏状况的有效表征。主要结果/结论包括:① 基于GDEM的青藏高原地形起伏度评价最佳窗口为41×41个像元的矩形邻域,对应面积约为1.51 km2,均值变点分析表明区域地形起伏度评价最佳窗口有其唯一性。② 青藏高原地形起伏度均值约为5.06,超3/5区域地形起伏度介于4.5~5.7之间;整体上,青藏高原地形起伏程度由其东北部向西南部、西部递增,仅在柴达木盆地、藏南谷地以及河湟谷地出现低起伏地貌特征。且地表起伏在不同纬度剖面变化较为一致(沿山脉走向),但不同经度剖面起伏层次错落(横切山脉走向)。③ 相关性分析表明不同地形起伏度分别对应不同平均海拔、不同相对高差的地貌单元。青藏高原地形起伏度经纬向剖面分析表明,该区由东部的低山稳步爬升,山体经历骤然爬升(即地表起伏特征剧烈)后形成以极高山为主的有序错落起伏(喜马拉雅山脉)。  相似文献   

15.
电网企业因其垄断特性造成的成本信息不对称性,不仅制约了政府对电网企业监管的效率,而且使消费者对电价定价缺乏信任,因而,评估电网企业的成本合理性具有重要的理论和现实意义。从空间对标视角,以中国国家电网公司各分公司的运行维护费为样本,采用Gini准则融合多种DEA模型的测算结果,并进行空间系统聚类分析,结果表明:① 全国大多数省级电网公司运行维护费支出处于合理水平,但部分电网企业的分量成本合理性水平较低;② 运营绩效水平较高的公司存在更高的绩效提升边际成本,较容易发生成本的支出不合理;③ 各电网公司在选择成本对标标准时,既要选择成本合理性程度较好的公司作为参照,又要依据动态参考原则随时调整合理成本的参照系。  相似文献   

16.
The Southern Alps of New Zealand are the topographic expression of active oblique continental convergence of the Australian and Pacific plates. Despite inferred high rates of tectonic and climatic forcing, the pattern of differential uplift and erosion remains uncertain. We use a 25-m DEM to conduct a regional-scale relief analysis of a 250-km long strip of the western Southern Alps (WSA). We present a preliminary map of regional erosion and denudation by overlaying mean basin relief, a modelled stream-power erosion index, river incision rates, historic landslide denudation rates, and landslide density. The interplay between strong tectonic and climatic forcing has led to relief production that locally attains 2 km in major catchments, with mean values of 0.65–0.68 km. Interpolation between elevations of major catchment divides indicates potential removal of l01–103 km3, or a mean basin relief of 0.51–0.85 km in the larger catchments. Local relief and inferred river incision rates into bedrock are highest about 50–67% of the distance between the Alpine fault and the main divide. The mean regional relief variability is ± 0.5 km.Local relief, valley cross-sectional area, and catchment width correlate moderately with catchment area, and also reach maximum values between the range front and the divide. Hypsometric integrals show scale dependence, and together with hypsometric curves, are insufficient to clearly differentiate between glacial and fluvial dominated basins. Mean slope angle in the WSA (ψ = 30°) is lower where major longitudinal valleys and extensive ice cover occur, and may be an insensitive measure of regional relief. Modal slope angle is strikingly uniform throughout the WSA (φ = 38–40°), and may record adjustment to runoff and landsliding. Both ψ and φ show non-linear relationships with elevation, which we attribute to dominant geomorphic process domains, such as fluvial processes in low-altitude valley trains, surface runoff and frequent landsliding on montane hillslopes, “relief dampening” by glaciers, and rock fall/avalanching on steep main-divide slopes.  相似文献   

17.
推动边境口岸与载体城镇协调发展是高质量发展“口岸经济带”的重要内容。运用熵权法和耦合协调模型对2009—2019年新疆陆路口岸与载体城镇耦合协调水平演进的时空特征进行度量。结果表明:(1)新疆主要陆路口岸与载体城镇综合发展水平总体稳步上升,2015年后两系统综合发展的动力由口岸先导逐渐切换到载体城镇先导,过度依赖进出口数量是口岸经济增速放缓的主要原因。(2)新疆主要陆路口岸与载体城镇的耦合协调水平整体趋于优化,耦合协调水平可以分为3类:以阿拉山口口岸代表的良好协调型口岸、以巴克图口岸代表的初级协调型口岸、以塔克什肯口岸为代表的勉强协调型口岸。(3)从空间上来看,新疆陆路口岸经济发展格局正在朝阿拉山口口岸与霍尔果斯口岸并重、南北疆多口岸均衡发展的空间格局演进,但部分载体城镇社会经济发展比较落后,限制了与口岸协调发展水平进一步提升。  相似文献   

18.
国家森林乡村建设是实施乡村振兴战略和改善农村人居环境的重要措施,但森林乡村在不同尺度的分异特征及优化方向尚不明晰。本文综合运用探索性空间数据分析、耦合度模型和Voronoi图分析等研究方法,从全国、区域和行政尺度分析了国家森林乡村空间格局、数量规模和内部分异特征,并基于森林乡村与人口耦合关系及乡村可达类型识别,分析了全国森林乡村的分区格局及其优化方向。结果表明:全国森林乡村密度具有明显的东高西低分异特征,长江三角洲地区是森林乡村高密度集中分布最大的连片区。基于县域单元的省域森林乡村泰尔指数差异较大,东南区域森林乡村分布相对均衡,西南和东北区域内部差异显著。森林乡村空间可达性呈现自东向西的梯度递减,森林乡村与人口密度的耦合类型分布具有较强的内部分异性。文章基于森林乡村可达类型与耦合分区的组合分析,将全国划分为重点发展区、特色挖掘区、集聚提升区、适度引导区和功能转型区五类,明确了不同类型区森林乡村建设的重点方向,将为面向乡村振兴的全国森林乡村建设与分区优化提供决策依据。  相似文献   

19.
选用2000—2019年11月—次年3月塔城地区7个国家气象观测站逐日降水、温度、常规地面和高空观测资料、美国国家环境预报中心(NCEP)再分析资料,确定近20 a塔城地区暖区暴雪天气过程并进行分析。结果表明:(1) 塔城地区暖区暴雪发生于塔额盆地的塔城站、裕民站和额敏站,塔城站出现频次最多;时间分布上,11月和12月出现暖区暴雪的频次最高,且主要集中在11月中旬—12月上旬,1月次之,2月最少。(2) 塔城地区暖区暴雪分为3类:低槽前部型、横槽底部型和西北急流型,地面低压为西方和西北路径。低槽前部型是最典型的暖区暴雪形势,主要出现在11月—12月上旬,发生在西西伯利亚低槽前部锋区与南支中纬度短波槽汇合区,地面低压为西北路径;横槽底部型主要出现在11月—次年1月,发生在极锋锋区底部偏西气流和中纬度暖湿西南气流汇合的强锋区中,地面低压为西方路径;西北急流型主要出现在11—12月,发生在极锋锋区西北气流中,地面低压为西北路径。(3) 500~300 hPa强西北或偏西急流、700 hPa偏西低空急流、850 hPa暖式切变的叠置区与暖区暴雪落区一致,低槽前部型和西北急流型为锋前暖区产生暴雪,横槽底部型为低压右前部暖锋锋生产生暴雪。(4) 低槽前部型和横槽底部型的水汽均为偏西路径,来自地中海、阿拉伯海的水汽经里海、咸海增强后向暴雪区输送;西北急流型有偏西和西北2条水汽输送路径,来自高纬度巴伦支海的水汽与来自中低纬度里海、咸海、地中海、阿拉伯海的水汽在巴尔喀什湖附近汇合后向暴雪区输送,较强的水汽输送伴随低层明显的水汽辐合,强辐合中心位于850~700 hPa之间。  相似文献   

20.
自中国与哈萨克斯坦建交以来,双方逐渐深化和拓展合作领域。两国推进中方丝绸之路经济带建设同哈方"光明之路"新经济政策的对接,更加注重旅游等人文交流合作领域。因此,研究哈萨克斯坦旅华客源市场具有十分重要的现实意义。本文以连续多年的统计数据为基础,研究哈萨克斯坦游客的入境旅游优势,并从历史发展阶段、人口统计学特征、人均消费与平均停留时间、人均消费构成、入境方式、年内时间分布规律、在华空间分布和出境流向等八个方面分析哈萨克斯坦旅华客源市场特征,并得出相应结论。文章最后从创新旅游合作领域、丰富游客入境条件和进行旅游宣传推广三方面为两国市场拓展提出建议。  相似文献   

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