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Cheng Wei-ming Ph.D. Zhou Cheng-hu Tang Qi-cheng Yao Yong-hui Zhang Bai-ping 《地理学报(英文版)》2002,12(1):23-28
The foothill belts of Tianshan Mountains are about 280 km long and 60 km wide, and the study area extends from Kuitun city
to Fukang city. They are transitional belts between mountains and plains, appearing in three rows of folds with different
morphologies and their age becoming younger from south to north. Based on GIS and RS methods, and materials of the previous
researchers, this paper deals with the genetics of the foothill belts and their landscape features resulting from folding
by neotectonic movements, and also describes their length, width and slope by remote sensing image interpretation. The characteristics
of the foothill belts are found to be very important for the surrounding environment by preventing groundwater from flowing
into plains, changing groundwater, increasing flow of surface runoff, in addition to their roles in protecting the surrounding
environment. The purpose of this paper is to provide an in-depth understanding of the foothill belts and influence on its
surrounding environment. 相似文献
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滕州市湿地资源现状及保护管理 总被引：1，自引：0，他引：1
山东省滕州市位于山东省南部,境内地形属鲁中南山区的西南麓延伸地带,地势从东北向西南倾斜,依次为低山、丘陵、平原、滨湖。现有湿地面积达1.69万hm^2,占全市面积的11.4%,其中：河流湿地0.22万hm^2,库塘湿地0.27万hm^2,滨湖湿地1.2万hm^2。湿地内生物多样性丰富。在调查分析湿地植物、动物资源现状及存在问题的基础上,提出了湿地资源保护管理对策。 相似文献
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近年来新疆盆地平原区域湖泊变化原因分析 总被引：26，自引：4，他引：26
由绿洲及其所在荒漠盆地平原与周边山地系统共同组成的新疆地域系统，是我国西北干旱区的主要部分之一。由于荒漠盆地平原系统不产生径流，因此，地表水、浅层地下水和泉水、湖泊都必然地以相邻的山地系统为供给水源地。从山地进入荒漠盆地平原的河流就成为主要供给渠道。博斯腾湖、艾丁湖、艾比湖1995年以来，湖水水位明显升高，湖水面积的不断扩大，从湖泊水面面积的演变过程，主要水源变化，气温略微上升，降水显著增多诸因素综合系统分析，说明在全球气候背景下，区域气候和水文变化周期与人类活动是影响其变化的主要原因。 相似文献
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近5 a来科尔沁沙地典型区域地下水埋深变化分析 总被引：4，自引：1，他引：3
从2002至2006年奈曼旗地下水埋深监测数据中,选取典型区域的18个监测点,分为三个样带,对其地下水埋深的时空变化及其与降雨量的关系进行分析。结果表明,近5 a典型区域地下水埋深均呈下降趋势,教来河沿岸变化最为明显,年际最大水位差达2.11 m,变化幅度13.6% ~51.4%;空间分布上以教来河沿岸地下水埋深最大,近5 a平均为6.15 m;典型区域年内最高地下水位出现在3—4月,最低水位在8—9月;近5 a来降雨量和多年降雨量分别与同期地下水埋深变化的分析表明,降雨量对研究区地下水埋深影响较小。 相似文献
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北京周围建设用地空间分布格局及解释 总被引：2，自引：0，他引：2
城市对其周围土地利用格局的影响历来是地理学研究的重点领域, 大城市周围建设用地比例高, 分析和解释大城市周围的建设用地格局可进一步拓展我们对此领域的认识。本文 以2005 年北京中心区周围50 km 范围内的建设用地数字化图件为基础, 由内而外, 建立5 个宽度为10 km 的缓冲带, 分析了北京2005 年建设用地空间格局的变化, 并从自然、历史和经济学的角度对此格局作出诠释。主要结论如下: 北京市周围建设用地格局呈现出四条非常清晰的放射带, 这几条放射带和2200 多年前的秦朝驰道吻合; 北京市周围建设用地图斑的空间分布的连续性并没有受到行政区域划分的影响; 缓冲带30-40 km 可能是北京城市中心区在平面上的影响界线; 在缓冲带10-20 km 和缓冲带30-40 km 内, 城市用地比例呈现出两个峰值。 相似文献
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辽南不同岩性地区地下水动态研究 总被引：2，自引：1，他引：1
本文从影响辽南地区地下水动态因素,主要从岩性、蓄水构造的制约因素,探讨分析了辽南不同岩性地带的地下水动态特点,划分了基本类型,揭示其规律性。为因地因时制宜地充分开发,合理有效利用珍贵的地下水资源提供科学依据。 相似文献
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Seven mesas (i.e. flat-topped, isolated mountains) and the Grootberg mountain in arid north-west Namibia were investigated with regard to floristic relationships in relation to environmental gradients. Relationships between mesas and their surrounding, species richness and number of mesa specialists were used as measures to explore the influence of elevation on these floristic parameters. Also soil properties were investigated along these elevation gradients. The overall questions were designed to investigate the importance, i.e. ‘special status’, of these mesas in terms of contributing to species diversity and to elucidating ecological processes in this arid landscape.With regard to special floristic status, the tops of mesas supported different plant communities than their surrounding plains, while slopes indicated various levels of intermingling with plain vegetation. Differences between mesas and plains became more pronounced with increasing elevation. There were, however, no clear vegetation belts related to elevation. Plant species richness and number of mesa specialists showed a trend of increasing numbers with elevation, but these trends were statistically poorly supported, largely due to high variability between samples.Do soil gradients and elevation, as two important environmental variables, affect this ‘special’ status? Pronounced soil gradients were evident for many soil properties. These in combination with altitudinal effects of increased moisture and lower temperatures were believed to directly influence plant species composition and richness. The soil gradients may also indicate nutrient flow from the mesas to the surrounding lowlands, a process of ecological importance, particularly should degradation due to over grazing become a problem in the lowland areas. 相似文献
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河北省中南部农田孢粉组合特征 总被引：4，自引：0，他引：4
河北省中南部82 个农田表土花粉组合研究表明：农田花粉组合不仅有农作物花粉类型,也有临近山区的植物成分。山区农田乔木花粉含量与浓度高于平原,对平原的影响随距离增加而降低,距太行山0～50 km 松属花粉含量为20%～30%,50～100 km 为10%～20%,100～150 km 增至20%～30%,海滨区降至16%以下,平原中部含量增加可能与焚风效应有关;山区至平原乔木花粉含量空间上的变化,可能类似于历史时期人类活动介入森林区后时间上的变化。山区和平原灌木花粉含量较低,但主要成分不同,山区以胡颓子科、榛属、虎榛子较常见,平原区蔷薇科、葡萄科花粉相对较多。平原区草本花粉含量高出山区,其中藜科花粉由山区向平原逐渐增高,可能反映人类活动不断增强的特征。山区中华卷柏含量高于平原,但平原区高达7%。中华卷柏不易被风搬运,推测平原区农田的中华卷柏可能是平原沉积时由河流从山区搬运而来。相同类型农业单元乔木、灌木花粉和蕨类百分比山区一般高于平原,草本低于平原;不同类型农业单元乔木、草本百分比平原区相近,山区差异较大。山区乔木花粉含量差异主要受草本类型影响,平原区草本花粉组合差异主要是农作物花粉(人工禾本科、十字花科) 含量的差异;不同农业单元孢粉浓度差异主要为草本花粉浓度不同。 相似文献
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Gilles Brocard Christian Teyssier Walker James Dunlap Christine Authemayou Thibaud Simon‐Labric Eric Noé Cacao‐Chiquín Axel Gutiérrez‐Orrego Sergio Morán‐Ical 《Basin Research》2011,23(6):631-651
Deeply incised drainage networks are thought to be robust and not easily modified, and are commonly used as passive markers of horizontal strain. Yet, reorganizations (rearrangements) appear in the geologic record. We provide field evidence of the reorganization of a Miocene drainage network in response to strike–slip and vertical displacements in Guatemala. The drainage was deeply incised into a 50‐km‐wide orogen located along the North America–Caribbean plate boundary. It rearranged twice, first during the Late Miocene in response to transpressional uplift along the Polochic fault, and again in the Quaternary in response to transtensional uplift along secondary faults. The pattern of reorganization resembles that produced by the tectonic defeat of rivers that cross growing tectonic structures. Compilation of remote sensing data, field mapping, sediment provenance study, grain‐size analysis and Ar40/Ar39 dating from paleovalleys and their fill reveals that the classic mechanisms of river diversion, such as river avulsion over bedrock, or capture driven by surface runoff, are not sufficient to produce the observed diversions. The sites of diversion coincide spatially with limestone belts and reactivated fault zones, suggesting that solution‐triggered or deformation‐triggered permeability have helped breaching of interfluves. The diversions are also related temporally and spatially to the accumulation of sediment fills in the valleys, upstream of the rising structures. We infer that the breaching of the interfluves was achieved by headward erosion along tributaries fed by groundwater flow tracking from the valleys soon to be captured. Fault zones and limestone belts provided the pathways, and the aquifers occupying the valley fills provided the head pressure that enhanced groundwater circulation. The defeat of rivers crossing the rising structures results essentially from the tectonically enhanced activation of groundwater flow between catchments. 相似文献
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内蒙古呼伦贝尔东明露天煤矿矿坑边帮地下水渗漏的问题日益严重,矿区原有的疏干降水井排水能力及效果已不能满足生产需求,同时对矿区生态环境也造成一定程度破坏。目前,对矿区周边的水文地质条件和水力联系缺乏精准全面的认识和数据。本文通过瞬变电磁法对矿区地下水渗漏较严重的西北部进行三条勘探线(77个物理点)勘查,结果表明该区存在三处视电阻率低阻异常带,判定其主要为含水断层(裂隙)所致;结合矿区地形、地层岩性与矿区地下水矿化度,对上述异常带进行了科学合理的综合解释,并结合新施工的疏干降水井抽水验证了上述异常的可靠性,为矿区后期布置疏干降水井圈定了靶区,对当地同类型矿区地下水渗漏灾害治理起到了应用示范作用。 相似文献
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基于MCR模型和DO指数的九江滨水城市生态安全网络构建 总被引：1，自引：1，他引：0
兼顾生态保护和经济增长的生态安全网络对引导滨水城市走可持续发展道路具有重要指导意义。本文以九江市为例,采用景观生态数据集和产业信息数据集,结合最小累积阻力模型（MCR）和连续空间的产业集聚测度指数（DO）构建了综合评价方法,分别对景观生态格局和经济生产空间进行分析,诊断二者的空间冲突确定战略节点并构建生态安全网络。结果表明：① 研究区包含重要生态源地29个,总面积为7323 km2;生态安全阻力高值区面积占39.69%,位于城市中部和东部连片区域,低值区则处于外围,且连通过渡区域较少,呈现空间上两极分化的“中心—外围”景观生态格局;② 经济生产空间临近水资源分布,呈现为小尺度集聚、大尺度分散的空间格局;主要产业集聚区的平均长度和数量均显示出重度污染行业>轻度污染行业>中度污染行业的空间关系;③ 识别出景观生态廊道总长685.57 km,选取了25个生态—经济战略节点,规划了18条总长424.53 km的重要绿带和26条总长662.46 km的一般绿带,共同构成了“蜂巢状”九江市生态安全网络格局。本文采用自然和经济条件相结合的综合分析视角,为生态安全格局的构建提供了多样化的实现途径。 相似文献
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基于DEM的地貌实体单元自动提取方法 总被引：17，自引：4，他引：13
我国传统地貌基本形态类型分类强调地貌单元的完整性,界线划分沿地貌实体边界而非规则统计单元,目前尚缺乏地貌实体单元的有效自动提取方法。针对这一难点,本文提出一种基于DEM的地貌实体单元数字提取方法。利用坡度分级,并搜索相邻栅格单元、计算坡度级别内相互连通栅格的面积,建立坡度、面积阈值综合判别规则进行山地平原的自动划分;利用地形倒置、水文淹没分析,将山体划分的二维判别规则扩展到实际三维地形中,并结合地形结构线提取算法进行山体界线自动提取、确定山地地貌实体单元。结果表明,该方法符合我国传统地貌分类体系,能够较好实现山地/平原的自动划分和山体界线的数字提取。 相似文献
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大连城市居住环境评价构造与空间分析 总被引：25，自引：6，他引：19
首先,根据大连市城市居民居住环境评价的问卷调查资料,利用因子分析方法构筑了由周边环境、利便环境和社区文化环境组成的居住环境评价构造。多元回归分析表明,利便环境、周边环境和社区文化环境在居住环境评价的重要程度依次降低。其次,利用ARC/INFO平台下划分的162个1km×1km的网格对居住环境评价的空间结构进行分析。周边环境高评价地区主要位于市区边缘和市中心的部分地区,后者与城市广场和绿地有关;利便环境评价由市中心到市区边缘渐次降低,与各地到市中心的时间距离显著负相关,高评价地区高度集中在市街区。利便环境评价则不存在明显的分异规律。最后,在ArcView平台下,充分发挥GIS的图形叠置和逻辑查询功能对居住环境进行评价,并建立了呈不规则四圈层的双核心居住环境评价空间结构模式图。 相似文献
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地下水稳定同位素组成的时空变化特征可以反映不同时期、不同区域地下水补给来源的差异。通过青海湖沙柳河流域浅层地下水氢氧稳定同位素组成的时空变化特征以及地下水、河水与降雨之间的补给关系的分析，结果显示：季风时期，地下水主要受降雨入渗和河流侧向补给为主，在补给过程中蒸发作用是影响地下水稳定同位素值的主要因素；非季风期，冰雪融水对低值区的地下水影响显著，同时降水的快速入渗则是该时期高值区地下水的主要补给方式之一。地下水同位素高值区，地下水与河水间补给作用较弱，补给时间超过5个月；地下水同位素低值区，地下水与河水补给关系较为密切，补给时间在1~4个月间。本文所得结论可初步反映干旱半干旱内陆流域地下水稳定同位素特征以及补给方式的基本规律，在一定程度上可为流域地下水及其他水体间的转换研究提供科学依据，并为地下水资源管理和水环境治理提供一定理论指导。 相似文献
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基于乡镇尺度的河南省人口分布的地统计学分析 总被引：5，自引：1，他引：4
基于地统计学方法,以乡镇层面的第六次人口普查数据为基础,对河南省人口分布及其影响因素进行分析。结果表明：全省人口分布基本上可划分为山区低密度、平原中密度和城市高密度三种类型;变异函数在东西、南北、东北—西南和西北—东南四个方向上趋向相近,距离超过80 km后,各向异性增强;变异函数的指数模型拟合效果最好,插值结果直观地表现了人口疏密的梯度变化;洛阳至淮滨一线为全省较明显的人口分界线;山区和平原两种地形条件是影响该省人口空间格局的基本因素;在平原地区,区位条件和社会经济发展的互动作用又成为影响城镇人口分布的主要因素。在推进城镇化的进程中,应结合主体功能区划和新型城镇化战略,有序推进城乡人口的再分布。 相似文献
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《The Professional geographer》2013,65(2):186-193
The fog climatology of the Sacramento, California, urban area is examined through hourly meteorological records from four Sacramento area airports for the six winter fog seasons of December 1979–January 1980 through December 1984–January 1985. It is hypothesized that winter fogs are more frequent over cities than the surrounding countryside. An assessment of moderate to dense fog (visibility 5/8 mile [1 km] or less) reveals that the urban environment does not experience more fogs. When the definition of fog is expanded to include light fogs with visibility less than 7 miles (11.3 km), a greater frequency of fogs is found within the city. The light fogs probably result from urban air pollution and therefore are not true fogs. It is concluded that the urban environment does not enhance fog accurrence. 相似文献
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Exploring the fringe belt concept in Auckland: An urban morphological idea and planning practice 总被引：1，自引：0，他引：1
Kai Gu 《New Zealand geographer》2010,66(1):44-60
The idea of urban fringe belts has been recognised as a powerful means of understanding the physical form of urban areas and the process of urban outward growth and internal change. Surrounding Auckland's city core, an inner fringe belt can be recognised. Farther out there are middle and outer fringe belts. Fluctuations in socio-economic development, the adoption of new transport modes, land reclamation and topography are major factors influencing the formation of these fringe belts. The examination of changes to fringe belts highlights important issues of urban transformation, which are pertinent to planning and design policies for urban landscape management. 相似文献