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1.
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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基于地理格网的新疆地貌区划方法与实现 总被引：3，自引：1，他引：2
利用遥感影像和Srtm-DEM等多源信息解译的新疆数字地貌图为基础数据源,运用地理格网方法对新疆地貌类型分布进行定性与定量分析,在此基础上,通过自下而上的合并与自上而下的划分相结合的系统聚类分析法,确定各级地貌区划单元及其区划界线,实现新疆地貌的智能化分区。将新疆地貌分为一级、二级和三级地貌区划。其中,一级为6个地貌区 ,二级为23个地貌区,三级为200个地貌区。研究结果表明,在所依据的地貌数据基础上,采用地理格网地貌区划方法,能够实现地貌区划的智能化分区。本研究中的地貌分区和区划等级合理,区划界线准确可靠,利用地理格网方法实现了区划的定量化和数字化。 相似文献
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邻域算法在景观分析中的应用 总被引：1，自引：1，他引：0
景观过渡带是景观空间异质性较高的地区,在分析中经常需要从中提取不同类型区的界线,确定相应的范围。提出一种基于邻域概念的简易算法,根据分界线两侧景观的显著差异,在非特定方向上对连续或者离散的景观单元进行类型判定,依据界线的位置特征和类型隶属上的双重属性设定临界值,在此基础上得到判定条件下的单元,消去孤立分布的单元后,经格式转换求出分界线。本文以首都圈景观为例,给出这种算法的明确步骤,解析出地貌分界线,检验了这种方法的准确程度,简要讨论这种方法的特点和适用性,并在其他景观分析中进行推广验证。这种算法能够确定两种复杂分布类型之间的界线,适用于划分农牧交错区,提取地貌分界线和谷缘线等分析。 相似文献
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我国幅员辽阔,地貌类型复杂,种类繁多。这些千变万化的区域地貌景观,都固有其发生、发展的规律。从宏观上来讲,一般认为反映在地貌上有三条重要界线;第一条是南北向界线,即贺兰山——六盘山——龙门山——横断山;第二、三条则为东西向的界线,即天山——阴山和昆仑山——秦岭——大别山。这几条界线相互交切,勾绘了中国地貌形态结构分区的主要轮廓。在第三条界线中的东段秦岭、大别山一线,北部以堆积平原、高原为主,高峻山地不多;南部绝大部分是山地、丘陵和小型盆地。因处于东部季风湿润区,在外营力的表现上以流水作用为主。天山——阴山以北的蒙新高平原地区, 相似文献
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《干旱区地理》2016,(2)
流域划分是研究区域水量平衡的基础和前提。山区和大平原区流域划分的技术已较为成熟,但在山区、平原区复合的复杂地形地貌特征区域,流域划分方法仍处于探索阶段。该地区陆面水文循环过程复杂,地表水和地下水相互补给关系密切,单以山区流域划分技术平原区流域划分技术无法完整的划分出研究区所在的全流域,进而导致流域内水文循环体系不完整。选择典型代表内蒙古河套灌区流域为例,综合山区山脊线、天然河流和灌域边界来进行流域划分,提出了采用修正系数处理平原灌区小地形起伏,依据灌溉排水系统重新划定子流域和结合土地利用图确定山区、平原复合地貌区边界的综合处理技术。划分结果表明,研究区河网拟合度高,水文循环单元符合用水管理特点,复合地貌区山区流域面积占总流域面积的58.1%。在以全流域尺度计算区域内水量平衡时,山区流域面积不能忽略。该方法的成功应用为灌区流域内的供水用水平衡及农业施肥对下游污染研究提供基础。同时也为其它具有相似地貌类型的地区流域划分提供思路和参考。 相似文献
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西北干旱区地表水与地下水资源转换的几个问题探讨 总被引：8，自引：0，他引：8
从山区至平原，地表水下地下水之间在不同地质地貌单元相互，是我国西北干旱区山前平原水资源的主要特点，直接影响到水资源开发利用模式的变化。 相似文献
8.
利用中国大陆160个地面站和寒潮关键区9个站点气象数据,采用聚类分析、相关分析、突变检验方法,分析1951~2005年中国大陆冬季温度变化过程的区域差异。结果表明,中国大陆冬季温度变化可分5个大区,共11个亚区(基本区域单元),各区分界线多与大地貌单元的界线相一致;除川黔桂区外,其余10个亚区均表现出显著升温趋势,升温率0.15~0.54℃/10 a;自北向南,升温速率逐渐减小,开始升温时间推迟。中国大陆冬季温度变化过程的空间差异与各区域受北方冷空气影响程度的不同密切相关,是冬季风环流与大地貌格局共同作用的结果。 相似文献
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针对当前单一地貌划分单元造成的分类结果破碎或漏分问题,该文引入双尺度流域单元划分方法,即采用两种不同大小流域单元的组合作为地貌划分基本单元,以提高地貌划分的细分性和完整性。以30 m ASTER GDEM数据为数据源,基于最佳地形因子组合(高程、地势起伏度、坡度、坡度变率、光照模拟值)、双尺度流域单元、CART决策树算法,实现了北回归线(云南段)地区平原(2类)和山地(7类)共9类地貌的划分,双尺度流域单元划分的最佳流量阈值分别为500、2000。通过平均值、标准差、Moran′s I和人工判读结果对分类结果进行检验,发现基于CART决策树的双尺度流域单元地貌分类方法在北回归线(云南段)地区总体精度可达82.1%,Kappa系数为0.793,总体能够准确识别出研究区的地貌类型空间分布特征,是地貌类型划分的一种可行方法。 相似文献
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华北平原地下水动态变化 总被引：2，自引：0，他引：2
The groundwater level of 39 observation wells including 35 unconfined wells and 4 confined wells from 2004 to 2006 in North
China Plain (NCP) was monitored using automatic groundwater monitoring data loggers KADEC-MIZU II of Japan. The automatic
groundwater sensors were installed for the corporation project between China and Japan. Combined with the monitoring results
from 2004 to 2006 with the major factors affecting the dynamic patterns of groundwater, such as topography and landform, depth
of groundwater level, exploitation or discharge extent, rivers and lakes, the dynamic regions of NCP groundwater were gotten.
According to the dynamic features of groundwater in NCP, six dynamic patterns of groundwater level were identified, including
discharge pattern in the piedmont plain, lateral recharge-runoff-discharge pattern in the piedmont plain, recharge-discharge
pattern in the central channel zone, precipitation infiltration-evaporation pattern in the shallow groundwater region of the
central plain, lateral recharge-evaporation pattern in the recharge-affected area along the Yellow River and infiltration-discharge-evaporation
pattern in the littoral plain. Based on this, the groundwater fluctuation features of various dynamic patterns were interpreted
and the influencing factors of different dynamic patterns were compared.
Foundation: National Natural Sciences Foundation of China, No.40671034; No.40830636
Author: Wang Shiqin (1981–), Ph.D., specialized in hydrology and water resources, water cycle of watershed. 相似文献
12.
WANG Shiqin SONG Xianfang WANG Qinxue XIAO Guoqiang LIU Changming LIU Jianrong 《地理学报》2009,19(2):175-188
The groundwater level of 39 observation wells including 35 unconfined wells and 4 confined wells from 2004 to 2006 in North China Plain (NCP) was monitored using automatic groundwater monitoring data loggers KADEC-MIZU II of Japan. The automatic groundwater sensors were installed for the corporation project between China and Japan. Combined with the monitoring results from 2004 to 2006 with the major factors affecting the dynamic patterns of groundwater, such as topography and landform, depth of groundwater level, exploitation or discharge extent, rivers and lakes, the dynamic regions of NCP groundwater were gotten. According to the dynamic features of groundwater in NCP, six dynamic patterns of groundwater level were identified, including discharge pattern in the piedmont plain, lateral recharge– runoff–discharge pattern in the piedmont plain, recharge–discharge pattern in the central channel zone, precipitation infiltration–evaporation pattern in the shallow groundwater region of the central plain, lateral recharge–evaporation pattern in the recharge-affected area along the Yellow River and infiltration–discharge–evaporation pattern in the littoral plain. Based on this, the groundwater fluctuation features of various dynamic patterns were interpreted and the influencing factors of different dynamic patterns were compared. 相似文献
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以新疆典型干旱区内陆河流域为研究对象,通过对地理、地貌、水文气象条件、流域水循环特征的系统分析,提出了水资源开发利用存在的三大问题,即:水资源匮乏且时空分布严重失衡,跨界河流水安全问题突出;水资源过度开发利用,人工绿洲与天然绿洲结构严重失调,生态环境恶化;水资源利用效率效益低,供需矛盾和水盐平衡失控。以水问题和水需求为导向,工程措施与生态保护并举,采用系统科学的基础理论与分析方法,构建了三层级多目标水循环调控理论与工程技术体系,分别从宏观、中观、微观三个层级,提出了区域、流域、灌区水循环调控与水资源高效利用的科学模式和关键技术。结合区域地形地貌特点和水资源禀赋条件,建立了北疆"网式"、南疆"环式"、东疆"串式"结构水循环调控框架,增强区域水资源合理配置的调控能力。针对流域水循环特点,提出山区水库替代平原水库和河道内与河道外引水"三七调控"、经济与生态耗水"五五分账"的综合调控模式。围绕现代灌区建设和面临的挑战,研究指出建立节水灌溉—水盐调控—地下水利用—生态保护"四位一体"的水资源高效利用综合调控技术体系,是干旱区绿洲农业可持续发展的方向。 相似文献
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The complete life cycle of a permafrost mound is reconstructed from its growth until its degradation. The study site is a lithalsa, which is the subject of a long-term monitoring that includes geocryological observations, measurements of permafrost properties on cores, ground temperature measurements, and observations of landform changes. The landform likely grew as a palsa under cold climatic conditions in the past. The peat cover was subsequently eroded. Early stages of degradation are witnessed since 2003 as a new thermokarst pond is starting to form though mound collapse. Settlement of the structure has been observed, and a rim ridge has begun to form. Ultimately, the lithalsa shall disappear and be replaced by a circular thermokarst pond surrounded by a rampart, similar to many other ones in the study area. The monitoring of the thermal regime of the lithalsa illustrates the pattern of internal warming and points to the causes of its degradation. 相似文献
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近年来黄河流域人与水资源矛盾愈发突出,尤其是地下水储量的过度消耗已成为限制该区域人与自然和谐发展的主要矛盾之一。基于重力反演与气候实验卫星数据和全球陆面数据同化系数数据,根据流域水循环与水量平衡原理,测算2003—2016年黄河流域地下水储量的变化情况,在探究其时空变化特征的基础上,识别了地下水储量下降明显区域的人口暴露度。结果表明：（1） 空间分布上,黄河流域地下水储量西多东少,由西向东下降程度不断加剧,且下降区域呈现由下游向中上游扩散的态势。下降区域主要集中在中东部地区,变化等级以较剧烈减少和剧烈减少为主。（2） 时间变化上,2003—2016年黄河流域地下水储量整体呈下降趋势,年均降幅为5.93 mm·a-1。其中,2004—2016年为连续下降,2015—2016年的下降幅度最大;另外,地下水储量时间变化存在季节效应,地下水储量下降幅度春季最大、冬季次之、秋季再次之、夏季最小。（3） 地下水暴露风险状态下的地级市人口密度在空间上呈东高西低、中部交错分布的状态,暴露风险人口密度最大地级市共16个;地下水储量下降人口累积百分比呈现明显上升的趋势,在2016年达到最大值。研究结果以期为黄河流域地下水资源可持续利用提供科学参考。 相似文献
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Mima-like mounds in the Laramie Basin occur where: (1) impervious bedrock (shale) is at a shallow depth (∼ 2–5 m); (2) bedrock is overlain by a thin veneer (∼ 1–4 m) of alluvial gravels; and (3) a strong argillic/calcic or petrocalcic soil caps the landform, typically a terrace. Active and inactive mounds contain churned materials, including pebbles derived from adjacent/subjacent units. The mounds are circular in plan view and lens- or funnel-shaped in cross-section. The strong intermound (premound) soil collapses beneath the mound, is entirely or partly destroyed at its base, or is truncated at the mound edge. Stratigraphic relationships on the youngest terrace of the Laramie River indicate that the inactive mounds are Holocene in age.Sodium concentrations (used as a tracer) in mound material and adjacent/subjacent units suggest that the mounds rotate counterclockwise. This movement may be driven by free spiral vortices (low hydraulic head) in confined (artesian) groundwater flow in alluvium between shallow bedrock and strong surface soil. The vortices (similar to water draining from a bathtub or a whirlpool in a river) may result from enlargements, constrictions, or changes in permeability of the aquifer — or meandering of groundwater flow. Groundwater, dissolved ions, and materials in suspension, or through friction and turbidity, then would move from adjacent high-hydraulic head areas into and down the vortex. In effect, the high head (intermound) areas would act as a pump whereas the vortex (which would form a mound) would act as a turbine — responding, therefore, to energy transformations between groundwater velocity and pressure according to the Bernoulli principle and Newton's Second Law of Motion. Soil or sediment, incapable of being fully moved into and down the vortex, would amass at the land surface as a circular mound that in cross-section would have a lens or funnel (turbine) shape. Computer modelling shows that mounds tend to form over deep bedrock and thick alluvium.The groundwater vortex hypothesis can account for the building of the mound higher at its center, the circular plan view and lens (or funnel) shape in cross-section, the inward spiral of sodium, the churned character of mound material, and the collapse (or truncation) of soils and other units beneath and along mound edges. The hypothesis, however, must not be applied to all other Mima or mima-like mounds, unless vortex motion can be determined and if stratigraphic similarities can be demonstrated. 相似文献
18.
YE Qinghua TIAN Guoliang LIU Gaohuan YE Jingmin YAO Xin LIU Qingsheng LOU Weiguo WU Shuguang 《地理学报》2004,14(2):131-142
Comprehensive study on land-use change of spatial pattern and temporal process is the key component in LUCC study nowadays. Based on the theories and methods of Geo-information Tupu (Carto-methodology in Geo-information, CMGI), integration of spatial pattern and temporal processes of land-use change in the Yellow River Delta (YRD) are studied in the paper, which is supported by ERDAS and ARC/INFO software. The main contents include: (1) concept models of Tupu by spatial-temporal integration on land-use change, whose Tupu unit is synthesized by "Spatial·Attribute·Process" features and composed of relatively homogeneous geographical unit and temporal unit; (2) data sources and handling process, where four stages of spatial features in 1956, 1984, 1991, and 1996 are acquired; (3) integration of series of temporal-spatial Tupu, reconstruction series of "Arising" Tupu, spatial-temporal Process Tupu and the spatial temporal Pattern Tupu on land-use change by remap tables; (4) Pattern Tupu analysis on land-use change in YRD during 1956-1996; and (5) spatial difference of the Pattern Tupu analysis by dynamic Tupu units. The various landform units and seven sub-deltas generated by the Yellow River since 1855 are different. The Tupu analysis on land-use in the paper is a promising try on the comprehensive research of "spatial pattern of dynamic process" and "temporal process of spatial pattern" in LUCC research. The Tupu methodology would be a powerful and efficient tool on integrated studies of spatial pattern and temporal process in Geo-science. 相似文献
19.
雅鲁藏布江河谷风沙地貌分类与发育问题 总被引：8，自引：7，他引：8
雅鲁藏布江河谷风沙地分类体系则４级２１个类型组成，其中风积地貌划分为谷底与谷坡风积地貌２个亚类。河谷风沙地貌面积１９２９．９４６ｋｍ＾２，可称为“雅鲁藏布江河谷沙地”。河谷区具有沙源，风动力和堆积场地等风沙地貌形成的基本条件。 相似文献