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911.
分布式时变增益流域水循环模拟   总被引:55,自引:0,他引:55  
夏军  王纲胜  吕爱锋  谈戈 《地理学报》2003,58(5):789-796
针对分布式水文模拟的问题,结合河西走廊黑河流域实际资料条件,提出将水文循环空间数字化信息与水文系统理论相结合的分布式时变增益水循环模型 (DTVGM)。DTVGM将单元时变增益水文非线性模型(TVGM)拓广到由DEM划分的流域单元网格上建立非线性地表水产流模型,基于水量平衡方程和蓄泄方程建立土壤水产流模型,并应用运动波方法建立分级网格汇流模型。最后,以黑河干流山区流域为例应用DTVGM开展了实例研究,设计开发了模型系统。研究区域被划分为38 277个网格单元 (网格大小为500 m×500 m),在此基础上将流域划分为456级带状汇流区域。考虑到黑河干流山区的寒区特点,模型耦合了融雪径流模型。模拟结果表明,DTVGM既有分布式水文概念性模拟的特征,同时具有水文系统分析适应能力强的优点,能够在水文资料信息不完全或者有不确定性干扰条件获得比较好的分布式水文模拟效率,在黑河干流山区的应用能够较好地满足水资源管理的要求。  相似文献   
912.
In this study, long‐term discharge data and climate records, such as temperature and precipitation during 1977–2006, have been used to define basin climatic and hydrologic regimes and changes. Discharge analyses at four key gauging stations (Eagle, Stevens Village, Nenana, and Pilot Station) in the Yukon River Basin show that the runoff in the cold season (November to April) is low with small variations, whereas it is high (28 500–177 000 ft3/s; 810–5000 m3/s) with high fluctuations in the warm season (May to October). The Stevens Village Station is in the upper basin and has similar changes with the flow near basin outlet. Flow increases in May (61 074 ft3/s; 1729 m3/s) and September (23 325 ft3/s; 660 m3/s); and decreases in July (35 174 ft3/s; 996 m3/s) and August (6809 ft3/s; 193 m3/s). Discharge in May at the Pilot Station (near the basin outlet) shows a positive trend (177 000 ft3/s; 5010 m3/s). Daily flow analyses show high fluctuation during the warm season and very low flow during the cold season; the 10‐year average analyses of daily flow at Pilot Station show a small increase in the peak and its timing shifted to a little earlier date. The annual flow, average of 227 900 ft3/s (6450 m3/s) with high inter‐annual fluctuations, has increased by 18 200 ft3/s (or 8%; 520 m3/s) during 1977–2006. From 1977 to 2006, basin air temperature in June has increased by 3.9 °F (2.2 °C) and decreased by 10.5 °F (5.8 °C) in January. A strong and positive correlation exists between air temperature in April and discharge in May, whereas a strong and negative correlation relates August temperature and September discharge. Negative trend during 1977–2006 is observed for precipitation in June (0.6 in.; 15 mm) with a confidence over 93%. Precipitation in August and September has strong and positive correlations with discharge in September and October at basin outlet; the precipitation in other months has weak correlation with the discharge. The mean annual precipitation during 1977–2006 increased by 1.1 in. (or 8%; 28 mm), which contributes to the annual flow increase during the study period. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
913.
我对白云鄂博铁铌稀土矿床的研究过程及往见新识   总被引:1,自引:1,他引:0  
白鸽 《地质学报》2012,86(5):679-682
80年前,丁道衡先生奉命去西北进行古生物考查研究工作,取道乌蒙草原,突然看到荒漠大地上有一座高耸美丽的神山,作了旅游参观之举.走到山脚下,就看到很多黑黑的滚石,到山上,更见有大块致密的磁铁矿石和红绿条带相间的赤铁矿石,就这样偶然发现了白云鄂博大型铁矿床.  相似文献   
914.
基于等价分析法评估溢油事故的自然资源损害   总被引:2,自引:0,他引:2  
尽管国际公约和许多国家立法已将海上溢油事故导致的自然资源损失列入索赔范围,然而,在量化和货币化损害以及确定索赔和修复范围等方面尚未建立被广泛接受的计算方法。生境等价分析(Habitat Equivalency Analysis,HEA)和资源等价分析(Resource Equivalency Analysis,REA)是美国和欧盟应用于评估自然资源损害的理论方法,二者的关键假设是受损的生态服务损失和修复计划的服务收益应当相等。HEA结果依赖于生态服务价值标尺选择、服务价值水平、恢复曲线形状、修复计划时长以及贴现率等;REA结果受死亡生物数量和年龄组成的影响。HEA和REA的非货币形式结果补偿的并非生态环境,而是人类社会福祉。目前,一些货币化损失的方法已被提出,然而传统经济学家和生态经济学家之间存在争议。美国部分法庭承认HEA和REA方法,其结果为法庭索赔提供数据支持。如果将生态学和经济学原理结合考虑,将能够促进等价分析法的深入发展,推动索赔工作更加有理有据。  相似文献   
915.
The Zhangjiajie Sandstone Peak Forest Geopark in northwest Hunan Province, China, is a comprehensive geopark containing many spectacular quartz sandstone landforms, limestone karst landscapes and various other important geoheritage resources. It is listed as a UNESCO World Geopark and is also part of the World Heritage Wulingyuan Scenic and Historic Interest Area for its important landscape features. Many of the sandstone landforms, particularly the vast number of thin pillars or spires, are very unusual and serve as the core landscapes of the geopark. But Zhangjiajie displays a diverse range of landform types, exhibiting spectacular patterns and regular distributions. In this paper, the geomorphic traits, distribution pattern and constraints of the sandstone landforms of the Zhangjiajie Geopark are examined. Our study indicates that in the outcropping areas, the sandstones display four distinctive levels from 300 to 1,000 m above sea level, and these extend clearly from the highest sandstone plateau platform to the center of the valleys. The high sandstone platforms developed close to a flat high-level erosional surface, and subsequent erosion into this plateau has resulted in successively lower levels of landforms that transition gradually from peak walls, peak clusters, peak forests and peak pillars to remnant peaks in the lower valley bottoms. The form and distribution of the Zhangjiajie sandstone landforms are primarily dominated by the geological setting, particularly the presence of brittle structures (fractures and joint sets) trending NNW, ENE and NE. Triggered by the episodic tectonic movements, major streams and escarpments frequently occur along these structural directions, while some of the peak walls, peak clusters and peak forests have their longer elongated axes corresponding to NE or NNW directions, with an increased density of peak forms at the intersection of these fractures and joints. The geometry of the diverse sandstone landforms is also influenced to a certain degree by the climatic, water system distribution, lithologic properties, biological process, meteorological features and denudation processes. The suite of quartz sandstone landforms in Zhangjiajie can be compared with other sandstone landscapes regionally, and our interpretation of the sandstone peak forest formation processes offers a significant contribution to the study of topographic features and the geomorphic evolution of sandstone landscapes.  相似文献   
916.
Generally, pixels are the basic unit for assessment of landslide susceptibility. However, even if the results facilitate the comparison, a pixel-based analysis does not clearly illustrate the distribution relationships. To eliminate this deficiency, the concept of the Landslide Response Unit (LRU) is proposed in this study, for which adjacent pixels that have similar properties are combined as a basic unit for susceptibility assessment. The Subao River basin, seriously impacted by the Wenchuan Earthquake, was selected as the study area, and three factors including slope gradient, slope aspect, and slope shape, which have a significant impact on landslides, were chosen to divide the basin into 25,984 LRUs. Then topographic, geologic, and distance factors were applied for the landslide susceptibility evaluation. The logistic regression method was used to establish the susceptibility assessing model by analyzing 2,000 susceptible LRUs and 2,000 un-susceptible LRUs. The model accuracy was defined in terms of the ROC curve value and the κ value, 0.531 and 0.84, respectively. The susceptibility of landslides was divided into low, moderate, high, and very high in Subao River basin, and 73% of historical landslides and all four new landslides are in the highly susceptible zone and very highly susceptible zones. Finally, the LRUs with houses, farmlands, and roads prone to sliding and burial hazard were assessed separately. On the basis of considering the potential movement directions of the LRUs, the result found that 1,001 and 835 LRUs probably would be destroyed by slope sliding and landslide burial, respectively.  相似文献   
917.
大天区面积多目标光纤光谱望远镜(LAMOST)使用了16台低色散光谱仪、32台科学级CCD相机对目标进行光谱拍摄。CCD集总控制器MASTER是其32台CCD相机的中枢,它控制CCD按观测需要进行曝光、管理CCD状态和诊断相机故障。针对LAMOST相机系统的结构和UCAM控制器的特点,设计了MASTER系统;介绍了与OCS和UCAM接口的方式,并分析了对命令和状态的管理。  相似文献   
918.
大河河口的动力沉积过程一直是陆海相互作用研究的核心内容,其中水体泥沙的垂向交换是河口动力-沉积机制分析中的关键环节。基于2011年12月对长江河口及其邻近海湾采集的大范围、高密度的近底层悬沙、海床表层1~2cm(表层沉积物)和垂向向下约2~10cm的沉积物(次表层沉积物)同步3组303个样品,利用经验正交函数方法,对河口地区的悬沙和沉积物交换过程进行研究。结果表明:近底层水体悬沙的空间分布模式主要以粉砂粒级为主,空间分布差异性不大;表层及次表层沉积物的空间分布模式相似,但较近底层水体悬沙的分布复杂,存在明显的区域性特征,其中南汇边滩水域中部辐散区的沉积物表现为粗粉砂-细砂模式,其他区域由粉砂组分模式组成。近底层水体悬沙、表层和次表层沉积物的第一模态主要反映了粒径较细的泥沙运动,第二模态主要反映了粒径较粗的泥沙运动。在近底层水体悬沙与表层沉积物的垂向交换中,主要交换粒级为粉砂组分粒级。在表层沉积物与次表层沉积物的垂向交换中,南汇边滩中部辐散区的主要交换粒级为粗粉砂-细砂组分粒级,其他区域主要为粉砂组分粒级。  相似文献   
919.
中国成菱镁矿区带与关键科学问题   总被引:5,自引:0,他引:5  
赵正  白鸽  王登红  陈毓川  徐志刚 《地质学报》2014,88(12):2326-2338
我国菱镁矿资源丰富,储量巨大,目前位居世界首位.类型上以晶质菱镁矿为主,便于开发利用.晶质菱镁矿又以沉积变质型为主,集中分布在辽东地区,形成了世界级的大型—超大型菱镁矿集中区和生产基地,其次为成因上与超镁铁质杂岩密切相关的热液交代型和风化残积型,青藏班公湖成矿带可作为我国湖相沉积型菱镁矿找矿的重要靶区.本次在对全国62处菱镁矿矿产地资料系统梳理的基础上,深入总结了全国菱镁矿的成矿规律,进一步划分了菱镁矿的矿床类型,并划分出13个成菱镁矿带,编制了“中国菱镁矿成矿规律图”、“中国菱镁矿成矿体系图”和“中国成菱镁矿带分布图”等图件,为我国菱镁矿资源潜力评价的预测工作提供了理论依据.同时,本文对我国辽东超大型菱镁矿的成因机制问题和菱镁矿中镁的物质来源等关键科学问题展开了探讨.  相似文献   
920.
In this paper, the data envelopment analysis (DEA) method is introduced to analyze the input–output efficiency of energy consumption and economic indicators in Beijing city under the influence of short-term climatic factors. Total energy consumption, fixed asset investment, average temperature, precipitation, sunshine hours, average wind velocity and the average pressure being employed as the input variables, gross domestic product (GDP) and per capita disposable income being employed as the output variables, effective technology and the validity of the scale of DEA of 31 decision-making units (DMUs) under the influence of the short-term climatic factors are analyzed, and the inefficient DMUs are improved. Empirical analysis shows that both energy consumption and economic growth are sensitive to short-term climate condition, and the reasonable employing of extreme climatic conditions is a question worthy of consideration. This study provides effective basis for the scientific and reasonable arrangement of Beijing city’s short-term climatic resources and energy–economic development.  相似文献   
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