新疆地形复杂度的空间格局及地理特征     

张雪莹  张正勇  刘琳  田浩  康紫薇  王统霞  陈泓瑾 《地理研究》2022,41(10):2832-2850

地形复杂度（TCI）是区域地表外在形态结构的数字化表达,既可表征坡面单元的多样性及其组合形式的复杂性,也可映射地球内外营力在地表留下“烙印”的过程,其客观描述和定量表达可为地表形态定义、刻画及分异等地形地貌理论研究提供重要依据。新疆独特的山盆地貌结构为地貌学研究提供了理想的场所。本文基于“倒金字塔滤网系统”逐步筛选微观和宏观坡面因子并确定权重进而构建地形复杂度模型;运用均值变点法确定新疆地形复杂度的最佳窗口,分析不同地貌单元地形复杂度的空间异质性,进一步探究不同营力作用对地表复杂程度的贡献。结果显示：① 地形复杂度模型综合相关性分析、聚类分析、变异系数法与主成分分析等方法对地形因子进行客观筛选与科学组合,使其具有全面客观性及独立有效性。② 地形复杂度以ASTER GDEM数据（30 m）为基础,得到最佳窗口（14×14）下全疆TCI介于0.13~46.36。山地与盆地相同地貌类型TCI面积占比峰值相近,不同地貌类型可比较其斜率、偏度及峰度得以区分。在经纬向上能更好的刻画出独立山峰及深切峡谷等局部地形分异,TCI≈1可作为平原与山地地貌单元之间的分界值。在高程分区下TCI>2时为各山系（山群）震荡高程区起始处,山麓处TCI曲线差异显著。③ 地形复杂度能较好的体现不同外营力在地表留下的痕迹,一定程度上也可表征外营力对不同成因地貌类型的贡献度。本研究对新疆地形地貌的形态特征和形成原因等方面提供理论依据和科学方法,可为地形地貌研究、生态环境影响以及区域发展评价提供实践指导。  相似文献   

基于肝-肠-脑轴探讨承气汤联合针灸对肝性脑病的治疗作用          下载免费PDF全文

刘水馨  刘琳  刘洁 《应用海洋学学报》2021,37(4):181

  相似文献   

莱芜市被征地农民基本养老保险问题初探     

李伟  刘琳 《山东地质》2010,(4):43-45

莱芜市本着即征即保和被征地后人均农用地不足0.3亩整体参保的原则,将全市所有被征地农民全部纳入基本养老保险范围,全面实施了被征地农民基本养老保险制度。但具体实施过程中仍然遇到一些困难和问题。对莱芜市被征地农民基本养老保险现行政策及实施过程中遇到的困难和存在问题进行了分析,并提出了合理化建议。  相似文献   

基于J2EE的Web GIS-GeoSurf的体系结构与实现技术   总被引：5，自引：0，他引：5  

朱欣焰  龚健雅  陈能成  刘琳 《地理信息世界》2003,1(6):18-25

主要介绍基于J2EE的网络地理信息系统平台GeoSurf的构成、体系结构和主要功能。重点讨论了GeoSurf的主要实现原理和关键技术。  相似文献   

太子河本溪城区段河流水生态系统健康评价     

于英潭  王首鹏  刘琳  邢芳芳  张朝星  钟达  赵文博  王俭 《气象与环境学报》2020,36(1):89-95

太子河作为本溪的主要河流,是本溪工业、农业、生活的主要水源,为了更好的了解太子河本溪城区段的水体情况,以太子河本溪城区段流域为研究对象,基于2017年的平水期（4月）、丰水期（8月）、枯水期（11月）18个监测断面的监测数据,结合太子河本溪城区段的实际情况和特点,利用层次分析法的评价指标体系,对太子河本溪城区段进行水生态系统健康评价。通过比较分析,最终以平水期的评价结果为主,丰水期和枯水期的评价结果为辅。结果表明：仅有22%的监测断面处于健康状态、56%的监测断面处于亚健康状态、22%的监测断面处于一般状态,说明太子河本溪城区段大部分流域处于亚健康状态,水生态系统退化,需要加强管理和治理保护。  相似文献   

Features and spatial distribution of circumpolar deep water in the southern Indian Ocean and the effects of Antarctic circum polar current     

蒲书箴  董兆乾  于卫东  卢燕  项宝强 《极地研究(英文版)》2007,18(2):100-109

The data from the Southern Ocean observations of World Ocean Circulation Experiment(WOCE) are used for analysis and illustration of the features and spatial distributions of Circumpolar Deep Water(CDW) in the southern Indian Ocean.It is learnt from the comparison among the vertical distributions of temperature/salinity/oxygen along the 30°E,90°E and 145°E sections respectively that some different features of CDW and the fronts can be found at those longitudes,and those differences can be attributed to the zonal transoceanic flow and the merizonal movement in the Circumpolar Deep Water.In fact,the zonal transoceanic flow is the main dynamic factor for the water exchange between the Pacific Ocean and the Indian Ocean or between the Atlantic Ocean and the Indian Ocean,and for the effects on the spatial distributions of the physical properties in CDW.  相似文献   

Thermohaline structure inhomogeneity associated with polynia at the northern margin of Emery Ice-shelf     

蒲书箴  葛人峰  董兆乾  于卫东  史久新  项宝强 《极地研究(英文版)》2007,18(1):18-26

Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.  相似文献   

极端降水天气预报指数对气候累积概率分布敏感性研究     

汪娇阳  陈静  刘琳  田华 《湖北气象》2014,(4)

针对中国气象局T213全球集合预报系统历史样本较短、极端降水天气预报指数数学模型中气候累积概率分布样本不足的问题,选取气候背景和地理地貌特征较为相似的长江中下游地区,利用扩展时间序列和空间范围的方法,增加T213全球集合预报系统的降水预报气候分布样本数,改进模式降水预报气候累积概率分布,利用2011年6月10—20日集合预报资料进行极端降水天气预报指数预报试验,分析气候累积概率分布敏感性。结果显示:扩展时间序列和空间范围增加模式T213集合预报气候样本数的方法,生成的模式气候累积概率分布较单一格点方法更具代表性,能提高极端降水天气预报指数的识别技巧,并提前8 d发出长江中下游地区极端强降水预报信号。  相似文献   

印尼爪哇上升流海域次表层叶绿素最大值层的浮游植物色素分布特征     

高春蕾  傅明珠  宋洪军  王磊  韦钦胜  孙萍  刘琳  张学雷 《海洋学报(英文版)》2018,37(12):97-106

Upwelling occurs on the coast of Java between June and October, forced by local alongshore winds associated with the southeasterly monsoon. This causes variations in phytoplankton community composition in the upwelling zone compared with the surrounding offshore area. Based on pigments analysis with subsequent calculations of group contributions to total chlorophyll a(Chl a) using CHEMTAX, we studied the distribution and composition of phytoplankton assemblages in the subsurface chlorophyll maximum along the south coast of Java and the influence of upwelling. Nineteen phytoplankton pigments were identified using high-performance liquid chromatography, and CHEMTAX analysis associated these to ten major phytoplankton groups. The phytoplankton community in the coastal area influenced by upwelling was characterized by high Chl a and fucoxanthin concentrations, indicating the dominance of diatoms. In contrast, in the offshore area, the Chl a and fucoxanthin concentrations declined to very low levels and the community was dominated by haptophytes represented by 19′-Hexanoyloxyfucoxanthin. Accordingly, microphytoplankton was found to be the major size class in the coastal area influenced by upwelling, while nanophytoplankton was most abundant in the offshore area. Low concentrations of other accessory pigments indicated less contribution from dinoflagellates,prasinophytes, chlorophytes and cryptophytes. Photo-pigment indices revealed that photosynthetic carotenoids(PSCs) were the largest component of the pigment pool, exceeding the proportion of Chl a, with the average PSCTP up to 0.62. These distribution trends can mainly be explained by phytoplankton adaption strategies to upwelling and subsurface conditions by changing species composition and adjusting the pigment pool.  相似文献   

1011号台风“凡亚比”粤西暴雨二次加强过程的分析     

刘琳  麻素红 《成都信息工程学院学报》2012,27(4):429-436

为了能够深入了解1011号台风"凡亚比"粤西暴雨过程发生发展机制,采用天气学诊断方法、Ncep1°×1°再分析资料和观测降水资料对凡亚比登陆后在广东西部地区造成的两次暴雨过程进行了研究。通过初步诊断分析得到以下结论:粤西暴雨二次增强的主要原因是强冷空气侵入和水汽输送增加,二次增强过程偏南风主导的水汽条件造成了暴雨增强。假相当位温的垂直剖面显示暴雨主要发生在等值线密集陡峭的区域,等值线的斜率增加对暴雨二次增强有指示作用。湿位涡在暴雨区为上正下负的垂直分布形式,对流层上层高值位涡向下传递,高层干冷空气与低层暖湿气流交汇促使降水增加。  相似文献