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991.
成都市土地利用现状遥感调查研究   总被引:2,自引:0,他引:2  
利用美国陆地卫星TM遥感图像资料,对成都市土地利用现状进行调查研究,全面系统地查明了成都市土地利用状况及其分布规律,分析与评价了土地利用的合理程度,揭示了土地利用中存在的主要问题,并提出了土地资源可持续利用的对策与建议,可为政府有关部门合理利用土地资源,制定国土整治规划提供科学依据。  相似文献   
992.
本文以黄骅坳陷港西开发区为例,探讨在油田开发阶段,如何通过密井网区沉积微相定量几何学数据对新近系明化镇组沉积环境相似的稀井网区进行沉积微相三维建模的方法。密井网区研究表明,港西开发区河流相的单河道砂体宽度约50-300 m,一般为100-200 m,厚度约5-15 m,一般为6-10 m;漫溢砂体长、宽一般小于200 m;砂体结构主要为迷宫状和拼合板状两种型式。应用密井网区沉积微相定量几何学数据,采用标点过程方法,对井网较稀的目标研究区进行了三维沉积微相建模研究,并取得了良好的应用效果。  相似文献   
993.
通过对近10年北太平洋冬季阻塞性高压的建立、维持及崩溃的天气形势分析,结合船舶气象导航的原理、气象航线的设计以及影响航线选择的因素,指出了有利于北太平洋冬季西行高纬度航线的阻塞高压形式,为船舶西行选择高纬度航线提供了气象理论依据。  相似文献   
994.
-- The main idea of the Load-Unload Response Ratio (LURR) is that when a system is stable, its response to loading corresponds to its response to unloading, whereas when the system is approaching an unstable state, the response to loading and unloading becomes quite different. High LURR values and observations of Accelerating Moment/Energy Release (AMR/AER) prior to large earthquakes have led different research groups to suggest intermediate-term earthquake prediction is possible and imply that the LURR and AMR/AER observations may have a similar physical origin. To study this possibility, we conducted a retrospective examination of several Australian and Chinese earthquakes with magnitudes ranging from 5.0 to 7.9, including Australia's deadly Newcastle earthquake and the devastating Tangshan earthquake. Both LURR values and best-fit power-law time-to-failure functions were computed using data within a range of distances from the epicenter. Like the best-fit power-law fits in AMR/AER, the LURR value was optimal using data within a certain epicentral distance implying a critical region for LURR. Furthermore, LURR critical region size scales with mainshock magnitude and is similar to the AMR/AER critical region size. These results suggest a common physical origin for both the AMR/AER and LURR observations. Further research may provide clues that yield an understanding of this mechanism and help lead to a solid foundation for intermediate-term earthquake prediction.  相似文献   
995.
克孜尔水库大坝的地震安全性评估   总被引:1,自引:0,他引:1  
通过对克孜尔水库地震活动和地震地质构造背景,地震危险性,地震动力反应等的分析,评估土坝的抗震性能与安全性,并对大坝及库区周围的地质灾害进行了预测。  相似文献   
996.
The Hongzuisi Section in Lanzhou area is used to infer the paleoclimate since the late glacial epoch. Through combined analysis of organic carbon isotope and CaCO3 content, paleoenvironment evolution of Hongzuisi Section since the late glacial epoch is discussed. There were changes in both dry-moist and warm-cold. Especially the climate changes can be compared with synchronous sections of other areas, which provides useful information for our future forecast.  相似文献   
997.
Preface     
TheInternationalSymposiumontheGSSPofthePermian TriassicBoundaryandthePaleozoic MesozoicEventswasheldinChangxingCounty ,ZhejiangProvince,ChinaonAugust 1 0 - 1 3,2 0 0 1 .Thesymposiumreceivedand printed 47abstracts.About 60geologistsfrom 1 3countriesattendedthescientifi…  相似文献   
998.
干旱对生态系统碳循环具有重要影响,随着气候变暖,全球干旱事件频率不断上升,研究干旱对植被净初级生产力的影响具有重要意义。提高植被净初级生产力(NPP)的时间分辨率是认识干旱对其影响机制的重要途径。基于5天NDVI遥感数据,以河西走廊为研究区,利用CASA模型估算2010—2015年5天步长尺度的NPP,将5天降水为零定义为干旱基本单元,利用标准分数来探究干旱对植被NPP的影响。结果表明:基于高时间分辨率遥感数据能有效探测干旱对NPP的影响机制,研究期间河西走廊年干旱频次6—44次,干旱对该地NPP有负效应,对5天均值的影响为-0.23 g·m-2,影响幅度为-1.93%,整体影响较小。干旱对林地NPP影响最大,下降3.70%,草地次之,荒漠最小。随着干旱持续时间的增加,NPP变化趋势呈现为先降低,然后降低趋势增加,最后趋于稳定的过程。干旱对夏季的NPP影响最大,冬季最小,秋季干旱对林地影响最大。  相似文献   
999.
Chen  Fahu  Wu  Shaohong  Cui  Peng  Cai  Yunlong  Zhang  Yili  Yin  Yunhe  Liu  Guobin  Ouyang  Zhu  Ma  Wei  Yang  Linsheng  Wu  Duo  Lei  Jiaqiang  Zhang  Guoyou  Zou  Xueyong  Chen  Xiaoqing  Tan  Minghong  Wang  Xunming  Bao  Anming  Cheng  Weixin  Dang  Xiaohu  Wei  Binggan  Wang  Guoliang  Wang  Wuyi  Zhang  Xingquan  Liu  Xiaochen  Li  Shengyu 《地理学报(英文版)》2021,31(1):3-45
Physical geography is a basic research subject of natural sciences.Its research object is the natural environment which is closely related to human living and development,and China's natural environment is complex and diverse.According to national needs and regional development,physical geographers have achieved remarkable achievements in applied basis and applied research,which also has substantially contributed to the planning of national economic growth and social development,the protection of macro ecosystems and resources,and sustainable regional development.This study summarized the practice and application of physical geography in China over the past 70 years in the following fields:regional differences in natural environments and physical regionalization;land use and land cover changes;natural hazards and risk reduction;process and prevention of desertification;upgrading of medium-and low-yield fields in the Huang-Huai-Hai region;engineering construction in permafrost areas; geochemical element anomalies and the prevention and control of endemic diseases;positioning and observation of hysical geographical elements;and identification of geospatial differentiation and geographical detectors. Furthermore, we have proposed the future direction of applied research in the field of physical geography.  相似文献   
1000.
Zhou  Kan  Yin  Yue  Li  Hui  Shen  Yuming 《地理学报(英文版)》2021,31(1):91-110
Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and socioeconomic databases of the counties in Beijing–Tianjin–Hebei region, this paper comprehensively calculates the environmental stress index(ESI) for the urban agglomeration using the entropy weight method(EWM) at the county scale and analyzes the spatiotemporal patterns and the differences among the four types of major functional zones(MFZ) for the period 2012–2016. In addition, the socioeconomic driving forces of environmental stress are quantitatively estimated using the geographically weighted regression(GWR) method based on the STIRPAT model framework. The results show that:(1) The level of environmental stress in the Beijing–Tianjin–Hebei region was significantly alleviated during that time period, with a decrease in ESI of 54.68% by 2016. This decrease was most significant in Beijing, Tangshan, Tianjin, Shijiazhuang, and other central urban areas, as well as the Binhai New Area. The level of environmental stress in counties decreased gradually from the central urban areas to the suburban areas, and the high-level stress counties were eliminated by 2016.(2) The spatial spillover effect of environmental stress increased further at the county scale from 2012 to 2016, and spatial locking and path dependence emerged in the cities of Tangshan and Tianjin.(3) Urbanized zones(development-optimized and development-prioritized zones) were the major areas bearing environmental pollution in the Beijing–Tianjin–Hebei region in that time period. The ESI accounted for 65.98% of the whole region, where there was a need to focus on the prevention and control of environmental pollution.(4) The driving factors of environmental stress at the county scale included population size and the level of economic development. In addition, the technical capacity of environmental waste disposal, the intensity of agricultural production input, the intensity of territorial development, and the level of urbanization also had a certain degree of influence.(5) There was spatial heterogeneity in the effects of the various driving factors on the level of environmental stress. Thus, it was necessary to adopt differentiated environmental governance and reduction countermeasures in respect of emission sources, according to the intensity and spatiotemporal differences in the driving forces in order to improve the accuracy and adaptability of environmental collaborative control in the Beijing–Tianjin–Hebei region.  相似文献   
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