鄂豫皖交界地区地震地质背景与中强地震复发特征的研究   总被引：1，自引：2，他引：1  

张杰  王行舟  沈小七  张毅 《地震地磁观测与研究》2003,24(6):18-25

鄂豫皖交界地区位于东大别山西部，历史中强地震(M≥43/4)主要发生在土地岭-落儿岭及商城-麻城断裂带上，且“互动”和“连动”的特征较为显著。根据这一特征，在研究东大别山区域地质、地壳结构、断裂活动及地震构造应力场特征的基础上，可将鄂豫皖交界地区的中强地震作为秦岭-大别山活动地块中的次级地块的整体活动来看待。该区历史地震活动整体表现为丛集特征，而主要发震断层(土地岭-落儿岭断裂)的历史地震活动则具有相对较好的准周期性。地震复发周期研究提示，该地块近期发生M≥5．0左右地震的危险性较大，而霍山-六安地区为未来发生中强地震的主要危险区。  相似文献   

CHARACTERISTICS OF EVAPOTRANSPIRATION IN THE YANGTZE DELTA REGION FOR PAST 40 YEARS AND MAIN INFLUENCE FACTORS^*          下载免费PDF全文

LIU Jingmiao  ZHOU Xiuji  DING Guoan  LU Longhua 《Acta Meteorologica Sinica》2003,17(2):178-189

The Kotoda-Bortan (KB) model (Liu and Kotoda 1998) used for estimating evapotranspiration was modified.The monthly evapotranspiration for various surfaces in the Yangtze Delta (118-123°E,28-33°N) was calculated using the modified model,and the annual regional average of evapotranspiration from 1961 to 1998 was obtained using a weighting method.The spatial and temporal distribution characteristics of evapotranspiration were analyzed.It is found that the regional averaged annual evapotranspiration has a decreasing trend over the past 40 years;the value dropped by about 24mm from 1961 to 1998.The main reason for this tendency is due to the change of land surface condition.Compared with the case of 1980,the current proportions of paddy field,farmland and water surface have decreased by 1.353%,4.42% and 2.597% respectively,while the proportions of urban area and non-agriculture land have increased by 3.345%.These changes clearly result in a decrease of the regional averaged evapotranspiration.  相似文献   

A training model for GIS application in land resource allocation     

Fuhu Ren 《ISPRS Journal of Photogrammetry and Remote Sensing》1997,52(6):261-265

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陆面特征非均一作用参数化及其对区域气候影响的数值模拟试验   总被引：2，自引：1，他引：2  

张耀存  钱永甫 《气象科学》1997,17(2):125-130

本文首先改进了陆地下垫面特征非均一性的次网格尺度参数化方法，然后利用三维地气耦合的区域气候模式，设计一系列值试验，研究了下垫面特征改变对区域气候环境变化的影响，主要分析了陆地表面特征变化对我国苏南附近地区夏季温度化的影响，结果表明采用地下垫面特征非均一作用的次网格尺度参数化方法对于改进数值模拟结果的质量有一定效果。  相似文献   

黑河实验区地表净辐射区域分布及季节变化   总被引：22，自引：3，他引：22       下载免费PDF全文

马耀明  王介民  Massimo Menenti  Wim Bastiaanssen 《大气科学》1997,21(6):743-749

利用卫星遥感信息和地面观测资料，分析研究黑河实验区地表净辐射的区域分布及季节变化特征。结果表明，卫星遥感结合地面观测，首先可以得到较为精确的地表反射率和地表温度分布，进而得到较为合理的地表净辐射的区域分布和季节变化特征。  相似文献   

集对分析及其在城市地面沉降研究中的应用   总被引：5，自引：0，他引：5  

龚士良 《上海国土资源》1997,(4):43-47

集对分析是处理本确定性问题的理论,认为在一系统中不确定性与确定性互相联系、影响、制约,并在一定条件下互相转化,用联系度及其数学表达式统一描述系统的各种不确定性,由此实现系统调控的辅助决策。本文应用集对分析理论与方法剖析了上海地面沉降问题,探讨了社会需求、资源状况、地质环境三者间的制约关系,并以此提出城市地面沉降系统调控的对策与途径。  相似文献   

人地非线性相关作用的探讨   总被引：12，自引：2，他引：12  

刘继生  陈涛 《地理科学》1997,17(3):224-230

从自组织系统思想出发，提出了人地关系的基本特性，通过逻辑斯蒂听数学变换，分析了人地非线性相关作用的混沌特性，进而讨论了人地关系的分形性质。基于混 过程与分形结构的因果关系，指出：地球表层系统中的人文分形景观乃是人地非线性关系的混沌作用所致。  相似文献   

影响上海市地价空间分布的区位因子分析   总被引：28，自引：5，他引：28  

杜德斌  徐建刚 《地理学报》1997,52(5):403-411

本文采用ＧＩＳ技术和多元线性回归分析方法，以土地批租地块为样本，分析上海市地价与城市区位因子的线性关系。回归分析结果表明；南京路，市中心和淮海路是影响上海市寺价空间差异的主要区位因子，外滩，次级商业中心和交通结节点对地价的影响很小，表明上海市地价的空间分布具有很高的向心性。  相似文献   

LAND DEGRADATION AND ITS MANAGEMENT IN THE ARID AND SEMI ARID AREAS OF CHINA     

Leng Shuying Zheng Du Institute of Geography  CAS  Beijing People''s Republic of China 《地理学报(英文版)》1997,(4)

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Colonization and evolution of lakes on the central Norwegian coast following deglaciation and land uplift 9500 to 7800 years B.P.     

John O. Solem  Thyra Solem  Kaare Aagaard  Oddvar Hanssen 《Journal of Paleolimnology》1997,18(3):269-281

Invertebrate colonization of lakes following the uplift of land from the sea was studied in four lakes, currently situated between 39 and 24 m a.s.l., on the central Norwegian coast. The lakes were isolated from the sea between 9500 and 7700 years B.P. Animal and algal remains picked from core samples showed that the first colonizers preserved as fossils were usually members of the Chironomidae, Daphnidae/Chydoridae, Acarina, Porifera (Ephydatia mülleri and Spongilla lacustris), Bryozoa (Cristatella mucedo and Plumatella spp.) and Charophyta (Chara sp.). Of the chironomids, the genus Chironomus was present in the oldest lacustrine layers of all four lakes, but other genera recorded at the marine/lacustrine boundary were Dicrotendipes, Procladius (?), Einfeldia, Microtendipes, and Glyptotendipes. Remains of the caddis fly family Limnephilidae were also present in the earliest lacustrine sediments in Kvennavatnet and Kvernavatnet. The oldest invertebrate fauna is typical for mesotrophic lakes. However, chironomids and mites have been present in this area from at least about 10?500 years B.P. A diverse chironomid community was established between 300 and 800 years after isolation from the sea at Kvernavatnet on the island of Hitra, while only between 80 and 120 years passed before a comparably diverse community developed at Kvennavatnet on the mainland coast. A similar development of the invertebrate fauna occurred in Kvennavatnet, Kvernavatnet and Storkuvatnet. However, Litjvatnet deviates greatly from the ‘normal’ pattern because a tsunami disturbed the bottom sediments and fauna. The tsunami, a gigantic sea wave, was caused by a submarine slide from the Norwegian continental slope. It reached Litjvatnet, today located 24 m a.s.l., but was not traced in Storkuvatnet at 30 m a.s.l. This event happened about 7200 years B.P.  相似文献