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61.
青海湖地区生态环境动态变化遥感监测 总被引:9,自引:0,他引:9
由于青海湖地区的生态环境较为脆弱,且人类活动进一步加剧,人口、资源与环境的矛盾日渐突出,因此,近年来.青海湖及其周边地区的生态环境出现了明显变化,主要表现在水位下降及水域面积减小、草原退化、沙质荒漠化土地面积扩大等。文章采用1975年MSS卫星图像及1987、2000年TM卫星图像作为遥感信息源,并结合地理信息系统方法,旨在查明青海满地区耕地、沙质荒漠化土地和水域等生态环境要素的时空演化规律,为青海湖地区实现资源开发与环境协调发展提供科学依据。监测结果表明,25a来,青海湖地区的耕地及沙质荒漠化土地面积出现明显的扩大,而水域面积出现明显缩小,同时由于湖周各河流土壤侵蚀的加剧,在部分河流入湖处泥沙淤积较为严重,生态环境出现明显恶化。 相似文献
62.
概略回顾了中国20世纪遥感地质的辉煌成就,列举4项重大突破:极块构造的论证与线性形迹分析,数字地质与找矿、第四纪地质与地貌学的新发现、工程地质选线与选址。指出21世纪面对国土普查的新任务,需要加强遥感信息机理研究,信息融合与共享,学科交叉,社会经济统计空间分析的能力,关注探月计划与遥感制图。 相似文献
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66.
文章简述了李连捷先生为中国的土壤科学和为生产服务而奋斗的一生。20世纪40年代,他在去美国深造之前,就在国内到贵州、广西和华南的许多省区进行了大面积的土壤调查工作。新中国成立后,他欣然接受先后到黑龙江、青海和内蒙古等省区进行荒地资源垦殖的调查任务,并于50~60年代,先后参与和组织了对西藏、新疆等地多专业的大型综合考察。通过这些考察,为西部大开发摸清和积累了大批可贵的自然资源资料,为我国土壤的发生和分类、土地资源的合理利用以及国民经济的发展做出了积极贡献。李先生在他近半个世纪的教学工作中,为我国培养了大批土壤科学人才。他一生刚正不阿、高风亮节,为我们树立了学习的榜样。在李连捷先生逝世10周年之际,仅以此文表达对他的深切怀念。 相似文献
67.
A multi-scale study on land use and land cover quality change: The case of the Yellow River Delta in China 总被引:5,自引:0,他引:5
This paper presents a case study of the Yellow River Delta in China, to trace land use and land cover changes during the past
20 years, with an emphasis on land quality changes. Three sets of data are used in this case study: remote sensing data derived
from satellite images; crop yield data from statistics; and soil data collected by the researchers in the field. Our study
reveals that at the regional scale, LUCC has taken place in a positive direction: vegetation cover has been expanding and
crop yields per hectare have been on rise. However, while the overall eco-environment has improved, the improvement is uneven
across the Delta region. At local levels, some areas show signs of increased salinization and declining organic content. Both
natural forces and human activities are responsible for the LUCC, but human activities play a more important role. While some
impacts of human activities are positive, the damages are often long-lasting and irreversible. We also conclude that it is
necessary to use both macro data (such as remote sensing data) and micro data (data collected in the field) to study land
quality change. The former are efficient in examining land quality changes at the regional scale, the latter can serve to
verify ground patterns revealed from macro data and help to identify local variations, so as to get a comprehensive understanding
of LUCC and promote sustainable land use and land management.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
68.
This paper assesses the agricultural land resources of Guiyang City by means of GIS,on the basis of the pressure-state-response model in which soil heavy metal contamination is selected as a pressure indicatror.he results suggest that most of the agricultural land resources are of good quality,However,there are 17.11km^2 dry land and paddy field,which belong to the region of serious heavy metal contamination and are not fit for planting crops.At the same time,the high quality plowland,which is suitable for cultivation,has decreased nearly by 1/3 due to soil heavy metal contamination.These findings may improve our understanding that it is very important to prevent and cure heavy metal contamination of Guiyang City. 相似文献
69.
We have identified an extinct E–W spreading center in the northern Natal valley on the basis of magnetic anomalies which was active from chron M11 (133 Ma) to 125.3 Ma, just before chron M2 (124 Ma) in the Early Cretaceous. Seafloor spreading in the northern Natal valley accounts for approximately 170 km of north–south motion between the Mozambique Ridge and Africa. This extension resolves the predicted overlap of the continental (central and southern) Mozambique Ridge and Antarctica in the chron M2 to M11 reconstructions from Mesozoic finite rotation parameters for Africa and Antarctica. In addition, the magnetic data reveal that the Mozambique Ridge was an independent microplate from at least 133 to 125 Ma. The northern Natal valley extinct spreading center connects to the spreading center separating the Mozambique Basin and the Riiser-Larsen Sea to the east. It follows that the northern Mozambique Ridge was either formed after the emplacement of the surrounding oceanic crust or it is the product of a very robust spreading center. To the west the extinct spreading center connects to the spreading center separating the southern Natal valley and Georgia Basin via a transform fault. Prior to chron M11, there is still a problem with the overlap of Mozambique Ridge if it is assumed to be fixed with respect to either the African or Antarctic plates. Some of the overlap can be accounted for by Jurassic deformation of the Mozambique Ridge, Mozambique Basin, and Dronning Maud land. It appears though that the Mozambique Ridge was an independent microplate from the breakup of Gondwana, 160 Ma, until it became part of the African plate, 125 Ma. 相似文献
70.
近年来,在国土资源部的高度重视下,我区相继建立了一系列地学数据库。这些地学数据库的建立不仅为地矿行业提供了基础性数据,也加速了"数字国土工程"和国土资源信息化建设的步伐。随着信息技术的高速发展,利用地理信息系统(GIS)将各类地学数据有机地结合起来,形成地学数据应用与管理系统,最终通过网络服务于社会,必将是各类地学数据发展的必然趋势。 相似文献