A preliminary study on the advance and the retreat of Qingtu Lake and its climatic records of the Holocene lacustrine deposits has been made through comprehensive analysis. The study shows that the modes characteristi...A preliminary study on the advance and the retreat of Qingtu Lake and its climatic records of the Holocene lacustrine deposits has been made through comprehensive analysis. The study shows that the modes characteristics of climatic change in Eastern Hexi Corridor was provided with the corresponding relationship of warm moist and cold dry during the scale longer than hundred years. As a result of climatic changes and human activities, Qingtu Lake cycle has undergone four lake retreated and three lake advanced stages since 6000 a B.P. Based on the study on lacustrine sedimentary color, grain size, Fe 3+ /Fe 2+ and organic matter, the authors put forward that a warm period existed during the phase of 335-480 A.D. in the studied area. This warm period could be further testified by a lot of evidences obtained from the historical documents and the natural records of Qingtu Lake. In brief, the evolution of lakes in Eastern Hexi Corridor is characterized by sedimentary continuity, fast sedimentary rate and high resolution, it not only indicate the paleoenvironmental and climatic change in Holocene, but also can reflect the intensity of Eastern Asia monsoon.展开更多
随着获取的遥感数据越来越多,定量遥感正处于一个飞速发展的时期。本文从反演方法和遥感数据产品生成两个主要方面对近期陆表定量遥感的发展进行评述。由于大气—陆表系统的环境变量数远远超过遥感观测数,定量遥感反演的本质是个病态反...随着获取的遥感数据越来越多,定量遥感正处于一个飞速发展的时期。本文从反演方法和遥感数据产品生成两个主要方面对近期陆表定量遥感的发展进行评述。由于大气—陆表系统的环境变量数远远超过遥感观测数,定量遥感反演的本质是个病态反演问题。在评述机器学习方法(包括人工神经网络、支持向量回归、多元自适应回归样条函数等)的应用基础上,重点关注克服病态反演的7种正则化方法:多源数据、先验知识、最优化反演的求解约束、时空约束、多反演算法集成、数据同化和尺度转换。定量遥感发展的另外一个显著特征是由数据提供者(比如数据中心)将观测的遥感数据转换成不同的地球生物物理化学参数产品,即遥感高级产品,并服务于数据使用者。概括介绍了北京师范大学牵头研发的GLASS(Global LAnd Surface Satellite)产品的新进展与全球气候数据集的研发情况。展开更多
文摘A preliminary study on the advance and the retreat of Qingtu Lake and its climatic records of the Holocene lacustrine deposits has been made through comprehensive analysis. The study shows that the modes characteristics of climatic change in Eastern Hexi Corridor was provided with the corresponding relationship of warm moist and cold dry during the scale longer than hundred years. As a result of climatic changes and human activities, Qingtu Lake cycle has undergone four lake retreated and three lake advanced stages since 6000 a B.P. Based on the study on lacustrine sedimentary color, grain size, Fe 3+ /Fe 2+ and organic matter, the authors put forward that a warm period existed during the phase of 335-480 A.D. in the studied area. This warm period could be further testified by a lot of evidences obtained from the historical documents and the natural records of Qingtu Lake. In brief, the evolution of lakes in Eastern Hexi Corridor is characterized by sedimentary continuity, fast sedimentary rate and high resolution, it not only indicate the paleoenvironmental and climatic change in Holocene, but also can reflect the intensity of Eastern Asia monsoon.
文摘随着获取的遥感数据越来越多,定量遥感正处于一个飞速发展的时期。本文从反演方法和遥感数据产品生成两个主要方面对近期陆表定量遥感的发展进行评述。由于大气—陆表系统的环境变量数远远超过遥感观测数,定量遥感反演的本质是个病态反演问题。在评述机器学习方法(包括人工神经网络、支持向量回归、多元自适应回归样条函数等)的应用基础上,重点关注克服病态反演的7种正则化方法:多源数据、先验知识、最优化反演的求解约束、时空约束、多反演算法集成、数据同化和尺度转换。定量遥感发展的另外一个显著特征是由数据提供者(比如数据中心)将观测的遥感数据转换成不同的地球生物物理化学参数产品,即遥感高级产品,并服务于数据使用者。概括介绍了北京师范大学牵头研发的GLASS(Global LAnd Surface Satellite)产品的新进展与全球气候数据集的研发情况。
