忻州市气象局拓展科技服务产业的一些思考

近年来,忻州市气象局党组一班人在产业发展思路上,认真学习领会中国气象局和山西省气象局发展科技服务与产业的精神,充分吸取发达地区、先进地市的产业经验,全面研究贫困地区产业发展对策,结合忻州当地的实际情况,一致把忻州产业发展的潜力定位在依托部门科技优势,努力寻找与相关部门的结合点,大胆探索,勇于创新,奋力开拓,使忻州局的科技产业走上了稳定传统项目,不断拓展新的服务领域的良性循环的路子,并取得一定的成绩。1立足忻州实际,确立产业思路1.1忻州自然经济基础薄弱,连年财政收入不能令人乐观忻州地处晋北黄土高原腹中,土地贫瘠,人…     

晋中市人工防雹减灾系统研究

利用雷达探测信息、地面气象观测资料和高空探测资料 ,通过计算机分析处理 ,对冰雹天气的发生、发展进行分析预报 ,并计算多单体任意雹云核心部位的覆盖面积 ,对不同地理位置的各炮点 ,经过极坐标和三维直角坐标系的变换 ,确定雹云相对于不同空间位置的各炮点的准确位置 ,并对各炮点不同弹型的弹道方程进行连续模拟和分析计算 ,最终确定在炮控范围内的雹云体内弹着点的准确位置 ,并通过计算云中含水量、零度层高度、云体体积 ,准确得出各个炮点的射击诸元 (射击仰角、方位、扇面和射击剂量等 ) ,通过通讯网络 ,通知各有关炮点实施作业     

上海市15-17ka.BP.的古地貌与工程地质条件

编制了100m以浅多幅地质剖面图和30ka.BP.以来多个时段的古地理图。这些图件清楚地反映出在于25－24.5ka.BP和17－15ka.BP的低海面时期，地面曾经历过两次强烈的侵蚀切割。本文着重分析研究埋深60m以浅各陆相粘性土层（俗称暗绿色粘土或硬粘土层）的成因、时代、空间分布和17－15ka.BP间的古叶貌格局及其与工程地质分区的关系。     

柴达木盆地新生代波动过程及与油气关系

通过对柴达木盆地新生代沉积充填的地质滤波分析证明,约10Ma和约20Ma周期的波动过程是控制柴达木盆地新生代沉积和构造演化最显著的波动过程。在平面上,这两个周期波相近大小的周期大致沿近东西向和北西-南东向分布,分别反映波的传播方向为近南北向和南西-北东向。柴达木盆地新生代的这种波动过程与油气具有十分密切的关系,影响着烃源岩的热演化,并控制了生油凹陷和油气藏的分布。理论分析与勘探实践均证明,波谷带与波峰带之间的波动转换带是油气聚集成藏的有利部位。     

Eolian evidence from the Chinese Loess Plateau: the onset of the Late Cenozoic Great Glaciation in the Northern Hemisphere and Qinghai-Xizang Plateau uplift forcing

On the basis of a newly-constructed record of magnetic susceptibility (SUS) and the depositional rate change of eolian loess-red clay sequences in the last 7.2 Ma BP from the hea Plateau, together with a cornperison of a record of °¹⁸O values from the equatorial East Pacific Ocean and eolian Quartz flux variations fmm the North Pacific Ocean, the evolutiomuy process of the Late Cenozoic Great Glaciation in the Northern Hemisphere can be divided into three stages: the arrival stage around 7.2–3.4 Ma BP, the initial stage at about 3.4—2.6 Ma BP, and the Great Ice Age since 2.6 Ma BP. The evolution of the East Asian monsoon is characterized by paid winter and summer monsoons, and it is basically composed of the initial stage of weak winter and summer monsoons, the transitional stage of simultaneous increase in intensity of winter and summer monsoons, and the prevailing stage of strong winter and week summer monsoons, or weak winter and strong summer monsoons. The Late Cenowic global tectonic uplift, paaicdarly the Qinghai-Xizang Plateau uplift and the associated CO₂ concentration variation, controls the dng processes of the onset of Great Glaciation and the long-term changes of East Asian monsoom climate in the Northern Hemisphere to a large extent. The accelerating uplift of the Qinghai-Xizang Plateau between 3.4 and 2.6 Ma BP provided an important driving force to global climiatic change. Project supported by the foundation of Chinese Academy of Sciences (Grant No. KZ951-A1-402), the State Science and Technology Committee (Grant No. 95-pre-40)and the Chinese Nature Science Foundation (Grant No. 49672140)     

Evaluating the vegetation growing season changes in the arid region of northwestern China

Temperature has long been accepted as the major controlling factor in determining vegetation phenology in the middle and higher latitudes. The influence of water availability is often overlooked even in arid and semi-arid environments. We compared vegetation phenology metrics derived from both in situ temperature and satellite-based normalized difference vegetation index (NDVI) observations from 1982 to 2006 by an example of the arid region of northwestern China. From the satellite-based results, it was found the start of the growing season (SOS) advanced by 0.37 days year^?1 and the end of the growing season (EOS) delayed by 0.61 days year^?1 in Southern Xinjiang over 25 years. In the Tianshan Mountains, the SOS advanced by 0.35 days year^?1 and the EOS delayed by 0.31 days year^?1. There were almost no changes in Northern Xinjiang. Compared with satellite-based results, those estimates based on temperature contain less details of spatial variability of vegetation phenology. Interestingly, they show different and at times reversed spatial patterns from the satellite results arising from water limitation. Phenology metrics derived from temperature and NDVI conclude that water limitation of onset of the growing season is more severe than the cessation. Phenology spatial patterns of four oases in Southern Xingjiang show that, on average, there is a delay of the SOS of 1.6 days/10 km of distance from the mountain outlet stations. Our results underline the importance of water availability in determining the vegetation phenology in arid regions and can lead to important consequences in interpreting the possible change of vegetation phenology with climate.     

Radiocarbon constraints on the Holocene flood deposits of the Ning‐Zhen Mountains,lower Yangtze River area of China

Lying athwart both the temperate and subtropical zones, the Ning‐Zhen Mountains are particularly prone to extreme floods in the summer months when cold fronts collide with the subtropics‐derived warm airmasses. The Holocene flood deposits in the region may provide a long‐term perspective on hydrographical change and its palaeoclimatic implications. Radiocarbon dates on carbonised wood preserved in flooding sediments reveal that the region has experienced a number of catastrophic floods throughout the middle Holocene. These extreme flooding events cluster into three periods: (i) 9200–8200 cal. yr BP, (ii) 7600–5800 cal. yr BP and (iii) 5200–4000 cal. yr BP, corresponding to the times when the East Asian monsoon has been intensified under warm conditions. The significant falls in flooding frequency around 8200 cal. yr BP, 5800 cal. yr BP and 4000 cal. yr BP may have resulted from substantial reduction in regional precipitation, probably associated with meridional displacement of the planetary frontal system. Copyright © 2003 John Wiley & Sons, Ltd.     

融入土壤湿度指标的青藏高原近地表土壤冻融机器学习监测算法

青藏高原作为中低纬度地区最大的高山冻土区,多年冻土和季节冻土广泛分布。高精度的地表冻融监测结果对研究该区域的水热交换、碳氮循环和土壤冻融侵蚀非常重要。本文基于4个青藏高原典型地区的土壤温湿度观测网数据,开展利用LightGBM算法和随机森林算法进行土壤冻融循环监测的研究。在构建土壤冻融监测模型的过程中,发现土壤湿度是影响冻融判别的一个关键因子。使用AMSR2亮温数据和ERA5-Land土壤湿度数据,基于两种机器学习算法判别地表冻融状态,将结果与传统冻融判别式算法进行对比分析。结果表明：相比冻融判别式算法,LightGBM算法在白天和夜间的总体判对率提高了12.09%;14.45%,随机森林算法在白天和夜间的总体判对率提高了13.23%和14.96%。近80%的错分样本分布在-4.0℃～4.0℃之间,说明2个机器学习算法能够识别出稳定的土壤冻结状态和融化状态。另外,LightGBM算法和随机森林算法得到的日冻融转换天数的平均RMSE降低了112.82和117.00;冻结天数的平均RMSE降低了47.87和53.96;融化天数的平均RMSE降低了37.10和39.80。同时,基于随机森林算...     

A Study of Global Change Population and Economic System Risk Forming Mechanism and Assessment

Global climate change featured with warming has created serious challenge to world sustainable development and human security. It has become an important consensus of the international society to assess global change risk at the global scale and carry out tailored governance and risk-based adaptation. National Key Research and Development Program “Study on global change population and economic system risk forming mechanism and assessment” aims at quantitatively predicting future global climate change and population and economic system exposure and vulnerability change, developing global change population and economic system risk assessment model based on complex system dynamics, synthesizing risk assessment model with proprietary intellectual property rights, assess global change population and economic system risk of the near and mid future at the global scale, and compiling the atlas of global change population and economic system risk. The outcomes intend to serve the participation of global risk governance and international climate negotiation, and to provide scientific support to the implementation of international disaster risk reduction strategy.