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1.
This paper describes the paleoclimatic changesoccurring in the Chaiwopu Basin since 730,000 yr.B.P., together with theformation and evolution of Chaiwopu Lake based on the chronology and characteristics of a core drilled in the basin. Analysis of the drilling core provides information on the climate and environment of the area. It would appear that the paleoclimatic changes that occurred in the basin during the Pleistocene was controlled by the relationship between the sun and the earth and by Long-term (10,000 yr.) climatic cycles. The climate tended to cold-dry during the glacial period (ice age) and warm-moist during the interglacial. Following the warm period of the Holocene, short-term (1,000 yr.) climatic cycles occurred in cool-moist periods, similar to the "Little Ice Age", alternated with warm-dry periods. 相似文献
2.
青藏高原西南部塔若错湖泊沉积物记录的近300年来气候环境变化 总被引：4，自引：1，他引：3
以青藏高原西南部塔若错的34cm浅湖芯为研究对象,对其沉积物样品进行总有机碳、无机碳、总氮、微量元素、正构烷烃含量及碳氮比等多项指标的分析测定。采用过剩210 Pb和137 Cs计年法对该湖芯进行了定年和沉积速率研究,获得了近300年的连续湖泊沉积环境序列。在明确了各指标气候环境指示意义的前提下,综合对比分析湖芯中各项气候环境指标,并结合定年结果重建了塔若错湖区近300年来的气候环境变化。结果表明:塔若错湖区气候环境变化可分为3个明显阶段:早期为1705～1778年,该地区气候环境温暖湿润,湖区植被广泛发育;中期为1778～1860年,湖区处于小冰期末次阶段,气候环境寒冷而湿润,植被发育受阻;后期为1860年至今,为小冰期结束后偏暖干化时期。其中,后期又可分为3个亚阶段:1860～1924年,湖区气候环境稍暖且干旱,植被稍有发育;1924～1969年,湖区气候环境呈现偏冷干特点,植被发育暂缓;1969年至今,湖区气候回暖,环境干旱化有所缓解,植被开始逐渐发育。在气候冷暖变化上,该湖芯记录与古里雅冰芯记录和青海湖湖泊沉积记录都有较好的可对比性,只是在起讫年代上存在一些差异。 相似文献
3.
This paper describes the paleoclimatic changesoccurring in the Chaiwopu Basin since 730,000 yr.B.P., together with theformation
and evolution of Chaiwopu Lake based on the chronology and characteristics of a core drilled in the basin. Analysis of the
drilling core provides information on the climate and environment of the area. It would appear that the paleoclimatic changes
that occurred in the basin during the Pleistocene was controlled by the relationship between the sun and the earth and by
Long-term (10,000 yr.) climatic cycles. The climate tended to cold-dry during the glacial period (ice age) and warm-moist
during the interglacial. Following the warm period of the Holocene, short-term (1,000 yr.) climatic cycles occurred in cool-moist
periods, similar to the “Little Ice Age”, alternated with warm-dry periods. 相似文献
4.
THE LITTLE ICE AGE OF THE NORTHWEST REGION,CHINA 总被引：1，自引：0，他引：1
王宗太 《中国地理科学(英文版)》1992,2(3):215-225
The Little Ice Age began in the early 15 the century and ended in 16 the century in the northwest region of China. In the Northern Hemisphere, the age of the Little Ice Age postponed form north to south, form west to east, and moist region to drought. Judged by the data the Little Ice Age of the Northwest China is later than the eastern China and Europe. The climate of the Little Ice Age in northwest China was cold-wet. In northwest China, as compared with the Little Ice Age, the recently annual temperature have raised about 1-1.3℃, the precipitation have reduced 50-78 mm, the evaporation have increased 7%, the glacier area have reduced about 21-46%, and the runoff have reduced about 14% in the river which the meltwater supply proportion is less than 10%. To sum up, since the Little Ice Age the warm-dry tendency of climatic variation is quite obviously in northwest China. If it goes on like this, its influence will be more severe to the river which meltwater proportion is more than 50%. 相似文献
5.
陈家其 《中国地理科学(英文版)》1994,(2)
ＴＨＥ ＡＰＰＬＩＣＡＢＩＬＩＴＹ ＯＦ ＲＥＳＥＡＲＣＨ ＯＮ ＦＬＯＯＤ－ＤＲＯＵＧＨＴ ＴＥＮＤＥＮＣＹ－ＡＮ ＡＮＡＬＹＳＩＳ ＯＮ ＤＩＳＡＳＴＲＯＵＳ ＦＬＯＯＤ ＯＦ ＴＡＩＨＵ ＬＡＫＥ ＢＡＳＩＮＩＮ ＪＵＮＥ－ＪＵＬＹ，１９９１ ... 相似文献
6.
Jiaqi Chen 《中国地理科学(英文版)》1994,4(2):129-133
In Taihu Lake basin during June–July in 1991, there happened a catastrophic flood, the precipitation reached that of 1954
and the water level was the highest in the history in Taihu Lake. This heavy flood, happening in the relatively humid period
and being well accord with flood-drought change tendency, was early precautioned. The occurrence of the flood illustrated
that using records of historical climate to predict flood-drough tendency is practically significant for hazard-reduction
project. 相似文献
7.
Patel NILANCHAL 《中国地理科学(英文版)》2006,(1)
1INTRODUCTIONMandelbrot stated the uncertainty of the length of a coastline in his paper "How long is the coast of Britain? Statistical self-similarity and fractional dimension" pub- lished in Science in 1967 (MANDELBROT, 1967). The concepts of fractal and fractal dimension were presented for the first time in that paper and have been applied to quantitatively describing the difference of crooked coastlines of British and South Africa. Compared with the Euclidean geometry with more… 相似文献
8.
ZHU Xiao-hua Patel NILANCHAL ZUO Wei YANG Xiu-chun 《中国地理科学(英文版)》2006,16(1):48-55
Based on the fractal theory, the spatial structure of China＇s vegetation has been analyzed quantitatively in this paper. Some conclusions are drawn as the following. 1） The relationships between size and frequency of patch area and patch shape index exist objectively for China＇s vegetation. 2） The relationships between perimeter and area exist objectively for China＇s vegetation. 3） The fractal dimension of evergreen needleleaf forests on mountains in subtropical and tropical zones is the largest, while the smallest for deciduous broadleafand evergreen needleleaf mixed forests in temperate zone, reflecting the most complex spatial structure for evergreen needleleaf forests on mountains in subtropical and tropical zones and the simplest for deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone. 4） The fractal dimensions of China＇s vegetation types tend to decrease from thc subtropics to both sides. 5） The stability of spatial structure of deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone is the largest, while the smallest for double-cropping rice, or double-cropping rice and temperate-like grain, and tropical evergreen economic tree plantations and orchards, reflecting the steadiest for deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone and the most unstable for double-cropping rice, or double-cropping rice and temperate-like grain, and tropical evergreen economic tree plantations and orchards in spatial structure. 6） The stability of spatial structure of China＇s vegetation tends to decrease from the temperate zone to both sides, it is significantly pertinent to understand the formation, evolution, dynamics and complexity rule of ecosystem of vegetation. 相似文献
9.
Traditionally, the mid-Holocene in most parts of China was thought to be warmer with higher precipitation, resulting from a strong Asian summer monsoon. However, some recent researches have proposed a mid-Holocene drought interval of millennial-scale in East Asian monsoon margin areas. Thus whether mid-Holocene was dry or humid remains an open issue. Here, Zhuyeze palaeolake, the terminal lake of the Shiyang River Drainage lying in Asian monsoon marginal areas, was selected for reconstructing the details of climate variations during the Holocene, especially mid-Holocene, on the basis of a sedimentological analysis. Qingtu Lake (QTL) section of 6.92m depth was taken from Zhuyeze palaeolake. Multi-proxy analysis of QTL section, including grain size, carbonate, TOC, C/N and δ13C of organic matter, was used to document regional climatic changes during 9-3 cal ka B.P. The record shows a major environmental change at 9.0-7.8 cal ka B.P., attributed to a climate trend towards warmth and humidity. This event was followed by a typical regional drought event which occurred during 7.8-7.5 cal ka B.P. And a warm and humid climate prevailed from 7.5 to 5.0 cal ka B.P., attributed to the warm/humid Holocene Optimum in this region. After that, the climate gradually became drier. Moreover, comparison of the climate record from this paper with the summer insolation at 30°N indicates that the climate pattern reflecting the Asian monsoon changes was caused by insolation change. 相似文献
10.
高寒区植被变化一直是气候和生态学领域关注的热点问题。本研究基于MODIS NDVI数据计算的植被覆盖度数据和高分辨率气象数据,分析了青海湖流域2001-2017年植被覆盖度分布格局及动态变化,探讨了其对气候变化、人类活动和冻土退化的响应。结果表明：① 近十几年青海湖流域植被覆盖度整体表现为增加趋势,不同植被类型增幅存在差异性,草地增幅最大,达到6.1%/10a,其它植被类型增幅在2%~3%/10a之间;② 流域局部地区仍存在植被退化现象,研究期植被退化面积表现为先增加后减小的变化趋势。2006-2011年重度退化区集中在青海湖东岸,2011-2017年重度退化区集中在流域的西北部,这些区域是青海湖流域荒漠分布区,植被覆盖度较低,是今后生态恢复需重点关注的区域;③ 气候变化是流域植被覆盖度变化的主导因素,气候变化对青海湖流域主要植被类型覆盖度变化的贡献率为84.21%,对草原、草甸和灌丛植被覆盖度变化的贡献率分别为81.84%、87.47%和75.96%;④ 人类活动对流域主要植被类型覆盖度变化的贡献率为15.79%,对草原、草甸和灌丛植被覆盖度变化的贡献率分别为18.16%、12.53%和24.04%,环青海湖地区人类活动对植被恢复有促进效应,在青海湖流域北部部分地区人类活动的破坏力度仍大于建设力度;⑤ 冻土退化对青海湖流域草甸和灌丛植被覆盖度变化影响很小,主要影响草原植被覆盖度变化,冻土退化造成草原植被覆盖度增长速率减小了1.2%/10a。 相似文献
11.
According to loess and palaeosol climatic record, field observation, analysis data and14C dating, we discuss the climatic changes and the water level fluctuations of Qinghai Lake. It is pointed out that there were
four relatively warm and moist stages in Qinghai Lake basin during the Holocene. They formed in the periods from 10,300 yr.B.P.
to 8,500 yr.B.P., 7,000 yr.B.P. to 3,500 yr.B.P., 2,800 yr.B.P. to 2,000 yr.B.P. and from 1,300 yr.B.P. up to now. the climate
in the Holocene optimum period, from 7,000 yr.B.P. to 3,500 yr.B.P., was much warmer and moister than that today. Polypodium
plant grew luxuriantly around Qinghai Lake. The annual temperature was 2.5°C higher than that today, but there was no forest
at Qinghai Lake shore. It is found that there was a good relationship between precipitation and water level fluctuation. In
warm and moist period water level was high and in the cold and dry period it was low in the Holocene. There were four high
water level periods for Qinghai Lake in the Holocene, but the highest level was less than 30m above present water level.
This research is supported by Youth Foundation of Natural Science Foundation of China (No. 49101015). 相似文献
12.
《中国海洋湖沼学报》2017,(5)
This paper discusses the long-term temperature variation of the Southern Yellow Sea Cold Water Mass(SYSCWM)and examines those factors that infl uence the SYSCWM,based on hydrographic datasets of the China National Standard Section and the Korea Oceanographic Data Center.Surface air temperature,meridional wind speed,and sea surface temperature data are used to describe the seasonal changes.Mean temperature of the two centers of the SYSCWM had diff erent long-term trends.The temperature of the center in the west of the SYSCWM was rising whereas that of the center in the east was falling.Mean temperature of the western center was related to warm water intrusion of the Yellow Sea Warm Current,the winter meridional wind,and the winter air temperature.Summer process played a primary role in the cooling trend of temperature in the eastern center.A decreasing trend of salinity in the eastern half of the SYSCWM showed that warm water intrusion from the south might weaken,as could the SYSCWM circulation.Weakened circulation provided less horizontal heat input to the eastern half of the SYSCWM.Less lateral heat input may have led to the decreasing trend in temperature of the eastern center of the SYSCWM.Further,warmer sea surface temperatures and less heat input in the deep layers intensifi ed the thermocline of the eastern SYSCWM.A stronger thermocline had less heat fl ux input from upper layers to this half of the SYSCWM.Stronger thermocline and weakened heat input can be seen as two main causes of the cooling temperature trend of the eastern center of the SYSCWM. 相似文献
13.
Seasonal ice cover is uncommon on Australian lakes. In the Snowy Mountains, there are five natural, seasonally ice-covered lakes including Lake Cootapatamba, the highest lake in Australia. Blue Lake is the only one of the five lakes with sufficient volume to be relatively independent of short-term changes in ambient temperature, and therefore is the lake most likely to be of use in tracking long-term regional climate change. Ice forms on Blue Lake near the winter solstice and ice-breakup occurs from late September to November. Timing of breakup is related to spring temperature and, as such, mirrors the timing of general snow thaw in the mountains. The existence of historic photographs taken of the lake at about the time of ice breakup allows for the possibility of reconstructing a history of alpine climate and in 1905 ice breakup was probably as late as mid-December. 相似文献
14.
Based on high-resolution tree-ring data from Dulan area of Qinghai Province, five spells have been divided: the warm period
before 230’s A. D., the cold period between 240’s A. D. and 800’s A. D., the significantly warm period between 810’s A. D.
and 1070’s, i. e. “Medieval Warm Period”, the cold period including the “Little Ice Age” 1420’ – 1870’s and the warming period
since 1880’s. All the eleven coldest or warmest decades and several great abrupt changes took place before the Middle Ages,
indicating that climatic system operated in great instability during the period 150’s – 1100’s A. D., Comparison of the tree-ring
data with other temperature proxy data from East China, Guliya ice core as well as the south of Qinghai-Xizang Plateau shows
that such great climatic events as Eastern Han warm period between the beginning of the 1st century and the previous fifty
years of the third century, the cold period covering the span of the Wei, the Jin, and the Southern and Northern dynasties,
the well-known “Medieval Warm Period” as well as the “Little Ice Age” appeared in these series such as East China and Dulan
area. Only the first two climatic events were recorded conspicuously in Guliya ice core while the “Medieval Warm Period” and
“Little Ice Age” is far weaker. Also, the well-defined “Medieval Warm Period” didn’t occurred in the south of Qinghai-Xizang
Plateau. The warming since the 20th century is the warmest in the last 2000 years Guliya ice core, the second in Dulan area
and East China, but it scarcely seems pronounced in the eastern part of Qinghai-Xizang Plateau.
Foundation item: Under the auspices of the projects of the Chinese Academy of Sciences (KZ951-A1-204-02 and KZ951-A1 402-03).
Biography: YANG Bao(1971–), male, a native of Yanggao County, Shanxi Province, Ph. D. His research interestinclude global
change. 相似文献
15.
1 INTRODUCTION δ13C in organic matters from lacustrine sedi- ments varies with several factors including aquatic plants, vegetation type in the catchment, atmos- pheric CO2 concentration, climate (temperature and precipitation), and properties of water, … 相似文献
16.
江苏省环太湖地区土地利用结构演变与驱动力分析 总被引：6，自引：0，他引：6
本文以江苏省环太湖地区为研究区域,以1996～2007年快速发展时期为研究时段,对这一特定时空的土地利用结构变化及其驱动机制进行研究。文章以大量数据为基础,分析了区域内土地利用结构动态度、信息熵和均衡度。1996年以来,江苏省环太湖地区用地结构调整即以趋向均衡的速度逐渐变缓。从2004年开始,江苏省环太湖地区用地结构趋向合理、均衡化发展。文章揭示了土地利用结构与经济发展驱动因素、农业集约化因素、城市化因素、人口因素、政策因素这五个因素有关。 相似文献
17.
IINTRODUCTION climate chang巳 divided d叮／wet penodS and discussed itsrelationships with cold／warm vanatlon and solar activityRecords ofellmate dlsasterhave been abundantly（CHEN198飞 1989）．IOund In Chinese historical literature．Previous works The present study tends to establish the dry／wethave collected such records to study the historical elf－series since 960 A．D．ofTal… 相似文献
18.
湖泊沉积物的矿物组成、成因、环境指示及研究进展 总被引：5，自引：1，他引：4
金章东 《地球科学与环境学报》2011,33(1):34-44,77
湖泊沉积物是不同地质、气候、水文条件下各类碎屑、黏土、自生/生物成因矿物以及有机物质等的综合体。沉积矿物蕴含着丰富区域和全球环境演变信息,如湖水的化学组成、流域构造、气候、水文以及人类活动的相互作用等。相关信息可以赋存在矿物外部微形貌、内部微结构、化学组成、物理和化学性质、同位素组成、谱学特征、成因以及共生组合等方面。因此,湖泊科学的许多关键课题都离不开矿物学,特别是在利用湖泊沉积物进行区域及过去全球变化研究中,深入的机理研究归根到底都要涉及矿物学,如流域化学风化作用、粒度组成、生物壳体化学组成、测年材料的选择等。然而,由于湖泊沉积物中矿物的多源性、复杂性,如何有效提取和解译其中的环境信息,是一项长期困扰研究者的课题,湖泊沉积矿物学的研究往往被许多研究者所忽视,中国的相关研究也较为薄弱。笔者综述了湖泊沉积物中碎屑、黏土、自生/生物矿物的矿物组合、特征、成因在(古)环境反演中的作用及最新研究进展,提出除了继续加强对湖泊沉积物中矿物来源、成因和古环境示踪的深入研究以外,矿物相间的转变及其对湖水和孔隙水组成的响应、一些非晶质或隐晶质及低丰度矿物相在湖泊化学和动力学中的作用也是很有潜力的研究领域,最后提出了研究中存在的一些问题、面对的挑战以及对研究前景的展望。 相似文献
19.
Study on the carbonate content and oxygen isotope of a sediment section in Dabusu Lake revealed that this region has experienced several cold-wet and warm-dry climatic cycles since 15400 a BP. It was about 6740 a BP when the climate in the region reached a relatively stable warm stage, so that the lake water was gradually condensed and finally a saline lake was formed. 相似文献
20.
According to palaeoclimatic and modern instrumental data, numerous studies have indicated that the Arctic climate has undergone a significant warming during the past 100 years, and this may lead to significant impact on the fragile lake ecosystem. In this study, we collected a lake sediment core from the Ny-(A)lesund of Svalbard and determined the concentrations of four pigments including chlorophyll derivatives, total carotenoids, oscillaxanthin and myxoxanthophyll in the sediments. Combined with other physical and chemical proxies such as calcium carbonate, total organic carbon, biogenic silicon etc., we have reconstructed the historical changes of lacustrine primary productivity in Ny-(A)lesund, especially for the past 100 years. The results showed that during the period of Little Ice Age (LIA), the climate was unfavorable for the growth of the lake algae, and thus the lacustrine productivity declined. This result was supported by the relatively low contents of pigment and biogenic silica in the sediments. In contrast, the contents of total organic carbon (TOC) and sediment pigments increased significantly in the upper 5 cm (~1890AD), reflecting the rapid growth of the lake algae, thus the great increase of lacustrine primary productivity, corresponding to the warming climate after LIA. However, the biogenic silica in the upper sediments still had a relatively low level, and this might be related to the growth competition with other algae species. Over the past 100 years, the ratio of Osc/Myx in the sediments decreased continuously, indicative of durative increase of myxoxanthophyll in blue-green algal pigments, and this might imply that the human activity had enhanced the nutrition level of the lake in the Arctic region. 相似文献