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1.
Based on the δ13C and δ18O fluctuation of lacustrine carbonate, CaCO3 content and sporo-pollen data, a palaeoclimatic history of Bosten Lake during the Holocene has been outlined, several stages
of climatic changes are divided, and the following result es are obtained: (1) Palaeoclimatic changes revealed by carbonate
isotope around Bosten Lake are basically identical with that revealed by other geological records in Xinjiang. Environmental
changes presented apparent Westlies Style model: during cold period, relative humidity increased, δ18O, δ13C and CaCO3 appeared low; but in warm periods, the dry regime aggravated. (2) The temperature reflected by δ18O exist evident features being increase in the late period during the Holocene. Together with the δ13C, pollen and CaCO3 analyses, several cold and warm phases which are of broad regional significance can be identified. The warm peaks occurred
at about 11.0 ka B.P., 9.4 ka B.P., 7.5 ka B.P., 5.0 ka B.P., 3.0 ka B.P. and 2.0 ka B.P.; the cold peaks at 11.5 ka B.P.,
10.5 ka B.P., 8.8 ka B.P., 5.5 ka B.P., 3.3 ka B.P., 2.2 ka B.P. and 1.5 ka B.P.. (3) Several climatic events with the nature
of “abrupt climatic changes” are revealed in the periods of 11.0 ka B.P. −10.5 ka B.P., 9.4 ka B.P. −8.8 ka B.P., 5.5 ka B.P.
−5.0 ka B.P. and 2.0 ka B.P. −1.5 ka B.P.. (4) The results show that carbonate isotopic record of lacustrine sediment in arid
area is very sensitive to climatic changes, and may be play a very important role in understanding the features and mechanism
of palaeoclimatic changes. 相似文献
2.
基于博斯腾湖1955—2012年湖水位变化资料,利用树木年轮法分析了博斯腾湖年和月水位变化与湖滨柽柳(Tamarix ramosissina)年轮生长关系,利用敏感度指数得出博斯腾湖滨柽柳年轮生长的敏感水位范围。结果表明:(1)1955—2012年博斯腾湖年平均水位经历了3个明显变化阶段,即1955—1987年下降至最低,1987—2002年上升至最高。受向下游生态输水影响,2002—2012年博斯腾湖水位快速下降。输水对博斯腾湖月平均水位和季节性水位变化有影响。(2)博斯腾湖滨柽柳年轮指数与当年的湖水位变化和前1年的湖水位变化均显著相关(p0.05)。柽柳年轮指数与前1年10月至当年4月各个月份的湖水位表现出显著相关(p0.05)。柽柳年轮指数与前1年冬季湖水位相关显著(p0.05),与当年春季3—4月月平均湖水位相关性显著,与当年夏季和秋季湖水位的相关性不显著。(3)博斯腾湖滨柽柳年轮生长对月湖水位变化响应比较敏感。当湖水位在1045.3m时,柽柳年轮指数灵敏度指数(Sk)存在最低值;当湖水位在1 046.3m时,Sk出现最高值。 相似文献
3.
博斯腾湖向塔里木河输水风险分析方法 总被引：12，自引：7，他引：5
为了拯救塔里木河下游生态环境，塔里木河流域管理局根据博斯腾湖从1999年到2003年处于丰水期，湖泊处于高水位的有利时机，从2000年5月到2003年6月实施5次向塔里木河下游生态应急输水，结束塔里木河下游300多km河道近30年的断流历史。现在的问题是“博斯腾湖向塔里木河生态输水能否持续?”，“保证可持续输水的风险有多大?”本文以解决此问题为实例，介绍一般水库调节计算和水库特征水位确定方法；主要探讨水库(湖泊)向下游输水可持续性风险分析问题，提出的方法称为“水库输水可持续性风险计算时历试算法”，简称为“试算法”(T＆E方法)；并将此方法应用于实例中，计算博斯腾湖向塔里木河下游输水的可持续风险。 相似文献
4.
博斯腾湖的水盐平衡与矿化度 总被引：16，自引：5，他引：11
博斯腾湖曾是中国内陆区最大的淡水湖，因人类活动影响约在１９６８年演变为微咸水湖。本文依据湖泊水平衡太矿化度基本原理，结合博斯滕湖实际，分析计算了该湖各个时期的水盐平衡与矿化度；经推地整理，提出了预测矿化度的计算式，经检验与实测值基本吻合。 相似文献
5.
近期博斯腾湖水位变化及其原因分析 总被引：32，自引：5，他引：27
新疆博斯腾湖1987年以来湖泊水位的变化（上升）与要补给河流开都河径流量的变化有直接关系，而这与发源于天山中段降水和高山冰雪融水的河流，受到气候变化影响很大有关，全球变化研究结果显示，中亚干旱区是全球温度上升幅度较大的地区，当地的气象资料表明，过去20a年平均温度明显升高的趋势，对水资源储量和补给来源影响深远。 相似文献
6.
近50年来人类活动对博斯腾湖水位影响的量化研究 总被引：22，自引：5，他引：17
博斯腾湖是新疆最大的湖泊，也是中国最大的内陆淡水湖，其巨大的环境、生态和经济价值一向为人们所关注。近50年来，博斯腾湖水位发生了很大变化，1958—1987年水位持续下降，1988～2002年水位又转为持续上升，目前处于50年来的最高水位。针对其水位变化，利用近50年来的实测数据分析了人类活动对水位变化的影响，定量还原了天然状况下博斯腾湖的水位。研究结果表明，自1958年以来人类活动对博斯腾湖水位变化的影响经历了弱→强→弱的变化过程，其中20世纪70—80年代人类活动对水位变化影响最为显著，90年代以后影响强度有所减弱。 相似文献
7.
High-Resolution Records of the Holocene Paleoenvironmental Variation Reflected by Carbonate and Its Isotopic Compositions in Bosten Lake and Response to Glacial Activities 总被引：1，自引：0，他引：1 
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下载免费PDF全文 ZHANG Chengjun ZHENG Mianping Alexander PROKOPENKO Steffen MISCHKE GOU Xiaohui YANG Qili ZHANG Wanyi FENG Zhaodong 《《地质学报》英文版》2009,83(6):1101-1115
Abstract: The Early Holocene paleoclimate in Bosten Lake on the northern margin of the Tarim Basin, southern Xinjiang, is reconstructed through an analysis of a 953 cm long core (BSTC2000) taken from Bosten Lake. Multiple proxies of this core, including the mineral components of carbonate, carbonate content, stable isotopic compositions of carbonate, Ca/Sr, TOC and C/N and C/S of organic matter, are used to reconstruct the climatic change since 8500 a B.P. The chronology model is made by nine AMS 14C ages of leaves, seeds and organic matter contained in two parallel cores. The climate was cold and wet during 8500 to 8100 a B.P. Temperature increased from 8100 to 6400 a B.P., the climate was warm and humid, and the lake expanded. The lake level was highest during this stage. Then from 6400 to 5100 a B.P., the climate became cold and the lake level decreased slightly. During the late mid-Holocene, the climate was hot and dry from 5100 to 3100 a B.P., but there was a short cold period during 4400 to 3800 a B.P. At this temporal interval, a mass of ice and snow melting water supplied the lake at the early time and made the lake level rise. The second highest lake level stage occurred during 5200 to 3800 a B.P. The climate was cool and wet during 3100 to 2200 a B.P., when the lake expanded with decreasing evaporation. The lake had the last short-term high level during 3100 to 2800 a B.P. After this short high lake level period, the lake shrank because of the long-term lower temperature and reduced water supply. From 2200 to 1200 a B.P., the climate was hot and dry, and the lake shrank greatly. Although the temperature decreased somewhat from 1200 a B.P. to the present, the climate was warm and dry. The lake level began to rise a little again, but it did not reach the river bed altitude of the Konqi River, an outflow river of the Bosten Lake. 相似文献
8.
2002年前后博斯腾湖水位变化及其对中亚气候变化的响应 总被引：7，自引：1，他引：6
通过对湖泊补给水量的分析,博斯腾湖2002年前后水位由高向低的转折变化是由开都河径流变化造成的.对2002年前后天山南北其它主要湖泊的水位和河流径流变化作了比较分析结论.由于山区河源径流补给组成不同,表现出在同一中亚气候背景下,即2002年前后该地区气温降低而降水东西各有差异,使得天山西段受降水补给为主的河流,2002年后径流仍有增加,具体反映在伊塞克湖、巴尔喀什湖等水位持续上升和托什干河等径流的偏丰;而天山东部的开都河,受降水减少和气温降低对冰川变化的双重影响,2003年以来径流明显减少,导致博斯腾湖的水位持续下降. 相似文献
9.
博斯腾湖向塔里木河生态输水效果及风险 总被引：10，自引：5，他引：5
为了挽救濒临毁灭的塔里木河下游生态环境,中国政府2000~2003年实施5次向塔里木河下游生态应急输水,结束塔里木河下游300 km河道近30年的断流历史。文章基于大量数据资料,简单介绍塔里木河断流过程;再分析近期博斯腾湖向塔里木河下游输水效果;最后从博斯腾湖来水水文特性分析、博斯腾湖调节计算和输水风险分析等方面,阐述博斯腾湖向塔里木河下游输水的风险及控制措施。 相似文献
10.
Carbon and Oxygen Isotopic Composition of Surface-Sediment Carbonate in Bosten Lake (Xinjiang, China) and its Controlling Factors 总被引：1，自引：1，他引：0
Steffen MISCHKE ZHENG Mianping Alexer PROKOPENKO GUO Fangqin FENG Zhaodong 《《地质学报》英文版》2009,83(2):386-395
Bosten Lake is a mid-latitude lake with water mainly supplied by melting ice and snow in the Tianshan Mountains. The depositional environment of the lake is spatially not uniform due to the proximity of the major inlet and the single outlet in the western part of the lake. The analytical results show that the carbon and oxygen isotopic composition of recent lake sediments is related to this specific lacustrine depositional environment and to the resulting carbonate mineralogy. In the southwestern lake region between the Kaidu River inlet and the Kongqi River outlet, carbon isotope composition (δ13C) values of the carbonate sediment (?1‰ to ?2‰) have no relation to the oxygen isotope composition of the carbonate (δ18O) values (?7‰ to ?8‰), with both isotopes showing a low variability. The carbonate content is low (<20%). Carbonate minerals analyzed by X-ray diffraction are mainly composed of calcite, while aragonite was not recorded. The salinity of the lake water is low in the estuary region as a result of the Kaidu River inflow. In comparison, the carbon and oxygen isotope values are higher in the middle and eastern parts of the lake, with δ13C values between approximately +0.5‰ and +3‰, and δ18O values between ?1‰ and ?5‰. There is a moderate correlation between the stable oxygen and carbon isotopes, with a coefficient of correlation r of approximately 0.63. This implies that the lake water has a relatively short residence time. Carbonate minerals constitute calcite and aragonite in the middle and eastern region of the lake. Aragonite and Mg–calcite are formed at higher lake water salinity and temperatures, and larger evaporation effects. More saline lake water in the middle and eastern region of the lake and the enhanced isotopic equilibrium between water and atmospheric CO2 cause the correlating carbon and oxygen isotope values determined for aragonite and Mg–calcite. Evaporation and biological processes are the main reasons for the salinity and carbonate mineralogy influence of the surface-sediment carbonate in Bosten Lake. The lake water residence time and the CO2 exchange between the atmosphere and the water body control the carbon and oxygen isotope composition of the carbonate sediment. In addition, organic matter pollution and decomposition result in the abnormally low carbon isotope values of the lake surface-sediment carbonate. 相似文献