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1.
基于HIMS的黑河上游山区径流模拟分析 总被引：1，自引：0，他引：1
基于HIMS（Hydro-Informatic Modeling System）,构建了黑河上游山区的分布式水文模型,取得了较高的模拟与验证精度,并在不同的气候变化情景下模拟分析黑河上游山区莺落峡水文站径流,结果表明：①HIMS在黑河上游山区具有适应性,日过程模型率定期和验证期Nash-Suttcliffe效率系数均达0.80,月过程模型率定期和验证期均高达0.97;②莺落峡站年径流量与气温呈负相关关系,与降水量呈正相关关系,气温升高和降水量减少都会减少年径流量;③降水不变情景下,气温对不同月份径流量影响不同,气温降低2℃时会加剧径流年内分配不均的程度;而在气温不变的情景下,月径流量均随降水增加而增加,但径流量年内分配格局未受到降水变化的显著影响;④不同气候变化情景下年径流量差异明显,对年径流量最不利的气候变化情景是气温升高2℃,降水减少20%;最有利的情景是气温降低1℃,降水增加20%。 相似文献
2.
近10 年黑河流域上游积雪时空分布特征及变化趋势 总被引：2，自引：0，他引：2
基于黑河流域上游1960年-2011年降水、气温数据及2000年-2011年MODIS（Moderate-resolution ImagingSpectroradiometer）积雪产品,采用Mann-Kendall非参数检验和累积距平曲线,研究了降水、气温序列的变化趋势和突变点,分析了黑河流域上游积雪面积的年内分布过程和年际变化趋势,探讨了近10a来降水、气温变化对积雪覆盖面积的影响。结果表明：①黑河流域上游年平均气温呈显著的上升趋势,年降水量也呈微弱增加趋势;②黑河流域上游积雪面积年内分布呈双峰型,峰值分别出现在秋季和春季,夏季积雪面积最小;③2000年-2011年积雪面积呈微弱上升趋势,但各季变化不同。春、秋季积雪面积呈上升趋势,夏季为减少趋势,冬季没有明显的变化;④积雪频率有3个高值区,分布在黑河流域上游西岔札马什克水文站周围及以上区域。积雪频率与流域内高程存在显著的相关性;⑤各个季节积雪面积与气温呈负相关的关系;除秋季外,与降水呈正相关的关系。也即较大的降水在较低的气温条件下,有利于积雪的增加,温度的升高则使积雪面积减少。 相似文献
3.
利用博尔塔拉河流域内(简称博河)4个气象代表站1960-2010年气温和降水量资料以及2个代表水文站1980-2010年径流量观测资料,进行了气候、径流量的趋势分析及突变检验,并探讨其相关关系和影响效应。结果表明:1博河流域年平均气温和年降水量呈现增加趋势,其中冬季气温上升对流域气温变化的贡献率最大;2博河年平均径流量呈波动中增加态势,并在1997-1998年发生一次由偏低期转为偏高期的突变;3流域气候变化与博河径流量的关系研究表明,其上游河源区气温与径流量的相关性比下游的大。就降水量而言,下游降水量与径流量的相关性比上游更为显著;4多元回归分析显示,当降水不变,温度每升高1℃时,博河径流量增加4.1%,而当温度不变,降水量每增加10%时,径流量增加4.6%,说明径流量对流域降水量及其气温变化的响应较为显著。 相似文献
4.
研究表明西藏气温随全球气候变暖而升高明显。本文利用拉萨l96l—2000年最低气温、极端最高气温以及与农业生产联系密切的界限温度，分析了拉萨近40年的气温变化。拉萨40年来气温不断上升，尤其以20世纪90年代升温最为显著。在水份条件满足的情况下，气温升高对本地的农业生产有利。 相似文献
5.
本文利用1961～2018年青海湖流域气象站逐日观测资料,分析了近58年来青海湖流域气候变化特征及对青海湖水位、面积的影响。结果表明:1961～2018年青海湖流域年平均气温呈显著升高趋势,平均每10年升高0.4℃;年平均降水量明显增加,平均每10年增加14.5mm;年平均风速降低。暴雨日数显著增多,中雨日数、降水强度及强降水量增加,而干旱日数微弱减少。受降水量增加、布哈河来水量增多的影响,自2005以来,青海湖水位连续14年回升,累计上升2.37m,湖面积总体增加。未来在温室气体中等排放情景下(RCP4.5情景),青海湖流域气温将呈上升趋势,降水增加,蒸发增大,受气候暖湿化影响,青海湖水位可能继续上升、湖面积有进一步扩张趋势。 相似文献
6.
利用杭州国家基准气候站1951-2016年地面观测资料,分析了近66年杭州市气候变化特征。结果表明:杭州市气温呈极显著的上升趋势,最低气温上升最快,平均气温次之,最高气温相对较慢;冬、春季增温最快,秋季次之,夏季最为缓慢;气温一般在90年代至2000年发生突变,之后气候显著变暖。降水主要集中在春季和夏季。近66年杭州市春季和秋季降水量减少,而夏季和冬季降水量增多,年降水量呈波动变化特点,2000年之后,年降水量有增大之势。暴雨发生次数对年降水量的贡献作用举足轻重。分析发现未来杭州市年降水量和年暴雨日数增多的概率均较大。杭州市气候变化普遍存在较长尺度的32～34年及较短尺度的准2年振荡周期。 相似文献
7.
长江黄河源区近45年气候变化特征分析 总被引：14，自引：1，他引：13
气候要素序列的变化主要包括趋势变化、随机变化和周期变化,因此本文采用M-K趋势分析、R/S分析及小波分析研究长江黄河源区近45年(1961年-2007年)气候变化特征。经M-K检验和R/S分析,表明近45年长江黄河源区气温显著升高,增幅明显高于青藏高原平均值,其对全球变暖的响应更为显著,降水变化不一致,总体呈现增加的趋势;气候变暖存在非对称变化现象,长江源区年平均最高气温和极端最高气温变化明显,而黄河源区正好相反,年平均最低气温和极端最低气温变化显著;各项气候要素变化长期相关性特征均表现为持续性,过去总体升温的趋势预示未来气温总体趋势仍将继续上升,降水变化趋势与过去一致;小波分析结果表明,长江黄河源区各个站点的年降水量和年均气温的变化周期及相位都具有很好的一致性,基本上都存27～28年、16～21年、7～11年、3～5年等时间尺度的周期。 相似文献
8.
《资源科学》2019,(1)
了解西藏高原冬虫夏草产区气候变化对当地冬虫夏草资源可持续利用和生态环境保护十分重要。本文利用产区24个气象站1981—2015年的气温、降水、日照资料,采用线性趋势分析、Mann-Kendall突变检验等方法,对产区气温、降水和日照的变化时空特征进行了分析,并集合平均5种气候模式在RCP4.5、RCP8.5两种情景下对产区未来年平均气温和年降水量进行了模拟预估。结果表明:近35年产区年平均气温表现为明显的升高趋势,冬春季升温最为显著,其次为夏秋季;雨季平均气温升温率小于年平均气温升温率。年和雨季的平均最高气温、平均最低气温均呈显著升高趋势,绝大部分站点的年、雨季平均最低气温升温率和平均最高气温升温率均明显大于同期平均气温升温率。年降水量大部分站点为增加趋势,但地区差异性较大;年平均日照时数和雨季日照时数均表现为明显的减少趋势。预估表明产区21世纪未来不同时段气候均表现为气温升高,降水增多的暖湿化发展趋势。未来冬虫夏草适宜海拔下限直接抬升将导致适宜区范围缩小,气候变化将对冬虫夏草的产生和生长造成严重威胁。 相似文献
9.
中国小流域径流对气候变化的敏感性分析 总被引：16，自引：0，他引：16
全球变暖导致的水文水资源问题越来越突出。为了预测气候变化对径流水资源的影响,本文利用全国469个小流域20多年年平均降水量、年平均气温和年平均径流量数据,细分不同的气候情景,分析径流变化对气候变化的响应程度。结果表明：一般来说,径流与降水变化趋势一致,与气温变化趋势相反,但是在局部地区由于温度的升高增加的降水超过蒸发的影响,径流随着气温升高反而增加;干旱地区径流对气温比对降水的响应更加显著,而在湿润地区径流对降水比对气温的响应更加显著;其中年平均气温11℃－15℃、年降水量400 mm---800 mm的华北地区,年均径流深对年均降水量的响应最敏感,而年平均气温低于5℃、年降水量低于400 mm的内蒙古高原西部及新疆北部的天山和阿尔泰山迎风坡低山地带,年均径流深对降水的响应最小;年均降水量200 mm ---400 mm、年平均气温6℃---10℃的内蒙古高原东部,气温对径流的影响最明显,而年平均气温16℃---25℃,年平均降水量800 mm---1600 mm的长江中下游地区、西南的大部分地区以及华东华南的大部分地区,径流对气温的响应相对不显著。 相似文献
10.
气候变化背景下近50年来黑河流域冰川资源变化特征分析 总被引：10，自引：1，他引：9
本文运用RS和GIS,基于航空相片、地形图和遥感影像数据分析了近50a来黑河流域冰川资源变化特征。研究表明,1950s/1970s-2003年,该流域的335条冰川总面积缩小了29.6%,平均每条冰川缩小0.10km2,冰川末端平均后退258m,退缩比率达31.0%,且黑河干流以西的冰川面积缩小及末端退缩幅度均强于干流以东。分析认为,气温显著升高是黑河流域冰川快速萎缩的主导因素。与我国西部其它地区冰川变化相比,黑河流域冰川面积缩小幅度明显较大,且祁连山东、中、西段冰川变化存在显著的区域差异性,这是区域气候差异、冰川规模等因素综合作用的结果。 相似文献
11.
A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
12.
《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
13.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
14.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
15.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
16.
Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
17.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
18.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
20.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献