近50年来ENSO与祁连山区气温降水和出山径流的对应关系   总被引：11，自引：0，他引：11       下载免费PDF全文

蓝永超  康尔泗  张济世  胡兴林 《水科学进展》2002,13(2):141-145

根据有关水文气象台、站的观测资料,分析了恩索(ENSO)与祁连山区气温、降水的对应关系,研究了祁连山区出山径流对厄尔尼诺(ElNino)现象响应.结果表明:ElNino现象对祁连山区的气温、降水和径流的影响随着发生时间和地段的不同而不同.ElNino现象发生之年,整个祁连山区均出现气温偏高、降水减少及径流偏枯的现象,尤以东段和中段最为明显.ElNino现象次年,祁连山区东段和中段气温偏高、降水减少及径流偏估的程度不如ElNino现象当年那样显著,而西段的气温、降水及径流与ElNino现象则无明显关系.  相似文献   

北祁连-河西走廊志留纪和泥盆纪古地理及其对同造山过程的沉积响应   总被引：17，自引：3，他引：17       下载免费PDF全文

杜远生  张哲  周道华  彭冰霞 《古地理学报》2002,4(4):1-8

北祁连-河西走廊志留系包括下志留统鹿角沟砾岩和肮脏沟组、中志留统泉脑沟山组和上志留统旱峡组，泥盆系包括中、下泥盆统老君山组和上泥盆统沙流水组。鹿角沟砾岩为水下冲积扇沉积，断续分布于北祁连西段。肮脏沟组在北祁连-河西走廊分布广泛，主要为半深海碎屑复理石沉积。泉脑沟山组和旱峡组分布于北祁连和河西走廊西段，前者以浅海相砂泥岩和泥灰岩为主，后者以滨海潮坪-浅海碎屑岩沉积为主。老君山组分布于古祁连山山前和山间盆地，为粗碎屑磨拉石沉积。沙流水组分布于河西走廊东段，为湖相沉积。区域古地理分析表明，北祁连-河西走廊志留纪-泥盆纪的古地理主要受北祁连加里东-早海西期不规则造山作用控制。鹿角沟砾岩标志着弧-陆碰撞最早发生于早志留世早期。早志留世北祁连-河西走廊由弧后残余盆地向前陆盆地转化。中、晚志留世北祁连东段剧烈造山并与阿拉善古陆的连接，前陆盆地限于北祁连-河西走廊西段。志留纪末期为北祁连的主造山期，泥盆纪形成高峻的古祁连山。早、中泥盆世形成山前和山间盆地的粗碎屑磨拉石沉积。晚泥盆世造山带西段造山作用剧烈，形成剥蚀区。东段造山作用微弱，山地被剥蚀，山前形成湖泊相的晚泥盆世沉积。  相似文献   

Predicting fine sediment dynamics along a pool-riffle mountain channel   总被引：1，自引：0，他引：1  

Sara Rathburn  Ellen Wohl   《Geomorphology》2003,55(1-4):111

Fine sediment dynamics in mountain rivers are of concern because of implications for aquatic habitat, channel stability, and downstream sediment yields. Many mountain river systems have episodic fine sediment transport because of infrequent, point-source sediment inputs from landslides; basin instability triggered by land uses such as logging; or infrequent mobilization of the coarse surface layer in channels. Dam removal, which is now more likely along mountain rivers, may also provide a substantial fine sediment input to downstream channel reaches.Fine sediment storage in the interstices of spawning gravels and within pools along mountain rivers is of particular interest because of impacts to aquatic organisms. In this study we focus on sediment dynamics within pools of the North Fork Poudre River in Colorado as an example of the processes controlling fine sediment deposition, storage, and transport within laterally constricted pools. The 1996 release of 7000 m³ of silt-to gravel-sized sediment from a reservoir on the North Fork provided an opportunity to develop a field data set of fine sediment dynamics and to test the predictions of three different one- or two-dimensional sediment transport and hydraulic models against the field observations.The models were calibrated against quantitative measurements of pool scour and fill. One-dimensional HEC-6 results indicate that robust simulations yield the greatest agreement between predicted and measured pool bed elevation change. Model calibration on two pools and validation on one pool indicate that at least 58% of observed bed changes after the sediment release were predicted by HEC-6. Modeling accuracy using quasi-two-dimensional GSTARS 2.0 was considerably more variable, and no pool-wide trends were obtained. The two-dimensional model RMA2 substantially improved the representation of eddy pool hydraulics within a compound pool of the North Fork. Results from the hydraulic modeling, coupled with bed load and total load computations, delineate areas of scour and deposition which are consistent with observations in the field.A conceptual model of sediment delivery and storage for laterally confined pools suggests that persistent deposition of fine sediment within eddies distal from the sediment source may result from sediment releases. The original loss of channel capacity facilitated additional deposition within eddies as sediment within upstream proximal pools became mobilized. At high discharges, the development of a strong shear zone prevents degradation of sediment deposits within the eddy. Central portions of these proximal pools may clear according to existing models, whereas deposition within recirculating zones may be long-term. Water managers could use these models to estimate minimum pool volume for overwinter habitat and residence time of pool sediment.  相似文献   

The relationship between ENSO cycle and temperature, precipitation and runoff in the Qilian mountain area     

LAN Yongchao  DING Yongjian  KANG Ersi  ZHANG Jishi 《地理学报》2003,13(3):293-298

El Nino and La Nina are the events concerned internationally. The corresponding relationship between El Nino events, temperature, precipitation and runoff in the Qilian mountain area are analyzed according to the date from the weather and the hydrometric stations in the area, the results show that effects of El Nino events to temperature, precipitation and runoff are different in the different time and zones. When El Nino occurs, temperature rises, but precipitation and runoff decrease in the whole Qilian mountain area, especially in the east and middle parts of the area. Temperature rises, precipitation and runoff still decrease in the eastern Qilian mountain area in the next year El Nino occurring, but decrease extent is fewer. There are not obvious relationship between temperature, precipitation and runoff with El Nino events in the western Qilian mountain area.  相似文献   

根据土壤化学特征划分伏牛山亚热带北界   总被引：1，自引：0，他引：1  

马建华  许叔明  韩晋仙  ZHU Lianqi  Zhao Qingliang 《地理学报(英文版)》2003,13(3):299-304

The boundary between subtropical zone and temperate zone is not only important in physical geography, but also attractive in agricultural production. Seven soil profiles studied in this paper are placed along the southern slope of Funiu Mountain at different heights above sea level.Many compositions and properties of these soils have been determined in laboratory. In this paper,the laws of migration and accumulation of soil materials on the southern slope of Funiu Mountain are discussed first, then the division of the boundary between subtropical zone and temperate zone in this area according to soil geochemistry is discussed with qualitative methods and mathematical classification method in which twelve selected indexes such as Km, Saf, Ba, β, Feo/Fet, Mno/Mnt and so on are used. The result indicates that the boundary between subtropical zone and temperate zone on the southern slope of Funiu Mountain is about 950 m above sea level.  相似文献   

2001年昆仑山口西8.1级大震预报的再讨论   总被引：3，自引：1，他引：3  

郭增建  韩延本  吴瑾冰 《地震研究》2002,25(4):309-313

由立交模式、静中动判据和高山峰指标讨论了2001年昆仑山口西8．1级大震的地点骤报。由74年周期性、三性法和倍九律讨论了这个8．1级大震的时间预报。倍九律包括热红外异常、6级地震活动和K＝8的大磁暴在震前出现的倍九天时间特征。  相似文献   

Carbon cycling of alpine tundra ecosystems on Changbai Mountain and its comparison with arctic tundra   总被引：4，自引：0，他引：4  

代力民  吴钢  赵景柱  孔红梅  邵国凡  邓红兵 《中国科学D辑(英文版)》2002,45(10):903-910

The alpine tundra on Changbai Mountain was formed as a left-over ‘island’ in higher elevations after the glacier retrieved from the mid-latitude of Northern Hemisphere to the Arctic during the fourth ice age. The alpine tundra on Changbai Mountain also represents the best-reserved tundra ecosystems and the highest biodiversity in northeast Eurasia. This paper examines the quantity of carbon assimilation, litters, respiration rate of soil, and storage of organic carbon within the alpine tundra ecosystems on Changbai Mountain. The annual net storage of organic carbon was 2092 t/a, the total storage of organic carbon was 33457 t, the annual net storage of organic carbon in soil was 1054 t/a, the total organic carbon storage was 316203 t, and the annual respiration rate of soil was 92.9% and was 0.52 times more than that of the Arctic. The tundra-soil ecosystems in alpine Changbai Mountain had 456081 t of carbon storage, of which, organic carbon accounted for 76.7% whereas the mineral carbon accounted for 23.3%.  相似文献   

祁连L山主要植被下土壤水的时空动态变化特征   总被引：13，自引：1，他引：13  

牛云  张宏斌  刘贤德  张学龙  葛双兰 《山地学报》2002,20(6):723-726

通过对祁连山青海云杉林、祁连圆柏林、亚高山灌丛林、牧坡草地等4种主要植被类型的土壤水测量数据进行分析表明，土壤水的空间垂直动态表现为随深度的增加而减少，可划分为土壤水分易变层、利用层、调节层三个层次；土壤水的时间动态可划分为土壤失水期、聚水期、退水期、稳水期四个时期。土壤水总的特征是，不同植被地类的土壤水季节变化规律基本一致，主要受降水量及其分配的影响。  相似文献   

河南省连康山光萼苔科植物区系地理成分研究     

赵建成  崔彦伟  叶永忠  袁志良 《地理与地理信息科学》2002,18(4):107-110

该文在研究标本和文献的基础上,介绍河南省连康山自然保护区所产的光萼苔科(Porellaceae)植物2属8种,即光萼苔属Porella(7种)和多瓣苔属Macvicaria(1种)。讨论了它们的生境、识别特征和植物区系地理成分,并编制了河南省连康山自然保护区光萼苔科植物的分属、分种检索表。  相似文献   

衡山旅游客源市场的开发与营销对策研究   总被引：3，自引：0，他引：3  

刘玉桥 《热带地理》2002,22(4):350-354

分析了衡山旅游客源市场规模、时空分布规律和游客行为特征等旅游需求特征，在此基础上研究了衡山的旅游客源市场竞争机制和开发定位，提出了衡山旅游业可持续发展的旅游客源市场营销策略。  相似文献