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1.
堰塞湖的水文特征过程对于库区洪水宏观调控、预报预警、安全防治等具有重要意义。为了及时掌握萨雷兹堰塞湖水文特征和历史演化过程,本文基于密集时间序列遥感数据,综合调查全面系统地分析了1972—2019年帕米尔高原萨雷兹堰塞湖的水文特征以及时空变化过程;并通过“面积-水位”关系模型重建了1972—2019年萨雷兹堰塞湖的历史水位面积演变时序过程;在此基础上采取M-K趋势和突变检验分析了水文变化特征。研究结果表明:① 萨雷兹堰塞湖水位总体上呈现波动性显著上升趋势,这种波动趋势主要表现为年内波动和高位震荡,但振幅在逐年减小。② 萨雷兹堰塞湖水文时序演化过程在2013年前后出现了一个突变拐点,面积水位变化特征表现为由原来的缓慢增加转变到加速上升。③ 1972—2019萨雷兹堰塞湖面积和水位关系模型为:y=-0.1003x2+18.181x+2440,(R2=0.63,P<0.05,双尾)。结合流域气象、径流以及相关文献数据分析得出萨雷兹堰塞湖的水文特征年内/际波动直接受穆尔加布河径流补给量的影响;区域冰川积雪加速消融带来的河道径流补给量增加是近年来面积水位加速上升的主要原因。  相似文献   

2.
在全球气候变暖的大背景下,中国西北地区呈现出了由暖干向暖湿转型的变化特征,且新疆是显著转型区,温度上升,降水量、冰川消融量和径流量连续多年增加,湖泊水位显著上升。博斯腾湖水质的变化,水位的变化以及湿地芦苇资源的变化都直接或间接的受全球或区域气候的影响。总体来说,博斯腾湖环境变化受自然和人为两种因素制约。但这两种因素对水位变化的影响力在不同时期是有差异的。20世纪70年代以前人为活动对湖水位变化的影响力略大于自然因素对湖水位变化的影响力,在80年代以后湖水位变化主要受自然因素影响。总体来说,湖水位变化以自然因素影响为主,但人为活动加剧了湖水位的变化。  相似文献   

3.
利用遥感影像数据的分类解译结果,从湿地面积时空变化、景观破碎度变化和水文连接度等角度,对1992年、2005年和2015年莫莫格国家级自然保护区的景观格局变化特征和湿地水文连通性变化进行定量分析,研究了该保护区湿地的景观格局和水文连通性;利用长时间序列的年降水量、年平均气温、年径流量和年平均水位数据,探讨了气候、水文和人类活动对该区湿地的影响因素。研究结果表明,与1992年相比,2015年莫莫格保护区湿地总面积共减少了45.99 km2,其中,沼泽和洪泛湿地的面积分别减少了95.27 km2和52.76 km2;与1992年相比,2005年和2015年湿地景观明显破碎化,尤其以沼泽区景观破碎最严重;与1992年相比,受湿地景观破碎的影响,2005年和2015年湿地水文连接性变差。极端干旱和洪水事件直接影响整个莫莫格湿地的水源补给和水域覆盖面积;河流径流量和水位变化直接导致其与周边洪泛湿地的水力联系发生改变,进而影响洪泛湿地的消长;研究区的人类活动主要是保护区内的湿地开垦和流域内的水利工程建设。  相似文献   

4.
1974—2009年西藏羊卓雍错湖泊水位变化分析   总被引:3,自引:0,他引:3  
羊卓雍错(简称羊湖)是青藏高原南部最大的一个封闭型内陆湖泊,位于西藏自治区浪卡子县境内,与纳木错、玛旁雍错一起并列为西藏三大圣湖,是藏南地区重要的风景旅游区。始建于1989年的羊湖发电站于1997年正式投入运营,为世界上海拔最高的抽水蓄能电站。在全球气候变暖和人类活动的影响下,其湖面水位变化及其成因备受国内外关注。利用1974—2009年羊湖白地水文观测资料,分析了36年来羊湖水位年际、年内变化特征及其与自然要素(气温、降水和蒸发等)和人类活动之间的关系。结果表明,羊湖平均水位为19.06 m,历史最高值出现在1980年,为21.37 m,2009年水位降至17.08 m的历史最低值。自1974年有水位观测资料以来,羊湖水位呈波动式下降趋势,其中,1974—1977年水位表现为逐年下降,幅度为0.26 m/a;之后至1980年以0.4 m/a呈上升态势,1980年羊湖水位达到了历史最高值;此后,至1996年水位呈显著下降趋势,减少速率为2.08 m/(10 a),1996年是羊湖水位上升的一个转折点,至2004年水位在逐年上升;2004—2009年是一个水位显著下降的时段,速率为0.57 m/a,也是水位下降趋势最为显著的时段。羊湖水位下降年份占整个时段的56%,而44%的年份水位在上升。1974—1984年及2001—2005年水位高于多年平均值,而1985—2000年及2006年之后水位都低于多年平均值。羊湖水位的年内最低值一般出现在6月,最高值则在10月。羊湖年内水位变化对流域降水量的响应具有一定的滞后性,时间为2个月左右。羊湖水位变化主要是由降水波动、气温上升、蒸发的变化等自然因素共同作用的结果,特别是,流域年际降水量波动是湖面水位升降的主要影响因子,人为和工程的影响范围和程度均较小。自羊湖电站1997年运行以来,流域的环境在暖湿的气候大背景下有所改善,且对羊湖水位变化无明显影响。但如果电站不能蓄水与发电并举,达不到总体不消耗羊湖水量的设计目标和水量平衡,对羊湖水位的影响将不可忽视。  相似文献   

5.
1958—2012年博斯腾湖水位变化驱动力   总被引:3,自引:0,他引:3  
利用1958—2012年博斯腾湖流域水文、气象与社会经济资料序列,采用灰色关联法分析了博斯腾湖水位变化特征及其影响因素。结果表明:(1)在过去半个多世纪,博斯腾湖水位经历了下降、上升、再下降3个阶段,各阶段内各驱动因素的权重不同;(2)博斯腾湖水位变化主要是入湖流量、降水及气温波动等自然因素和耕地面积、灌溉面积、灌溉引水量及灌溉净耗水量等人为因素共同作用的结果,特别是入湖流量变化是博斯腾湖水位升降的主要影响因素。1958—1987年,开都河处于偏枯年份,博斯腾湖水位呈缓慢下降的趋势,水位从1958年的1 048.00m下降至1987年的1 045.03m,平均水位为1 047.20m,这期间自然因素对水位的影响较大;1988—2002年,开都河处于丰水年,入湖水量较多,博斯腾湖水位呈快速上升趋势,水位从1988年的1 045.21m上升至2002年的1 048.60m,平均水位为1 046.80m,这期间人类活动对水位的影响开始增强,但自然因素对水位的影响仍强于人类活动对水位的影响;2003—2012年,入湖水量减少,博斯腾湖水位又呈急剧下降趋势,水位从2003年的1 048.55m下降至2012年的1 045.68m,这期间人类活动对水位的影响呈显著增加趋势;(3)1958—2012年博斯腾湖水位变化的主要驱动因素总体呈自然因素向人类活动的变化趋势。  相似文献   

6.
基于主成分分析法的博斯腾湖水位变化驱动力研究*   总被引:1,自引:0,他引:1  
利用1958~2010年博斯腾湖流域水文、气象与社会经济资料,采用相关分析法与主成分分析法,分析了博斯腾湖水位动态变化情况及其驱动机理。结果表明,1)博斯腾湖水位从1958年的1 048.0 m下降至2010年的1 045.75 m,净下降2.25 m。水位变化经历了波动式下降(1958~1987年)→急剧上升(1988~2002年)→急剧下降(2003~2010年)的变化过程;2)博斯腾湖水位变化主要是由入湖流量、降水与气温波动等自然因素和耕地面积与人口的增加等人为因素共同作用的结果,特别是入湖流量变化是湖面水位升降的主要影响因子。研究结果能为干早区湖泊水资源的合理利用和生态环境的保护提供科学依据。  相似文献   

7.
湖泊是陆地水资源的重要组成部分,也是局地气候和全球环境变化的敏感指示器之一。湖泊面积增加和水位的变化直接反映了流域内水量平衡变化过程,对区域和全球的气候变化的反映较为敏感。利用线性趋势法对青海湖流域长时间序列气象、水文资料以及流域水热条件和植被生长状况进行分析研究,利用皮尔逊相关系数法计算了各因素与湖水位的相关关系,旨在定量评估区域气象、水文、植被等要素的变化对和湖泊水位变化过程的贡献,开展细致的青海湖水位变化特征的影响因子探讨与分析。结果表明:该流域气候呈现显著的暖湿化趋势,其中流域年降水量总体上呈现弱的增加态势,气候倾向率为10.8 mm·(10 a)-1;流域年平均气温呈显著的升高趋势(P <0.01)。流域年可能蒸散率和年实际蒸散波动较大,年实际蒸散虽有波动但增加趋势非常明显(P <0.01)。流域净第一性生产力(P)平均值为2.86 t DM·hm-2·a-1,呈现显著的增加趋势(P <0.01)。从1961年开始湖水位呈现逐年波动下降的趋势,到2004年水位最低(P<0.01);2004—2015年的近10 a连续上升,上升速率达14.4 m·(10 a)-1P <0.01)。流域气温升高、降水量增加,流域气候呈显著的暖湿化特征,入湖河流径流量也呈现出弱的增加态势;气候暖湿化特征导致流域生物温度增加,植被生长状况得到改善,[WTBX]NPP[WTBZ]显著增加。年降水量增多,河流径流量增大,湖水位抬升;前一年的降水量、≥0 ℃积温、温度、径流量、NPP和蒸发量对湖水位的影响更大;NDVINPP的增加反映流域植被生长状况得到好转,从而增加了流域植被水土保持和水源涵养能力,对湖水位产生间接的影响。降水量、≥0 ℃积温、温度、径流量和NPP对青海湖水位起到正反馈效应,而蒸发量对湖水位主要起负反馈效应,年降水量和年径流量是湖水位变化的最直接的影响因子。  相似文献   

8.
青海湖水量变化模拟及原因分析   总被引:4,自引:1,他引:3  
为了探讨气候变化和人类活动对流域水文过程的影响,以分布式水文模型SWAT为基础,结合湖泊水量平衡模型,建立了青海湖水位(水量)模型,模拟了青海湖过去几十年水位变化过程。水文因子分析表明,20世纪80~90年代青海湖流域径流和湖泊水位变化的主要原因是气候变化。根据不同气候情景,对未来青海湖水位变化进行了预测。结果表明,未来30年径流增加的可能性比较大,青海湖水位下降速度将会减缓甚至出现上升趋势。这一结果将会缓解青海湖流域水资源日益紧张的局势,并有利于植被的恢复,减少土地沙化面积,对流域生态环境的改善和社会经济的发展将会有极大的帮助。  相似文献   

9.
叶许春  吴娟  李相虎 《地理科学》2022,42(2):352-361
基于对鄱阳湖开放水文系统特点和影响因素的深入分析,通过构建一组联合的神经网络模型,定量辨识了包括湖盆地形变化、三峡工程作用、长江流域气候变化等因素对湖泊水位变化的影响分量、时空差异及其发展趋势,并对其作用机制进行了探讨。结果表明:相对于1980—1999年,2003—2014年鄱阳湖湖盆地形变化、三峡工程运行、长江流域气候变化和其他人类活动对湖泊水位降低的平均贡献率分别为50%、18%和32%。由于影响机制的不同,湖泊水位对这3个驱动因子的响应表现出明显的时空差异。冬、春季节湖泊水位降低主要由湖盆地形变化引起,而夏、秋季节的水位降低则主要归因于长江流域气候变化及其他人类活动的综合影响。湖盆地形变化对湖泊水位的影响在湖区都昌站附近最为突出,并且该影响仍呈长期增加趋势。三峡工程引起的湖泊水位变化在湖口处最大,向南部湖区逐渐减弱,其长期变化趋势日渐稳定。长江流域气候变化及其他人类活动的作用值得特别注意,该影响年际间波动较大,在某些年份里(如2006年、2011年)可成为湖泊水位降低的主导因素,但年际变化趋势不明显。  相似文献   

10.
孙烨琳  樊文有  史培军  王铸  孙劭 《地理研究》2021,40(4):1064-1077
湖北省是中国重要的植棉省份之一,气候和管理因素变化对棉花生长产生重要影响。因此,本文采用1986—2016年湖北气温、降水量和太阳辐射量3个气候因子数据,有效灌溉面积、农用化肥施用量和棉花品种3个管理因素数据,构建了面板回归模型,定量计算得到气候因子和管理因素的趋势和波动变化对棉花单产的影响及其相对贡献率。结果表明:① 气候和管理因素的波动变化大于气候和管理因素的趋势变化对棉花单产的影响。② 气温和太阳辐射量对湖北省大部分地级市的棉花单产呈现正影响,降水量对湖北省大部分地级市的棉花单产呈现负影响;有效灌溉面积、农用化肥施用量和棉花品种都对湖北省大部分地级市的棉花单产呈现正影响。③ 气温、降水量和有效灌溉面积是影响湖北省大部分地级市棉花单产的主导因子。④ 1986—2016年武汉市等地级市棉花增产的主要原因是管理因素变化主导的增产抵消了气候因子变化的减产影响。  相似文献   

11.
Relative ages of late Cenozoic stratigraphy throughout the Caspian region are referenced to regional stages that are defined by changes in microfauna and associated extreme (>1000 m) variations in Caspian base level. However, the absolute ages of these stage boundaries may be significantly diachronous because many are based on the first occurrence of either transgressive or regressive facies, the temporal occurrence of which should depend on position within a basin. Here, we estimate the degree of diachroneity along the Akchagyl regional stage boundary within the Caspian basin system by presenting two late Miocene‐Pliocene aged measured sections, Sarica and Vashlovani, separated by 50 km and exposed within the Kura fold‐thrust belt in the interior of the Kura Basin. The Kura Basin is a western subbasin of the South Caspian Basin and the sections presented here are located >250 km from the modern Caspian coast. New U‐Pb detrital zircon ages from the Sarica section constrain the maximum depositional age for Productive Series strata, a lithostratigraphic package considered correlative with the 2–3 Myr‐long regional Eoakchagylian or Kimmerian stage that corresponds to a period of extremely low (>500 m below the modern level) Caspian base level. This new maximum depositional age from the Productive Series at Sarica of 2.5 ± 0.2 Ma indicates that the regionally extensive Akchagyl transgression, which ended the deposition of the Productive Series near the Caspian coast at 3.2 Ma, may have appeared a minimum of 0.5 Myr later in the northern interior of the Kura Basin than at the modern Caspian Sea coast. The results of this work have important implications for the tectonic and stratigraphic history of the region, suggesting that the initiation of the Plio‐Pleistocene Kura fold‐thrust belt may have not been as diachronous along strike as previously hypothesized. More generally, these results also provide a measure of the magnitude of diachroneity possible along sequence boundaries, particularly in isolated basins. Comparison of accumulation rates between units in the interior of the Kura subbasin and the South Caspian main basin suggest that extremely large variations in these rates within low‐stand deposits may be important in identifying the presence of subbasins in older stratigraphic packages.  相似文献   

12.
This work deals with changes recorded by lacustrine sediments from SW Anatolia in Turkey in the context of increasing stress on the Mediterranean environment in relation to human-climate-environmental interactions. Paleolimnological investigations were carried out on Lake Burdur (Lake District geographical subregion of Turkey), which has been subject to rapid changes in its hydrological system that caused a ~10-m water-level drop in the last 30 years. Study of a 5-m-long sediment core, taken from the recently dried out part of the lake, shows significant variation in granulometry, clay mineralogy, nitrogen and organic carbon content and its isotopic composition (?13Corg) throughout the sedimentary sequence, which represents the last 2,300 years. Chronology is based on radiocarbon dates obtained from plant fragments. The results provide a record of environmental changes, including biological productivity and erosion intensity, in relation to changes in water level and humidity of the area. The lowest previous water level, which is the same as observed today, occurred at approximately 300 BC, after which time a water-level increase led to a maximum stage between AD 200 and 1200. From AD 1200 to the present, the climate became drier accompanied by an overall lowering of water level, with periods of water-level fluctuations superimposed. The lake never dried out as is observed today at the coring site. The present drop in the lake water level is attributed to human activity rather than to climate change. This record of climate and environmental change in the Lake Burdur area appears to be stratigraphically complete. This study provides rare data for the late Holocene in Anatolia as well as information about rapid climate changes during specific periods. The influence of both the Northern hemisphere atmospheric circulation and Indian monsoon on the east Mediterranean remains unclear. Nevertheless, the North Sea—Caspian atmospheric teleconnection could be an important factor that explains local differences in climatic evolution of Anatolia during the period considered.  相似文献   

13.
本文是俄罗斯科学院库尔纳科夫普通和无机化学研究所天然盐化学和工艺学研究室多年来对卡拉博加兹海湾的研究结果.他们对该海湾的地理环境、气候条件、里海海水对湾内卤水的补给与相互作用等进行了研究,给出海湾成盐化学模式.尤其是1980年在把里海与卡拉博加兹海湾连接峡口堵塞后,引起海湾完全干涸,导致环境灾害,这是一件值得盐湖化学家们借鉴的教训.  相似文献   

14.
From a rare freshwater lake characteristic of alkalescence, named “Cattle Pond”, on the Dongdao Island of South China Sea (16°39′–16°41′ N, 112°43′–112°45′ E), we collected two undisturbed sediment cores that contain seabird droppings. In this paper, we determined the concentration-versus-depth profiles of the geochemical elements in the ornithogenic sediment layers of the two cores, analyzed these profiles by various statistical methods, and studied their geochemical characteristics. The concentration profiles of As, Cd, Cu, Se, Zn, P and S are significantly correlated with each other and with loss on ignition (LOI) at 550°C, the measure for the abundance of organic matter. Similar geochemical characteristics, however, were not observed in the upper sediment layer of the Cattle Pond notably affected by cattle excrements, as well as in the bottom sediment layer compositionally dominated by coral sand and gravel. This shows that these “bio-elements” are mainly derived from seabird feces and their geochemical composition is an important geochemical characteristic of the lacustrine ornithogenic sediments. By Q-mode factor analysis (QFA) on the concentration profiles of these bio-elements, we reconstructed the historical seabird population on Dongdao Island between 1350 and 350 year B.P., and observed significant fluctuations in the calculated population. The fluctuations seem to be related to the change of sea surface temperature (SST) in the Southern China Sea. This study provides new paleoenvironmental information of past seabird population changes in low latitude areas using an indirect geochemical method.  相似文献   

15.
We provide a test of the hypothesis that most Palaearctic-African migratory passerines breeding to the east of Eastern Europe avoid crossing western deserts of Central Asia during autumn migration and make a detour through the steppes and semi-deserts north of the Caspian Sea. Trapping data at a migratory stopover and moon-watch observations in September 2003 in western Kazakhstan in a semi-desert location 375 km north of the Caspian Sea support this hypothesis.  相似文献   

16.
里海地区能源安全及西方对该地区的地缘政治战略   总被引:1,自引:0,他引:1  
里海地处欧亚大陆的接合处,地理位置极其重要。近年来,随着一批新的里海大型油汽田的探明,里海的石油地位也迅速上升,再次成为世界关注的焦点。苏联解体后,里海地区一方面因其丰富的油气资源储备备受国际社会关注;另一方面,里海面临着激烈的国际竞争局面和不稳定的区域发展前景。本文论述了里海地区油气资源的储备和生产、出口现状以及国际竞争的局面,尤其是西方参与里海地区油气资源竞争的格局,这不仅引起该地区非国家主体的地缘政治的改变,从而也深刻影响着西方国家主体对该地区的战略和政策。  相似文献   

17.
The paper discusses time and space variations of ice extent in the Caspian and Aral seas during the last decade (1992-2002). It uses synergy of data from active (radar altimeter) and passive (radiometer) microwave nadir-looking instruments onboard the TOPEX/Poseidon satellite. The proposed approach is substantiated and validated using both in situ and satellite imagery data for the Caspian Sea. The results indicate significant spatial and temporal variability of ice conditions, with a significant decrease of both the duration of ice season and ice extent during the last four winters (1998-2002). The TOPEX/Poseidon-derived time series of sea ice extent are very valuable in view of the fragmentary and mostly unpublished data on ice conditions on the Caspian and Aral seas since the mid-1980s.  相似文献   

18.
An understanding of the contemporary biogeography of a region must be predicated not only on the current environmental conditions that influence species distributions but also on historical factors including anthropogenic disturbance regimes. Increasingly, researchers are using historical data, such as the Public Land Survey System (PLSS) records, to create baselines from which subsequent biogeographic changes can be gauged. The present-day state of Oklahoma is unique in that two separate PLSS surveys were conducted in the state during a relatively short time span. We compare these two historical data sets, from the 1870s and 1890s, respectively, to quantify changes in landscape structure and woody plant assemblages corresponding to rapid demographic changes occurring within the Arbuckle Mountains in Oklahoma. During this period, the PLSS data show a landscape that became increasingly fragmented, as well as differences in stand composition and density. The documentation of these important historical anthropogenic changes occurring on the western fringes of the eastern deciduous forest could serve as a valuable guide for conservation and restoration initiatives.  相似文献   

19.
Methods for detection of pore fluid overpressures in shales from seismic data have become widespread in the oil industry. Such methods are largely based on the identification of anomalous seismic velocities, and on subsequent determination of pore pressures through relationships between seismic velocities and the vertical effective stress (VES). Although it is well known that lithology variations and compaction mechanisms should be accounted for in pore pressure evaluation, a systematic approach to evaluation of these factors in seismic pore pressure prediction seems to be absent. We have investigated the influence of lithology variations and compaction mechanism on shale velocities from acoustic logs. This was performed by analyses of 80 wells from the northern North Sea and 24 wells from the Haltenbanken area. The analyses involved identification of large‐scale density and velocity variations that were unrelated to overpressure variations, which served as a basis for the analyses of the resolution of overpressure variations from well log data. The analyses demonstrated that the overpressures in neither area were associated with compaction disequilibrium. A significant correlation between acoustic velocity and fluid overpressure nevertheless exists in the Haltenbanken data, whereas the correlation between these two parameters is weak to non‐existing in the North Sea shales. We do not presently know why acoustic velocities in the two areas respond differently to fluid overpressuring. Smectitic rocks often have low permeabilities, and define the top of overpressures in the northern North Sea when they are buried below 2 km. As smectitic rocks are characterized by low densities and low acoustic velocities, their presence may be identified from seismic data. Smectite identification from seismic data may thus serve as an indirect overpressure indicator in some areas. Our investigations demonstrate the importance of including geological work and process understanding in pore pressure evaluation work. As a response to the lack of documented practice within this area, we suggest a workflow for geological analyses that should be performed and integrated with seismic pore pressure prediction.  相似文献   

20.
张明 《热带地理》2014,34(3):414-421
大宝山矿历史悠久,矿业遗迹数量众多,类型多样。文章通过调查大宝山矿的矿产地质遗迹、矿业生产遗址、矿业活动遗迹、矿业制品、矿业开发史籍的基本特征,对主要矿业遗迹的科学价值、经济价值和历史文化价值进行定性评价;采用层次分析法建立评价指标体系,对主要矿业遗迹进行定量评价。结果表明,大宝山矿主要矿业遗迹景观资源有珍稀级5处、重要级7处,呈现出景观品质高、互补性强、配套性好、特色突出等特点,具有极高的科研科普价值、游览观光价值和历史文化价值,开发矿山工业旅游的潜在优势明显。  相似文献   

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