共查询到20条相似文献，搜索用时 156 毫秒
1.
2.
新疆艾比湖是典型的干旱区湖泊,具有特殊的湿地-干旱生态系统。晚更新世晚期开始,由于气候逐渐变干,艾比湖不断萎缩。20世纪50～80年代末,由于湖区人口的激增及其对水土资源的不合理开发利用加速了湖泊干缩的进程。本文对艾比湖干缩引起的生态响应进行了初步的分析,分析指出,艾比湖湖滨荒漠自然植被呈退化衰败趋势,生物多样性面临严重威胁;干涸湖底盐漠化,湖滨沙丘活化,沙漠扩展,浮尘天气成百倍增长;绿洲与荒漠之间缓冲空间日益缩小,盐碱化趋势增大。艾比湖的干缩是自然因素和人为因素共同作用的结果,但人为因素是第一位的,其中以河流上游大量截流引水和大规模开荒为主要原因。 相似文献
3.
全新世内蒙南缘黄旗海湖面的波动 总被引：7，自引：1，他引：6
黄旗海是一封闭湖泊,气候是控制其湖面变化的主要因素。地貌、沉积物、地球化学分析及历史考古资料均证实,一万年以来湖面在总体收缩下降过程巾不断地波动着。全新世初期,湖面扩张抬升,9000a B.P.前后湖面达最高(1340m),湖面面积也最大(约560km~2),其后,湖面持续地收缩下降。 相似文献
4.
高海拔地区由于特殊的自然环境对气候变化和营养输入的响应十分敏感.在人类活动逐渐加强的背景下,高山湖泊高分辨率的沉积物记录了人与自然相互作用的演变过程.选取云南西北部典型高山湖泊——错恰湖,获取长度37 cm的连续湖泊沉积序列,基于铅铯测年法得到年代深度模型,并对湖芯样品进行总有机碳、总氮及正构烷烃的多指标测定和元素测量,结合气象监测数据探讨分析错恰湖的有机质来源和流域环境演化特征.根据气候代用指标的变化,两百年来错恰湖泊环境及区域气候演化可以分成4个主要阶段：1807-1900年：湖泊水位上升、湖面扩大,有机质丰度下降,有机质以外源贡献为主,内源比例上升;1900-1950年：湖泊水位开始下降、湖面收缩,有机质丰度下降,外源有机质来源增加;1950-1982年：湖泊水位下降、湖面进一步收缩,有机质丰度下降,外源输入比例继续增加;1982-2007年：湖泊水位下降、湖面收缩,有机质含量上升且以陆源输入为主,同时内源贡献比例开始增加.在元素测定结果中,人类活动对应了湖泊沉积重金属含量变化的3个阶段：1950年以前,重金属含量低且稳定,可视作自然背景阶段,人类影响忽略不计;1950年以后,湖泊流域工农业逐渐发展,人为干扰凸显;直到1982年以后,冶炼工业的进步加强了重金属的污染态势,并通过大气传输沉降被湖泊沉积物记录.错恰湖沉积记录的分析讨论在总结该区域气候环境演化历史的同时,加深了对气候人类活动湖泊生态系统相互作用过程的理解,为高山湖泊响应人类活动影响提供了证据. 相似文献
5.
拉斯曼丘陵区的湖泊均为淡水湖,总数近150个,湖泊总面积6.3km~2,占陆地总面积的3.15％。东部地区湖泊数量少但多深大湖,西部地区数量多但多浅小湖。湖泊地貌发育初始,A_1/A_c之值较大,湖岸地貌形态不发育,全年封冻期长达300天,限制了湖水动力对地貌和沉积物形成的作用强度,冰雪融水量与湖面蒸发量控制了湖水平衡和湖面变化过程。湖积物厚度小,颗粒粗,分选差,风力混杂堆积作用明显。夏季水温变化复杂,并常有明显的逆温现象。水体pH值介于6.0～8.0之间,Na~+占绝对优势。 相似文献
6.
中昆仑山区封闭湖泊湖面波动及其气候意义 总被引：24，自引：6，他引：18
封闭湖泊湖面波动是气候变化很敏感的指示器,其水量平衡特征对此可给予理论证明,进而可将这种灵敏度表示为Z=A_l/A_b=(P_b-E_b)/(E_l—P_l)。中昆仑山区的封闭湖泊自17000a B.P.以来曾经历了三次高湖面,即17000a B.P.前后、12000a B.P.前后及8000—6000a B.P.。其中第一期的高湖面与高山区冰体消融、西风带位置的变动及土壤湿度、太阳辐射值的变化有关,第二次的高湖面是湖泊总体收缩下降过程中出现的相对稳定或短暂回升,第三期的高湖面是全球性温湿气候的产物。理论探讨与实例分析均说明,封闭湖泊湖面波动不仅对无人类观测记录的地质历史时期的气候变化有着重要的指示性,而且可以弥补人类观测资料的不足,是研究气候变化的理想场所。 相似文献
7.
8.
中亚近期气候变化的湖泊响应 总被引：6，自引：0，他引：6
本世纪以来,气候的暖干化趋势在北半球中纬度地区表现突出,对该地区水资源造成了一系列的影响,基于这一事实,本文主要考察了中亚干旱和半干旱地区内陆湖泊对气候变化的响应。研究表明,气候变化对湖泊影响主要有二种途径,其一是通过热量平衡影响湖泊水量收支中的支出项,即蒸发量;其二是影响湖泊收入项,即降水与地表径流。伊塞克湖以前者为主,青海湖以后者为主。在相同的气候变化背景下,不同湖盆形态的湖泊对此作出的响应不尽相同:湖盆浅平,以面积变化为主;湖盆深凹,则以水位变化为主。 相似文献
9.
2000-2010年东北地区湖泊动态变化及驱动力分析 总被引：2，自引：0，他引：2
以2000、2005和2010年的Landsat TM和ETM遥感影像为主要数据源,利用面向对象的分类方法,提取3期东北地区湖泊数据;在GIS技术的支持下,分析了过去10年东北地区湖泊的时空变化特征,并对导致湖泊面积变化的自然和人文驱动因素进行分析.结果表明:2000-2010年间,东北地区湖泊面积由12234.02 km2减少至11307.58 km2,其中,2005-2010年间湖泊萎缩剧烈程度大于2000-2005年;湖泊数量先增加后减少,10年间共减少了4092个;10年间天然湖泊面积大幅减少,人工湖泊面积略增加;研究区内西北方向湖泊萎缩程度小于东南方向,质心向西北偏移;湖泊变化受自然因素和人类活动的共同影响,人类活动叠加在自然因素之上,对湖泊变化产生了放大作用. 相似文献
10.
1986-2008年吉林省湖泊变化及驱动力分析 总被引：6，自引：3，他引：3
利用1986年、1995年、2008年覆盖吉林省的LandsatTM遥感影像,通过目视解译,获取3期土地利用数据;基于GIS技术,分析了过去23年吉林省湖泊的时空变化特征,并对导致湖泊面积变化的自然和人文驱动因素进行分析.结果表明:1986-2008年间,吉林省湖泊面积从1986年的3442km2减少到2008年的2622km2;湖泊个数由3134个减少到2718个.其中1986-1995年间湖泊面积萎缩主要以大中型湖泊(面积大于等于50km2)为主,减少面积为479.7km2;1995年以后,虽然大中型湖泊面积有微弱增加,但中小型湖泊的面积剧烈减少,因此导致湖泊总面积减少311.7km2.湖泊面积变化存在区域差异:过去23年间,东部地区湖泊面积增加42.1km2,中部地区减少98.9km2,西部地区湖泊面积减少最多,为337.7km2.气候干旱化、人口增加带来的压力和水利工程修建等因素对湖泊面积变化产生重要影响. 相似文献
11.
12.
Integrated dynamic water and chloride balance models with a catchment‐scale hydrological model (PRMS) are used to investigate the response of a terminal tropical lake, Lake Abiyata, to climate variability and water use practices in its catchment. The hydrological model is used to investigate the response of the catchment to different climate and land‐use change scenarios that are incorporated into the lake model. Lake depth–area–volume relationships were established from lake bathymetries. Missing data in the time series were filled using statistical regression techniques. Based on mean monthly data, the lake water balance model produced a good agreement between the simulated and observed levels of Lake Abiyata for the period 1968–83. From 1984 onwards the simulated lake level is overestimated with respect to the observed one, while the chloride concentration is largely underestimated. This discrepancy is attributed to human use of water from the influent rivers or directly from the lake. The simulated lake level and chloride concentration are in better agreement with observed values (r2 = 0·96) when human water use for irrigation and salt exploitation are included in the model. A comparison of the simulation with and without human consumption indicates that climate variability controls the interannual fluctuations and that the human water use affects the equilibrium of the system by strongly reducing the lake level. Sensitivity analysis based on a mean climatic year showed that, after prolonged mean climatic conditions, Lake Abiyata reacts more rapidly to an abrupt shift to wetter conditions than to dry conditions. This study shows the significant sensitivity of the level and salinity of the terminal Lake Abiyata to small changes in climate or land use, making it a very good ‘recorder’ of environmental changes that may occur in the catchment at different time scales. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
13.
北方半干旱区土地利用/覆被变化对湖泊水质的影响:以岱海流域为例(2000—2018年) 总被引：2，自引：0，他引：2
土地利用/覆被变化对明晰气候变化和人类活动对湖泊水环境的影响有重要作用.以北方典型农牧交错的岱海流域为研究对象,基于遥感解译技术、马尔可夫转移矩阵、综合污染指数法等方法,对2000-2018年岱海流域土地利用/覆被和湖泊水质的变化进行分析,并结合冗余分析法和计量分析模型探究长时间序列尺度下土地利用/覆被变化对湖泊水质的影响.结果表明:近20年来,岱海流域的土地利用/覆被类型以耕地和草地为主,其变化特征主要是草地和林地转化为耕地,水域转化为季节性河流,岱海转化为内陆滩涂、沼泽草地和灌丛沼泽;岱海湖泊水质因子高锰酸盐指数、五日生化需氧量、总磷和总氮浓度存在不同程度的超标现象;岱海、湿地、林地对水质具有积极的改善作用,耕地、草地、建设用地是加剧水质污染的主要原因.该研究为岱海湖泊流域土地资源合理利用、湖泊水质改善和生态保护提供了一定的科学理论依据. 相似文献
14.
Timothy M. Shanahan Jonathan T. Overpeck W. E. Sharp Christopher A. Scholz Justice A. Arko 《水文研究》2007,21(13):1678-1691
Historical changes in the level of Lake Bosumtwi, Ghana, have been simulated using a catchment‐scale hydrological model in order to assess the importance of changes in climate and land use on lake water balance on a monthly basis for the period 1939–2004. Several commonly used models for computing evaporation in data‐sparse regions are compared, including the Penman, the energy budget, and the Priestley–Taylor methods. Based on a comparison with recorded lake level variations, the model with the energy‐budget evaporation model subcomponent is most effective at reproducing observed lake level variations using regional climate records. A sensitivity analysis using this model indicates that Lake Bosumtwi is highly sensitive to changes in precipitation, cloudiness and temperature. However, the model is also sensitive to changes in runoff related to vegetation, and this factor needs to be considered in simulating lake level variations. Both interannual and longer‐term changes in lake level over the last 65 years appear to have been caused primarily by changes in precipitation, though the model also suggests that the drop in lake level over the last few decades has been moderated by changes in cloudiness and temperature over that time. Based on its effectiveness at simulating the magnitude and rate of lake level response to changing climate over the historical record, this model offers a potential future opportunity to examine the palaeoclimatic factors causing past lake level fluctuations preserved in the geological record at Lake Bosumtwi. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
15.
Salsvatn,a lake with old sea water 总被引：1，自引：0，他引：1
Dr. Anders Bøyum 《Aquatic Sciences - Research Across Boundaries》1973,35(2):262-277
Salsvatn is a 464 m deep lake laying 16 m above sea level in North Trøndelag, Norway. The lake was isolated from the sea some 3,000 years ago. It is assumed that salt-water in the deepest 50 m of the lake is the remain of sea water being trapped in the lake at this time. The concentration of cloride in the salt-water layer corresponds to a salinity of 29‰ in ordinary sea water. Hydrography of the lake and changes in some components of the salt water compared with ordinary sea water are discussed. Comparison is made with changes in the stagnant layers of the Black Sea and Lake Rørholtjorden. The latest is another lake with old sea-water at its bottom. Surface sediment samples have been collected from the freshwater and salt-water layers in Lake Rørholtfjorden and from the salt-water layer of Lake Salsvatn. Some chemical components of the sediments and interstitial water have been analysed and discussed. 相似文献
16.
Inter‐annual changes of alpine inland lake water storage on the Tibetan Plateau: Detection and analysis by integrating satellite altimetry and optical imagery 
下载免费PDF全文
下载免费PDF全文 The effects of climate change have a substantial influence on the extremely vulnerable hydrologic environment of the Tibetan Plateau. The estimation of alpine inland lake water storage variations is essential to modeling the alpine hydrologic process and evaluating water resources. Due to a lack of historical hydrologic observations in this remote and inaccessible region, such estimations also fill a gap in studies on the continuous inter‐annual and seasonal changes in the inland lake water budget. Using Lake Siling Co as a case study, we derived a time‐series of lake surface extents from MODIS imagery, and scarce lake water level data from the satellite altimetry of two sensors (ICESat/GLAS and ENVISAT RA‐2) between 2001 and 2011. Then, based on the fact that the rise in lake water levels is tightly dependent on the expansion of the lake extent, we established an empirical model to simulate a continuous lake water level dataset corresponding to the lake area data during the lake's unfreezing period. Consequently, from three dimensions, the lake surface area, water level and water storage variations consistently revealed that Lake Siling Co exhibited a dramatic trend to expand, particularly from 2001 to 2006. Based on the statistical model and lake area measurements from Landsat images since 1972, the extrapolated lake water level and water storage indicate that the lake has maintained a continual expansion process and that the cumulative water storage variations during 1999–2011 account for 66.84% of the total lake water budget (26.87 km3) from 1972 to 2011. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
17.
Remote-sensing images of Ebinur Lake Basin including six years (1960, 1972, 1990, 2000, 2005 and 2010) were interpreted through RS and GIS. Land use changes in Ebinur Lake Basin during the past five decades were analyzed according to interpretation results. On this basis, effect of land use changes on hydrology and water resources was analyzed. Results show that the land use pattern in Ebinur Lake Basin changed greatly from 1960 to 2010. Cultivated Land and Urban-Rural Construction Land increased, while other landuse types decreased. Most areas were Unused Land. Generally, oasis expanded continuously, but oasis in Ganjiahu Zone at downstream of the Kuitun River Basin reduced to some extent. Runoff of the Kuitun River and Jinghe River increased gradually, but runoff of the Bortala River reduced continuously. Both inflows and lake area declined year by year. The groundwater level dropped significantly and water deteriorated continuously. Due to the decelerating wind blowing, evaporation in the basin reduced accordingly. Hydrology and water resources changes in Ebinur Lake Basin in past five decades were mainly caused by continuous expansion of Cultivated Land and oasis, continuous population growth and hydraulic engineering constructions. However, oasis expansion shall be limited within the carrying capacity of water resources. To maintain ecological security in the basin, it is necessary to determine reasonable oasis area, optimize river system structure, and improve utilization efficiency of water resources. 相似文献
18.
湖泊变化是气候变化的指示器.为探索利用单一短时间尺度的卫星水位数据源估算长时间序列的湖泊水量变化的可行性,本文利用短时间尺度（2016—2018年） Sentinel-3A合成孔径雷达高度计（SRAL）作为唯一卫星水位数据源,以藏北高原内陆湖泊当惹雍错为例,结合基于Landsat光学遥感数据提取的1988—2018年的湖泊面积,综合分析2016—2018年间的非结冰期遥感湖泊面积与遥感湖泊水位变化,基于该时段范围的水位变化-面积变化关系和水量估算公式,估算1988—2018年湖泊水位水量变化与2001—2018年的年内变化,并结合GLDAS产品数据与雪线变化情况初步探讨湖泊变化的可能原因.结果表明：当惹雍错近30年湖泊面积扩张明显,湖泊水位、水量增加显著,相比1988年,2018年的湖泊面积、水位、水量分别增加21.1 km2、5.29 m、44.75亿m3.其中1988—1998年湖泊面积-水位-水量有所减少,2000—2018年间湖泊变化总体呈增加趋势.2001—2018年内湖泊面积、水位、水量变化呈现干湿季特征.1996—2014/2015年湖泊水量变化为38.3亿/35.5亿m3,水量变化趋势、变化量与以往对应时间段的研究结果具有较强的一致性.湖泊面积扩张主要发生在水下地形平缓的东南部和中西部区域.结合气候因素与雪线变化的分析表明,湖泊水量变化受降雨、气温影响复杂,长时间年际尺度上的湖泊水量增长与气温的一致性较降水量强,湖泊湿季受降水量与气温的影响都较大,其中2008—2018年的湿季降水量、气温与水量变化散点拟合的确定性系数R2分别为0.613、0.845.该研究表明Sentinel-3A合成孔径雷达数据在湖泊水量变化估算上的潜力,为利用单一且只具有短时段数据的卫星雷达数据估算长时间序列湖泊水量变化提供依据. 相似文献
19.
Using lake Stechlin in northeastern Germany as an example of a small groundwater‐feed lake without surface inflows and outflows, we estimated the temporal scales and the variability ranges of the net groundwater contribution to the lake water budget. High‐resolution water level measurements by a bottom‐mounted pressure logger provided the background for the estimation of the total lake water budget. This method has demonstrated reliability for estimation of lake level variations during periods ranging from subdiurnal to perennial. The typical amplitudes of the synoptic‐to‐perennial variability characterizing the groundwater climate of lake Stechlin are estimated by comparing the two subsequent years 2006 and 2007; one of these years shows an extremely high, and the other an extremely low, annual precipitation–evaporation balance. The net groundwater flow, estimated as the difference between the total water budget and the precipitation–evaporation balance at the surface, revealed synoptic effects of lake water exfiltration into the groundwater aquifer following strong precipitation events. Perennial variations between wet and dry years superimposed seasonal oscillations. The probable origin of the latter is seasonality in the groundwater level on the watershed, although the exact amplitudes are subject to further quantification on account of seasonality in the evaporation estimation error. The results emphasize the non‐stationary behaviour of groundwater flow on timescales shorter than climatic ones. The analysis yielded a net quantitative relationship between groundwater flow and water balance at the lake surface: The water level changes in the lake due to evaporation and precipitation are damped to 60% because of the lake–groundwater exchange by means of intermittent infiltration and exfiltration events. Assuming the remaining 40% of the surface water budget may potentially result in perennial water level variability, we estimated an effect of the precipitation decrease on the lake water budget as predicted by the regional climate scenarios for the next century. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
20.
Global wanning resulting from increasing greenhouse gases in the atmosphere and the local climate changes that follow affect local hydrospheric and biospheric environments. These include lakes that serve surrounding populations as a fresh water resource or provide regional navigation. Although there may well be steady water-quality alterations in the lakes with time, many of these are very much climate-change dependent. During cool and wet periods, there may be water-level rises that may cause economic losses to agriculture and human activities along the lake shores. Such rises become nuisances especially in the case of shoreline settlements and low-lying agricultural land. Lake Van, in eastern Turkey currently faces such problems due to water-level rises. The lake is unique for at least two reasons. First, it is a closed basin with no natural or artificial outlet and second, its waters contain high concentrations of soda which prevent the use of its water as a drinking or agricultural water source. Consequently, the water level fluctuations are entirely dependent on the natural variability of the hydrological cycle and any climatic change affects the drainage basin. In the past, the lake-level fluctuations appear to have been rather systematic and unrepresentable by mathematical equations. Herein, monthly polygonal climate diagrams are constructed to show the relation between lake level and some meteorological variables, as indications of significant and possible climatic changes. This procedure is applied to Lake Van, eastern Turkey, and relevant interpretations are presented. 相似文献