共查询到18条相似文献，搜索用时 968 毫秒
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基于CryoSat-2卫星测高数据分析南极海冰厚度的时空变化 总被引：1，自引：1，他引：0
利用卫星测高数据能够获取大尺度、长时序的海冰厚度信息。相较于北极,目前南极海冰厚度特别是近期变化信息仍很缺乏。基于2013-2018年的CryoSat-2卫星测高数据,采用最低点高程法和静力平衡方程模型反演了近6年逐月平均海冰厚度并分析其时空变化规律。结果表明：2013-2018年南极海冰厚度整体呈现先上升后下降的趋势,其中,2014-2017年年平均海冰厚度表现为快速变薄。南极较厚的海冰集中在威德尔海西南海域,最大值出现在该海域2014年的7月（6.27 m）。年平均海冰厚度在2017年达到最低值。南极海冰厚度的时空变化研究可为深入研究海冰变化与全球变化的关系提供参考。 相似文献
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未来江苏中部沿海相对海面变化预测 总被引：2，自引：0，他引：2
相对海面变化是由全球绝对海面变化和区域性地面和海面因素共同控制。通过对江苏沿海近几十年来的潮位记录的分析,得出江苏沿海近期的相对海面变化速率。在此基础上根据近期绝对海面的变化速率计算出局地因素对江苏沿海相对海面变化的贡献量。在假设未来局地因素影响基本不变的前提下与IPCC对未来100年绝对海面的变化趋势
进行叠加,预测了江苏沿海未来相对海面变化的趋势。结果显示,江苏中部沿海海面在2000-2100年的100年间将上升15～152 cm,较IPCC对同期全球平均海平面上升的预测结果大的多。最后就区域性海面气压对相对海面变化的影响进行了讨论。 相似文献
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新世纪上海地区相对海平面变化影响因素及预测方法 总被引：1，自引：0，他引：1
针对传统相对海平面变化分析方法均将理论海平面变化和地面沉降进行的叠加分析,本文讨论和分析了近20年来全球理论海平面上升速率加快背景下的区域海平面变化速率,利用灰色线性回归组合模型预测上海地区海平面变化趋势。考虑了上海地面沉降发展的新特点,以及长江流域来沙显著减少和河口大型工程建设对上海地区相对海平面变化的影响。在流域来沙量显著减少但来水量变化不大情况下,流域大坝的坝下冲刷使得河槽刷深,河口水位降低,同时长江口深水航道整治工程和促淤围垦工程束狭入海口,使得潮位站水位发生变化,两者的综合效应是目前研究长江口相对海平面变化时必须考虑的重要因素。 相似文献
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政府间气候变化专门委员会1995年气候变化评价报告指出,全球海平面在过去的100年里上升了18cm,预测全球海平面将加速上升,在2050年时上升20cm,2100年时上升49cm.根据近40多年的验潮资料分析,中国沿岸海平面上升速率为1.4～2.0mm/a,与全球上升速率一致。由于沿海许多地区的严重地面沉降,地壳垂直升降的不同,以及其它因素的影响,我国沿岸海平面的相对上升各不相同,严重地区的上升速率要大得多。海平面的加速上升必将使我国沿海大部地区的风暴潮等自然灾害更加严重。 相似文献
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《水文地质工程地质》2003,30(5)
由中国科学院、广东省科学院等 13个单位、10 0多位科技人员历时 8a合作完成的一项研究表明 ,珠江三角洲地区沿海的海平面到 2 0 30年可能会上升 30cm。研究内容包括广东海平面变化的历史背景、近期趋势和预测以及海平面上涨后的影响和对策。该项研究的数据来源于广东沿海 11个验潮站的验潮记录。根据数据 ,专家计算出相对海平面上升速率为平均每年 2至 2 5mm。据推断 ,海平面上升30cm可能会加重珠江三角洲的洪水灾害 ,使得原来按 10 0a一遇洪水设计的堤围 ,连 2 0a一遇的洪水都抵御不了。同时 ,地势低平的珠江三角洲届时将有 4 2 %的面积… 相似文献
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2000-2014年祁连山西段老虎沟12号冰川高程变化 总被引：3，自引：3，他引：0
祁连山冰川自1990s以来持续萎缩,冰川融水径流变化对邻近的干旱区水资源产生重要影响。以往遥感与实测研究显示祁连山西段老虎沟12号冰川面积减少、末端退缩、运动速度降低及平衡线高度升高。为了进一步验证老虎沟12号冰川变化规律,利用高分辨率TerraSAR-X/TanDEM-X微波影像数据,与SRTM-C DEM进行差分干涉,得出老虎沟12号冰川2000-2014年高程年平均变化值为（-0.29±0.09）m·a-1。为了验证遥感观测结果,利用RTK-GPS对老虎沟12号冰川表面进行测高,并与SRTM-C DEM上相应点的高程值进行比较,计算测量点的高程年变化值,结果显示两种方法获得的年平均变化值之间具有很好的正相关性,表明利用TerraSAR-X/TanDEM-X微波影像数据及差分干涉技术监测祁连山冰川高程变化具有较好的可行性。 相似文献
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利用ICESat-1和CryoSat-2测高数据获取了2003—2017年洞庭湖流域内湖泊的水位信息,分析了湖泊水位的时间变化过程,并结合TRMM卫星降水数据及人类用水等数据,讨论了湖泊水位变化对气候及人类活动的响应.结果表明,流域中80%的湖泊在2003—2009年呈现出水位下降趋势（-0.18~-0.09 m/a）;75%的湖泊在2010—2017年呈现出水位稳定或上升趋势（0~0.39 m/a）;总体来看,75%的湖泊在2003—2017年呈现出水位上升趋势（0.02~0.22 m/a）.分析表明,湖泊水位变化为多种因素共同作用的结果,降水为近年来洞庭湖流域内湖泊水位变化的主要驱动因子;以三峡水库为代表的水库运行会对湖泊水位产生季节性影响;同时,人类用水的持续增长也对湖泊水位有一定的影响.多源测高卫星为长时序大范围的湖泊水位监测提供了有力的手段,这对研究湖泊水位变化及其与气候和环境的响应具有重要意义. 相似文献
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Albert Parker 《Natural Hazards》2013,65(1):991-997
It is shown in the short comment that the sea levels are oscillating about a longer-term trend and that the sea level rise (SLR) computed with time windows of 20, 30 or 60?years also oscillates, with the amplitude of these latter oscillations reducing as the time window increases. The use of only two values of the SLR distribution is misleading to infer conclusions about the accelerating behaviour. In particular, the comparison of the 30-year SLR 1950?C1979 with the 30-year SLR 1980?C2009 for the tide gauges along the Atlantic coast of North America north of Cape Hatteras to infer an accelerating behaviour is particularly wrong because the 30-year time window is a too short interval to appreciate the longer-term sea level trend cleared of the multi-decadal oscillations, and the two values from the SLR distribution are computed, respectively, at the times of a valley and a peak for the 60-year Atlantic Ocean multi-decadal oscillation. By using a 60-year time window or all the data since opening when more than 60?years of recording are available and by analysing the SLR time history, the only conclusion that can be inferred from the analysis of the tide gauges along the North American Atlantic coast is that the sea levels are oscillating without too much of a positive acceleration along their longer-term trend. 相似文献
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An efficient approach for evaluating storm tide return levels along the southeastern coastline of Australia under present
and future climate conditions is described. Storm surge height probabilities for the present climate are estimated using hydrodynamic
model simulations of surges identified in recent tide gauge records. Tides are then accounted for using a joint probability
method. Storm tide height return levels obtained in this way are similar to those obtained from the direct analysis of tide
gauge records. The impact of climate change on extreme sea levels is explored by adding a variety of estimates of mean sea
level rise and by forcing the model with modified wind data. It is shown that climate change has the potential to reduce average
recurrence intervals of present climate 1 in 100 year storm tide levels along much of the northern Bass Strait coast to between
1 and 2 years by the year 2070. 相似文献
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通过对我国大型水库蓄水的时空特征进行深入分析, 统计得到近60年来大型水库蓄水累积的库容量已达到697km3, 占全国所有水库库容量的83.3%及全球库容量的6.5%;而2000年以来的大型水库数量及蓄水量的变化有明显的加速, 库容量的变化率为16.7km3/a, 远高于1950年到2000年的4.9km3/a的增长率; 同时借助卫星重力(Gravity Recovery and Climate Experiment, GRACE)观测手段, 对2000年以后主要分布在长江流域以南地区的水库进行水储量估算, 结果显示GRACE仅能估算得到63%的水库变化量, 两者之间的差异可能反映了该地区地下水的长期变化. 结合大型水库的分布位置与库容量, 基于海平面变化方程计算得到了中国近海相对海平面的空间变化. 水库蓄水导致的渤海与东南沿海海域的相对海平面上升明显, 最大上升高度约为8mm; 而2000年以后的水库对海平面的影响主要集中在东南沿海, 其中南海海域较为突出, 上升高度约为2~3mm, 在此期间蓄水造成的近海不同验潮站位置的海平面增长速度在0.02~0.11mm/a之间变化. 相似文献
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J. S. Mani 《Natural Hazards》2004,31(2):523-536
Chennai coast, right from the inception of Madras harbourin the year 1876, has been experiencinghostile conditions such as (i) coastal erosion, (ii) sandbar formation at the entrance to inlets, (iii) sea water ingression and (iv) change insea bed elevation, etc. In addition, construction of a new satellite harbour, about18 km north of Madras harbour has produced a negative impact on the delicatecoastal features such as (i) Pulicat lake, (ii) Ennore shoals, etc. Construction ofthis satellite harbour has led to the accumulation of sand south of the southbreakwater of the harbour and its accelerated growth is of concern to an inletlocated 2.6~km south of the harbour. `Coastal erosion', a perennial problemassociated with north Chennai sea front for the past 100 years has been addressedin this paper. The paper discusses on a long term solution and details of themethodologies to be adopted for effective management of the coast. Thesolution presented in this paper is based on numerical model study consideringthe nearshore currents and wave induced sediment transports. 相似文献
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Densely populated coastal zones of India are highly exposed to natural environment. These are impacted by episodic natural events, continuous coastal process, gradually rising sea levels and coexisting human interventions. The present study is an attempt to assess the implication of the sea level rise and coastal slope in the coastal erosion for entire mainland of India. In this regard, two methods were employed to estimate the shoreline change rate (SCR): (1) satellite-derived SCR using the Landsat TM and ETM+ acquired during 1989–2001 and (2) SCR derived by Bruun Rule using the parameters coastal slope and sea level trend derived from satellite altimetry. Satellite-derived SCR has been compared with the shoreline change estimated based on Bruun Rule, revealing a better agreement with each other in terms of trend. Peaks of shoreline retreat calculated using Bruun model and satellite-observed SCR offset by 25–50 km. Offset in these peaks was observed due to net drift towards north in the east coast and south in the west coast of India, revealing the applicability of the Bruun Rule along the Indian coast. The present study demonstrates that coastal slope is an additional parameter responsible for the movement of shoreline along with sea level change. The results of satellite-derived SCR reveal the highest percentage of erosion along West Bengal coast with 70% followed by Kerala (65%), Gujarat (60%) and Odisha (50%). The coastlines of remaining states recorded less than 50% of coasts under erosion. Results of this study are proving critical inputs for the coastal management. 相似文献
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广西北海市海水入侵状况分析 总被引：7，自引：0，他引：7
北海市海水入侵，主要出现在在市区北部海城区海角大道至四川路北段沿海岸。１９８９年初海水入侵到海角大道是Ｓ３１井一带，总的趋势是向南、东扩展；至１９９３年３月，海水入侵面积已超过３ｋｍ＾２，地下水Ｃｌ＾－最大含量约为入侵前的２０倍。１９９３年夏季双来，海水入侵范围略有缩小。自１９９４年年底起，在市区南侧侨港镇一带沿海，又出现海水从是海岸信侵的迹象。 相似文献
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相对海平面变化对腕足动物群落取代的影响——以吐哈盆地北缘桃西沟上石炭统祁家沟组—奥尔土组剖面为例 总被引：6，自引：0，他引：6
相对海平面的升降变化引起的相对水深及相关生态条件的改变对腕足动物群具有影响。相对海平面变化的速度和幅度是引起腕足动物群面貌变化的重要因素。相对海平面的持续缓慢上升有利于腕足动物丰度的增加和分异度的提高,海平面的大幅度快速变化对腕足动物群落则是一个不利的因素,是造成腕足动物物种丰度下降、新种增加量减少乃至彻底死亡的重要原因。吐哈盆地北缘晚石炭世发育的5个腕足动物群落全部与相对海平面上升期有关。在海平面的持续缓慢上升期,腕足动物的丰度不断增加,分异度迅速提高;而在相对海平面下降期,本区陆源粗碎屑物大量注入,不适合腕足动物的生存。 相似文献
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December 2004 tsunami in the Indian Ocean region has been simulated using MIKE-21 HD model. The vertical displacement of the seabed is incorporated into the numerical simulation by using time-varying bathymetry data. In the open ocean, sea surface height from altimeter observation has been used to validate the model results. To the west of the rupture zone, the crest is observed to precede the trough of the tsunami waves while to the east, trough preceded the crest. The model performance along the coastal region has been validated using de-tided sea levels from tide gauge measurements at Tuticorin, Chennai, Vishakapattanam, and Paradip ports along the east coast of India. Unique coastal characteristics of the tsunami waves, wave height, and wave celerity are reasonably simulated by the numerical model. Spectral analysis of tide gauge observations and corresponding model results has been done, and the distribution of frequency peaks from the analysis of gauge observations and the model results is observed to have a reasonable comparison. Low-frequency waves, contributed from the coastally trapped edge waves, are found to dominate both the tide gauge observations and the model results. The subsequent increase in the tsunami wave height observed at Chennai, Vishakapattanam, and Paradip has been explained on the basis of coastally trapped edge waves. From the validation studies using altimeter data and tide gauge data, it is observed that the model can be used effectively to simulate the tsunami wave height in the offshore as well as in the coastal region with satisfying performance. 相似文献