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1.
湖泊水位是评估湖泊水量变化的重要指标。本文以洪泽湖、高邮湖及洞庭湖为研究对象,利用集中度的概率密度函数方法(CPDF)来提高Jason-2测高数据精度,分析了降水量与各个湖泊水位变化的相关性,并基于实测水位数据对比评价了Jason-2测高卫星原始GDR数据和CPDF方法处理后的卫星数据的精度。结果表明:①Jason-2原始GDR数据点的分布存在疏密之分,大部分数据分布相对集中,且有一定的周期变化,但评价结果显示精度较差,故原始GDR数据不能直接用于湖泊水位监测;②CPDF方法可以极大提高测高卫星的水位数据精度,洪泽湖与高邮湖的均方根误差分别由1.92 m与1.74 m减少到了0.32 m和0.36 m,相关系数由0.28和0.04提高到了0.85和0.72。对于南北宽度较窄且日水位变化较大的湖泊(如洞庭湖),CPDF方法提高原始GDR结果的精度有限;③洞庭湖降水与水位相关性最强,高邮湖次之,而洪泽湖降水与水位成不显著的负相关,是洪泽湖水利工程对于水位的调节导致了这一结果。本研究对于利用测高卫星获得湖泊水位值,进而对湖泊进行动态监控,特别是在填补资料匮乏地区湖泊水位数据方面具有重要意义。 相似文献
2.
渤海湾盆地东营凹陷始新统孔店组一段(孔一段)发育了垂向叠置的“红-灰”组合岩层,并呈现出一定的旋回沉积特征。为了深入了解该地层的沉积过程及其对古气候变化的响应,研究以东营凹陷王家岗地区重点探井王46井为例,基于年代地层格架的约束,利用岩心、录井和自然伽马测井曲线对孔一段进行了旋回沉积记录的研究,揭示了地层的旋回沉积过程。红层响应于洪水漫湖产生的漫湖泥和漫湖砂滩,而灰绿色韵律层属于间歇性湿润期的浅湖砂滩沉积,二者在垂向上突变接触。伽马曲线的连续小波分析和频谱分析表明该地层的沉积过程受控于米兰科维奇天文旋回的偏心率和岁差周期,造成的旋回地层厚度分别为39.4 m和6.9 m。通过对125 ka的偏心率周期进行带通滤波,建立了孔一段的“浮动”天文年代标尺。孔一段共记录了33个偏心率周期,判定的沉积时限约为4.13 Ma,地层的视平均沉积速率在0.236~0.408 m/ka之间变化。偏心率和岁差旋回对地层沉积的控制表现为偏心率为极大值时,间歇性湖泊沉积频繁发生,反之则以洪水漫湖沉积为主,同时岁差的极小值对应了间歇性湖泊沉积,反之则主要发生了洪水漫湖沉积。 相似文献
3.
湖泊（特别是内陆湖）作为全球气候变化的敏感区域,是气候变化与环境变异的指示器,其面积变化在一定程度上可反映区域的气候变化。因此,精确监测湖泊面积的时空变化,对分析区域生态环境变化具有重要的意义。本文基于ESTARFM时空数据融合模型,利用MODIS数据模拟了2000年后无法得到的Landsat数据;利用NDWI和MNDWI 2种水体指数并辅以DEM数据分析了1976-2014年西藏色林错湖湖面面积的时空变化;综合湖区周围6个气象站点的气象数据(1970-2014年),探究了湖面面积变化的原因及其对气候变化的响应。结果表明：(1)利用ESTARFM时空融合模型得到的Landsat-Like数据与真实的Landsat数据在水体信息提取方面具有较高的相关性,R2可达0.93,时空数据融合的结果可用于湖泊水体的信息提取;(2)近40年来（1976-2014年）,色林错湖处于持续扩张状态,面积呈较显著的增长趋势,增加了近711.652 km2,增幅为42.36%,年平均增长速率约为18.728 km2a-1,增长最快时可达55.954 km2a-1;湖面面积变化先后经历了平稳变化-迅速变化-平稳变化3个阶段;北部湖区在40年间变化最为明显,向北扩展了约22.812 km;2003-2005年,南部湖区已与雅根错湖连为一体,随后二者共同扩张;(3)气温的持续升高造成的冰雪融水补给增加可能是导致湖泊面积扩张的主要因素,风速的降低为次要因素,湖面的面积变化与降水量、日照时数的变化相关性不明显。 相似文献
4.
《广东海洋大学学报》2016,(3)
2012年7月现场调查了海南岛东部陆架海(琼东海域),结合其中4个断面的实测数据和卫星遥感数据,探究该海域2012年海表温度锋面的季节性变化以及夏季锋面结构特征。研究表明,琼东海域温度锋面的季节性变化明显,强锋面中心会随季节变化。夏季锋面主要分布在上升流区,是典型的上升流锋面,锋带宽20~40 km,大致沿100 m等深线,随深度增加锋面强度减小,位置向外海移动。 相似文献
5.
基于新疆区域地震台网记录的地震观测报告,采用有限差分层析成像方法反演新疆天山中东段地区的地壳P波速度结构,获得了2012年新源和静6.6级地震前后该区域12 km和24 km深度处半年尺度的P波速度结构的时间演化过程。结果表明,12 km深度处震前震源区及附近区域P波速度差在空间上形成NNE向变化剧烈的高值异常区,异常幅度达0.3 km/s。这种明显的速度差异表明,将半年尺度不同时间段相同深度的P波速度进行差分析,能较好地反映一定区域内地壳介质特性的变化。 相似文献
6.
五龙背温泉地下热水有两种类型——赋存于热储构造中的“深循环型热水”和赋存于基岩裂隙中的“浅循环型热水”。“深循环型热水”的水温大子60℃;多为自流水;正水头大于4m;单位涌水量大于0.21/s.m;水质类型以C·H—N型为主,F~-、Na~+、SiO_2、CO_3~(2-)、SO_4~(2-)含量高,水温不受季节性气温影响。“浅循环热水”的水温小于60℃;有微弱涌水现象;单位涌水量小于0.11/s.m;水质类型为H—N型;HCO_3~-、Ca~(2+)、Mg~(2+)、K~+含量高;水温受季节性气温制约。两种类型地下热水水温具相关关系,水力联系微弱,两者可能为基本独立的水热循环系统。“深循环型热水”受热储构造控制,由区域大气降水补给,热源可能为放射性元素衰变所释放的能量而形成的地温场。“浅循环型热水”与基岩裂隙水成因相同,热源与“深循环型热水”加热作用有关。 相似文献
7.
青藏高原西南部塔若错湖泊沉积物记录的近300年来气候环境变化 总被引：4，自引：1，他引：3
以青藏高原西南部塔若错的34cm浅湖芯为研究对象,对其沉积物样品进行总有机碳、无机碳、总氮、微量元素、正构烷烃含量及碳氮比等多项指标的分析测定。采用过剩210 Pb和137 Cs计年法对该湖芯进行了定年和沉积速率研究,获得了近300年的连续湖泊沉积环境序列。在明确了各指标气候环境指示意义的前提下,综合对比分析湖芯中各项气候环境指标,并结合定年结果重建了塔若错湖区近300年来的气候环境变化。结果表明:塔若错湖区气候环境变化可分为3个明显阶段:早期为1705～1778年,该地区气候环境温暖湿润,湖区植被广泛发育;中期为1778～1860年,湖区处于小冰期末次阶段,气候环境寒冷而湿润,植被发育受阻;后期为1860年至今,为小冰期结束后偏暖干化时期。其中,后期又可分为3个亚阶段:1860～1924年,湖区气候环境稍暖且干旱,植被稍有发育;1924～1969年,湖区气候环境呈现偏冷干特点,植被发育暂缓;1969年至今,湖区气候回暖,环境干旱化有所缓解,植被开始逐渐发育。在气候冷暖变化上,该湖芯记录与古里雅冰芯记录和青海湖湖泊沉积记录都有较好的可对比性,只是在起讫年代上存在一些差异。 相似文献
8.
对 2 0 0 0年 5～ 7月北太平洋中东部海域鱿钓探捕调查所获的不同深度海水温度和柔鱼渔获量等资料进行分析 ,结果表明在西经调查水域的 1 74°W和 1 71°W附近 ,1 0 0m ,2 0 0m和 3 0 0m水温分布均形成明显的暖水舌 ,其特征水温依次为 1 0～ 1 1℃ ,9～ 1 0°C及 8～ 9°C ;在东经调查水域 ,表层以下各层水温较往年有所偏低 1～ 2度。分析结果还表明 ,西经调查水域的中心渔场均处在暖水舌前锋一侧 ,中心渔场形成的水温指标为 :表层 1 3～ 1 4°C ,1 0 0m水层 1 0～ 1 1°C、2 0 0m水层 9～ 1 0°C及 3 0 0m水层 8～ 9°C ;在东经调查水域 ,调查期间没有形成中心渔场 ,这可能与深层水温偏低有关 相似文献
9.
利用山东地区2010—2012年6期流动重力测量资料,研究了鲁南网重力场的变化特征。结果表明重力场呈明显的季节性变化,即每年的3月与8月,重力场存在反向变化,变化幅值相近;季节性变化与降水有关。 相似文献
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11.
以1972、1989、1996、2006、2017年5个不同时段的Landsat MSS/TM/ETM+/OLI遥感影像数据、数字高程模型（DEM）数据和气象数据为数据源,通过计算机自动提取与人工目视解译相结合的方法获取南阿尔泰山中部地区各时段的冰湖信息,利用GIS空间分析方法对该地区的冰湖面积进行统计,并分析研究区冰湖在不同规模、不同坡度、不同海拔状态下的时空变化特征。结果表明:①近45年来南阿尔泰山中部地区的冰湖面积呈"先减后增"趋势。1972-1996年研究区的冰湖面积从411.14 km2减少至400.83 km2,共减少了10.31 km2,减少速率为0.43 km2/a。从1996-2017年冰湖面积增加了15.42 km2;增长率为0.514 km2/a。②研究区冰湖分布主要集中在海拔低于2 200 m、坡度小于25°的区域,不同海拔区间和不同坡度区间的冰湖面积均呈"先减后增"趋势。③结合气温、降水、冰川面积以及冰储量变化数据分析发现,南阿尔泰山中部地区冰湖对气候变化具有明显的响应。温度、降水量及冰川融水是影响冰湖面积变化的主要因素;且这三者之间存在一种平衡关系,即温度升高冰川消融速度加快,从而对冰湖的收支平衡产生直接影响。当冰湖的补给量（即冰川融水和降水量之和）大于由温度升高引起的蒸发量时,冰湖面积会呈增长趋势;反之亦然。1970-1980年整个阿勒泰地区年代际降水量减少了19.28 mm,温度上升了0.25℃,因此1972-1989年研究区冰湖的蒸发水量大于补给水量,导致该时段冰湖面积呈退缩态势。1989-1996年该区降水量增加了19.67%,温度升高了0.62℃,但是增加的降水量却无法弥补由温度升高引起的冰湖蒸发量,因此1989-1996年研究区冰湖面积仍处于退缩状态。1996-2017年由于温度和降水量大幅增加导致冰湖面积呈不断增长趋势。 相似文献
12.
2000-2013年青藏高原湖泊面积MODIS遥感监测分析 总被引：2，自引：0，他引：2
青藏高原上分布着大量的高原内陆湖泊群,该区域湖泊面积与区域及全球气候变化之间存在较强的耦合关系,遥感监测湖泊的分布和面积变化趋势,对分析区域自然生态环境具有重要意义。本研究将MOD09A1（地表反射率8天合成数据）进行逐月合成,提出了一种综合多种水体指数的青藏高原地区湖泊提取方法,并通过活动窗口、DEM和时间序列去噪等方法,消除山体阴影、冰雪等因素的干扰。最后,提取和合成了2000-2013年青藏高原逐年和逐月的湖泊范围,并选取色林错和卓乃湖2个典型湖泊与人工解译Landsat系列影像进行验证分析,其线性拟合度分别为0.99和0.97,从时空变化趋势上分析了青藏高原湖泊面积动态变化。结果表明：（1）2000-2013年,青藏高原地区湖泊范围整体上呈较显著的扩张趋势,湖泊总面积增加速率约为490.98 km2 a-1（R2约为0.96）;（2）1-12月份湖泊面积逐月变化率均大于0,表明青藏高原湖泊面积呈整体扩张,而非季节性扩张。除2-4月份外,其他月份增加速率均在400 km2 a-1以上（R2>0.79）,表现为稳定且持续扩张趋势。 相似文献
13.
阎百兴 《中国地理科学(英文版)》1998,8(4):352-361
Ｉ．ＩＮＴＲＯＤＵＣＴＩＯＮＭｏｓｔｖｏｌｃａｎｏｅｓａｒｅｄｉｓｔｒｉｂｕｔｅｄｉｎｎｏｒｔｈｅａｓｔｏｆＣｈｉｎａ．Ｔｈｅｖｏｌｃａｎｉｃｅｒｕｐｔｉｏｎｓｃａｎｃｈａｎｇｅｔｈｅｇｅｎｅｒａｌｍｏｒｐｈｏｌｏｇｉｃｃｏｎｆｉｇｕｒａｔｉｏｎｏｆ... 相似文献
14.
《山地科学学报》2021,(7)
Numerous lakes in western China are excellent sites for understanding environmental change. However, what dominates rare earth element(REE) variations are still under debate in the lake environmental research. In this study, we selected 28 surface sediment samples from 17 lakes(i.e. largescale lakes, small water bodies, etc.) in the QinghaiTibet Plateau and Xinjiang area. These samples were analyzed to reveal the behavior of the REEs and major elements. These REE patterns are characterized by light rare earth element(LREE) enrichment, weak Ce anomaly(0.84-0.98, 0.94 on average) and negative Eu anomaly(0.53-1.00, 0.67 on average). The homogeneous REE patterns may reflect similar REE of the source lithologys. However, the REE abundances showed some significant differences. In this study, water chemistry data analyses inferred that the highly REE values appear possibly in the saltwater lake, and also related to carbonate mineral, whereas p H played a minor role in REE concentrations. In large-scale lakes(e.g. Lake Bosten and Lake Ulungur), the results showed that the relatively larger REE values are in the margins of lakes. Moreover, lower REE contents are towards the central region. Comprehensive study suggested that five major factors control the REE contents:(1) The REE tends to increase with the increase of the weathering intensity.(2) Likewise, heavy mineral(i.e. rutile, anatase, zircon, etc.) are probably primary in these sediments because they are highly enriched in the REE.(3) The contribution of Fe-Mn oxides is significant in sediments because their concentrations highly correlate with the REE.(4) The carbonate mineral(mainly calcite) played a significant role on the REE values in the lakes because the REEs are incorporated into the carbonate minerals generating the low REE concentrations.(5) Major element analysis, mineral analysis, and grain-size data analysis showed that the REE distribution is chiefly influenced by finer grain-size component of lake sediments due to the decreasing proportion of quartz and feldspar than coarser one. Moreover, the clay minerals in finer grain-size sediments can highly absorb the REE. 相似文献
15.
《中国地理科学(英文版)》2019,(5)
Lake monitoring by remote sensing is of significant importance to understanding the lake and ambient ecological and environmental processes. In particular, whether lake water storage variation could predict lake surfacial temperature or vice versa has long fascinated the research community, in that it would greatly benefit the monitoring missions and scientific interpretation of the lake change processes. This study attempted to remotely detect the dynamics of the Aral Sea and pursue the relationships between varying lake water storage attributes and surface water temperature by using MODIS LST(Moderate-resolution Imaging Spectroradiometer Land Surface Temperature) 8-day composite products, satellite altimeter data, and actual meteorological measurements. Their associations with lake Surface Water Temperatures(SWT) were then analyzed. Results showed the lake water surface areas and elevations of the North Aral Sea tended to increasing trend from 2001(2793.0 km~2, 13.6 m) to 2015(6997.8 km~2, 15.9 m), while those of the South Aral Sea showed a decreasing trend during 2001(20 434.6 km~2, 3.9 m) and 2015(3256.1 km~2, 0.9 m). In addition, the annual daytime and nighttime lake SWT both decreased in the North Aral Sea, while only the daytime SWT in the South Aral Sea exhibited an increase, indicating a rising deviation of diurnal temperatures in the South Aral Sea during the past 15 yr. Moreover, a lower correlation was found between variations in the daytime SWT and storage capacity in the South Aral Sea(R~2 = 0.33; P 0.05), no fair correlations were tested between lake water storage and daytime SWT in the North Aral Sea nor between lake water storage and nighttime SWT in either part of the sea. These results implied that climate change, if any at least during the research period, has no significant effects on lake dynamics over the two sectors of the Aral Sea with anthropogenic disturbances. However, climate change and human activities may overlap to explain complex consequences in the lake storage variations. Our results may provide a reference for monitoring the spatiotemporal variations of lakes, increasing understanding of the lake water storage changes in relation to the lake SWT, which may benefit the ecological management of the Aral Sea region, in the effort to face the likely threats from climate change and human activities to the region. 相似文献
16.
Seasonal ice cover is uncommon on Australian lakes. In the Snowy Mountains, there are five natural, seasonally ice-covered lakes including Lake Cootapatamba, the highest lake in Australia. Blue Lake is the only one of the five lakes with sufficient volume to be relatively independent of short-term changes in ambient temperature, and therefore is the lake most likely to be of use in tracking long-term regional climate change. Ice forms on Blue Lake near the winter solstice and ice-breakup occurs from late September to November. Timing of breakup is related to spring temperature and, as such, mirrors the timing of general snow thaw in the mountains. The existence of historic photographs taken of the lake at about the time of ice breakup allows for the possibility of reconstructing a history of alpine climate and in 1905 ice breakup was probably as late as mid-December. 相似文献
17.
斯里兰卡是海上丝绸之路沿线重要的节点国家,其周边海域生态环境变化与经济发展、休闲生活和食品安全密切相关。利用2002—2017年的MODIS遥感反演产品对斯里兰卡岛周边海域、关键节点港口科伦坡的生态环境参数年际变化规律分别进行分析和2003—2012年的MERIS遥感反射率产品对保克海峡进行水体类型时空分析,结论如下：① 研究区内光合作用有效辐射高值出现在马纳尔湾,海域沿岸浮游植物生物量相对较高,与海表温度负相关,外海浮游植物生物量极低,与透明度负相关。② 科伦坡港附近水温（海表温度）、海面光照强度（光合作用有效辐射）、水体清洁度（海水透明度）、海洋食物网基础的浮游植物生物量（叶绿素浓度）和浮游植物净初级生产力最大值分别出现在4月、3月、3月、8月、7月,致灾因素重点关注8月潜在的赤潮。③ 保克海峡浑浊带的源头是印度的卡里梅尔角,由高韦里河携带大量泥沙造成。这有助于了解和认识高时空变化的保克海峡及斯里兰卡周边海域在不同时间-空间的海洋生态环境。 相似文献
18.
The thermal strati?cation of the lakes impedes the transfer of atmospheric oxygen into the lower layers of the lake. In lakes which are af fected by diverse anthropogenic in?uences, the increasing organic matter amounts lead to a sharp decrease in hypolimnetic oxygen amounts, aided by thermal strati?cation,and anaerobic conditions arise. The determination of hypolimnetic oxygen demand(HOD) and areal hypolimnetic oxygen demand(AHOD) and their monitoring represent an integrated approach to investigate the oxygenation of lakes, the nutrient conditions, and the physicochemical dynamics. In this study, two lakes dif fering by size and af fected by dif ferent anthropogenic sources, are investigated in this respect. At?rst, bathymetric studies were conducted to determine the depth, surface area, and volume relationships.Then, based on monitoring studies conducted in 2013 and 2014, the thermal strati?cation dynamics and layer properties were established using the relative thermal resistance to mixing(RTRM) index based on temperature and density pro?les. Following this, the oxygen depletion rates were determined by oxygen and temperature pro?ling in the hypolimnion. For the years of 2013 and 2014, the AHOD values for the Borabey Pond which is far from anthropogenic in?uences, were found to be 0.848 and 0.569 g O 2/(m·d), respectively.The AHOD values for the Porsuk Reservoir which was overburdened for years by industrial and domestic pollution were found to be 4.263 and 5.099 g O 2/(m·d), larger than its counterpart by almost sevenfold. The HOD and AHOD monitoring can be considered to a valuable tool for assessing the ecological and chemical status of lakes within Annex 5 of the Water Framework Directive and as an integrated approach to assess and monitor the status of lakes. 相似文献
19.
Virioplankton dynamics at seven sample sites (from two freshwater lakes) with different trophic states were monitored over
the period of a year. Water was sampled monthly from August 2004 to July 2005, and the abundances of viruses and bacteria
were measured using direct epifluorescence microscopy counting. Results indicated that both natural and anthropogenic factors
could influence the distribution of virioplankton. Temporally, viral abundance was significantly correlated to bacterial density
and water temperature. Spatially, viral abundance was significantly correlated to trophic state. This in turn indicated that
viral abundance was directly dependant on host abundance in eutrophic lakes, while trophic state and temperature could drive
the distribution of virioplankton. The virus-bacteria ratio was significantly lower in less productive water-bodies. The result
implied that the control of virioplankton on their hosts may change according to the host density. 相似文献