共查询到18条相似文献，搜索用时 125 毫秒
1.
我国湖泊环境演变及其成因机制研究现状 总被引：8，自引：0，他引：8
湖泊沉积忠实地记录了湖泊环境变化的各类信息.不同时问尺度的湖泊环境变化分别受到构造、气候与人类活动三个方面的驱动机制的影响.影响中同湖泊环境变化的最主要的构造运动是青藏高原的隆升;气候变化的影响主要是东亚季风系统带来的一系列作用;而人类活动的影响则比较复杂,不仅有流域植被、土壤性质的改变导致输入湖泊物质的变化,也有人类活动直接改造湖泊,如围垦、封堵等.准确地分析湖泊环境变化的各种过程与规律,特别是定量刻画人与自然相互作用下的湖泊环境响应过程与驱动机理,是当今科学界的热点. 相似文献
2.
龙感湖近百年来沉积物磷的时空分布特征及其人类活动影响 总被引：5，自引：5，他引：0
湖泊沉积物蓄积的磷在湖泊环境发生变化(如pH值、Eh改变)时,往往能释放到水体,形成湖泊内源释放,造成湖泊富营养化.因此了解湖泊沉积物磷的蓄积特征,对于湖泊环境的治理和保护有重要意义.通过长江中游龙感湖不同部位钻孔的210Pb、沉积物磷和其他环境指标分析表明,近百年来东部湖区沉积速率明显大于西部湖区,北部湖区略大于南部湖区,人类活动在20世纪50年代后期主要通过修建水库和闸坝,改变龙感湖水系结构,也改变了龙感湖的物源供给,因而西部湖区沉积速率略有放缓,东部湖区变化不明显.龙感湖沉积物磷的浓度空间上表现为东部高于西部,这与不同物源磷的背景值相关,时间序列上近百年来呈上升趋势,上世纪50年代以来上升趋势更为明显.在确定沉积物磷背景值的基础上,由于人类活动导致的磷的增加量表明,20世纪50年代开始人类活动导致沉积物磷的增加量持续上升,20世纪70年代末开始增加幅度更大,这一特征与人类活动的方式有关. 相似文献
3.
气候变化和人类活动对伊塞克湖水位变化的影响及其演化趋势 总被引：1，自引：0，他引：1
结合气象、水文、冰川变化和人类活动序列资料,应用水量平衡方法分析了气候变化和人类活动对吉尔吉斯坦伊塞克湖1927—2008年水位变化的影响.结果表明:降水量和入湖径流量是湖泊水位变化的决定因素.在水量平衡各要素中,降水量和入湖径流量与湖泊水位变化的正相关关系最为密切,而灌溉耗水对目前湖泊水位的变化的影响仅处于次要地位.由于气候变化,流域高山区气温上升显著,湖面降水量和入湖径流量增加明显,导致湖面于1998年停止下降,开始回升,到2008年底已经上升了0.59 m.按照所有SRES情景预估的未来升温情况,伊塞克湖水位还将会因为雨雪比例的增大及冰川融水的大量增加而上升.因此,伊塞克湖水位现在已经处于自然波动恢复状态中,不需要从其他流域向伊塞克湖调水来恢复湖水位,但要注意灌溉回归水可能会对湖水造成一定的污染. 相似文献
4.
近50a中国寒区与旱区湖泊变化的气候因素分析 总被引：41，自引：8，他引：33
以青藏和蒙新两大湖区代表的我国寒区和旱区湖泊为对象,通过各湖区典型湖泊与气候变化的时间序列分析,揭示了湖泊与气候变化的动态关系;通过区域尺度湖泊面积的阶段性变化过程与区域气候变化的关系,分析了湖泊变化的区域气候影响背景.结果表明:位于我国寒区和旱区的湖泊对气候变化具有高度敏感性,从气候的角度来看,内蒙古的湖泊受降水影响较为明显,新疆湖泊总体上受降水影响显著,但由于冰川的存在气温对湖泊也有一定影响.青藏高原典型湖泊变化的分析表明,降水、气温对不同湖泊有着不同的影响,在区域上湖泊与气候的变化关系表现的更为复杂,在降水增加、气温上升的情况下由于升温引起的湖泊蒸发效应超过降水增加导致的补给影响,湖泊总体趋于萎缩. 相似文献
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6.
新疆干旱区处于内陆腹地,降水稀少而蒸发量大,区内湖泊经长期自然演化后多为盐湖和咸水湖.近几十年来,在气候持续增暖和人类活动驱动下,湖泊波动变化频繁,对湖泊资源环境及其区域生态环境产生重大影响.本文通过新疆地区山地、平原等不同地貌单元的6个淡水和微咸水湖泊的水量、水质状况分析和对比研究,进行了近期湖泊水资源变化分析.研究表明,近十多年来,喀纳斯湖和赛里木湖等山地湖泊有一定的扩展,但湖泊的水量和水质没有明显的变化.博斯腾湖和柴窝堡湖等山前绿洲湖泊以及乌伦古湖和吉力湖等河流尾间湖泊总体收缩,水体咸化.湖泊的变化总体上是对区域气候变化的响应,但湖泊流域人类活动和湖盆形态特征等方面的不同,导致湖泊演化过程的空间差异.湖泊水质变化与湖泊水量变化具有明显的对应关系,湖泊水量增加水体淡化,反之咸化.近十多年来,山地湖泊赛里木湖和喀纳斯湖水质变化相对稳定,山前绿洲湖泊博斯腾湖和柴窝堡湖水质则持续恶化,而河流尾闾湖泊乌伦古湖和吉力湖水质变化波动较大,并从2008年开始逐渐好转,处于水化学类型易变的过渡阶段. 相似文献
7.
基于永定河流域内1957~2010年降雨、蒸发和径流数据,采用Mann-Kendall趋势检验法结合距平序列变化情况分析蒸发能力、降雨和径流的变化趋势;运用Mann-Kendall突变检验法、Hurst系数法分析流域径流序列的突变年及对应的突变程度;在此基础上以径流突变年为界划分基准期和变化期,采用弹性系数法定量分析气候变化和人类活动对径流的影响,并简要分析其原因。结果表明:流域蒸发能力呈现上升趋势,降雨和径流呈现递减趋势;径流序列突变点发生在1984年,突变程度属中度变异;永定河流域由气候变化引起的径流变化率为28%,而由于人类活动引起的径流变化率为72%,可见人类活动是影响永定河流域径流变化的主要驱动因素。 相似文献
8.
利用薄膜扩散梯度技术估算红枫湖沉积物磷释放通量 总被引：2，自引：0，他引：2
《矿物岩石地球化学通报》2015,(5)
湖水因季节性分层而导致底层滞水带缺氧的亚深水型湖泊,其沉积物内源磷释放对水体磷循环和富营养化有着重要影响。选取典型的高原亚深水型湖泊——贵州红枫湖为研究对象,借助氧化锆薄膜扩散梯度技术获取了5个代表性湖区沉积物有效磷(labile P)的原位、二维、高分辨分布信息,在此基础上估算夏季红枫湖沉积物内源磷释放通量。结果表明,红枫湖后五沉积物有效磷浓度最高,羊昌河、大坝次之,南湖中与北湖中较低。红枫湖沉积物labile P浓度在亚毫米水平上有很大差异,空间分布不均一,时间上夏季磷释放量为6270~7999kg,占全湖水体总磷的22%~28%。沉积物磷释放是红枫湖水体磷的重要来源,在湖泊富营养化防治过程中应予以重视。 相似文献
9.
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
10.
湖泊沉积物中包含有丰富的气候变化信息.其中生物分子标志物稳定氢同位素作为优良的气候变化代用指标已经得到广泛应用.由于湿润地区和干早地区湖泊的蒸发作用和水文条件不同,用来重建所得的降水稳定同位素变化所指示的气候意义也不相同.文章介绍作者过去几年内在湿润地区和干早地区所进行的探索,并探讨这些生物分子标志物同位素变化所代表的气候指示意义.在湿润地区,主要由水生植物产生的C22脂肪酸可以很好地记录湖水同位素变化和降水同位素变化,而后者又与采样地点的地表气温变化一致,因此C22脂肪酸的稳定氢同位素在湿润地区可以作为温度代用指标.在干早地区,湖水受强烈的蒸发作用影响,由水生生物产生的生物分子标志物氢同位素不能反映降水同位素变化,而在湖泊沉积物保存的、由陆生植物产生的叶蜡化合物可以很好地记录降水同位素变化.最后介绍了在湿润地区的湖泊中应用Czz脂肪酸稳定氢同位素成功重建北美洲东北部地区晚更新世到早全新世气候变化,并讨论其变化机制. 相似文献
11.
Assessing the impact of climate change on Mogan and Eymir Lakes’ levels in Central Turkey 总被引：1，自引：1，他引：0
Global warming is likely to have significant effect on the hydrological cycle. Some parts of the world may see significant
reductions in precipitation or major alterations in the timing of wet and dry seasons. Climate change is one of the serious
pressures facing water resources and their management over the next few years and decades. As part of the southern belt of
Mediterranean Europe, Turkey is highly vulnerable to anticipated climate change impacts. The changes in global climate will
seriously affect inland freshwater ecosystems and coastal lakes. Mogan and Eymir Lakes located in Central Turkey are shallow
lakes that may be impacted significantly by climate change. The interaction between the lakes and groundwater system has been
modelled in order to analyse the response of lake levels to climate change over a planning period of 96 years, beginning from
October 2004 and ending in September 2100. The impacts of the emission scenarios of A2 and B1 of the Intergovernmental Panel
on Climate Change (IPCC) on lake levels have been analyzed with the help of the lake-aquifer simulation model. The fluctuations
in lake levels due to climate change scenarios are compared with the results of a scenario generated by the assumption of
the continuation of the average recharge and discharge conditions observed for 1999 and 2004. The results show that very small,
but long-term changes to precipitation and temperature have the potential to cause significant declines in lake levels and
temporary drying of the lakes in the long-term. The impact of climate change on lake levels will depend on how these water
resources are managed in the future. 相似文献
12.
Effects of climatic changes and anthropogenic activities on lake eutrophication in different ecoregions 总被引：1，自引：0，他引：1
X. Chuai X. Chen L. Yang J. Zeng A. Miao H. Zhao 《International Journal of Environmental Science and Technology》2012,9(3):503-514
Climatic changes and anthropogenic activities could affect nutrients?? status significantly in the different lake ecosystems. Nutrients in Lake Hulun and Lake Taihu, two largest shallow cyanobacteria-blooming lakes in northern and southern China, respectively, were at eutrophicated levels in 2009. The concentrations of total nitrogen and total phosphorus were 3.346 and 2.250?mg/L as well as 0.435 and 0.062?mg/L, respectively, in these two lakes with different causes of eutrophication. For Lake Hulun, it was the decreased amount of water as a result of the warming and drying climate that accounted for the abrupt increase of total nitrogen and total phosphorus levels through inspissation. In addition, the icebound effects, no outflows, low nutrients sequestration by the sediment and the reduction of aquatic productivity made the situation even worse. On the contrary, high population densities, the rapid development of agriculture and industry as well as urbanization have increased the nitrogen and phosphorus loads on Lake Taihu. Therefore, higher criteria of total nitrogen and total phosphorus should be applied in Lake Hulun given the difficulties in controlling climatic changes while much more rigorous standards should be established for Lake Taihu since the anthropogenic impacts on nutrient status are relatively easy to control. 相似文献
13.
青藏高原热喀斯特湖演化及其对多年冻土的热影响模型计算研究北大核心CSCD 总被引：1，自引：0，他引：1
青藏高原热喀斯特湖分布广泛,近年来在气候变暖背景下快速发展。热喀斯特湖的形成和发展与地下冰含量及气候变化有着密切关系,强烈影响多年冻土的热稳定性。为了更深入理解在气候变暖背景下热喀斯特湖的发展及其对下伏多年冻土的影响,以青藏高原北麓河地区一个典型热喀斯特湖的长期监测数据为资料,发展了耦合大气—湖塘—冻土三个过程要素的一维热传导模型,模拟了四种不同深度热喀斯特湖在气候变暖背景下的发展规律及其对多年冻土的热影响。结果表明:浅湖(<1.0m)在目前稳定气候背景下处于较稳定状态,湖冰能够回冻至湖底,对下伏多年冻土影响较小;较深湖塘(≥1.0m)冬季不能回冻至湖底,湖深不断增加,且底部在50年内将会形成不同深度的融区。随着气候变暖,热喀斯特湖的热效应显著,深度快速增加,较深湖塘的最大湖冰厚度减小,底部多年冻土快速融化形成开放融区。研究将有助于理解气候变化对青藏高原多年冻土区地貌演化及水文过程的影响。 相似文献
14.
藏南羊卓雍错流域主要湖泊水质状况及其评价 总被引：9，自引：0，他引：9
湖泊水质是研究湖泊变化及其对气候变化响应的重要指标.分析了藏南羊卓雍错流域主要湖泊的水化学指标概况、 水化学组成、 矿化度时空分布及其驱动, 并在此基础上对各湖泊的水质现状进行了评价. 研究表明: 流域内各湖泊水化学性质虽有一定的相似性, 但矿化度等水化学指标浓度存在显著差异, 各湖泊水化学组成亦差异显著. 羊卓雍错和巴纠错均为硫酸盐类-镁组, 沉错为硫酸盐类-钠组, 普莫雍错和空姆错则分别为重碳酸盐类-镁组和重碳酸盐类-钙组. 各湖泊矿化度差异较大的主要原因在于其补给来源不同, 以降水补给为主的湖泊矿化度远高于以冰雪融水补给为主的湖泊. 与全球气候变暖相对应, 各湖泊矿化度变化反映了气候变化的影响, 而水电站运行对羊卓雍错水体化学性质变化有所贡献. 目前, 羊卓雍错、 普莫雍错水质为劣V类, 空姆错、 沉错、 巴纠错水质为V类. 深入探讨该流域水质对气候变化的响应, 亟需更长时间序列的数据支持. 为此, 必须继续在该流域长期开展全方位的水化学观测与水质监测、 评价工作. 相似文献
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16.
Mianping Zheng 《Environmental Earth Sciences》2011,64(6):1537-1546
The Chinese salt lake mega-region is controlled by an arid and semi-arid climate, and modern salt lakes are mainly distributed
within areas with mean annual precipitation <500 mm. According to their geomorphological features, structural conditions,
and material composition, salt lakes in China can be broadly divided into four regions. The degrees of exploitation and utilization
of these salt lakes differ because these four regions have experienced different climatic changes and structural activities
and have had their own characteristics of salt lake evolution since the beginning of the Quaternary. The salt lakes in these
regions have different scales, economic value, and technical conditions for traffic. Among others, Jarantai (Jartai) Salt
Lake and Yuncheng Salt Lake are better in terms of comprehensive utilization and environmental protection, and the potash
salt lakes represented by Qarhan are most important in terms of exploitation. At present, there exist many environmental problems
in the salt lake regions of China, especially in remote, small and medium-sized basins, where abusive or wasteful mining,
low recovery, and mining of a single saline mineral have caused impoverishment and large quantities of byproducts. Furthermore,
climatic environmental factors can also cause significant changes of salt lake environment. Since 1987, against the background
of global warming, the climate in the northwest salt lake region has turned warm and wet, and lakes have exhibited a tendency
for expansion and rise, whereas in the east of the region, the climate has remained in a warm dry stage, lake levels have
dropped, and salt lakes have become desertified. With the implementation of the strategy of building an environmentally friendly
society in China, increasing attention is being paid to eco-environmental protection. It is suggested that experience and
advanced techniques in terms of comprehensive utilization, overall development, and environmental protection of salt lakes
at home and abroad be further developed to strengthen observation and monitoring of environmental changes of salt lakes and
build an environmentally friendly, great salt lake industry. 相似文献
17.
John W. Day Robert R. Christian Donald M. Boesch Alejandro Yáñez-Arancibia James Morris Robert R. Twilley Larissa Naylor Linda Schaffner Court Stevenson 《Estuaries and Coasts》2008,31(3):477-491
Climate impacts on coastal and estuarine systems take many forms and are dependent on the local conditions, including those
set by humans. We use a biocomplexity framework to provide a perspective of the consequences of climate change for coastal
wetland ecogeomorphology. We concentrate on three dimensions of climate change affects on ecogeomorphology: sea level rise,
changes in storm frequency and intensity, and changes in freshwater, sediment, and nutrient inputs. While sea level rise,
storms, sedimentation, and changing freshwater input can directly impact coastal and estuarine wetlands, biological processes
can modify these physical impacts. Geomorphological changes to coastal and estuarine ecosystems can induce complex outcomes
for the biota that are not themselves intuitively obvious because they are mediated by networks of biological interactions.
Human impacts on wetlands occur at all scales. At the global scale, humans are altering climate at rapid rates compared to
the historical and recent geological record. Climate change can disrupt ecological systems if it occurs at characteristic
time scales shorter than ecological system response and causes alterations in ecological function that foster changes in structure
or alter functional interactions. Many coastal wetlands can adjust to predicted climate change, but human impacts, in combination
with climate change, will significantly affect coastal wetland ecosystems. Management for climate change must strike a balance
between that which allows pulsing of materials and energy to the ecosystems and promotes ecosystem goods and services, while
protecting human structures and activities. Science-based management depends on a multi-scale understanding of these biocomplex
wetland systems. Causation is often associated with multiple factors, considerable variability, feedbacks, and interferences.
The impacts of climate change can be detected through monitoring and assessment of historical or geological records. Attribution
can be inferred through these in conjunction with experimentation and modeling. A significant challenge to allow wise management
of coastal wetlands is to develop observing systems that act at appropriate scales to detect global climate change and its
effects in the context of the various local and smaller scale effects. 相似文献
18.
In response to the impact of climate change, the US Army Corps of Engineers proposed a large-scale implementation plan for an aquifer storage and recovery (ASR) project in the Kissimmee River Basin, Florida, in 2009. It is envisaged that the routine operation of the ASR will deliver recovered water from ASR wells into Lake Okeechobee with inherently different water quality parameters. However, the addition of ASR well water into such a large, shallow lake has raised concerns about sediment phosphorus stability, which could lead to increased eutrophication in Lake Okeechobee. This paper presents a geochemical assessment to explore possible impacts of the addition of ASR well water on lake sediment in terms of phosphorus adsorption, desorption, and diffusion processes via laboratory-scale batch and column tests. Based on five different mixing ratios of ASR well water and lake water, estimated isotherms, and piston velocity calculations, a mechanistic modeling analysis provided a better understanding of the fate of sediment phosphorus and its transport processes. A final multicriteria decision analysis suggests that the mixing ratio of 1:10 between ASR well water and lake water is deemed more applicable than others based on the given composition of ASR well water, which might buffer more external phosphorus loading in the long run. 相似文献