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1.
根据我国２４个有代表性湖泊的１９８７－１９８８年调查资料，选择Ｃｈｌａ，Ｔｎ，ＴＰ，ＣＯＤＭｎ，ＳＤ作为评价参数，采用综合评分指数法，对湖泊富营养化程度进行了初步评价。结果表明，所调查的２４个湖泊中，富营养湖泊１６个，占调查总数的６６．６％；中富营养湖泊４个，占１６．７％；中营养湖泊４个，占１６．７％；贫营养湖泊为零。与国外湖泊相比较，主要评价参数Ｃｈｌａ，ＴＮ，ＴＰ的数值普遍较高，富营养湖泊的比 相似文献
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Lakes Waihola and Waipori are shallow, coastal, tidal lakes that experience wind‐induced sediment resuspension, saline intrusions, and high inputs of nutrients. To determine the influence of externally‐driven, physical factors on spatial and temporal patterns of water quality in the two lakes, meteorological, hydrological, and water quality data were collected over 1 year. Multivariate analyses indicated that wind energy was driving the main water quality gradient in the lakes, which was primarily related to wind‐induced resuspension of lake sediments. The major, seasonally regulated, non‐tidal freshwater inflow was important in determining nutrient and salinity gradients in the lakes. The main nutrient inputs to the system were identified as the regulated, non‐tidal inflow (the upper Waipori River) and the tidal inflow (lower Waipori River). The impact of water quality gradients on zooplankton community structure in the lakes was assessed by canonical multivariate methods. Salinity gradients, caused by seasonal saltwater intrusions, were strongly related to zooplankton community structure in the lakes. Nutrient gradients (indicative of trophic state) were also related to zooplankton community structure. Although wind‐induced sediment resuspension had the largest impact on water quality in the lakes, it had little impact on the zooplankton community structure in either lake. The relationships between water quality and zooplankton community structure were confounded in Lake Waipori because of its very short hydraulic residence time (annual mean =1.9 days). Zooplankton community structure was resilient to short‐term changes in suspended particulate matter concentrations but not to seasonal changes in salinity. The results of this study support others which have shown impacts of even relatively small variations in salinity on the structure of zooplankton communities. This highlights the vulnerability of zooplankton communities in coastal lakes and wetlands to increasing salinity resulting from sea level rise and global climate change. 相似文献
3.
江苏省主要湖泊的降水量与湖泊的降水效应 总被引：10，自引：0，他引：10
本文分析了江苏境内主要湖泊的降水量特征,揭示了长江是江苏各湖泊不同降水量特征的一条十分明显的天然界线;估算了太湖的降水效应,并据此推估出江苏主要湖泊的降水效应不太明显;江苏各湖泊的降水量与其水位年过程趋势相似,只是后者位相滞后于前者而已。 相似文献
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J. Irwin 《新西兰海洋与淡水研究杂志》2013,47(4):591-605
A preliminary study has been made of temperatures in some of the lakes of the Rotorua district, in the North Island of New Zealand. Seasonal and diurnal variations are discussed. Two main thermal structure types are present. One, in which stratification is irregular or absent, is present in lakes that are relatively shallow and large in area, and the other, in which there is thermal Stratification from early summer to early winter, is present in lakes that are comparatively deep and large in area or else of medium depth and size. 相似文献
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可可西里地区湖泊水体地球化学特征 总被引：8，自引：0，他引：8
根据于１９８９年５－６月和１９９０年５－８月对可可西里地区综合科学考察所得资料，采用常规化学分析法，利用ＩＣＰ－３５２０光谱测定仪分析研究该地区湖泊及其补给水系的化学成分和展布规律。 相似文献
7.
贡湖及其相关水域风生流模拟研究 总被引：9，自引：0，他引：9
在太湖风生流的数值模拟研究的基础上，设计模拟贡湖及其相关水域风生流的套网格数值模式。应用该模式研究不同风情下，梅梁湖，太湖主体湖水对贡湖的影响。 相似文献
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洞庭湖地区水系水动力耦合数值模型 总被引：2，自引：0，他引：2
针对洞庭湖地区复杂水系和复杂水情下的实际水流运动特征,建立了完全基于水力学方法的洞庭湖地区水系的一、二维耦合的全局水动力学模型,实现了不同水体数值模拟的自动有机衔接。模型包括湖泊、河网水系两部分。对长江干流荆江段、湘资沅澧四水、三口分流河道,运用能够反映河道主槽和边滩不同行洪特征的扩展一维水量模型进行模拟;对于洞庭湖湖区部分,采用二维非结构的有限体积法建立水动力模型;应用重叠投影法实现模型的耦合。模型具有动边界的自动处理,河道分区计算,分洪、溃堤过程实时模拟等功能。剖分的网格较为细致地刻画了湖区的地形,使模型能够模拟"高水湖相、低水河相"的湖流特征。运用1996年7月的实际洪水过程,进行了模型的验证,较为准确地模拟了实际水流特征。 相似文献
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Y. M. Polishchuk N. A. Bryksina V. Y. Polishchuk 《Izvestiya Atmospheric and Oceanic Physics》2015,51(9):999-1006
Regularities of changes in the number of thermokarst lakes in the cryolithozone of Western Siberia have been studied using multitemporal satellite images. The studies were conducted on 33 test sites selected in different landscape zones of the study area with the use of 134 cloud-free Landsat images obtained during warm months in the period from 1973 to 2013. It is shown that the total number of new lakes is significantly (almost 20 times) higher than the number of disappeared lakes. The area of newly formed thermokarst lakes is, on average, 22 times smaller than the size of disappearing lakes. Therefore, one can assume that the rapid growth in the number of small thermokarst lakes that is observed under the conditions of global warming will lead to an increase in methane emissions into the atmosphere in permafrost zones in the Arctic territories. Results of remote sensing of statistical distribution of small thermokarst lakes with respect to their sizes are given. The studies were performed on eight test sites selected in different permafrost zones of Western Siberia. The size of small lakes was determined according to QuickBird super-high resolution satellite images. It is shown that histograms of distribution of lakes with respect to their sizes allow their approximation by power and exponential functions, which can be used for modeling and predicting the dynamics of thermokarst methane emission in permafrost zones. 相似文献
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Seismic data and cores from the Waitaki continental shelf, New Zealand, indicate a major reduction in terrigenous deposition
about 10,000 years ago when the accumulation of extensive marine sand wedges ceased. This change reflects the impact of lacustrine
traps on the main sediment supplier to the shelf, the Waitaki River. Prior to 10,000 years BP, lakes Ohau, Pukaki and Tekapo
were glaciated and glacio-fluvial detritus was fed directly to the river and shelf where marine deposition was ca. 6.8×106 t/yr. Following deglaciation, the newly created lakes acted as efficient sediment traps that denied the river 22.2×106 t/yr. Accordingly, modern shelf deposition is around 0.04×106 t/year. 相似文献
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本文旨在探讨酸雨对台湾地区湖泊、水库等自然水域酸化的影响程度。主要内容为建立水域酸化程度之资料，以及不ＰＨ值湖水中，铝离子释放的情形。 相似文献
14.
根据１９８９－１９９０年两个夏季对阿尔泰山哈纳斯河流域冰川湖泊的野外调查并结合室内分析，对该流域冰川湖泊及其沉积类型进行了分类，按其成因冰川湖泊可分为：冰蚀湖、冰川阻塞湖，冰碛湖，冰川热融湖、以及复合成因的冰川湖泊，按补给类型，冰川湖泊还可以分为冰水湖和非冰水湖泊；冰川湖泊除了受到一般湖泊所具有的波浪作用，地表径流作用、块体运动、坡面水流作用以外，还存在冻胀作用，冰川作用和热力作用等。主要沉积类型 相似文献
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The emission of methane from tundra lakes in western Siberia is estimated on the basis of experimental data. According to these estimates, over the warm season, the methane flux from the surfaces of lakes to the atmosphere amounts to 0.5 KtCH4 for Arctic tundra, 2.9 KtCH4 for typical tundra, and 8.5 KtCH4 for southern tundra. The short-term spring emission of methane as ice melts in tundra lakes of the region under consideration is determined with consideration for published estimates of the rate of generation of methane in northern-latitude lakes during the cold season. The contribution made by tundra lakes in western Siberia to the atmospheric methane budget is estimated at 20 KtCH4/year. 相似文献
16.
The comparative limnology of some New Zealand lakes 总被引：1，自引：1，他引：0
V. Hilary Jolly 《新西兰海洋与淡水研究杂志》2013,47(2):214-259
The morphometry, environmental conditions, and some physical and chemical data are given for twenty‐four New Zealand lakes: seven are in the southern part of the South Island, the others, excluding Lakes Waikaremoana and Waikareiti, are in the “thermal region” of the central North Island. These lakes form two separate groups and include the largest and deepest lakes in both islands. The lakes in which stratification was established were found to belong to the class known as warm monomictic Two lakes, Rotorua and Rotoehu, were found to be homothermous throughout the year. Open water surface temperatures did not exceed 23°c in the North Island lakes or 19°c in the South Island, and minimum temperatures recorded were 7°c in the northern lakes and 5°c in the southern. In deep lakes the range of temperature was much less: Wakutipu had a range of 16–8.85°c. The disappearance level of a Secchi disc varied from 18 m (Lake Taupo) to 0.8 m (Lake Rotongaio). The transparency of the water in the glacial and volcanic lakes was comparable to that of similar lakes in other parts of the world. It was found that total ions, measured by the ion‐exchange resins reached high concentrations in lakes fed by thermal waters: Rotomahana 14.32m.e./l. By contrast Tikitapu, a seepage lake, had the low concentration of. 0.28m.e./l, and Wakatipu, a glacial fed lake, a concentration of O.58m.e./1. The pH range was 8.1–5.8, the lowest value being in Tikitapu, a volcanic lake. Slightly lower pH values were recorded in the bottom waters of lakes when stratified. Lakes were usually supersaturated with oxygen at the surface, and only a few small lakes showed a hypolimnial deficiency. Silica and phosphate were found in high concentrations in some thermal lakes but nitrogen in the forms measured, was found to be low. 相似文献
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Eight ophiuroid species, six from the northern Kattegat-eastern Skagerrak and three from the northern Adriatic Sea, were examined for regeneration of arms. The species were separated into groups based upon mode of feeding and habitat. Comparison between groups collected in the northern Kattegat-eastern Skagerrak showed that infaunal suspension- and deposit-feeding species (Amphiura filiformis and A. chiajei) had significantly more scars per arm (mean number 0.78) than epibenthic suspension feeders (Ophiothrix fragilis and Ophiocomina nigra, 0.29) or epibenthic carnivores and deposit feeders (Ophiura ophiura and O. albida, 0.13). Spatial variation in arm regeneration incidence was found between sampling sites in the northern Kattegat-eastern Skagerrak for Amphiura filiformis and in the northern Adriatic Sea for Ophiothrix quinquemaculata. The ash-free dry weight (AFDW) and nitrogen (N) contents were measured in arms of six species of brittle-stars from the northern Kattegat-eastern Skagerrak. Differences between species were found, with highest concentrations of AFDW and N in Amphiura filiformis, intermediate in A. chiajei, Ophiocomina nigra and Ophiothrix fragilis, and lowest in Ophiura ophiura and O. albida. As the infaunal suspension- and deposit-feeding brittle-stars (Amphiura spp.) had the highest proportions of damaged arms and highest AFDW and N contents in their arms in this comparison, it is suggested that selective cropping of arms by demersal fish is the main cause of arm damage on Amphiura spp. in this area. 相似文献
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洪泽湖风生流数值模拟 总被引：2，自引：0，他引：2
湖流是湖泊中污染物质扩散，悬浮物沉降及输移等的主要水动力学要素，造成湖水运动的成因机制很复杂，其中风生流是重要形式，本文通过构造一个二维闭边界数值模拟，对不同风情下的洪泽湖湖流流态进行模拟研究，探讨其入流较小，沿岩各闸关闭的枯季情况下的风生流特征。 相似文献
19.
Intermittently closed and open lakes and lagoons (ICOLLs) are important features of the Australian coastline. Local authorities frequently open lakes by bulldozing or dredging the mouths, in an effort to improve water-quality and to reduce the risk of flooding and these interventions provided an opportunity to examine large-scale patterns in meiobenthos in relation to isolation from the sea. Even at a coarse level of taxonomic resolution (phylum, class and order), consistent differences between assemblages of meiobenthos in different reaches of the lakes and between open and closed lakes were revealed. The abundance of meiobenthos generally decreased with increasing distance from the sea. Multivariate analyses showed that nematodes, copepods and turbellarians were characteristic of assemblages near the mouths of lakes while polychaetes and oligochaetes characterised those in more isolated areas. Furthermore, assemblages in the inner reaches of open lakes also differed from those in closed lakes. Isolated localities were less diverse and more spatially variable. Differences in meiobenthos between natural lakes and those that are artificially opened became apparent when open and closed were analysed separately. Lakes that are kept open artificially are similar to naturally open lakes despite other impacts associated with human activities. These results are considered in the context of isolation and the implications of proposed changes in the way mouths are manipulated are discussed. 相似文献
20.
We reviewed lakes in New Zealand reported to have undergone regime shifts between macrophyte‐dominated clear water states and de‐vegetated, turbid states. Regime‐shifting lakes (RSLs) occurred along a wide latitudinal gradient. We obtained catchment land‐use data as well as data on the occurrences of introduced (non‐indigenous) macrophytes and herbivorous and benthivorous fish for the 37 RSLs and for 58 lakes with similar maximum depths and climates, but which had not been reported to have undergone regime shifts. All RSLs had a maximum depth <20 m and mean annual surface air temperature between 9 and 16°G Regime shifts were positively related to the percentage of the catchment in pasture and negatively related to the percentage of the catchment in forest. The occurrences of the introduced macrophyte Egeria densa and the introduced fish, Ameiurus nebulosus (catfish), Carassius auratus (goldfish), Scardinius erythrophthalmus (rudd), Cyprinus carpio (koi carp), and Tinca tinca (tench), were significantly correlated to regime shifts in lakes. Although the presence of other introduced aquatic macrophytes was not significantly correlated with RSLs, the number of exotic fish taxa present in lakes was strongly positively correlated with increasing prevalence of regime shifts. The strength of the correlations between land use and introduced species versus regime shifts illustrates a number of factors which could be managed to reduce the susceptibility of lakes to regime shifts and to restore lakes that have become de‐vegetated. Our findings also suggests that regime shifts in lakes were unlikely to have been common in New Zealand lakes before anthropogenic deforestation and introductions of introduced aquatic taxa. 相似文献