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Analysis of dynamic changes and influence factors of Lake Balkhash in the last twenty years 预览
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作者 TANG Hai-long LU Shan-long +4 位作者 CHENG Yan-pei GE Li-qiang ZHANG Jian-kang DONG Hua SHAO Huai-yong 《地下水科学与工程:英文版》 2019年第3期214-223,共10页
Lake Balkhash is the third largest inland lake in Central Asia after the Caspian Sea and the Aral Sea.The Ili River-Balkash Lake Basin resides in the southeastern part of the Republic of Kazakhstan and the western par... Lake Balkhash is the third largest inland lake in Central Asia after the Caspian Sea and the Aral Sea.The Ili River-Balkash Lake Basin resides in the southeastern part of the Republic of Kazakhstan and the western part of China's Ili Prefecture,which belongs to the arid and semi-arid region.In the middle to late 20~(th)century,the Ili River-Balkash Lake Basin was affected by climate change and human activities,and the problems of water ecology and water resources became increasingly prominent,which became the focus of attention for China and Kazakhstan.In this study,the water level derived from radar altimeter data,the water surface area extracted from Landsat data,and the temperature and precipitation data in the basin were comprehensively utilised.Data analysis of the time course and correlation of hydrological,meteorological elements in the lake basin,water dynamic changes,and influencing factors of Lake Balkhash was studied.The results show that the cyclical change of regional climate is the main factor affecting the change of lake water,and human activities in the short term can regulate the change of water volume in Lake Balkhash.The research results in this paper can provide a scientific basis for the solution of water disputes in cross-border rivers between China and Kazakhstan. 展开更多
关键词 LAKE area LAKE water LEVEL REMOTE SENSING LAKE Balkhash
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Dynamic changes in lakes in the Hoh Xil region before and after the 2011 outburst of Zonag Lake
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作者 LIU Wen-hui XIE Chang-wei +6 位作者 ZHAO Lin WU Tong-hua WANG Wu ZHANG Yu-xin YANG Gui-qian ZHU Xiao-fan YUE Guang-yang 《山地科学学报:英文版》 SCIE CSCD 2019年第5期1098-1110,共13页
Zonag, Kusai, Hedin Noel and Yanhu Lakes are independent inland lakes in the Hoh Xil region on the Qinghai-Tibet Plateau. In September2011, Zonag Lake burst after the water level had increased for many years. Floods f... Zonag, Kusai, Hedin Noel and Yanhu Lakes are independent inland lakes in the Hoh Xil region on the Qinghai-Tibet Plateau. In September2011, Zonag Lake burst after the water level had increased for many years. Floods flowed through Kusai and Hedin Noel Lakes into Yanhu Lake;since then, the four small endorheic catchments merged into one larger catchment. This hydrological process caused the rapid shrinkage of Zonag Lake and continuous expansion of Yanhu Lake. In this study,based on satellite images, meteorological data and field investigations, we examined the dynamic changes in the four lakes and analyzed the influencing factors. The results showed that before 2011, the trends in the four lake areas were similar and displayed several stages. The change in the area of Zonag Lake corresponded well to the change in annual precipitation(AP), but the magnitude of the change was less than that of a non-glacier-fed lake. Although increased precipitation was the dominant factor that caused Zonag Lake to expand, increased glacier melting and permafrost thawing due to climate warming also had significant effects. After the 2011 outburst of Zonag Lake, due to the increasing AP and accelerating glacier melting, the increases in water volume of the three lakes were absorbed by Yanhu Lake, and Yanhu Lake expanded considerably. According to the rapid growth rates in water level and lake area, Yanhu Lake is likely to burst in 1-2 years. 展开更多
关键词 Dynamic CHANGE LAKE areas Influencing factors GLACIER CHANGE PERMAFROST thawing Zonag LAKE
2013—2017年班公湖地区冷季湖泊冰情变化分析——中国西部高寒高海拔地区冰冻圈遥感调查(一) 预览
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作者 燕云鹏 徐辉 +1 位作者 刘刚 刘建宇 《国土资源遥感》 CSCD 北大核心 2019年第3期209-215,共7页
开展高寒高海拔区域的湖泊冰情变化分析,对于冷季湖冰通行能力评价、暖季冰碛湖溃决防灾减灾以及湖区下游洪涝灾害预测,均具有重要意义。基于2013—2017年Landsat8陆地成像仪(operational land imager,OLI)传感器获得的遥感数据序列,选... 开展高寒高海拔区域的湖泊冰情变化分析,对于冷季湖冰通行能力评价、暖季冰碛湖溃决防灾减灾以及湖区下游洪涝灾害预测,均具有重要意义。基于2013—2017年Landsat8陆地成像仪(operational land imager,OLI)传感器获得的遥感数据序列,选择了班公湖地区4个有代表性的湖泊(区域),开展了冷季湖泊冰情变化分析,调查结果显示班公湖Zone1区和Zone2区作为同一个湖泊,冻结开始时间、封冻时间、解冻开始时间和完全解冻开始时间基本一致。尽管斯潘古尔湖和莫里里湖的湖面海拔比班公湖高,但是冻结过程三者基本一致。斯潘古尔湖解冻比班公湖要晚;而最终的完全解冻开始时间两者基本一致。莫里里湖的解冻开始时间比班公湖要晚0.5~1个月;而完全解冻时间比别的湖泊约晚1个月。 展开更多
关键词 中国西部 高寒高海拔 冰冻圈 遥感 湖泊 冰情 班公湖
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区域气候变化对西藏扎布耶、当雄错、班戈湖变化的影响
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作者 王云生 郑绵平 +2 位作者 闫丽娟 卜令忠 齐文 《地理学报:英文版》 SCIE CSCD 2019年第11期1895-1907,共13页
The lake hydrological and meteorological data of the Tibetan Plateau are not rich.This research reports the observed climatic data and measured water levels of saline lakes from the local meteorological stations in th... The lake hydrological and meteorological data of the Tibetan Plateau are not rich.This research reports the observed climatic data and measured water levels of saline lakes from the local meteorological stations in the Zabuye salt lake,the Dangqiong Co salt lake and the Bankog Co salt lake in recent two decades.Combining with satellite remote sensing maps,we have analyzed the changes of the water level of these three lakes in recent years and discussed the origins of the changes induced by the meteorological factors.The results show that the annual mean temperature and the water level reflect a general ascending trend in these three lakes during the observation period.The rising rates of the annual mean temperature were 0.08℃/yr during 1991–2014 and 0.07℃/yr during 2004–2014,and of the water level,were 0.032 m/yr and 0.24 m/yr,respectively.Analysis of changes of the meteorological factors shows the main cause for the increase of lake water quantity are the reduced lake evaporation and the increased precipitation in the lake basins by the rise of average temperature.Seasonal variation of lake water level is powered largely by the supply of lake water types and the seasonal change of regional climate. 展开更多
关键词 TIBETAN PLATEAU SALINE LAKE CLIMATE variation LAKE change
Paleo-shoreline changes in moraine dammed lake Khagiin Khar, Khentey Mountains, Central Mongolia
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作者 OH Jeong-Sik SEONG Yeong Bae +1 位作者 HONG Seongchan YU Byung Yong 《山地科学学报:英文版》 SCIE CSCD 2019年第6期1215-1230,共16页
The formation and evolution of glacier moraine-dammed lakes are closely related to past glacier expansion and retreat. Geomorphic markers such as lacustrine terraces and beach ridges observed in these lakes provide im... The formation and evolution of glacier moraine-dammed lakes are closely related to past glacier expansion and retreat. Geomorphic markers such as lacustrine terraces and beach ridges observed in these lakes provide important evidence for regional paleoenvironment reconstruction. We document the magnitude of paleo-shoreline fluctuations and timings of highstands of lake water by using cosmogenic 10Be surface exposure dating and optically stimulated luminescence(OSL) dating on samples collected from lacustrine sediment and bedrock strath in Lake Khagiin Khar. The lake was initially impounded by glacier moraine at the Global Last Glacial maximum(gLGM;21–19 ka), and the lake reached its maximum paleo-shoreline level of 1840 m at sea level(a.s.l.). At that time, the stored lake water amount was up to seven times greater and the surface area was three times larger than the present values. The paleolake experienced higher shoreline levels at 1832, 1822, and 1817 m a.s.l. and reached the present lake level after 0.4 ka. We interpret that decrease in the paleolake level was caused by spillover. The increase in melt water after the gLGM and the Late Glacial exceeded the storage threshold of the lake, and the paleolake water overflowed across the lowest drainage divides. The lake spilled over across the lowest bedrock ridge at 15.9 ± 0.6 ka, and the outlet was incised since that time at a rate of 3.72 ± 0.15 mm/yr. The initial stream of the Khiidiin Pass River was disturbed by LGM moraine damming and was rerouted into the present course running through moraine after the spillover at 15.9 ± 0.6 ka. 展开更多
关键词 Moraine-dammed LAKE LAKE Khagiin Khar SHORELINE SPILLOVER 10Be exposure DATING
我国湖泊环境司法之检视与完善--以洞庭湖环境资源法庭为中心 预览
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作者 彭中遥 《华侨大学学报:哲学社会科学版》 CSSCI 北大核心 2019年第3期102-113,共12页
我国湖泊环境司法保障之关键在于推进其环境司法专门化,切入点为构建专门的、针对特定湖泊的环境资源审判机构。为顺应新时代洞庭湖环境司法之现实需求,湖南省于2017年成立了专门的洞庭湖环境资源法庭。然而在实践中,洞庭湖环境资源法... 我国湖泊环境司法保障之关键在于推进其环境司法专门化,切入点为构建专门的、针对特定湖泊的环境资源审判机构。为顺应新时代洞庭湖环境司法之现实需求,湖南省于2017年成立了专门的洞庭湖环境资源法庭。然而在实践中,洞庭湖环境资源法庭存在法律依据缺失、司法资源匮乏、案件来源不足、跨行政区域管辖困难等挑战。亟需通过明确法律依据、优化资源配置、拓宽案件来源、规范跨区域管辖等措施来应对上述挑战。洞庭湖环境资源法庭之探索经验与运行实践,既可助力于湖南省生态文明建设与环境司法改革,亦可为全国其他湖泊环境资源审判机构之专门化建设提供可资借鉴的范本。 展开更多
关键词 湖泊 洞庭湖环境资源法庭 环境司法 跨区域集中管辖
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Modelling Chorabari Lake outburst flood, Kedarnath, India
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作者 Mohammd RAFIQ Shakil Ahmad ROMSHOO +1 位作者 Anoop Kumar MISHRA Faizan JALAL 《山地科学学报:英文版》 SCIE CSCD 2019年第1期64-76,共13页
In this study,the Glacier Lake Outburst Flood(GLOF)that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS).The lake breach parameters such as area,dept... In this study,the Glacier Lake Outburst Flood(GLOF)that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS).The lake breach parameters such as area,depth,breach,and height have been estimated from the field observations and Remote Sensing(RS)data.A number of modelling approaches,including Snow Melt Runoff Model(SRM),Modified Single Flow model(MSF),Watershed Management System(WMS),Simplified Dam Breach Model(SMPDBK)and BREACH were used to model the GLOF.Estimations from SRM produced a runoff of about 22.7 m3 during 16–17,June 2013 over Chorabari Lake.Bathymetry data reported that the lake got filled to its maximum capacity(3822.7 m3)due to excess discharge.Hydrograph obtained from the BREACH model revealed a peak discharge of about 1699 m3/s during an intense water flow episode that lasted for 10–15 minutes on 17 th June 2013.Excess discharge from heavy rainfall and snowmelt into the lake increased its hydrostatic pressure and the lake breached cataclysmically. 展开更多
关键词 GLACIER LAKE OUTBURST FLOOD GIS MODELLING Snow Melt RUNOFF Kedarnath GLACIER LAKE
Denitrification and the controlling factors in Yunnan Plateau Lakes (China): Exploring the role of enhanced internal nitrogen cycling by algal blooms
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作者 Sifeng Wu Zhen Wu +2 位作者 Zhongyao Liang Yong Liu Yilin Wang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第2期349-358,共10页
Denitrification plays an important role in nitrogen (N) removal in freshwater ecosystems. This internal process regulates the fluctuations of N concentration, especially for lakes with high nutrients concentrations an... Denitrification plays an important role in nitrogen (N) removal in freshwater ecosystems. This internal process regulates the fluctuations of N concentration, especially for lakes with high nutrients concentrations and long residence time. Lakes in Yunnan plateau (southwestern China) provide typical cases, while studies in this region have been rare. Therefore, we studied denitrification of two lakes (Lake Dianchi in hypereutrophic state and Lake Erhai in mesotrophic) in this region. We used acetylene inhibition technique to quantify potential denitrification rate (PDR) of these lakes in April and August, 2015 and 2016. PDR of the sediments ranged 0–1.21μmol/(N·m^2·hr), and that of overlying water ranged 0–0.24μmol/(N·L·hr). Then, we used Least Angle Regression to determine the controlling factors for denitrification. Nutrients controlled PDR from two aspects: providing essential nitrogen sources;and affecting the richness and metabolism of denitrifying bacteria. In April, both aspects limited PDR;while only nitrogen sources limited PDR in August, due to depleted nitrate and enhanced denitrifying bacteria activity. Ammonia was most significant to denitrification, indicating that nitrate from nitrification transported to the bottom of well-mixed lake provide major N source by denitrification. The high PDR and low nitrate concentrate in August were evidence of an enhanced internal N cycling by algal blooms. 展开更多
关键词 DENITRIFICATION Controlling factors LAKE Dianchi LAKE Erhai ALGAL bloom INTERNAL CYCLING
Sedimentary model reconstruction and exploration significance of Permian He 8 Member in Ordos Basin,NW China 预览
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作者 XIAO Hongping LIU Rui’e +2 位作者 ZHANG Fudong LIN Changsong ZHANG Mengyuan 《石油勘探与开发:英文版》 2019年第2期280-292,共13页
Based on the Late Paleozoic geological background and the latest exploration achievements of the Ordos Basin and North China platform, it is concluded that during the sedimentary period of Permian He 8 Member, the are... Based on the Late Paleozoic geological background and the latest exploration achievements of the Ordos Basin and North China platform, it is concluded that during the sedimentary period of Permian He 8 Member, the area in concern had multiple material sources, multiple river systems, flat terrain, shallow sedimentary water, widely distributed fluvial facies sand body and no continuous lake area, so alluvial river sedimentary system developed in the whole region. Based on stratigraphic correlation and division, and a large number of drilling and outcrop data, a comprehensive analysis of lithofacies and sedimentary facies types and distribution was carried out to reconstruct the ancient geographic pattern of the He 8 Member sedimentary period. The results of paleogeography restoration show that the area of Ordos Basin was the "runoff area" in the sedimentary slope in the western part of the North China platform during the sedimentary period of He 8 Member, the whole region was mainly alluvial plain sedimentation featuring alternate fluvial facies, flood plain facies and flood-plain lake facies. According to the results of flume deposition simulation experiment, a new sedimentary model of "alluvial river & flood-plain lake" is established, which reveals the genesis of large area gravel sand body in He 8 Member of this area and provides geological basis for the exploration of tight gas in the south of the basin. 展开更多
关键词 ORDOS Basin He 8 MEMBER North China platform paleogeographic restoration ALLUVIAL river flood-plain lake SEDIMENTARY model exploration significance
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基于生态过程的湖泊水文健康评价体系研究Ⅰ:理论 预览 被引量:1
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作者 卢路 裴中平 贾海燕 《三峡生态环境监测》 2019年第1期40-46,共7页
湖泊水文健康作为河湖健康评价的重要子项,其健康程度与人类活动紧密相关。但现实中湖泊的水文过程相当复杂,涉及大量信息和规律,研究表明湖泊水文过程一般和湖泊生态系统在不同尺度、不同层次上存在多维结构关系。因此,通过建立生态水... 湖泊水文健康作为河湖健康评价的重要子项,其健康程度与人类活动紧密相关。但现实中湖泊的水文过程相当复杂,涉及大量信息和规律,研究表明湖泊水文过程一般和湖泊生态系统在不同尺度、不同层次上存在多维结构关系。因此,通过建立生态水文指标体系来研究变化复杂条件下湖泊水文过程是一种有效方式。目前,对河湖健康的认识限制于河流的自然状况,是在河流受到人类活动影响后提出的希望河湖回到未受人类影响的状态的愿望,但是人类发展到现在已经很难再回到没有人类的状态,所以后期河流健康的研究旨在寻求一种人类与河流和谐相处的平衡,而湖泊水文健康的评估目的是弄清楚湖泊水文变化过程中对河流造成影响的要素。 展开更多
关键词 生态过程 水文健康 湖泊 生态修复
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Evaluating the efficiency of the Dong model in determining fire vulnerability in Iran’s Zagros forests 预览
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作者 Sabri Baqer Rasooli Amir Eslam Bonyad 《林业研究:英文版》 CAS CSCD 2019年第4期1447-1458,共12页
Recent fires in Iran’s Zagros forests have inflicted heavy,extensive losses to the environment,forests,villages,and forest inhabitants,resulting in a huge financial loss to the country.With the increasing risk of fir... Recent fires in Iran’s Zagros forests have inflicted heavy,extensive losses to the environment,forests,villages,and forest inhabitants,resulting in a huge financial loss to the country.With the increasing risk of fire and the resulting losses,it has become ever more necessary to design and develop efficient fire control and prediction procedures.The present study utilizes the Dong model to develop a map of areas vulnerable to fire in the Zarivar lake forests as a representative sample of Zagros forests.The model uses as its inputs some of the most significant factors(such as vegetation,physiographic features,and the human component)that affect the fire occurrence and spread.Having assigned weights to each factor based on the model,all maps were overlapped in the ArcMap and then the region was divided into five zones.The results showed that 74%of the region was located in three classes:highly vulnerable,vulnerable,and medially vulnerable.To validate the proposed zoning map it was compared with a map based on real data obtained from previous fires.The results showed that 81%of fire incidents were located in highly vulnerable,vulnerable and medially vulnerable zones.Furthermore,the findings indicated a medium to a high degree of fire vulnerability in Zarivar Lake forests. 展开更多
关键词 Dong MODEL FIRE incidents Zarivar lake ZONING
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贝加尔地区萨彦山东部Jom-Bolok火山谷湖泊古环境研究
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作者 Alexander SHCHETNIKOV Elena V. BEZRUKOVA 《地理学报:英文版》 SCIE CSCD 2019年第11期1823-1840,共18页
This article describes the lake basins of the Jom-Bolok volcanic region in the East Sayan (the largest manifestation of the Holocene eruptions in Central Asia).The geomorphological position,origins,aspects of the stru... This article describes the lake basins of the Jom-Bolok volcanic region in the East Sayan (the largest manifestation of the Holocene eruptions in Central Asia).The geomorphological position,origins,aspects of the structure and development are reviewed considering its sedimentary filling.The limnic morphogenesis here develops under the conditions of contrasting relief,high energy of neotectonic and exogenous processes.We established that Lake Khara-Nur,formed as a result of lava-damming of the Jom-Bolok river valley,emerged in its present form approximately 6500 years ago.A complex record on the environment and climatic changes,acquired from its sediments,made it possible to determine for the first time in this region the long-term trends in the development of the Middle and Late Holocene mountain geosystems and also the distinction of several paleogeographic stages of the formation of the natural environment.An average geochemical record resolution for the bottom sediments of the lake was made uniquely for the East Siberian lake records and is equal to 35 years,while the palynological record approximates 110 years. 展开更多
关键词 lake MORPHOGENESIS Holocene VOLCANISM lava-dammed LAKES environmental change
Remotely sensed estimation and mapping of soil moisture by eliminating the effect of vegetation cover 预览
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作者 WU Cheng-yong CAO Guang-chao +6 位作者 CHEN Ke-long E Chong-yi MAO Ya-hui ZHAO Shuang-kai WANG Qi SU Xiao-yi WEI Ya-lan 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第2期316-327,共12页
Soil moisture(SM), which plays a crucial role in studies of the climate, ecology, agriculture and the environment, can be estimated and mapped by remote sensing technology over a wide region. However, remotely sensed ... Soil moisture(SM), which plays a crucial role in studies of the climate, ecology, agriculture and the environment, can be estimated and mapped by remote sensing technology over a wide region. However, remotely sensed SM is constrained by its estimation accuracy, which mainly stems from the influence of vegetation cover on soil spectra information in mixed pixels. To overcome the low-accuracy defects of existing surface albedo method for estimating SM, in this paper, Qinghai Lake Basin, an important animal husbandry production area in Qinghai Province, China, was chosen as an empirical research area. Using the surface albedo computed from moderate resolution imaging spectroradiometer(MODIS) reflectance products and the actual measured SM data, an albedo/vegetation coverage trapezoid feature space was constructed. Bare soil albedo was extracted from the surface albedo mainly containing information of soil, vegetation, and both albedo models for estimating SM were constructed separately. The accuracy of the bare soil albedo model(root mean square error=4.20, mean absolute percent error=22.75%, and theil inequality coefficient=0.67) was higher than that of the existing surface albedo model(root mean square error=4.66, mean absolute percent error=25.46% and theil inequality coefficient=0.74). This result indicated that the bare soil albedo greatly improved the accuracy of SM estimation and mapping. As this method eliminated the effect of vegetation cover and restored the inherent soil spectra, it not only quantitatively estimates and maps SM at regional scales with high accuracy, but also provides a new way of improving the accuracy of soil organic matter estimation and mapping. 展开更多
关键词 SOIL moisture remote sensing BARE SOIL ALBEDO TRAPEZOID feature space QINGHAI Lake Basin
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Editorial: Effects of metal contamination on ammonia-oxidizing microorganisms in a freshwater reservoir
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作者 Wei Feng Xiaowen Yan Chris Le 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第5期364-366,共3页
Ammonia-oxidizing microorganisms,including ammoniaoxidizing bacteria(AOB)and archaea(AOA),are important to the global nitrogen cycle.These microbes catalyze the oxidization of ammonia(NH3)to nitrite(NO2-),the ratelimi... Ammonia-oxidizing microorganisms,including ammoniaoxidizing bacteria(AOB)and archaea(AOA),are important to the global nitrogen cycle.These microbes catalyze the oxidization of ammonia(NH3)to nitrite(NO2-),the ratelimiting step in the biogeochemical cycling of nitrogen(Stahl and de la Torre,2012). 展开更多
关键词 ACCIDENTAL metal SPILL Ammonia-oxidizing ARCHAEA Ammonia-oxidizing bacteria AMOA gene Arsenic cadmium copper lead zinc Lake sediment Nitrogen cycling
对湖(库)不同深度下五日生化需氧量含量变化的研究
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作者 李国栋 《黑龙江环境通报》 2019年第2期37-39,共3页
五日生化需氧量(BOD5)是一种表示水体中可被微生物氧化的物质的含量,是衡量水中有机物含量的重要参数。以尼尔基水库水样为研究样本,研究了自然水体湖(库)不同深度下BOD5含量随水深的变化趋势。研究表明:自然水体中,湖(库)的BOD5含量随... 五日生化需氧量(BOD5)是一种表示水体中可被微生物氧化的物质的含量,是衡量水中有机物含量的重要参数。以尼尔基水库水样为研究样本,研究了自然水体湖(库)不同深度下BOD5含量随水深的变化趋势。研究表明:自然水体中,湖(库)的BOD5含量随深度的增加而降低。 展开更多
关键词 五日生化需氧量 水库 趋势 水质监测
Impact of Drain Effluent on Surficial Sediments in theMediterranean Coastal Wetland: SedimentologicalCharacteristics and Metal PollutionStatus at Lake Manzala, Egypt 预览
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作者 FARHAT Hassan I 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第4期834-848,共15页
Surface sediments were collected from Lake Manzala, the Mediterranean coastal wetland located to the east of the Nile Delta, Egypt, to assess the effect of drain effluent on the spatial variations of sedimentary chara... Surface sediments were collected from Lake Manzala, the Mediterranean coastal wetland located to the east of the Nile Delta, Egypt, to assess the effect of drain effluent on the spatial variations of sedimentary characteristics and heavy metal pollution. Grain-size compositions, textures, and heavy metal distribution patterns in sediments are presented using GIS technique. Results of the analysis of the sediment showed a clear effect of drain effluent, with an increase in fine fractions and homogeneous suspensions in transportation mode. Lake sediments were dominated by sandy mud textures, and mode of transportation was homogeneous sus- pension and rolling. Spatial distribution of heavy metals (Fe, Mn, Zn, Cu, Ni, Cr, and Pb) was studied in the lake’s surficial sediments, along with their relationship to drain effluent and their contamination status in the ecological system. Heavy metal pollution status was assessed by means of accepted sediment quality guidelines and contamination assessment methods (contamination factor, con- tamination degree, modified contamination degree, geo-accumulation, and enrichment factor). Among the determined heavy metals, Pb had the most ecological risk. Generally, the heavy metals in the surface sediments indicated pollution risk ranging from moderate to considerable, particularly, in those sites facing drains and inlets that had the highest toxic effluent. The results were interpreted by statistical means. A cluster analysis defined areas facing drain discharge and inlets as separated groups. ANOVA indicated that most of the sedimentation and studied metals directed this clustering. 展开更多
关键词 LAKE Manzala Mediterranean WETLAND metal POLLUTION sedimentological characteristics
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Clay minerals in the late Quaternary sediment of Tulare Lake, California: Implications for climate change, weathering, and erosion processes 预览
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作者 Junhua Guo Christine Pyles +1 位作者 William Krugh Rob Negrini 《国际泥沙研究:英文版》 SCIE 2019年第5期432-443,共12页
The clay mineralogy of Tulare Lake sediment was examined to investigate hydroclimatic and environmental changes in the southern Sierra Nevada Mountains (SNM) since the most recent glacial maximum. Evolution of clay mi... The clay mineralogy of Tulare Lake sediment was examined to investigate hydroclimatic and environmental changes in the southern Sierra Nevada Mountains (SNM) since the most recent glacial maximum. Evolution of clay mineral assemblages elucidates significant changes in weathering, erosion, and hydroclimatic condition in the catchment. During the last glacial period (24.4–15.1 cal ka BP), low illite content implies less physical erosion of the granitic batholith rocks and a cold and arid environment in the southern SNM. Abrupt increases of illite content at 21.8–20.8 and 17.6 cal ka BP resulted from the glacier advances to the ablation zone and illite-rich glacier flour was transported down to the lake. The gradual increase of smectite induced by progressive depletion of illite-rich glacier flour from 17.6 cal ka BP toward the end of this period indicates climate was beginning to get warm and wet. From 11.9 to 5.3 cal ka BP, two warm and wet periods (10.7–9.4 and 8.2–5.2 cal ka BP) were characterized by high smectite/illite content ratios and low illite crystallinity values, suggesting intensive rainfall precipitation and more physical erosion in the highland and lowland catchment as well as more smectite formation in the terrace soils. Since the last glacial period, physical erosion, in comparison to the chemical weathering, was the dominant process responding to the hydroclimatic change in the Tulare Lake catchment. Moderate to weak chemical weathering was signified by the mostly low illite chemical weathering index of the core sediments. Such results suggest that vegetation cover in the southern SNM was low and limited. 展开更多
关键词 CLAY MINERALOGY Sierra NEVADA MOUNTAINS Glaciers WEATHERING Tulare LAKE
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Microbial diversity in Huguangyan Maar Lake of China revealed by high-throughput sequencing 预览
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作者 HOU Qinghua FANG Zhou +1 位作者 ZHU Qingmei DONG Hongpo 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第4期1245-1257,共13页
Huguangyan Maar Lake is a typical maar lake in the southeast of China. It is well preserved and not disturbed by anthropogenic activities. In this study, microbial community structures in sediment and water samples fr... Huguangyan Maar Lake is a typical maar lake in the southeast of China. It is well preserved and not disturbed by anthropogenic activities. In this study, microbial community structures in sediment and water samples from Huguangyan Maar Lake were investigated using a high-throughput sequencing method. We found significant differences between the microbial community compositions of the water and the sediment. The sediment samples contained more diverse Bacteria and Archaea than did the water samples. Actinobacteria, Betaproteobacteria, Cyanobacteria, and Deltaproteobacteria predominated in the water samples while Deltaproteobacteria, Anaerolineae, Nitrospira, and Dehalococcoidia were the major bacterial groups in the sediment. As for Archaea, Woesearchaeota (DHVEG-6), unclassified Archaea, and Deep Sea Euryarchaeotic Group were detected at higher abundances in the water, whereas the Miscellaneous Crenarchaeotic Group, Thermoplasmata, and Methanomicrobia were significantly more abundant in the sediment. Interactions between Bacteria and Archaea were common in both the water column and the sediment. The concentrations of major nutrients (NO^3-, PO4^3-, SiO3^2- and NH4^+) shaped the microbial population structures in the water. At the higher phylogenetic levels including phylum and class, many of the dominant groups were those that were also abundant in other lakes;however, novel microbial populations (unclassified) were often seen at the lower phylogenetic levels. Our study lays a foundation for examining microbial biogeochemical cycling in sequestered lakes or reservoirs. 展开更多
关键词 Huguangyan MAAR LAKE HIGH-THROUGHPUT SEQUENCING MICROBIAL diversity
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Evaluation of SWAT Model performance on glaciated and non-glaciated subbasins of Nam Co Lake, Southern Tibetan Plateau, China
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作者 Muhammad ADNAN KANG Shi-chang +3 位作者 ZHANG Guo-shuai Muhammad Naveed ANJUM Muhammad ZAMAN ZHANG Yu-qing 《山地科学学报:英文版》 SCIE CSCD 2019年第5期1075-1097,共23页
This paper presents an assessment of the Soil and Water Assessment Tool(SWAT) on a glaciated(Qugaqie) and a non-glaciated(Niyaqu) subbasin of the Nam Co Lake. The Nam Co Lake is located in the southern Tibetan Plateau... This paper presents an assessment of the Soil and Water Assessment Tool(SWAT) on a glaciated(Qugaqie) and a non-glaciated(Niyaqu) subbasin of the Nam Co Lake. The Nam Co Lake is located in the southern Tibetan Plateau, two subbasins having catchment areas of 59 km~2 and 388 km~2, respectively. The scores of examined evaluation indices(i.e., R~2, NSE, and PBIAS) established that the performance of the SWAT model was better on the monthly scale compared to the daily scale. The respective monthly values of R~2, NSE, and PBIAS were 0.94, 0.97, and 0.50 for the calibration period while 0.92, 0.88, and -8.80 for the validation period. Glacier melt contribution in the study domain was simulated by using the SWAT model in conjunction with the Degree Day Melt(DDM) approach. The conjunction of DDM with the SWAT Model ensued improved results during both calibration(R~2=0.96, NSE=0.95, and PBIAS=-13.49) and validation (R~2=0.97, NSE=0.96, and PBIAS=-2.87) periods on the monthly time scale. Average contribution(in percentage) of water balance components to the total streamflow of Niyaqu and Qugaqie subbasins was evaluated. We found that the major portion(99.45%) of the streamflow in the Niyaqu subbasin was generated by snowmelt or rainfall surface runoff(SURF_Q), followed by groundwater(GW_Q, 0.47%), and lateral(LAT_Q, 0.06%) flows. Conversely, in the Qugaqie subbasin, major contributor to the streamflow(79.63%) was glacier melt(GLC_Q), followed by SURF_Q(20.14%), GW_Q(0.13%), and LAT_Q(0.089%). The contribution of GLC_Q was the highest(86.79%) in July and lowest(69.95%) in September. This study concludes that the performance of the SWAT model in glaciated catchment is weak without considering glacier component in modeling;however, it performs reasonably well in non-glaciated catchment. Furthermore, the temperature index approach with elevation bands is viable in those catchments where streamflows are driven by snowmelt. Therefore, it is recommended to use the SWAT Model in conjunction with DDM or energy base model to simulat 展开更多
关键词 SWAT MODEL NAM Co Lake DEGREE-DAY MELT MODEL Streamflow HYDROLOGICAL Response Unit
A Historical Sedimentary Record of Mercury in a Shallow Eutrophic Lake: Impacts of Human Activities and Climate Change 预览
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作者 Hanxiao Zhang Shouliang Huo +3 位作者 Kevin M. Yeager Beidou Xi Jingtian Zhang Fengchang Wu 《工程(英文)》 2019年第2期296-304,共9页
Mercury and its derivatives are hazardous environmental pollutants and could affect the aquatic ecosystems and human health by biomagnification. Lake sediments can provide important historical information regarding ch... Mercury and its derivatives are hazardous environmental pollutants and could affect the aquatic ecosystems and human health by biomagnification. Lake sediments can provide important historical information regarding changes in pollution levels and thus trace anthropogenic or natural influences. This research investigates the 100-year history of mercury (Hg) deposition in sediments from Chao Lake, a shallow eutrophic lake in China. The results indicate that the Hg deposition history can be separated into three stages (pre-1960s, 1960s–1980s, and post-1980s) over the last 100 years. Before the 1960s, Hg concentrations in the sediment cores varied little and had no spatial difference. Since the 1960s, the concentration of Hg began to increase gradually, and showed a higher concentration of contamination in the western half of the lake region than in the eastern half of the lake region due to all kinds of centralized human-input sources. The influences of anthropogenic factors and hydrological change are revealed by analyzing correlations between Hg and heavy metals (Fe, Co, Cr, Cu, Mn, Pb, and Zn), stable carbon and nitrogen isotopes (d13C and d15N), nutrients, particle sizes, and meteorological factors. The results show that Hg pollution intensified after the 1960s, mainly due to hydrological change, rapid regional development and urbanization, and the proliferation of anthropogenic Hg sources. Furthermore, the temperature, wind speed, and evaporation are found to interactively influence the environmental behaviors and environmental fate of Hg. 展开更多
关键词 Lake sediment MERCURY Vertical distribution ANTHROPOGENIC activities
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