检索结果-南通市图书馆

Evidence from isotopic geochemistry as an indicator of eutrophication of Meiliang Bay in Lake Taihu, china

Science china Earth sciences 2006年第Z1期49卷 62-71页

作者： lin lin, wu jinglu & wang sumin nanjing institute of geography & limnology, chinese academy of sciences, nanjing 210008, china Graduate University of the chinese academy of sciences, Beijing 100039, china nanjing institute of geography & limnology Chinese Academy of Sciences Nanjing China Graduate University of the chinese academy of sciences Beijing China

In this paper, Lake Taihu, a large shallow freshwater lake in china, is chosen as an example of reconstruction of eutrophication through the comparison between stable isotopes from dissolved nutrients and plants and water column nutrient parameters and integration of multiple proxies in a sediment core from Meiliang Bay including TN, TP, TOC, C/N, δ15N, δ13C, etc. Differences in aquatic plant species and trophic status between East Taihu Bay and Meiliang Bay are indicated by their variations in δ13C and δ15N of aquatic plants and δ15N of NH4+. A significant influence ofexternal nutrient inputs on Meiliang Bay is reflected in temporal changes in δ 15N of NH4+ and hydro-environmental parameters. The synchronous change between δ13C and δ15N values of sedimented organic matter (OM) has been attributed to elevated primary production at the beginning of eutrophication between 1950 and 1990, then recent inverse correlation between them has been caused by the uptake of 15N-enriched inorganic nitrogen by phytoplankton grown under eutrophication and subsequent OM decomposition and denitrification in surface sediments, indicating that the lake has suffered from progressive eutrophication since 1990. Based on the use of a combination of stable isotopes and elemental geochemistry, the eutrophication of Meiliang Bay in Lake Taihu could be better traced. These transitions of the lake eutrophication respectively occurring in the 1950s and 1990s have been suggested as a reflection of growing impacts of human activities, which is coincident with the instrumental data.

关键词： stable carbon isotope of OM, stable nitrogen isotope, eutrophication, Lake Taihu.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Amplification effect of intra-seasonal variability of soil moisture on heat extremes over Eurasia

引用

Advances in Climate Change Research 2024年第1期15卷 1-8页

作者： Yi-Nuo wang Zhi-Yan ZUO Liang QIAO Kai-Wen ZHANG Mei-Yu CHANG Dong XIAO Zou-Xing lin Huan wang Department of Atmospheric and Oceanic sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China CMA-FDU Joint Laboratory of Marine Meteorology Shanghai 200438China Key Laboratory of Cites Mitigation and Adaptation to Climate Change in Shanghai China Meteorological AdministrationShanghai 200030China Collaborative Innovation Centeron Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 211800China Shanghai Frontiers Science Center of Atmosphere-Ocean Interaction Shanghai 200123China College of geography and Resources Science Sichuan Normal UniversityChengdu 610101China National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary Shanghai 202183China chinese academy of Meteorological sciences China Meteorological AdministrationBeijing 100081China

Drying soil has been conducive to a high frequency of extreme high-temperature events over many regions worldwide in recent ***,changes in the intraseasonal variability of soil moisture can also influence the likelihood of extremely high *** previous investigators have examined the association between extremely high temperatures and large-scale atmospheric circulation variability,the role of land-atmosphere coupling dominated by soil moisture variability in extremely high temperatures,particularly over the Eurasian continent,is not well *** this study,on the basis of the Land Surface,Snow,and Soil Moisture Model Intercomparison Project,we found that land-atmosphere feedback amplified the variability of soil moisture in most regions of Eurasia during summer from 1980 to *** amplification of soil moisture variability is closely correlated with more intensive intraseasonal variability of surface air temperature and more frequent occurrences of extreme high-temperature events,particularly in Europe,Siberia,Northeast Asia,and the Indochina *** correlation implies that increasing the intraseasonal variability of soil moisture results in a high likelihood of heat extremes during summer in most parts of Eurasia except Asian desert *** the intraseasonal timescale,the land-atmosphere coupling increases the variability of surface sensible heat flux and net long-wave radiation heating the atmosphere by intensifying the soil moisture variability,thus amplifying the variability of surface air temperature and enhancing the extreme high-temperature *** finding demonstrates the importance of changes in intraseasonal soil moisture variability for the increasing likelihood of heat extremes in summer.

关键词： Soil moisture Intraseasonal variability Land-atmosphere coupling Heat extremes

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

江西和福建省植被覆盖时空特征及其地形梯度效应

引用

水土保持研究 2024年第1期31卷 290-300页

作者：林莹冰王小军全明英林杜锐卢毅刘光旭华南师范大学地理科学学院广州510631 中国科学院地质与地球物理研究所北京100029 中国科学院大学北京100049 中国科学院南京地理与湖泊研究所南京210008 赣南师范大学地理与环境工程学院江西赣州341000

[目的]探讨华南地区植被覆盖时空特征,为生态系统调查与保护提供参考。[方法]以江西和福建省为例,将1998年、2005年、2010年、2015年、2019年5年的植被覆盖由低到极高划分为6个等级,使用土地利用研究中的动态度、转移等思路分析植被覆... 详细信息

[目的]探讨华南地区植被覆盖时空特征,为生态系统调查与保护提供参考。[方法]以江西和福建省为例,将1998年、2005年、2010年、2015年、2019年5年的植被覆盖由低到极高划分为6个等级,使用土地利用研究中的动态度、转移等思路分析植被覆盖时空特征,并探讨其地形梯度效应。[结果](1)江西和福建植被覆盖以高和极高覆盖为主(78.47%~89.8%),尤其是在内陆山地丘陵区,而沿江、沿海等人口密集的城市区相对较低、面积较小;1998—2019年该区植被覆盖较好且变化的整体趋势仍是增加;最显著变化发生在2010—2015年由高覆盖转移为极高覆盖。(2)地形梯度指数显示,中等植被覆盖及以下主要分布在海拔低于200 m、坡度小于6°、地形位小于0.48的1~2级地形梯度区;较高覆盖及以上较为分散的分布在各地形梯度内,且随着覆盖度增加有向海拔高于200 m、坡度大于6°、地形位大于0.48的3~5级地形梯度区分布趋势。(3)在植被覆盖不变或改善类中,低覆盖转移主要发生在1级地形梯度,较低覆盖和中等覆盖转移主要发生在1~3级地形梯度区,较高覆盖及以上的转移在5类地形梯度均有发生且相对分散;在植被覆盖恶化类中,中等覆盖及以下的转移多发生在1~3级地形梯度区,较高覆盖及以上的转移在5类地形梯度区多有发生且相对分散;转移等级跨度较大的情况多发生在较低等级的地形梯度区。[结论]研究区植被覆盖率较高,植被覆盖变化存在时空差异,生态系统调查与保护需要考虑不同地形梯度下的影响因素。

关键词：植被覆盖时空特征地形梯度动态度弦图华南

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Land Use and Soil Organic Carbon in china’s Village Landscapes

引用

Pedosphere 2010年第1期20卷 1-14页

作者： JIAO Jia-Guo YANG lin-Zhang wu Jun-Xi wang Hong-Qing LI Hui-Xin E. C. ELLIS Department of Resources and Environmental sciences Nanjing Agricultural University Nanjing210095 （China） institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Department of Agronomy and Agroecology China Agricultural University Beijing 100094 （China） Department of geography ＆ Environmental Systems University of Maryland Baltimore County Baltimore 21250 （USA） Center for Louisiana Inland Water Studies University of Louisiana at Lafayette Lafayette Louisiana （USA）

Village landscapes, which integrate small-scale agriculture with housing, forestry, and a host of other land use practices, cover more than 2 million square kilometers across china. Village lands tend to be managed at very fine spatial scales (≤ 30 m), with managers both adapting their practices to existing variation in soils and terrain (e.g., fertile plains vs. infertile slopes) and also altering soil fertility and even terrain by terracing, irrigation, fertilizing, and other land use practices. Relationships between fine-scale land management patterns and soil organic carbon (SOC) in the top 30 cm of village soils were studied by sampling soils within fine-scale landscape features using a regionally weighted landscape sampling design across five environmentally distinct sites in china. SOC stocks across china’s village regions (5 Pg C in the top 30 cm of 2 × 10 6 km 2 ) represent roughly 4% of the total SOC stocks in global croplands. Although macroclimate varied from temperate to tropical in this study, SOC density did not vary significantly with climate, though it was negatively correlated with regional mean elevation. The highest SOC densities within landscapes were found in agricultural lands, especially paddy, the lowest SOC densities were found in nonproductive lands, and forest lands tended toward moderate SOC densities. Due to the high SOC densities of agricultural lands and their predominance in village landscapes, most village SOC was found in agricultural land, except in the tropical hilly region, where forestry accounted for about 45% of the SOC stocks. A surprisingly large portion of village SOC was associated with built structures and with the disturbed lands surrounding these structures, ranging from > 18% in the North china Plain to about 9% in the tropical hilly region. These results confirmed that local land use practices, combined with local and regional variation in terrain, were associated with most of the SOC variation within and across Chin

关键词：土地利用方式土壤有机碳乡村景观中国北方密度范围地形变化 SOC 管理人员

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characteristics of an early Holocene climate and environment from lake sediments in Ebinur region, NW china

引用

Science china Earth sciences 2005年第2期48卷 258-265页

作者： wu jinglu SHEN Ji wang sumin JIN Zhangdong YANG Xiangdong nanjing institute of geography & limnology Chinese Academy of SciencesNanjing210008China Nanjing Institute of Geography & LimnologyChinese Academy of SciencesNanjing210008China Nanjing Institute of Geography & LimnologyChinese Academy of SciencesNanjing210008China Nanjing Institute of Geography & LimnologyChinese Academy of SciencesNanjing210008China Nanjing Institute of Geography & LimnologyChinese Academy of SciencesNanjing210008China

The characteristics of climatic environment in the early Holocene epoch were studied through analyzing environmental proxies from the sediments in the Ebinur Lake--a closed one in the arid region. The pollen assemblage and other geochemical indices showed that, the temperature was somewhat low in the period (8.0-11.5 cal kaBP) as a whole, but in the early period (11.5-10.6 cal kaBP) the temperature was higher, in company with more precipitation. In the conversion period from the early Holocene epoch to the middle Holocene epoch (8.9-8.0 cal kaBP) the climate fluctuated remarkably. Particularly the three layers of peat sediment revealed the strong instability of climate in the early Holocene epoch in the Ebinur region. All information on the development of peat and the experimental data of pollen and stable isotopes implied that, the climatic condition at 8.2, 8.6 and 10.5 cal kaBP was characterized by noticeable cold and humidness, and could be regarded as three cold and humid events in the early Holocene epoch.

关键词： early Holocene epoch, climatic evolution, pollen assemblege, stable isotopic record, Ebinur Lake.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Storage and Spatial Variation of Phosphorus in Paddy Soils of china

引用

Pedosphere 2009年第6期19卷 790-798页

作者： lin Jin-Shi SHI Xue-Zheng LU Xi-Xi YU Dong-Sheng wang Hong-Jie ZHAO Yong-Cun SUN Wei-Xia State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 2100(78 (China) Department of geography National University of Singapore 119260 (Singapore) Graduate University of the chinese academy of sciences Beijing 100049 (China) College of Resources and Environment Fujian Agriculture and Forestry University Fuzhou 350002 (China)

Due to the growing concern about the agricultural phosphorus (P) losses pollution, an in-depth understanding of P in paddy soils of china would be helpful in providing a national perspective of the environmental impact of P cycling and fertility on china's farms. In this study, we evaluated the P storage and the P density of paddy soils in china, characterized the spatial variations of P among the subgroups of paddy soils and soil regions in china, and evaluated the P data using GIS-based analysis, which included a newly compiled 1:1 000 000 digital soil map of china, and using 1 490 soil profiles. The available and total P densities of paddy soils were 6.7 and 698.5 g m -3 , respectively. Overall in china, the total P storage within 1 m of paddy soils was estimated to be 330.2 Tg. The P density of paddy soils varied substantially with subgroups due to the different soil water regimes such as groundwater table and soil drainage. The P availability in paddy soils, especially in surface layer, was higher in high temperature and precipitation areas. Further research is needed to examine more anthropogenic impact factors, such as increasing use of chemical fertilizer.

关键词：中国地区空间变化水稻土土壤磷存储地理信息系统土壤全磷污染损失

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

21世纪全球新建水库编目:丰度、热点区及总蓄水量

引用

Science Bulletin 2024年第14期69卷 2179-2182页

作者：范晨雨宋春桥 Jida wang Yongwei Sheng 蔺亚玲苑春雨 Md Safat Sikder Jean-Francois Crétaux 刘凯陈探曾繁轩柯灵红 Key Laboratory of Watershed Geographic sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China University of chinese academy of sciences Beijing 100049China University of chinese academy of sciences Nanjing(UCASNJ)Nanjing 211135China Department of geography and Geographic Information Science University of Illinois Urbana-ChampaignUrbana IL 61801USA Department of geography and Geospatial sciences Kansas State UniversityManhattan KS 66506USA Department of geography University of CaliforniaLos Angeles CA 90095USA Laboratoire d’Études en Géophysique et Océanographie Spatiales(LEGOS) CNES-IRD-CNRS-UT3Universitéde ToulouseToulouse 31401France College of Hydrology and Water Resources Hohai UniversityNanjing 210098China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China

Dams and reservoirs play an essential role in regulating and managing water *** the middle of the 20th century,the growing demand for water and hydropower has led to an unprecedented boom in reservoir construction worldwide[1,2].Meanwhile,reservoir construction has also resulted in a variety of ecological and socioeconomic impacts[3–5].Reservoirs transform natural flow regimes into conditions favored by human *** associated flow regulations,especially in reservoirs constructed in recent decades(e.g.,after 2000)with greater seasonal variability[6,7],represent a strong human-induced alteration of the hydrologic *** reservoir construction continues to boom in many parts of the world,an up-to-date and openaccess inventory of reservoirs worldwide remains critically desired.

关键词： reservoir reservoirs alteration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

典型遥感降水产品的水文模拟性能评估

引用

遥感学报 2024年第2期28卷 398-413页

作者：李艳忠星寅聪庄稼成杨泽龙赵紫春李超凡王启素谢雨初王洁董剑萍林彬徐兴祝南京信息工程大学水文与水资源工程学院南京210044 南京信息工程大学水利部水文气象灾害机理与预警重点实验室南京210044 中国科学院地理科学与资源研究所北京100101 南京信息工程大学地理科学学院南京210044 宁夏吴忠市盐池县水务局吴忠751500 山东省第七地质矿产勘查院临沂276000 山东省临沂市自然资源和规划局临沂276037

遥感降水具备大尺度、近实时、高精度等优点,现已被广泛应用于流域水资源评估和生态环境保护的研究。但遥感降水产品众多,性能差异较大,不同产品在特定流域的适用性需要进行综合评估。本研究以渭河流域的4个子流域为研究区,以国家气象局... 详细信息

遥感降水具备大尺度、近实时、高精度等优点,现已被广泛应用于流域水资源评估和生态环境保护的研究。但遥感降水产品众多,性能差异较大,不同产品在特定流域的适用性需要进行综合评估。本研究以渭河流域的4个子流域为研究区,以国家气象局(CMA)逐日降水格点数据集为标准,借助ABCD水文模型,评估了5种典型的遥感降水产品(CHIRPS v2.0,CMORPH v1.0,PERSIANN-CDR,TRMM,MSWEP v2.0)对降水等级和水文过程模拟的性能。(1)在捕捉降水的时空变化格局方面,TRMM产品表现出较好的性能;(2)在基本统计指标和分类统计指标方面,多源集成产品MSWEP明显优于其他4种产品;但各遥感产品对中雨和大雨,尤其是大雨的预测效果欠佳;(3)在径流模拟方面,以TRMM降水作为输入时,ABCD模型模拟径流的效果明显优于其他遥感产品,其NSE在渭河上游、泾河上游、马莲河和北洛河分别达到了0.66、0.46、0.56和0.55。TRMM产品在捕捉降水空间格局和径流模拟方面优越,而MSWEP的统计性能较为优越。本文的研究结果,可为半干旱半湿润区域水文和气象等应用研究,在遥感降水数据源的选择方面提供科学参考依据,还可为黄河流域生态保护和高质量发展提供数据支撑。

关键词：遥感降水渭河流域 ABCD模型性能评估 MSWEP

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

三江源地区湖塘变化及其与多年冻土联系

引用

地理科学进展 2024年第7期43卷 1441-1455页

作者：汤芸淇汪凌霄赵林李艳李智斌刘世博邹德富王紫珊刘童丁嘉怡赵建婷南京信息工程大学地理科学学院南京210044 中国科学院南京地理与湖泊研究所中国科学院流域地理学重点研究室南京210008 中国科学院大学北京100049 中国科学院西北生态环境资源研究院冰冻圈科学国家重点实验室藏北高原冰冻圈特殊环境与灾害国家野外科学观测研究站兰州730000

近年来,青藏高原湖泊的快速扩张引起广泛关注,已有不少研究系统分析了大于1 km^(2)的大型湖泊的变化动态,但对于面积较小的由于多年冻土退化形成的热融湖塘,其在大范围流域尺度上的分布及变化研究尚不多见。论文基于光学和雷达影像,系... 详细信息

近年来,青藏高原湖泊的快速扩张引起广泛关注,已有不少研究系统分析了大于1 km^(2)的大型湖泊的变化动态,但对于面积较小的由于多年冻土退化形成的热融湖塘,其在大范围流域尺度上的分布及变化研究尚不多见。论文基于光学和雷达影像,系统分析了三江源区内湖塘(<1 km^(2))分布及其变化,以及与多年冻土之间的联系,并且首次揭示了湖塘底部融区的分布情况。结果表明:(1)三江源区2020年代(2020—2022年)的湖塘面积达917.03 km^(2),湖塘总数为61608个。其中长江源区湖塘数量最多,达到48987个,黄河源区12459个,澜沧江源区最少。(2)相较于1960年代,2020年代三江源区域面积小于1 km^(2)湖塘数量增加了76%,面积增加了13%。长江源区湖塘扩张明显,黄河源区、澜沧江源区的部分湖塘萎缩。1960年代的湖塘有53%在2020年代依然存在。(3)三江源区80.9%的湖塘底部冬季存在融区,其中长江源有78.2%,黄河源有90.8%,澜沧江源有98.7%。在多年冻土区,有一半底部有融区的湖塘在1960年代就已存在,新增湖塘底部冬季较少存在融区,目前浮冰湖塘范围要远大于触底冰湖塘范围,可能会进一步加速多年冻土融化。研究结果可为分析多年冻土退化状态以及多年冻土退化与热融湖塘发育之间的联系提供基础,为高原地区热融湖塘碳排放研究提供基础数据。

关键词：热融湖塘多年冻土退化三江源区湖塘底部融区

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

china's lakes at present:Number,area and spatial distribution

引用

Science china Earth sciences 2011年第2期54卷 283-289页

作者： MA RongHua YANG GuiShan DUAN HongTao JIANG JiaHu wang sumin FENG XueZhi LI AiNong KONG FanXiang XUE Bin wu jinglu LI ShiJie State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China Department of Geographic Information Science Nanjing University Nanjing 210093 China institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

Based on 11004 satellite images from CBERS CCD and Landsat TM/ETM,changes in the spatial characteristics of all lakes in china were determined following pre-established interpretation *** dataset was supported by 6843 digital raster images(1:100000 and 1:50000),a countrywide digital vector dataset(1:250000),and historical *** data were corrected for seasonal variations using precipitation *** are presently 2693 natural lakes in china with an area greater than 1.0 km2,excluding *** lakes are distributed in 28 provinces,autonomous regions and municipalities and have a total area of 81414.6 km2,accounting for-0.9% of china's total land *** the past 30 years,the number of newly formed and newly discovered lakes with an area greater than 1.0 km2 is 60 and 131,***,243 lakes have disappeared in this time period.

关键词：湖泊变化湖泊面积中国空间分布中巴地球资源卫星陆地卫星TM 〇平方技术手册

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：